Sheng-che Hung - Academia.edu (original) (raw)

Papers by Sheng-che Hung

Research paper thumbnail of Revisiting the relationship of three-dimensional fluid attenuation inversion recovery imaging and hearing outcomes in adults with idiopathic unilateral sudden sensorineural hearing loss

European Journal of Radiology, 2016

Research paper thumbnail of Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy

Medicine, 2016

The purpose of this study is to compare the clinical features and treatment outcomes among patien... more The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, inten...

Research paper thumbnail of Using Flat-Panel Perfusion Imaging to Measure Cerebral Hemodynamics

Medicine, 2016

Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing ... more Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing the penumbra in acute stroke equivalent to that of magnetic resonance perfusion (MRP). The aim of our study was to evaluate the feasibility of quantifying oligemia in the brain in patients with carotid stenosis.Ten patients with unilateral carotid stenosis of >70% were included. All MRPs and FD-CTPs were performed before stenting. Region-of-interests (ROIs) including middle cerebral artery territory at basal ganglia level on both stenotic and contralateral sides were used for quantitative analysis. Relative time to peak (rTTP) was defined as TTP of the stenotic side divided by TTP of the contralateral side, and so as relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative cerebral blood flow (rCBF). Absolute and relative TTP, CBV, MTT, CBF between two modalities were compared.For absolute quantitative analysis, the correlation of TTP was highest (r = 0.56), followed by CBV (r = 0.47), MTT (r = 0.47), and CBF (r = 0.43); for relative quantitative analysis, rCBF was the highest (r = 0.79), followed by rTTP (r = 0.75) and rCBV (r = 0.50).We confirmed that relative quantitative assessment of FD-CTP is feasible in chronic ischemic disease. Absolute quantitative measurements between MRP and FD-CTP only expressed moderate correlations. Optimization of acquisitions and algorithms is warranted to achieve better quantification.

Research paper thumbnail of Finding the optimal deconvolution algorithm for MR perfusion in carotid stenosis: Correlations with angiographic cerebral circulation time

Journal of Neuroradiology, 2016

The aim of our study is to explore the impacts of different deconvolution algorithms on correlati... more The aim of our study is to explore the impacts of different deconvolution algorithms on correlations between CBF, MTT, CBV, TTP, Tmax from MR perfusion (MRP) and angiography cerebral circulation time (CCT). Retrospectively, 30 patients with unilateral carotid stenosis, and available pre-stenting MRP and angiography were included for analysis. All MRPs were conducted in a 1.5-T MR scanner. Standard singular value decomposition, block-circulant, and two delay-corrected algorithms were used as the deconvolution methods. All angiographies were obtained in the same bi-plane flat-detector angiographic machine. A contrast bolus of 12mL was administrated via angiocatheter at a rate of 8mL/s. The acquisition protocols were the same for all cases. CCT was defined as the difference between time to peak from the cavernous ICA and the parietal vein in lateral view. Pearson correlations were calculated for CCT and CBF, MTT, CBV, TTP, Tmax. The correlation between CCT and MTT was highest with Tmax (r=0.65), followed by MTT (r=0.60), CBF (r=-0.57), and TTP (r=0.33) when standard singular value decomposition was used. No correlation with CBV was noted. MRP using a singular value decomposition algorithm confirmed the feasibility of quantifying cerebral blood flow deficit in steno-occlusive disease within the angio-room. This approach might further improve patient safety by providing immediate cerebral hemodynamics without extraradiation and iodine contrast.

Research paper thumbnail of Prolonged Cerebral Circulation Time Is the Best Parameter for Predicting Vasospasm during Initial CT Perfusion in Subarachnoid Hemorrhagic Patients

PloS one, 2016

We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from... more We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from baseline CT perfusion (CTP) to better predict vasospasm in patients with subarachnoid hemorrhage (SAH). Forty-one SAH patients with available DSA and CTP were retrospectively included. The vasospasm group was comprised of patients with deterioration in conscious functioning and newly developed luminal narrowing; remaining cases were classified as the control group. The angiography CCT (XA-CCT) was defined as the difference in TTP (time to peak) between the selected arterial ROIs and the superior sagittal sinus (SSS). Four arterial ROIs were selected to generate four corresponding XA-CCTs: the right and left anterior cerebral arteries (XA-CCTRA2 and XA-CCTLA2) and right- and left-middle cerebral arteries (XA-CCTRM2 and XA-CCTLM2). The CCTs from CTP (CT-CCT) were defined as the differences in TTP from the corresponding arterial ROIs and the SSS. Correlations of the different CCTs were cal...

Research paper thumbnail of Smoke in the Brain: The Clinical Implications of Imaging Features in Moyamoya Disease

Research paper thumbnail of Endovascular Management of Post-Irradiated Carotid Blowout Syndrome

PloS one, 2015

To retrospectively evaluate the clinical and technical factors related to the outcomes of endovas... more To retrospectively evaluate the clinical and technical factors related to the outcomes of endovascular management in patients with head-and-neck cancers associated with post-irradiated carotid blowout syndrome (PCBS). Between 2000 and 2013, 96 patients with PCBS underwent endovascular management. The 40 patients with the pathological lesions located in the external carotid artery were classified as group 1 and were treated with embolization. The other 56 patients with the pathological lesions located in the trunk of the carotid artery were divided into 2 groups as follows: group 2A comprised the 38 patients treated with embolization, and group 2B comprised the 18 patients treated with stent-graft placement. Fisher's exact test was used to examine endovascular methods, clinical severities, and postprocedural clinical diseases as predictors of outcomes. Technical success and immediate hemostasis were achieved in all patients. The results according to endovascular methods (group 1 ...

Research paper thumbnail of Toward Normalization of Intracranial Circulation Time: The Therapeutic Effects of Brain Vascular Disorders Evidenced by Color-Coded Quantitative Digital Subtraction Angiography (QDSA)

PURPOSE To define the role of color-coded QDSA in evaluating the therapeutic effects of various b... more PURPOSE To define the role of color-coded QDSA in evaluating the therapeutic effects of various brain vascular disorders. METHOD AND MATERIALS 85 patients with brain disorders that necessitated DSA were recruited. They were 15 arteriovenous malformations/fistulae (group A), 20 occlusive diseases (group B) and 50 without DSA detectable abnormal circulation time (group C, for control). The angio-catheters were placed at C4 vertebral body level for angiography (6 frames/sec using AXIOM-Artis® angiosystem, Siemens Healthcare)with total amount of 12 ml (for carotid) and 9 ml (for vertebral) 60% diluted contrast medium (340 mgI/ml) administrated in 1.5 sec by a power injector. Post-processing software (iFlow®, Siemens Healthcare) was used to define the time of maximal intensity (Tmax in sec) at selected angiographic mark points, namely, cavernous portion (I1) , supraclinoid (I2) portion of the internal carotid artery (ICA), proximal (A1) and distal (A2) anterior cerebral artery, first (M1...

Research paper thumbnail of Cross-modalities Comparative Study of Post-SAH Cerebral Hemodynamics: CT Perfusion versus Flat Detector DSA

PURPOSE Conventional digital subtraction angiography (DSA) helps to evaluate the severity of vasc... more PURPOSE Conventional digital subtraction angiography (DSA) helps to evaluate the severity of vascular spasm after subarachnoid hemorrhage (SAH). Being equipped with flat detector (FD), DSA is able to provide in-room assessment of peri-therapeutic cerebral hemodynamics and help tailoring endovascular treatments. The aim of current study is to compare the cerebral circulation time (CCT) that derived color-coded quantitative FD-DSA and CT perfusion (CTP) in SAH patients. METHOD AND MATERIALS Nineteen SAH patients entered our neurovascular service in 8 months interval and with available CCT derived from diagnostic FD-DSA and MDCT, were retrospectively recruited. The mean time interval between two examinations was 19 (4-36) hours. The CCT derived from FD-DSA was defined as the difference of Tmax (Time of maximum intensity) between the region-of-interest (ROI) of selected arteries and superior sagittal sinus (SSS). Four CCT were defined accordingly, namely, RA-CCT and LA-CCT (arterial ROI...

Research paper thumbnail of Pretreatment diagnosis of suprasellar papillary craniopharyngioma and germ cell tumors of adult patients

AJNR. American journal of neuroradiology, 2015

Suprasellar papillary craniopharyngiomas and germ cell tumors in adults share some clinical and i... more Suprasellar papillary craniopharyngiomas and germ cell tumors in adults share some clinical and imaging similarities but have different therapeutic strategies and outcomes. This study aimed to evaluate the pretreatment diagnosis of these 2 tumors to improve the therapeutic outcome. We retrospectively enrolled 18 adults with papillary craniopharyngiomas and 17 with germ cell tumors. The MR imaging findings were evaluated, including signal change and anatomic extension. The medical records were reviewed to collect clinical findings, management, and outcomes. The clinical findings of papillary craniopharyngiomas versus germ cell tumors were as follows: age: 46 ± 13.9 years versus 23 ± 7.1 years (P < .0001); diabetes insipidus: 2/18 (11%) versus 11/17 (65%) (P = .001); recurrence 13/16 (81%) versus 4/17 (24%) (P = .0031). The MR imaging findings of papillary craniopharyngiomas versus germ cell tumors were as follows-pituitary stalk thickening: 1.6 ± 0.4 mm versus 5.4 ± 4.2 mm (P <...

Research paper thumbnail of Imaging characteristics of primary spinal primitive neuroectodermal tumors. A report of five cases and literature review

The neuroradiology journal, 2012

Primary spinal primitive neuroectodermal tumors (PNETs) are rare and classified into peripheral a... more Primary spinal primitive neuroectodermal tumors (PNETs) are rare and classified into peripheral and central types because the treatment strategy and outcome are different. This study describes five cases of primary spinal peripheral type PNETs. Magnetic resonance imaging showed large extradural masses in the cervical and thoracic spine with bony invasion and paraspinal extension in four cases and a transdural mass in the sacral spinal canal in one case. We also briefly summarize the imaging characteristics of 36 peripheral type and six central type primary spinal PNETs in the literature.

Research paper thumbnail of In-room assessment of cerebral blood volume for guidance during intra-arterial thrombolytic therapy

Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 2012

In acute ischemic stroke, the ability to estimate the penumbra and infarction core ratio helps to... more In acute ischemic stroke, the ability to estimate the penumbra and infarction core ratio helps to triage those who will potentially benefit from thrombolytic therapies. Flat-panel post-contrast DynaCT imaging can provide both vasculature and parenchymal blood volume within the angio room to monitor hemodynamic changes during the endovascular procedures. We report on an 80-year-old woman who suffered from an acute occlusion of the right distal cervical internal carotid artery. She was transferred to the angio room where in-room post-contrast flat-panel DynaCT imaging (syngo Neuro PBV IR) was performed to access the ischemic tissue, followed by successful mechanical thrombolytic therapy.

Research paper thumbnail of Toward the Era of a One-Stop Imaging Service Using an Angiography Suite for Neurovascular Disorders

BioMed Research International, 2013

Transportation of patients requiring multiple diagnostic and imaging-guided therapeutic modalitie... more Transportation of patients requiring multiple diagnostic and imaging-guided therapeutic modalities is unavoidable in current radiological practice. This clinical scenario causes time delays and increased risk in the management of stroke and other neurovascular emergencies. Since the emergence of flat-detector technology in imaging practice in recent decades, studies have proven that flat-detector X-ray angiography in conjunction with contrast medium injection and specialized reconstruction algorithms can provide not only high-quality and high-resolution CT-like images but also functional information. This improvement in imaging technology allows quantitative assessment of intracranial hemodynamics and, subsequently in the same imaging session, provides treatment guidance for patients with neurovascular disorders by using only a flat-detector angiographic suite-a so-called one-stop quantitative imaging service (OSIS). In this paper, we review the recent developments in the field of flatdetector imaging and share our experience of applying this technology in neurovascular disorders such as acute ischemic stroke, cerebral aneurysm, and stenoocclusive carotid diseases.

Research paper thumbnail of Hepatobiliary and Pancreatic: Hemobilia caused by bleeding from hepatic artery aneurysms

Research paper thumbnail of Cognitive and epilepsy outcomes after epilepsy surgery caused by focal cortical dysplasia in children: early intervention maybe better

Child's Nervous System, 2014

Focal cortical dysplasia (FCD) is a specific malformation of cortical development harboring intri... more Focal cortical dysplasia (FCD) is a specific malformation of cortical development harboring intrinsic epileptogenicity, and most of the patients develop drug-resistant epilepsy in early childhood. The detrimental effects of early and frequent seizures on cognitive function in children are significant clinical issues. In this study, we evaluate the effects of early surgical intervention of FCD on epilepsy outcome and cognitive development. From 2006 to 2013, 30 children younger than 18 years old underwent resective surgery for FCDs at Taipei Veterans General Hospital. The mean age at surgery was 10.0 years (range 1.7 to 17.6 years). There were 21 boys and 9 girls. In this retrospective clinical study, seizure outcome, cognitive function, and quality of life were evaluated. To evaluate the effects to outcomes on early interventions, the patients were categorized into four groups according to age of seizure onset, duration of seizure before surgery, and severity of cognitive deficits. Eleven of 22 (50 %) patients demonstrated developmental delay preoperatively. The Engel seizure outcome achievements were class I in 21 (70 %), class II in 2 (7 %), class III in 6 (20 %), and class IV in 1 (3 %) patients. The locations of FCDs resected were in the frontal lobe in 18 cases, temporal lobe in 7, parietal lobe in 2, and in bilobes including frontoparietal lobe in 2 and parieto-occipital lobes in 1. Eight cases that had FCDs involved in the rolandic cortex presented hemiparesis before surgical resection. Motor function in four of them improved after operation. The histopathological types of FCDs were type Ia in 1, type Ib in 7, type IIa in 7, type IIb in 12, and type III in 3 patients. FCDs were completely resected in 20 patients. Eighteen (90 %) of them were seizure free (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) with three patients that received more than one surgery to accomplish complete resection. The patients who had early seizure onset, no significant cognitive function deficit, and early surgical intervention with complete resection in less than 2 years of seizure duration showed best outcomes on seizure control, cognitive function, and quality of life. Delay in cognitive development and poor quality of life is common in children treated for FCDs. Early surgical intervention and complete resection of the lesion help for a better seizure control, cognitive function development, and quality of life. FCDs involved eloquent cortex may not prohibit complete resection for better outcomes.

Research paper thumbnail of Improving thermal stability and efficacy of BCNU in treating glioma cells using PAA-functionalized graphene oxide

International Journal of Nanomedicine, 2012

Background: 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a commercial chemotherapeutic drug for t... more Background: 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a commercial chemotherapeutic drug for treating malignant brain tumors, has poor thermal stability and a short half-life. Immobilization of BCNU on a nanocarrier might increase the thermal stability of BCNU and extend its half-life. Methods: Nanosized graphene oxide (GO) could be modified by polyacrylic acid (PAA) to improve the aqueous solubility and increase the cell penetration efficacy of the nanocarrier. PAA-GO intended as a drug carrier for BCNU was prepared and characterized in this study. The size and thickness of PAA-GO was investigated by transmission electron microscopy and atomic force microscopy, and the presence of PAA functional groups was confirmed by electron spectroscopy for chemical analysis and thermogravimetric analysis. BCNU was conjugated to PAA-GO by covalent binding for specific killing of cancer cells, which could also enhance the thermal stability of the drug. Results: Single layer PAA-GO (about 1.9 nm) with a lateral width as small as 36 nm was successfully prepared. The optimum drug immobilization condition was by reacting 0.5 mg PAA-GO with 0.4 mg BCNU, and the drug-loading capacity and residual drug activity were 198 µg BCNU/mg PAA-GO and 70%, respectively. This nanocarrier significantly prolonged the half-life of bound BCNU from 19 to 43 hours compared with free drug and showed efficient intracellular uptake by GL261 cancer cells. The in vitro anticancer efficacy of PAA-GO-BCNU was demonstrated by a 30% increase in DNA interstrand cross-linking and a 77% decrease in the IC 50 value toward GL261 compared with the same dosage of free drug. Conclusion: Nanosized PAA-GO serves as an efficient BCNU nanocarrier by covalent binding. This nanocarrier will be a promising new vehicle for an advanced drug delivery system in cancer therapy.

Research paper thumbnail of Imaging quality and diagnostic reliability of low-dose computed tomography lumbar spine for evaluating patients with spinal disorders

The Spine Journal, 2014

Computed tomography (CT) scans of the lumbar spine (CTLS) have demonstrated a higher level of acc... more Computed tomography (CT) scans of the lumbar spine (CTLS) have demonstrated a higher level of accuracy than plain films and have been used to assess patients with spinal disorder when magnetic resonance imaging is not available. Nevertheless, radiation exposure remains a serious safety concern. Iterative reconstruction (IR) decreases the CT radiation dose for diagnostic imaging. However, the feasibility of using IR in CTLS is unclear. To evaluate the imaging quality and diagnostic reliability of CTLS with IR. A prospective study. All patients from outpatient departments who suffered from spinal disorders and were referred for CTLS. In acquired CT images, the signal-to-noise ratio (SNR) of the dural sac (DS), intervertebral disc (IVD), psoas muscle (PM), and L5 vertebral body, the contrast-to-noise ratio between the DS and IVD (D-D CNR), and the subjective imaging qualities were compared across groups. Interobserver agreement was evaluated with kappa values. Patients receiving low radiation CTLS were divided into three groups. A 150 mAs tube current with 120 kVp tube voltage was used with Group A and a 230 mAs tube current with 100 kVp tube voltage with Group B. Intended end radiation exposure was 50% less than that of the control group. Tube modulation was active for all groups. The images of the two low-radiation groups were reconstructed by IR; those of the control group by filtered back-projection (FBP). The SNRs of the DS, IVD, PM, BM, and D-D CNR of Group A were not inferior to those of the control group. All SNRs and D-D CNRs for Group B were inferior to those of the control group. Except for that of the facet joint, all subjective imaging ratings for anatomic regions were equivalent between Groups A and B. Interobserver agreement was highest for the control group (0.72-0.88), followed by Group A (0.69-0.83) and B (0.55-0.83). Fifty percent tube current reduction combined with IR provides equivalent diagnostic accuracy and improved patient safety when compared with conventional CTLS. Our results support its use as a screening tool. With the tube modulation technique, further adjustments in weighting IR and FBP algorithms based on body mass index become unnecessary.

Research paper thumbnail of Multidetector Computerized Tomography Urography as the Primary Imaging Modality for Detecting Urinary Tract Neoplasms in Patients With Asymptomatic Hematuria

The Journal of Urology, 2008

We determined whether multidetector computerized tomography urography is sensitive and specific f... more We determined whether multidetector computerized tomography urography is sensitive and specific for detecting urinary tract neoplasms when used as the primary imaging modality for evaluating patients with hematuria. A retrospective review was performed of the radiological, urological and pathological records of 468 patients without a history of urinary neoplasms who presented with hematuria. All patients underwent multidetector computerized tomography urography and complete urological evaluation, including cystoscopy. Laboratory urinalysis and cytology were done in 350 and 318 of the 468 patients, respectively. Multivariate logistic regression analysis was performed using the variables multidetector computerized tomography urography diagnosis, worst urine cytology, number of red blood cells per high power field, gross hematuria, age and gender to predict urinary tract neoplasm. A total of 50 urinary neoplasms were diagnosed in 468 patients. Multidetector computerized tomography urography detected 32 of 50 neoplasms for a sensitivity of 64%, specificity of 98%, positive predictive value of 76% and negative predictive value of 96%. There were 10 false-positive and 18 false-negative multidetector computerized tomography urography studies. Multivariate logistic regression showed that abnormal multidetector computerized tomography urography findings, ie neoplasm (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001), and suspicious or positive urine cytology (p = 0.0009) were significant. Patients with an abnormal multidetector computerized tomography urography diagnosis and suspicious or positive urine cytology had 44 and 47 times greater odds, respectively, of having urinary neoplasms compared to the odds in those with normal examinations. Multidetector computerized tomography urography is relatively sensitive and highly specific for detecting urinary neoplasms. It may serve as the primary imaging modality to evaluate patients with hematuria. Multidetector computerized tomography urography does not eliminate the role of cystoscopy in the evaluation of hematuria.

Research paper thumbnail of Contrast-Enhanced Multiphasic Computed Tomography for Identifying Life-Threatening Mesenteric Hemorrhage and Transmural Bowel Injuries

The Journal of Trauma: Injury, Infection, and Critical Care, 2011

Active mesenteric hemorrhage and bowel perforation after blunt abdominal trauma warrant immediate... more Active mesenteric hemorrhage and bowel perforation after blunt abdominal trauma warrant immediate surgical intervention. We investigate whether findings on multiphasic computed tomography (CT) can identify life-threatening mesenteric hemorrhage and bowel injuries. Within 1-year period, 106 patients underwent multiphasic CT for evaluation of blunt abdominal injuries. Images obtained at arterial phase, portal phase, and equilibrium phase were retrospectively reviewed with special focus on mesentery and bowel injuries. We compared the recorded findings with surgically proven active mesenteric hemorrhage and transmural bowel injuries. The diagnostic values and positive likelihood ratios of individual CT signs were calculated. Mesenteric contrast extravasation had 73.5 positive likelihood ratio and 75% sensitivity for active mesenteric hemorrhage. Hemorrhage first appeared at arterial phase and portal phase was active and life threatening, different from a contained hemorrhage appeared only at equilibrium phase. For transmural bowel injuries, positive likelihood ratio of full-thickness bowel wall abnormality and extraluminal air was large at 32.5 and 26.9, respectively. However, increased mesenteric fat density and peritoneal fluid had high negative predictive value at 98.9 and 97.8. Mean radiodensity of peritoneal fluid in transmural bowel injuries was significantly lower (30 vs. 44 Hounsfield unit, p = 0.008). Multiphasic CT is accurate in identifying life-threatening mesenteric hemorrhage and transmural bowel injuries.

Research paper thumbnail of Direct measurement of the signal intensity of diffusion-weighted magnetic resonance imaging for preoperative grading and treatment guidance for brain gliomas

Journal of the Chinese Medical Association, 2012

Background: Magnetic resonance diffusion-weighted imaging (DWI) has been widely used clinically i... more Background: Magnetic resonance diffusion-weighted imaging (DWI) has been widely used clinically in imaging diagnosis of intracranial disorders. The purpose of current study was to present a quantitative method of direct measuring the DWI signal intensity of brain gliomas on the monitors of hospital picture archiving and communicating system (PACS) for grading gliomas. Methods: This study recruited 135 patients with treatment-naïve brain gliomas. Direct measurement of the signal intensity of selected tumoral regions of interest (ROIs) by DWI on the monitors of the hospital PACS was performed for all patients. From the measurements, we obtained three values, defined as DWI T (tumor), DWI N (the homologous normal-appearing area of the tumor ROI in the contralateral hemisphere), and DWI WM (normal-appearing white matter) in the contralateral frontal lobe. Two ratios, DWI T/WM and DWI T/N , were obtained for each tumoral ROI. The same method was used for apparent diffusion coefficient (ADC) ratios of the tumoral ROI. Fractional polynomial regression and the ManneWhitney U test were applied to determine the correlation between tumor grading, MIB-1 labeling index, and DWI and ADC ratios. Logistic regression models and receiver operating characteristic curve analysis were used to establish diagnostic models. Measurements of intraobserver and interobserver agreement were also made at 1-month interval. Results: The DWI ratios correlated positively with tumor grade and MIB-1 value ( p < 0.01). Cut-off ratios of 1.62 for DWI T/WM and 1.47 for DWI T/N generated the optimal combination of sensitivity (0.82, 0.80), specificity (0.79, 0.86), and sound discriminating power, with an area under the curve of 0.87 and 0.84, respectively, to differentiate low-grade from high-grade gliomas. ADC ratios showed relatively worse sensitivity, specificity, and discriminating power than DWI ratios. Almost all intraobserver and interobserver measurements were within 95% agreement. Conclusion: The proposed method e direct measuring of tumor signal intensity of DWI on PACS monitors e is feasible for grading gliomas in clinical neuro-oncology imaging services and has a high level of reliability and reproducibility.

Research paper thumbnail of Revisiting the relationship of three-dimensional fluid attenuation inversion recovery imaging and hearing outcomes in adults with idiopathic unilateral sudden sensorineural hearing loss

European Journal of Radiology, 2016

Research paper thumbnail of Bacteremic Urinary Tract Infection Caused by Multidrug-Resistant Enterobacteriaceae Are Associated With Severe Sepsis at Admission: Implication for Empirical Therapy

Medicine, 2016

The purpose of this study is to compare the clinical features and treatment outcomes among patien... more The purpose of this study is to compare the clinical features and treatment outcomes among patients with bacteremic urinary tract infection (UTI) caused by multidrug-resistant (MDR) and non-MDR Enterobacteriaceae and to identify whether MDR pathogens were independently associated with severe sepsis or septic shock at presentation.The clinical data of adult patients visiting and being treated at Chia-Yi Christian Hospital due to bacteremic UTI caused by Enterobacteriaceae from January 2006 to August 2015 were retrospectively analyzed.A total of 585 patients were enrolled. Among them, 220 (37.6%) were caused by the MDR Enterobacteriaceae. A total of 206 patients (35.2%) developed severe sepsis or septic shock at presentation. Patients in the MDR group tend to be male and have a past history of gout, recurrent UTI, prior hospitalization, hydronephrosis, renal stone, ureteral stone, indwelling urinary catheter, newly development of renal dysfunction, severe sepsis or septic shock, inten...

Research paper thumbnail of Using Flat-Panel Perfusion Imaging to Measure Cerebral Hemodynamics

Medicine, 2016

Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing ... more Flat-detector CT perfusion (FD-CTP) imaging has demonstrated efficacy in qualitatively accessing the penumbra in acute stroke equivalent to that of magnetic resonance perfusion (MRP). The aim of our study was to evaluate the feasibility of quantifying oligemia in the brain in patients with carotid stenosis.Ten patients with unilateral carotid stenosis of &amp;amp;gt;70% were included. All MRPs and FD-CTPs were performed before stenting. Region-of-interests (ROIs) including middle cerebral artery territory at basal ganglia level on both stenotic and contralateral sides were used for quantitative analysis. Relative time to peak (rTTP) was defined as TTP of the stenotic side divided by TTP of the contralateral side, and so as relative cerebral blood volume (rCBV), relative mean transit time (rMTT), and relative cerebral blood flow (rCBF). Absolute and relative TTP, CBV, MTT, CBF between two modalities were compared.For absolute quantitative analysis, the correlation of TTP was highest (r = 0.56), followed by CBV (r = 0.47), MTT (r = 0.47), and CBF (r = 0.43); for relative quantitative analysis, rCBF was the highest (r = 0.79), followed by rTTP (r = 0.75) and rCBV (r = 0.50).We confirmed that relative quantitative assessment of FD-CTP is feasible in chronic ischemic disease. Absolute quantitative measurements between MRP and FD-CTP only expressed moderate correlations. Optimization of acquisitions and algorithms is warranted to achieve better quantification.

Research paper thumbnail of Finding the optimal deconvolution algorithm for MR perfusion in carotid stenosis: Correlations with angiographic cerebral circulation time

Journal of Neuroradiology, 2016

The aim of our study is to explore the impacts of different deconvolution algorithms on correlati... more The aim of our study is to explore the impacts of different deconvolution algorithms on correlations between CBF, MTT, CBV, TTP, Tmax from MR perfusion (MRP) and angiography cerebral circulation time (CCT). Retrospectively, 30 patients with unilateral carotid stenosis, and available pre-stenting MRP and angiography were included for analysis. All MRPs were conducted in a 1.5-T MR scanner. Standard singular value decomposition, block-circulant, and two delay-corrected algorithms were used as the deconvolution methods. All angiographies were obtained in the same bi-plane flat-detector angiographic machine. A contrast bolus of 12mL was administrated via angiocatheter at a rate of 8mL/s. The acquisition protocols were the same for all cases. CCT was defined as the difference between time to peak from the cavernous ICA and the parietal vein in lateral view. Pearson correlations were calculated for CCT and CBF, MTT, CBV, TTP, Tmax. The correlation between CCT and MTT was highest with Tmax (r=0.65), followed by MTT (r=0.60), CBF (r=-0.57), and TTP (r=0.33) when standard singular value decomposition was used. No correlation with CBV was noted. MRP using a singular value decomposition algorithm confirmed the feasibility of quantifying cerebral blood flow deficit in steno-occlusive disease within the angio-room. This approach might further improve patient safety by providing immediate cerebral hemodynamics without extraradiation and iodine contrast.

Research paper thumbnail of Prolonged Cerebral Circulation Time Is the Best Parameter for Predicting Vasospasm during Initial CT Perfusion in Subarachnoid Hemorrhagic Patients

PloS one, 2016

We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from... more We sought to imitate angiographic cerebral circulation time (CCT) and create a similar index from baseline CT perfusion (CTP) to better predict vasospasm in patients with subarachnoid hemorrhage (SAH). Forty-one SAH patients with available DSA and CTP were retrospectively included. The vasospasm group was comprised of patients with deterioration in conscious functioning and newly developed luminal narrowing; remaining cases were classified as the control group. The angiography CCT (XA-CCT) was defined as the difference in TTP (time to peak) between the selected arterial ROIs and the superior sagittal sinus (SSS). Four arterial ROIs were selected to generate four corresponding XA-CCTs: the right and left anterior cerebral arteries (XA-CCTRA2 and XA-CCTLA2) and right- and left-middle cerebral arteries (XA-CCTRM2 and XA-CCTLM2). The CCTs from CTP (CT-CCT) were defined as the differences in TTP from the corresponding arterial ROIs and the SSS. Correlations of the different CCTs were cal...

Research paper thumbnail of Smoke in the Brain: The Clinical Implications of Imaging Features in Moyamoya Disease

Research paper thumbnail of Endovascular Management of Post-Irradiated Carotid Blowout Syndrome

PloS one, 2015

To retrospectively evaluate the clinical and technical factors related to the outcomes of endovas... more To retrospectively evaluate the clinical and technical factors related to the outcomes of endovascular management in patients with head-and-neck cancers associated with post-irradiated carotid blowout syndrome (PCBS). Between 2000 and 2013, 96 patients with PCBS underwent endovascular management. The 40 patients with the pathological lesions located in the external carotid artery were classified as group 1 and were treated with embolization. The other 56 patients with the pathological lesions located in the trunk of the carotid artery were divided into 2 groups as follows: group 2A comprised the 38 patients treated with embolization, and group 2B comprised the 18 patients treated with stent-graft placement. Fisher's exact test was used to examine endovascular methods, clinical severities, and postprocedural clinical diseases as predictors of outcomes. Technical success and immediate hemostasis were achieved in all patients. The results according to endovascular methods (group 1 ...

Research paper thumbnail of Toward Normalization of Intracranial Circulation Time: The Therapeutic Effects of Brain Vascular Disorders Evidenced by Color-Coded Quantitative Digital Subtraction Angiography (QDSA)

PURPOSE To define the role of color-coded QDSA in evaluating the therapeutic effects of various b... more PURPOSE To define the role of color-coded QDSA in evaluating the therapeutic effects of various brain vascular disorders. METHOD AND MATERIALS 85 patients with brain disorders that necessitated DSA were recruited. They were 15 arteriovenous malformations/fistulae (group A), 20 occlusive diseases (group B) and 50 without DSA detectable abnormal circulation time (group C, for control). The angio-catheters were placed at C4 vertebral body level for angiography (6 frames/sec using AXIOM-Artis® angiosystem, Siemens Healthcare)with total amount of 12 ml (for carotid) and 9 ml (for vertebral) 60% diluted contrast medium (340 mgI/ml) administrated in 1.5 sec by a power injector. Post-processing software (iFlow®, Siemens Healthcare) was used to define the time of maximal intensity (Tmax in sec) at selected angiographic mark points, namely, cavernous portion (I1) , supraclinoid (I2) portion of the internal carotid artery (ICA), proximal (A1) and distal (A2) anterior cerebral artery, first (M1...

Research paper thumbnail of Cross-modalities Comparative Study of Post-SAH Cerebral Hemodynamics: CT Perfusion versus Flat Detector DSA

PURPOSE Conventional digital subtraction angiography (DSA) helps to evaluate the severity of vasc... more PURPOSE Conventional digital subtraction angiography (DSA) helps to evaluate the severity of vascular spasm after subarachnoid hemorrhage (SAH). Being equipped with flat detector (FD), DSA is able to provide in-room assessment of peri-therapeutic cerebral hemodynamics and help tailoring endovascular treatments. The aim of current study is to compare the cerebral circulation time (CCT) that derived color-coded quantitative FD-DSA and CT perfusion (CTP) in SAH patients. METHOD AND MATERIALS Nineteen SAH patients entered our neurovascular service in 8 months interval and with available CCT derived from diagnostic FD-DSA and MDCT, were retrospectively recruited. The mean time interval between two examinations was 19 (4-36) hours. The CCT derived from FD-DSA was defined as the difference of Tmax (Time of maximum intensity) between the region-of-interest (ROI) of selected arteries and superior sagittal sinus (SSS). Four CCT were defined accordingly, namely, RA-CCT and LA-CCT (arterial ROI...

Research paper thumbnail of Pretreatment diagnosis of suprasellar papillary craniopharyngioma and germ cell tumors of adult patients

AJNR. American journal of neuroradiology, 2015

Suprasellar papillary craniopharyngiomas and germ cell tumors in adults share some clinical and i... more Suprasellar papillary craniopharyngiomas and germ cell tumors in adults share some clinical and imaging similarities but have different therapeutic strategies and outcomes. This study aimed to evaluate the pretreatment diagnosis of these 2 tumors to improve the therapeutic outcome. We retrospectively enrolled 18 adults with papillary craniopharyngiomas and 17 with germ cell tumors. The MR imaging findings were evaluated, including signal change and anatomic extension. The medical records were reviewed to collect clinical findings, management, and outcomes. The clinical findings of papillary craniopharyngiomas versus germ cell tumors were as follows: age: 46 ± 13.9 years versus 23 ± 7.1 years (P < .0001); diabetes insipidus: 2/18 (11%) versus 11/17 (65%) (P = .001); recurrence 13/16 (81%) versus 4/17 (24%) (P = .0031). The MR imaging findings of papillary craniopharyngiomas versus germ cell tumors were as follows-pituitary stalk thickening: 1.6 ± 0.4 mm versus 5.4 ± 4.2 mm (P <...

Research paper thumbnail of Imaging characteristics of primary spinal primitive neuroectodermal tumors. A report of five cases and literature review

The neuroradiology journal, 2012

Primary spinal primitive neuroectodermal tumors (PNETs) are rare and classified into peripheral a... more Primary spinal primitive neuroectodermal tumors (PNETs) are rare and classified into peripheral and central types because the treatment strategy and outcome are different. This study describes five cases of primary spinal peripheral type PNETs. Magnetic resonance imaging showed large extradural masses in the cervical and thoracic spine with bony invasion and paraspinal extension in four cases and a transdural mass in the sacral spinal canal in one case. We also briefly summarize the imaging characteristics of 36 peripheral type and six central type primary spinal PNETs in the literature.

Research paper thumbnail of In-room assessment of cerebral blood volume for guidance during intra-arterial thrombolytic therapy

Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences, 2012

In acute ischemic stroke, the ability to estimate the penumbra and infarction core ratio helps to... more In acute ischemic stroke, the ability to estimate the penumbra and infarction core ratio helps to triage those who will potentially benefit from thrombolytic therapies. Flat-panel post-contrast DynaCT imaging can provide both vasculature and parenchymal blood volume within the angio room to monitor hemodynamic changes during the endovascular procedures. We report on an 80-year-old woman who suffered from an acute occlusion of the right distal cervical internal carotid artery. She was transferred to the angio room where in-room post-contrast flat-panel DynaCT imaging (syngo Neuro PBV IR) was performed to access the ischemic tissue, followed by successful mechanical thrombolytic therapy.

Research paper thumbnail of Toward the Era of a One-Stop Imaging Service Using an Angiography Suite for Neurovascular Disorders

BioMed Research International, 2013

Transportation of patients requiring multiple diagnostic and imaging-guided therapeutic modalitie... more Transportation of patients requiring multiple diagnostic and imaging-guided therapeutic modalities is unavoidable in current radiological practice. This clinical scenario causes time delays and increased risk in the management of stroke and other neurovascular emergencies. Since the emergence of flat-detector technology in imaging practice in recent decades, studies have proven that flat-detector X-ray angiography in conjunction with contrast medium injection and specialized reconstruction algorithms can provide not only high-quality and high-resolution CT-like images but also functional information. This improvement in imaging technology allows quantitative assessment of intracranial hemodynamics and, subsequently in the same imaging session, provides treatment guidance for patients with neurovascular disorders by using only a flat-detector angiographic suite-a so-called one-stop quantitative imaging service (OSIS). In this paper, we review the recent developments in the field of flatdetector imaging and share our experience of applying this technology in neurovascular disorders such as acute ischemic stroke, cerebral aneurysm, and stenoocclusive carotid diseases.

Research paper thumbnail of Hepatobiliary and Pancreatic: Hemobilia caused by bleeding from hepatic artery aneurysms

Research paper thumbnail of Cognitive and epilepsy outcomes after epilepsy surgery caused by focal cortical dysplasia in children: early intervention maybe better

Child's Nervous System, 2014

Focal cortical dysplasia (FCD) is a specific malformation of cortical development harboring intri... more Focal cortical dysplasia (FCD) is a specific malformation of cortical development harboring intrinsic epileptogenicity, and most of the patients develop drug-resistant epilepsy in early childhood. The detrimental effects of early and frequent seizures on cognitive function in children are significant clinical issues. In this study, we evaluate the effects of early surgical intervention of FCD on epilepsy outcome and cognitive development. From 2006 to 2013, 30 children younger than 18 years old underwent resective surgery for FCDs at Taipei Veterans General Hospital. The mean age at surgery was 10.0 years (range 1.7 to 17.6 years). There were 21 boys and 9 girls. In this retrospective clinical study, seizure outcome, cognitive function, and quality of life were evaluated. To evaluate the effects to outcomes on early interventions, the patients were categorized into four groups according to age of seizure onset, duration of seizure before surgery, and severity of cognitive deficits. Eleven of 22 (50 %) patients demonstrated developmental delay preoperatively. The Engel seizure outcome achievements were class I in 21 (70 %), class II in 2 (7 %), class III in 6 (20 %), and class IV in 1 (3 %) patients. The locations of FCDs resected were in the frontal lobe in 18 cases, temporal lobe in 7, parietal lobe in 2, and in bilobes including frontoparietal lobe in 2 and parieto-occipital lobes in 1. Eight cases that had FCDs involved in the rolandic cortex presented hemiparesis before surgical resection. Motor function in four of them improved after operation. The histopathological types of FCDs were type Ia in 1, type Ib in 7, type IIa in 7, type IIb in 12, and type III in 3 patients. FCDs were completely resected in 20 patients. Eighteen (90 %) of them were seizure free (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001) with three patients that received more than one surgery to accomplish complete resection. The patients who had early seizure onset, no significant cognitive function deficit, and early surgical intervention with complete resection in less than 2 years of seizure duration showed best outcomes on seizure control, cognitive function, and quality of life. Delay in cognitive development and poor quality of life is common in children treated for FCDs. Early surgical intervention and complete resection of the lesion help for a better seizure control, cognitive function development, and quality of life. FCDs involved eloquent cortex may not prohibit complete resection for better outcomes.

Research paper thumbnail of Improving thermal stability and efficacy of BCNU in treating glioma cells using PAA-functionalized graphene oxide

International Journal of Nanomedicine, 2012

Background: 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a commercial chemotherapeutic drug for t... more Background: 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a commercial chemotherapeutic drug for treating malignant brain tumors, has poor thermal stability and a short half-life. Immobilization of BCNU on a nanocarrier might increase the thermal stability of BCNU and extend its half-life. Methods: Nanosized graphene oxide (GO) could be modified by polyacrylic acid (PAA) to improve the aqueous solubility and increase the cell penetration efficacy of the nanocarrier. PAA-GO intended as a drug carrier for BCNU was prepared and characterized in this study. The size and thickness of PAA-GO was investigated by transmission electron microscopy and atomic force microscopy, and the presence of PAA functional groups was confirmed by electron spectroscopy for chemical analysis and thermogravimetric analysis. BCNU was conjugated to PAA-GO by covalent binding for specific killing of cancer cells, which could also enhance the thermal stability of the drug. Results: Single layer PAA-GO (about 1.9 nm) with a lateral width as small as 36 nm was successfully prepared. The optimum drug immobilization condition was by reacting 0.5 mg PAA-GO with 0.4 mg BCNU, and the drug-loading capacity and residual drug activity were 198 µg BCNU/mg PAA-GO and 70%, respectively. This nanocarrier significantly prolonged the half-life of bound BCNU from 19 to 43 hours compared with free drug and showed efficient intracellular uptake by GL261 cancer cells. The in vitro anticancer efficacy of PAA-GO-BCNU was demonstrated by a 30% increase in DNA interstrand cross-linking and a 77% decrease in the IC 50 value toward GL261 compared with the same dosage of free drug. Conclusion: Nanosized PAA-GO serves as an efficient BCNU nanocarrier by covalent binding. This nanocarrier will be a promising new vehicle for an advanced drug delivery system in cancer therapy.

Research paper thumbnail of Imaging quality and diagnostic reliability of low-dose computed tomography lumbar spine for evaluating patients with spinal disorders

The Spine Journal, 2014

Computed tomography (CT) scans of the lumbar spine (CTLS) have demonstrated a higher level of acc... more Computed tomography (CT) scans of the lumbar spine (CTLS) have demonstrated a higher level of accuracy than plain films and have been used to assess patients with spinal disorder when magnetic resonance imaging is not available. Nevertheless, radiation exposure remains a serious safety concern. Iterative reconstruction (IR) decreases the CT radiation dose for diagnostic imaging. However, the feasibility of using IR in CTLS is unclear. To evaluate the imaging quality and diagnostic reliability of CTLS with IR. A prospective study. All patients from outpatient departments who suffered from spinal disorders and were referred for CTLS. In acquired CT images, the signal-to-noise ratio (SNR) of the dural sac (DS), intervertebral disc (IVD), psoas muscle (PM), and L5 vertebral body, the contrast-to-noise ratio between the DS and IVD (D-D CNR), and the subjective imaging qualities were compared across groups. Interobserver agreement was evaluated with kappa values. Patients receiving low radiation CTLS were divided into three groups. A 150 mAs tube current with 120 kVp tube voltage was used with Group A and a 230 mAs tube current with 100 kVp tube voltage with Group B. Intended end radiation exposure was 50% less than that of the control group. Tube modulation was active for all groups. The images of the two low-radiation groups were reconstructed by IR; those of the control group by filtered back-projection (FBP). The SNRs of the DS, IVD, PM, BM, and D-D CNR of Group A were not inferior to those of the control group. All SNRs and D-D CNRs for Group B were inferior to those of the control group. Except for that of the facet joint, all subjective imaging ratings for anatomic regions were equivalent between Groups A and B. Interobserver agreement was highest for the control group (0.72-0.88), followed by Group A (0.69-0.83) and B (0.55-0.83). Fifty percent tube current reduction combined with IR provides equivalent diagnostic accuracy and improved patient safety when compared with conventional CTLS. Our results support its use as a screening tool. With the tube modulation technique, further adjustments in weighting IR and FBP algorithms based on body mass index become unnecessary.

Research paper thumbnail of Multidetector Computerized Tomography Urography as the Primary Imaging Modality for Detecting Urinary Tract Neoplasms in Patients With Asymptomatic Hematuria

The Journal of Urology, 2008

We determined whether multidetector computerized tomography urography is sensitive and specific f... more We determined whether multidetector computerized tomography urography is sensitive and specific for detecting urinary tract neoplasms when used as the primary imaging modality for evaluating patients with hematuria. A retrospective review was performed of the radiological, urological and pathological records of 468 patients without a history of urinary neoplasms who presented with hematuria. All patients underwent multidetector computerized tomography urography and complete urological evaluation, including cystoscopy. Laboratory urinalysis and cytology were done in 350 and 318 of the 468 patients, respectively. Multivariate logistic regression analysis was performed using the variables multidetector computerized tomography urography diagnosis, worst urine cytology, number of red blood cells per high power field, gross hematuria, age and gender to predict urinary tract neoplasm. A total of 50 urinary neoplasms were diagnosed in 468 patients. Multidetector computerized tomography urography detected 32 of 50 neoplasms for a sensitivity of 64%, specificity of 98%, positive predictive value of 76% and negative predictive value of 96%. There were 10 false-positive and 18 false-negative multidetector computerized tomography urography studies. Multivariate logistic regression showed that abnormal multidetector computerized tomography urography findings, ie neoplasm (p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.0001), and suspicious or positive urine cytology (p = 0.0009) were significant. Patients with an abnormal multidetector computerized tomography urography diagnosis and suspicious or positive urine cytology had 44 and 47 times greater odds, respectively, of having urinary neoplasms compared to the odds in those with normal examinations. Multidetector computerized tomography urography is relatively sensitive and highly specific for detecting urinary neoplasms. It may serve as the primary imaging modality to evaluate patients with hematuria. Multidetector computerized tomography urography does not eliminate the role of cystoscopy in the evaluation of hematuria.

Research paper thumbnail of Contrast-Enhanced Multiphasic Computed Tomography for Identifying Life-Threatening Mesenteric Hemorrhage and Transmural Bowel Injuries

The Journal of Trauma: Injury, Infection, and Critical Care, 2011

Active mesenteric hemorrhage and bowel perforation after blunt abdominal trauma warrant immediate... more Active mesenteric hemorrhage and bowel perforation after blunt abdominal trauma warrant immediate surgical intervention. We investigate whether findings on multiphasic computed tomography (CT) can identify life-threatening mesenteric hemorrhage and bowel injuries. Within 1-year period, 106 patients underwent multiphasic CT for evaluation of blunt abdominal injuries. Images obtained at arterial phase, portal phase, and equilibrium phase were retrospectively reviewed with special focus on mesentery and bowel injuries. We compared the recorded findings with surgically proven active mesenteric hemorrhage and transmural bowel injuries. The diagnostic values and positive likelihood ratios of individual CT signs were calculated. Mesenteric contrast extravasation had 73.5 positive likelihood ratio and 75% sensitivity for active mesenteric hemorrhage. Hemorrhage first appeared at arterial phase and portal phase was active and life threatening, different from a contained hemorrhage appeared only at equilibrium phase. For transmural bowel injuries, positive likelihood ratio of full-thickness bowel wall abnormality and extraluminal air was large at 32.5 and 26.9, respectively. However, increased mesenteric fat density and peritoneal fluid had high negative predictive value at 98.9 and 97.8. Mean radiodensity of peritoneal fluid in transmural bowel injuries was significantly lower (30 vs. 44 Hounsfield unit, p = 0.008). Multiphasic CT is accurate in identifying life-threatening mesenteric hemorrhage and transmural bowel injuries.

Research paper thumbnail of Direct measurement of the signal intensity of diffusion-weighted magnetic resonance imaging for preoperative grading and treatment guidance for brain gliomas

Journal of the Chinese Medical Association, 2012

Background: Magnetic resonance diffusion-weighted imaging (DWI) has been widely used clinically i... more Background: Magnetic resonance diffusion-weighted imaging (DWI) has been widely used clinically in imaging diagnosis of intracranial disorders. The purpose of current study was to present a quantitative method of direct measuring the DWI signal intensity of brain gliomas on the monitors of hospital picture archiving and communicating system (PACS) for grading gliomas. Methods: This study recruited 135 patients with treatment-naïve brain gliomas. Direct measurement of the signal intensity of selected tumoral regions of interest (ROIs) by DWI on the monitors of the hospital PACS was performed for all patients. From the measurements, we obtained three values, defined as DWI T (tumor), DWI N (the homologous normal-appearing area of the tumor ROI in the contralateral hemisphere), and DWI WM (normal-appearing white matter) in the contralateral frontal lobe. Two ratios, DWI T/WM and DWI T/N , were obtained for each tumoral ROI. The same method was used for apparent diffusion coefficient (ADC) ratios of the tumoral ROI. Fractional polynomial regression and the ManneWhitney U test were applied to determine the correlation between tumor grading, MIB-1 labeling index, and DWI and ADC ratios. Logistic regression models and receiver operating characteristic curve analysis were used to establish diagnostic models. Measurements of intraobserver and interobserver agreement were also made at 1-month interval. Results: The DWI ratios correlated positively with tumor grade and MIB-1 value ( p < 0.01). Cut-off ratios of 1.62 for DWI T/WM and 1.47 for DWI T/N generated the optimal combination of sensitivity (0.82, 0.80), specificity (0.79, 0.86), and sound discriminating power, with an area under the curve of 0.87 and 0.84, respectively, to differentiate low-grade from high-grade gliomas. ADC ratios showed relatively worse sensitivity, specificity, and discriminating power than DWI ratios. Almost all intraobserver and interobserver measurements were within 95% agreement. Conclusion: The proposed method e direct measuring of tumor signal intensity of DWI on PACS monitors e is feasible for grading gliomas in clinical neuro-oncology imaging services and has a high level of reliability and reproducibility.