Turgut Tali - Academia.edu (original) (raw)

Papers by Turgut Tali

Research paper thumbnail of Spinal Brucellosis

Neuroimaging Clinics of North America, 2015

Spinal involvement in human brucellosis is a common condition and a significant cause of morbidit... more Spinal involvement in human brucellosis is a common condition and a significant cause of morbidity and mortality, particularly in endemic areas, because it is often associated with therapeutic failure. Most chronic brucellosis cases are the result of inadequate treatment of the initial episode. Recognition of spinal brucellosis is challenging. Early diagnosis is important to ensure proper treatment and decrease morbidity and mortality. Radiologic evaluation has gained importance in diagnosis and treatment planning, including interventional procedures and monitoring of all spinal infections.

Research paper thumbnail of Blood-flow volume quantification in internal carotid and vertebral arteries: comparison of 3 different ultrasound techniques with phase-contrast MR imaging

AJNR. American journal of neuroradiology, 2006

Optimal estimation of cerebral blood-flow volume (BFV) may be an important indicator for better e... more Optimal estimation of cerebral blood-flow volume (BFV) may be an important indicator for better evaluation of the patients with cerebrovascular disorders. In this study, we compared the BFV values at bilateral internal carotid and vertebral arteries of healthy volunteers obtained with color Doppler, power Doppler, and B-flow ultrasound (US) studies and tried to determine which examination is more correlated with MR phase-contrast quantification. BFVs of the internal carotid and vertebral arteries of 40 healthy volunteers (19 men and 21 women; age range, 20-47 years) were measured by using color Doppler, power Doppler, B-flow US and MR phase-contrast imaging. The flow measurements obtained with the sonographic techniques were compared with MR phase contrast, which is accepted as the most reliable method for the estimation of cerebral BFV. Quantification with power Doppler imaging showed the highest values among sonography techniques, followed by color Doppler imaging, B-flow imaging ...

Research paper thumbnail of The application of contrast agents in the evaluation of neoplasms of the central nervous system

Topics in Magnetic Resonance Imaging, 1992

Research paper thumbnail of Isolated true anterior thoracic meningocele

AJNR. American journal of neuroradiology

Intrathoracic meningocele is rare and is usually associated with neurofibromatosis type I. Most o... more Intrathoracic meningocele is rare and is usually associated with neurofibromatosis type I. Most of the reported thoracic meningoceles are not strictly anterior in location, but also lateral or anterolateral. We report a case of true anterior thoracic meningocele with no associated generalized mesenchymal dysplasia.

Research paper thumbnail of Evaluation of Aqueductal Patency in Patients with Hydrocephalus: Three-Dimensional High-Sampling-Efficiency Technique (SPACE) versus Two-Dimensional Turbo Spin Echo at 3 Tesla

Korean Journal of Radiology, 2014

Objective: To compare the accuracy of diagnosing aqueductal patency and image quality between hig... more Objective: To compare the accuracy of diagnosing aqueductal patency and image quality between high spatial resolution three-dimensional (3D) high-sampling-efficiency technique (sampling perfection with application optimized contrast using different flip angle evolutions [SPACE]) and T2-weighted (T2W) two-dimensional (2D) turbo spin echo (TSE) at 3-T in patients with hydrocephalus. Materials and Methods: This retrospective study included 99 patients diagnosed with hydrocephalus. T2W 3D-SPACE was added to the routine sequences which consisted of T2W 2D-TSE, 3D-constructive interference steady state (CISS), and cine phase-contrast MRI (PC-MRI). Two radiologists evaluated independently the patency of cerebral aqueduct and image quality on the T2W 2D-TSE and T2W 3D-SPACE. PC-MRI and 3D-CISS were used as the reference for aqueductal patency and image quality, respectively. Inter-observer agreement was calculated using kappa statistics. Results: The evaluation of the aqueductal patency by T2W 3D-SPACE and T2W 2D-TSE were in agreement with PC-MRI in 100% (99/99; sensitivity, 100% [83/83]; specificity, 100% [16/16]) and 83.8% (83/99; sensitivity, 100% [67/83]; specificity, 100% [16/16]), respectively (p < 0.001). No significant difference in image quality between T2W 2D-TSE and T2W 3D-SPACE (p = 0.056) occurred. The kappa values for inter-observer agreement were 0.714 for T2W 2D-TSE and 0.899 for T2W 3D-SPACE. Conclusion: Three-dimensional-SPACE is superior to 2D-TSE for the evaluation of aqueductal patency in hydrocephalus. T2W 3D-SPACE may hold promise as a highly accurate alternative treatment to PC-MRI for the physiological and morphological evaluation of aqueductal patency.

Research paper thumbnail of Giant Vertebral Notochordal Rest: Magnetic Resonance and Diffusion Weighted Imaging Findings

Korean Journal of Radiology, 2009

Research paper thumbnail of Letter by Lee et al Regarding Article, "Training of Future Interventional Neuroradiologists: The European Approach

Research paper thumbnail of Magnetic Resonance Versus Computed Tomographic Imaging in Acute Stroke

Stroke, 1995

Background and Purpose This study was an attempt to determine whether CT and MRI are comparable o... more Background and Purpose This study was an attempt to determine whether CT and MRI are comparable or if one is superior to the other in the early detection of ischemic stroke or hematoma. Methods Patients with acute stroke were sought within 3 hours of onset for clinical examination and prospective evaluation by concurrently performed CT and MRI. Repeated clinical and imaging studies were undertaken when possible immediately after imaging and at 24 hours, 3 to 5 days, and 3 months. The study neurologists were blinded to the results of imaging, as were the study radiologists to the clinical findings. The study radiologists read the scans in sequence, mapping each imaging on standard templates before viewing a later scan. No retrospective revisions of imaging mapping of earlier images were undertaken. Results Sixty-eight patients were recruited within 4 hours and an additional 12 patients within 24 hours. Seventy-five strokes were due to infarction and five to hemorrhage. The median tim...

Research paper thumbnail of Sapho Syndrome Associated with Acne Fulminans and Prominent Acromioclavicular Joint Involvement

Scandinavian Journal of Rheumatology, 1996

The clinical and radiological findings of a 33 year-old male patient with acne fulminans and asso... more The clinical and radiological findings of a 33 year-old male patient with acne fulminans and associated SAPHO syndrome are described. The patient presented with prominent acromioclavicular joint involvement, unilateral sacroiliitis and subclavian vein compression which are relatively uncommon features of this syndrome.

Research paper thumbnail of The role of qualitative and quantitative MRI assessment of multiple sclerosis lesions according to their in evaluating the efficacy of intravenous immunoglobulin G

Research paper thumbnail of MR Evaluation of Acoustic Schwannoma with Fractional Contrast Doses

Journal of Computer Assisted Tomography, 1995

Research paper thumbnail of Diffusion-Weighted Imaging of the Appendicular Skeleton with a Non–Carr-Purcell-Meiboom-Gill Single-Shot Fast Spin-Echo Sequence

American Journal of Roentgenology, 2007

OBJECTIVE. The objective of our study was to prospectively evaluate the signal-to-noise ratio (SN... more OBJECTIVE. The objective of our study was to prospectively evaluate the signal-to-noise ratio (SNR) improvement in diffusion-weighted imaging (DWI) of the appendicular skeleton with the use of a newly developed non-Carr-Purcell-Meiboom-Gill (non-CPMG) single-shot fast spin-echo (SSFSE) sequence and to evaluate its effect on apparent diffusion coefficient (ADC) measurements. SUBJECTS AND METHODS. DWI of the bone was performed in 32 patients with an echo-planar imaging (EPI)-based sequence followed by a non-CPMG SSFSE technique. SNR and ADC values were measured over a lesion-free right femoral head. A score was assigned for each set of images to assess image quality. When a bone lesion was present, contrast-to-noise ratio (CNR) and ADC were also measured. Paired Student's t tests were used for statistical analysis. RESULTS. The mean (± SD) SNR values were 9.89 ± 2.20 and 81.68 ± 4.87 for EPI and non-CPMG SSFSE DWI, respectively. SNR values associated with the non-CPMG SSFSE technique were found to be significantly higher than those measured with the EPI-based DWI technique (p < 0.01). Mean ADCs of the bone were 0.57 ± 0.20 and 0.29 ± 0.15 × 10-3 mm 2 /s, respectively, for EPI and non-CPMG SSFSE DWI. Image quality scores were higher for the non-CPMG SSFSE DWI technique (p < 0.05) than for the EPI-based DWI technique. Overall lesion CNR was found to be higher in DWI performed with the non-CPMG SSFSE technique. CONCLUSION. The non-CPMG SSFSE technique provides a significant improvement over the currently used EPI-based DWI technique and has the potential to be a powerful tool in imaging the appendicular skeleton.

Research paper thumbnail of Delineation of gliomas with various doses of MR contrast material

AJNR. American journal of neuroradiology, 1994

To examine the effects of different gadolinium doses on the delineation of gliomas, particularly ... more To examine the effects of different gadolinium doses on the delineation of gliomas, particularly the demonstration of abnormal enhancement on T1-weighted images extending beyond the zone of apparent signal abnormality on corresponding T2-weighted images. During phase II clinical trials of gadoteridol, 23 patients with pathologically proved gliomas were studied by MR with various doses of gadoteridol, ranging from 0.05 to 0.3 mmol/kg. All of the gliomas were readily detected by T2-weighted images. Twelve of 23 patients demonstrated enhancement on T1-weighted images extending beyond the zone of apparent signal abnormality demonstrated on T2-weighted images. These findings were seen in none of the six patients (0%) studied at 0.05 mmol/kg, one of five patients (20%) studied at 0.1 mmol/kg, four of five patients (80%) studied at 0.2 mmol/kg, and seven of seven patients (100%) studied at 0.3 mmol/kg. The detection of symptomatic gliomas does not require a contrast agent because they are ...

Research paper thumbnail of Cystic acoustic schwannomas: MR characteristics

AJNR. American journal of neuroradiology

To evaluate the spectrum of MR characteristics of cystic acoustic schwannoma and to investigate i... more To evaluate the spectrum of MR characteristics of cystic acoustic schwannoma and to investigate its incidence. We retrospectively reviewed the MR findings and clinical records of 16 patients with cystic acoustic schwannomas. In addition, the MR examinations of 411 consecutive patients referred for clinical suspicion of acoustic schwannomas were reviewed retrospectively to assess the incidence of acoustic schwannomas with cystic lesions arising from the internal auditory canal. Of the 16 acoustic schwannomas with MR evidence of intramural cysts, 11 tumors had single small cysts, and five had multiple intramural cysts of variable size. Intramural cysts in 11 of the 16 tumors exhibited higher signal intensity than that of cerebrospinal fluid; the remainder were isointense to cerebrospinal fluid on both T1- and T2-weighted images. All intramural cysts showed circumferential enhancement after contrast administration. Nine of the 16 cystic acoustic schwannomas also had MR evidence of extr...

Research paper thumbnail of Intrathecal Gadolinium-Enhanced MR Cisternography in the Evaluation of CSF Leakage

American Journal of Neuroradiology, 2009

Radiologic identification of the location of the CSF leakage is important for proper surgical pla... more Radiologic identification of the location of the CSF leakage is important for proper surgical planning and increases the chance of dural repair. This article describes our experience in analyzing clinically suspected cranial CSF fistulas by using MR imaging combined with the intrathecal administration of a gadolinium-based contrast agent. MATERIALS AND METHODS: A total of 85 consecutive patients with suspected CSF fistulas who presented with persistent or intermittent rhinorrhea or otorrhea lasting for more than 1 month between 2003 and 2007 were included in this study. RESULTS: We observed objective CSF leakage in 64 of 85 patients (75%). The CSF leak was located in the ethmoidal region in 37 patients (58%), in the superior wall of the sphenoid sinus in 8 patients (13%), in the posterior wall of the frontal sinus in 10 patients (15%), in the superior wall of the mastoid air cells in 6 patients (9%), and from the skull base into the infratemporal fossa in 1 patient (2%). Two patients (3%) showed leakage into Ͼ1 paranasal sinus. CONCLUSIONS: MR cisternography after the intrathecal administration of gadopentate dimeglumine represents an effective and minimally invasive method for evaluating suspected CSF fistulas along the skull base. It provides multiplanar capabilities without risk of radiation exposure and is an excellent approach to depict the anatomy of CSF spaces and CSF fistulas.

Research paper thumbnail of Primary intraosseous meningioma: CT and MRI appearance

AJNR. American journal of neuroradiology, 2005

Benign primary intraosseous meningioma presenting with osteolytic skull lesion and soft-tissue co... more Benign primary intraosseous meningioma presenting with osteolytic skull lesion and soft-tissue component is rare. CT and MR imaging of a patient with frontoparietal scalp swelling showed an osteolytic intracalvarial lesion with an extradural soft-tissue component. Following wide surgical resection, the histological examination revealed an intraosseous chordoid meningioma. The clinical and radiological findings of primary intraosseous meningioma are discussed and the relevant literature is reviewed.

Research paper thumbnail of Diagnostic Value of Contrast-Enhanced Fluid-Attenuated Inversion-Recovery and Delayed Contrast-Enhanced Brain MRI in Multiple Sclerosis

Academic Radiology, 2008

Rationale and Objectives. In brain MRI of multiple sclerosis (MS) patients, enhancement of the le... more Rationale and Objectives. In brain MRI of multiple sclerosis (MS) patients, enhancement of the lesions is usually evaluated in early contrast-enhanced T1-weighted images (CE-T1WI). The objective of this study is to determine the sensitivity of contrast-enhanced fluid-attenuated-inversion-recovery (CE-FLAIR) and delayed contrast-enhanced MRI in evaluation of MS brain lesions. Materials and Methods. Brain MRI examination including early and delayed CE-T1WI and early and delayed CE-FLAIR images was performed for 46 patients with clinically definite MS disease. Number, size, location, degree, and pattern of enhancement of the enhanced lesions in each sequence were recorded separately. Results. A total number of 87 enhanced lesions was detected in 30 patients. Early CE-T1WI could detect only 63 lesions (72.4% of total) in 24 patients, while delayed CE-T1WI and early and delayed CE-FLAIR images showed 85 (97.7%), 84 (96.6%), and 81 (93.1%) lesions in 28, 28, and 26 patients, respectively. A greater degree of enhancement and larger lesion size were observed in the additional sequences compared with the early CE-T1WI. Conclusions. The sensitivity of early CE-T1WI for the detection of enhanced MS lesions is significantly lower than that for other additional sequences. Delayed CE-FLAIR images could not add significant information to other sequences. Therefore, early CE-FLAIR and delayed CE-T1WI brain MRI can be considered as part of the evaluation of MS patients, especially if, despite clinically suspected active disease, no enhanced lesion is found in the routine CE-T1WI.

Research paper thumbnail of MR of fetal central nervous system abnormalities

AJNR. American journal of neuroradiology, 1994

To investigate whether MR can provide additional information on fetuses with central nervous syst... more To investigate whether MR can provide additional information on fetuses with central nervous system abnormalities as demonstrated by ultrasonography. Fetal MR examinations were studied prospectively in 22 pregnant women whose fetuses showed evidence of anomalies on ultrasound performed in the High-Risk Obstetric Clinic. In 19 of 22 cases, postpartum confirmatory diagnoses were obtained by MR or CT examinations, autopsy, or surgery. In general, the image quality of MR is comparable with that of ultrasound. However, in six of 22 cases (27%), MR provided additional information that altered the ultrasound diagnosis; these included cases of infarction, diastematomyelia, normal hemimegalencephaly with early myelination, Dandy-Walker variant, and lipoma. All of these cases had postpartum confirmation. The additional information changed the treatment in three of six patients (no intervention or elective abortion). In certain situations MR can add valuable information to that obtained by son...

Research paper thumbnail of Venous sinus occlusive disease: MR findings

AJNR. American journal of neuroradiology, 1994

PURPOSE To study MR patterns of venous sinus occlusive disease and to relate them to the underlyi... more PURPOSE To study MR patterns of venous sinus occlusive disease and to relate them to the underlying pathophysiology by comparing the appearance and pathophysiologic features of venous sinus occlusive disease with those of arterial ischemic disease. METHODS The clinical data and MR examinations of 26 patients with venous sinus occlusive disease were retrospectively reviewed with special attention to mass effect, hemorrhage, and T2-weighted image abnormalities as well as to abnormal parenchymal, venous, or arterial enhancement after intravenous gadopentetate dimeglumine administration. Follow-up studies when available were evaluated for atrophy, infarction, chronic mass effect, and hemorrhage. RESULTS Mass effect was present in 25 of 26 patients. Eleven of the 26 had mass effect without abnormal signal on T2-weighted images. Fifteen patients had abnormal signal on T2-weighted images, but this was much less extensive than the degree of brain swelling in all cases. No patient showed abn...

Research paper thumbnail of T2-weighted vs. intrathecal contrast-enhanced MR cisternography in the evaluation of CSF rhinorrhea

Acta Radiologica, 2013

Background Endoscopic surgical approach is being more widely used in the treatment of cerebrospin... more Background Endoscopic surgical approach is being more widely used in the treatment of cerebrospinal fluid (CSF) rhinorrhea. Accurate localization of CSF fistulas prior to surgery is essential in increasing the success of dural repair and in decreasing negative or recurrent explorations. Purpose To evaluate and compare intrathecal contrast medium-enhanced magnetic resonance cisternography (CEMRC) with T2-weighted MR cisternography (T2MRC) in identifying the presence and site of CSF rhinorrhea. Material and Methods Sixty patients with suspected CSF rhinorrhea underwent MR cisternography including intrathecally enhanced fat-suppressed T1WI in three orthogonal planes and T2WI in the coronal plane. Both set of images were reviewed by two blinded radiologists for the presence and location of CSF leakage. Imaging data were compared with surgical findings and/or beta-2 transferrin testing. Results With surgery proven CSF leakage in 20 instances as reference, CEMRC detected 18 (90%), whereas...

Research paper thumbnail of Spinal Brucellosis

Neuroimaging Clinics of North America, 2015

Spinal involvement in human brucellosis is a common condition and a significant cause of morbidit... more Spinal involvement in human brucellosis is a common condition and a significant cause of morbidity and mortality, particularly in endemic areas, because it is often associated with therapeutic failure. Most chronic brucellosis cases are the result of inadequate treatment of the initial episode. Recognition of spinal brucellosis is challenging. Early diagnosis is important to ensure proper treatment and decrease morbidity and mortality. Radiologic evaluation has gained importance in diagnosis and treatment planning, including interventional procedures and monitoring of all spinal infections.

Research paper thumbnail of Blood-flow volume quantification in internal carotid and vertebral arteries: comparison of 3 different ultrasound techniques with phase-contrast MR imaging

AJNR. American journal of neuroradiology, 2006

Optimal estimation of cerebral blood-flow volume (BFV) may be an important indicator for better e... more Optimal estimation of cerebral blood-flow volume (BFV) may be an important indicator for better evaluation of the patients with cerebrovascular disorders. In this study, we compared the BFV values at bilateral internal carotid and vertebral arteries of healthy volunteers obtained with color Doppler, power Doppler, and B-flow ultrasound (US) studies and tried to determine which examination is more correlated with MR phase-contrast quantification. BFVs of the internal carotid and vertebral arteries of 40 healthy volunteers (19 men and 21 women; age range, 20-47 years) were measured by using color Doppler, power Doppler, B-flow US and MR phase-contrast imaging. The flow measurements obtained with the sonographic techniques were compared with MR phase contrast, which is accepted as the most reliable method for the estimation of cerebral BFV. Quantification with power Doppler imaging showed the highest values among sonography techniques, followed by color Doppler imaging, B-flow imaging ...

Research paper thumbnail of The application of contrast agents in the evaluation of neoplasms of the central nervous system

Topics in Magnetic Resonance Imaging, 1992

Research paper thumbnail of Isolated true anterior thoracic meningocele

AJNR. American journal of neuroradiology

Intrathoracic meningocele is rare and is usually associated with neurofibromatosis type I. Most o... more Intrathoracic meningocele is rare and is usually associated with neurofibromatosis type I. Most of the reported thoracic meningoceles are not strictly anterior in location, but also lateral or anterolateral. We report a case of true anterior thoracic meningocele with no associated generalized mesenchymal dysplasia.

Research paper thumbnail of Evaluation of Aqueductal Patency in Patients with Hydrocephalus: Three-Dimensional High-Sampling-Efficiency Technique (SPACE) versus Two-Dimensional Turbo Spin Echo at 3 Tesla

Korean Journal of Radiology, 2014

Objective: To compare the accuracy of diagnosing aqueductal patency and image quality between hig... more Objective: To compare the accuracy of diagnosing aqueductal patency and image quality between high spatial resolution three-dimensional (3D) high-sampling-efficiency technique (sampling perfection with application optimized contrast using different flip angle evolutions [SPACE]) and T2-weighted (T2W) two-dimensional (2D) turbo spin echo (TSE) at 3-T in patients with hydrocephalus. Materials and Methods: This retrospective study included 99 patients diagnosed with hydrocephalus. T2W 3D-SPACE was added to the routine sequences which consisted of T2W 2D-TSE, 3D-constructive interference steady state (CISS), and cine phase-contrast MRI (PC-MRI). Two radiologists evaluated independently the patency of cerebral aqueduct and image quality on the T2W 2D-TSE and T2W 3D-SPACE. PC-MRI and 3D-CISS were used as the reference for aqueductal patency and image quality, respectively. Inter-observer agreement was calculated using kappa statistics. Results: The evaluation of the aqueductal patency by T2W 3D-SPACE and T2W 2D-TSE were in agreement with PC-MRI in 100% (99/99; sensitivity, 100% [83/83]; specificity, 100% [16/16]) and 83.8% (83/99; sensitivity, 100% [67/83]; specificity, 100% [16/16]), respectively (p < 0.001). No significant difference in image quality between T2W 2D-TSE and T2W 3D-SPACE (p = 0.056) occurred. The kappa values for inter-observer agreement were 0.714 for T2W 2D-TSE and 0.899 for T2W 3D-SPACE. Conclusion: Three-dimensional-SPACE is superior to 2D-TSE for the evaluation of aqueductal patency in hydrocephalus. T2W 3D-SPACE may hold promise as a highly accurate alternative treatment to PC-MRI for the physiological and morphological evaluation of aqueductal patency.

Research paper thumbnail of Giant Vertebral Notochordal Rest: Magnetic Resonance and Diffusion Weighted Imaging Findings

Korean Journal of Radiology, 2009

Research paper thumbnail of Letter by Lee et al Regarding Article, "Training of Future Interventional Neuroradiologists: The European Approach

Research paper thumbnail of Magnetic Resonance Versus Computed Tomographic Imaging in Acute Stroke

Stroke, 1995

Background and Purpose This study was an attempt to determine whether CT and MRI are comparable o... more Background and Purpose This study was an attempt to determine whether CT and MRI are comparable or if one is superior to the other in the early detection of ischemic stroke or hematoma. Methods Patients with acute stroke were sought within 3 hours of onset for clinical examination and prospective evaluation by concurrently performed CT and MRI. Repeated clinical and imaging studies were undertaken when possible immediately after imaging and at 24 hours, 3 to 5 days, and 3 months. The study neurologists were blinded to the results of imaging, as were the study radiologists to the clinical findings. The study radiologists read the scans in sequence, mapping each imaging on standard templates before viewing a later scan. No retrospective revisions of imaging mapping of earlier images were undertaken. Results Sixty-eight patients were recruited within 4 hours and an additional 12 patients within 24 hours. Seventy-five strokes were due to infarction and five to hemorrhage. The median tim...

Research paper thumbnail of Sapho Syndrome Associated with Acne Fulminans and Prominent Acromioclavicular Joint Involvement

Scandinavian Journal of Rheumatology, 1996

The clinical and radiological findings of a 33 year-old male patient with acne fulminans and asso... more The clinical and radiological findings of a 33 year-old male patient with acne fulminans and associated SAPHO syndrome are described. The patient presented with prominent acromioclavicular joint involvement, unilateral sacroiliitis and subclavian vein compression which are relatively uncommon features of this syndrome.

Research paper thumbnail of The role of qualitative and quantitative MRI assessment of multiple sclerosis lesions according to their in evaluating the efficacy of intravenous immunoglobulin G

Research paper thumbnail of MR Evaluation of Acoustic Schwannoma with Fractional Contrast Doses

Journal of Computer Assisted Tomography, 1995

Research paper thumbnail of Diffusion-Weighted Imaging of the Appendicular Skeleton with a Non–Carr-Purcell-Meiboom-Gill Single-Shot Fast Spin-Echo Sequence

American Journal of Roentgenology, 2007

OBJECTIVE. The objective of our study was to prospectively evaluate the signal-to-noise ratio (SN... more OBJECTIVE. The objective of our study was to prospectively evaluate the signal-to-noise ratio (SNR) improvement in diffusion-weighted imaging (DWI) of the appendicular skeleton with the use of a newly developed non-Carr-Purcell-Meiboom-Gill (non-CPMG) single-shot fast spin-echo (SSFSE) sequence and to evaluate its effect on apparent diffusion coefficient (ADC) measurements. SUBJECTS AND METHODS. DWI of the bone was performed in 32 patients with an echo-planar imaging (EPI)-based sequence followed by a non-CPMG SSFSE technique. SNR and ADC values were measured over a lesion-free right femoral head. A score was assigned for each set of images to assess image quality. When a bone lesion was present, contrast-to-noise ratio (CNR) and ADC were also measured. Paired Student's t tests were used for statistical analysis. RESULTS. The mean (± SD) SNR values were 9.89 ± 2.20 and 81.68 ± 4.87 for EPI and non-CPMG SSFSE DWI, respectively. SNR values associated with the non-CPMG SSFSE technique were found to be significantly higher than those measured with the EPI-based DWI technique (p < 0.01). Mean ADCs of the bone were 0.57 ± 0.20 and 0.29 ± 0.15 × 10-3 mm 2 /s, respectively, for EPI and non-CPMG SSFSE DWI. Image quality scores were higher for the non-CPMG SSFSE DWI technique (p < 0.05) than for the EPI-based DWI technique. Overall lesion CNR was found to be higher in DWI performed with the non-CPMG SSFSE technique. CONCLUSION. The non-CPMG SSFSE technique provides a significant improvement over the currently used EPI-based DWI technique and has the potential to be a powerful tool in imaging the appendicular skeleton.

Research paper thumbnail of Delineation of gliomas with various doses of MR contrast material

AJNR. American journal of neuroradiology, 1994

To examine the effects of different gadolinium doses on the delineation of gliomas, particularly ... more To examine the effects of different gadolinium doses on the delineation of gliomas, particularly the demonstration of abnormal enhancement on T1-weighted images extending beyond the zone of apparent signal abnormality on corresponding T2-weighted images. During phase II clinical trials of gadoteridol, 23 patients with pathologically proved gliomas were studied by MR with various doses of gadoteridol, ranging from 0.05 to 0.3 mmol/kg. All of the gliomas were readily detected by T2-weighted images. Twelve of 23 patients demonstrated enhancement on T1-weighted images extending beyond the zone of apparent signal abnormality demonstrated on T2-weighted images. These findings were seen in none of the six patients (0%) studied at 0.05 mmol/kg, one of five patients (20%) studied at 0.1 mmol/kg, four of five patients (80%) studied at 0.2 mmol/kg, and seven of seven patients (100%) studied at 0.3 mmol/kg. The detection of symptomatic gliomas does not require a contrast agent because they are ...

Research paper thumbnail of Cystic acoustic schwannomas: MR characteristics

AJNR. American journal of neuroradiology

To evaluate the spectrum of MR characteristics of cystic acoustic schwannoma and to investigate i... more To evaluate the spectrum of MR characteristics of cystic acoustic schwannoma and to investigate its incidence. We retrospectively reviewed the MR findings and clinical records of 16 patients with cystic acoustic schwannomas. In addition, the MR examinations of 411 consecutive patients referred for clinical suspicion of acoustic schwannomas were reviewed retrospectively to assess the incidence of acoustic schwannomas with cystic lesions arising from the internal auditory canal. Of the 16 acoustic schwannomas with MR evidence of intramural cysts, 11 tumors had single small cysts, and five had multiple intramural cysts of variable size. Intramural cysts in 11 of the 16 tumors exhibited higher signal intensity than that of cerebrospinal fluid; the remainder were isointense to cerebrospinal fluid on both T1- and T2-weighted images. All intramural cysts showed circumferential enhancement after contrast administration. Nine of the 16 cystic acoustic schwannomas also had MR evidence of extr...

Research paper thumbnail of Intrathecal Gadolinium-Enhanced MR Cisternography in the Evaluation of CSF Leakage

American Journal of Neuroradiology, 2009

Radiologic identification of the location of the CSF leakage is important for proper surgical pla... more Radiologic identification of the location of the CSF leakage is important for proper surgical planning and increases the chance of dural repair. This article describes our experience in analyzing clinically suspected cranial CSF fistulas by using MR imaging combined with the intrathecal administration of a gadolinium-based contrast agent. MATERIALS AND METHODS: A total of 85 consecutive patients with suspected CSF fistulas who presented with persistent or intermittent rhinorrhea or otorrhea lasting for more than 1 month between 2003 and 2007 were included in this study. RESULTS: We observed objective CSF leakage in 64 of 85 patients (75%). The CSF leak was located in the ethmoidal region in 37 patients (58%), in the superior wall of the sphenoid sinus in 8 patients (13%), in the posterior wall of the frontal sinus in 10 patients (15%), in the superior wall of the mastoid air cells in 6 patients (9%), and from the skull base into the infratemporal fossa in 1 patient (2%). Two patients (3%) showed leakage into Ͼ1 paranasal sinus. CONCLUSIONS: MR cisternography after the intrathecal administration of gadopentate dimeglumine represents an effective and minimally invasive method for evaluating suspected CSF fistulas along the skull base. It provides multiplanar capabilities without risk of radiation exposure and is an excellent approach to depict the anatomy of CSF spaces and CSF fistulas.

Research paper thumbnail of Primary intraosseous meningioma: CT and MRI appearance

AJNR. American journal of neuroradiology, 2005

Benign primary intraosseous meningioma presenting with osteolytic skull lesion and soft-tissue co... more Benign primary intraosseous meningioma presenting with osteolytic skull lesion and soft-tissue component is rare. CT and MR imaging of a patient with frontoparietal scalp swelling showed an osteolytic intracalvarial lesion with an extradural soft-tissue component. Following wide surgical resection, the histological examination revealed an intraosseous chordoid meningioma. The clinical and radiological findings of primary intraosseous meningioma are discussed and the relevant literature is reviewed.

Research paper thumbnail of Diagnostic Value of Contrast-Enhanced Fluid-Attenuated Inversion-Recovery and Delayed Contrast-Enhanced Brain MRI in Multiple Sclerosis

Academic Radiology, 2008

Rationale and Objectives. In brain MRI of multiple sclerosis (MS) patients, enhancement of the le... more Rationale and Objectives. In brain MRI of multiple sclerosis (MS) patients, enhancement of the lesions is usually evaluated in early contrast-enhanced T1-weighted images (CE-T1WI). The objective of this study is to determine the sensitivity of contrast-enhanced fluid-attenuated-inversion-recovery (CE-FLAIR) and delayed contrast-enhanced MRI in evaluation of MS brain lesions. Materials and Methods. Brain MRI examination including early and delayed CE-T1WI and early and delayed CE-FLAIR images was performed for 46 patients with clinically definite MS disease. Number, size, location, degree, and pattern of enhancement of the enhanced lesions in each sequence were recorded separately. Results. A total number of 87 enhanced lesions was detected in 30 patients. Early CE-T1WI could detect only 63 lesions (72.4% of total) in 24 patients, while delayed CE-T1WI and early and delayed CE-FLAIR images showed 85 (97.7%), 84 (96.6%), and 81 (93.1%) lesions in 28, 28, and 26 patients, respectively. A greater degree of enhancement and larger lesion size were observed in the additional sequences compared with the early CE-T1WI. Conclusions. The sensitivity of early CE-T1WI for the detection of enhanced MS lesions is significantly lower than that for other additional sequences. Delayed CE-FLAIR images could not add significant information to other sequences. Therefore, early CE-FLAIR and delayed CE-T1WI brain MRI can be considered as part of the evaluation of MS patients, especially if, despite clinically suspected active disease, no enhanced lesion is found in the routine CE-T1WI.

Research paper thumbnail of MR of fetal central nervous system abnormalities

AJNR. American journal of neuroradiology, 1994

To investigate whether MR can provide additional information on fetuses with central nervous syst... more To investigate whether MR can provide additional information on fetuses with central nervous system abnormalities as demonstrated by ultrasonography. Fetal MR examinations were studied prospectively in 22 pregnant women whose fetuses showed evidence of anomalies on ultrasound performed in the High-Risk Obstetric Clinic. In 19 of 22 cases, postpartum confirmatory diagnoses were obtained by MR or CT examinations, autopsy, or surgery. In general, the image quality of MR is comparable with that of ultrasound. However, in six of 22 cases (27%), MR provided additional information that altered the ultrasound diagnosis; these included cases of infarction, diastematomyelia, normal hemimegalencephaly with early myelination, Dandy-Walker variant, and lipoma. All of these cases had postpartum confirmation. The additional information changed the treatment in three of six patients (no intervention or elective abortion). In certain situations MR can add valuable information to that obtained by son...

Research paper thumbnail of Venous sinus occlusive disease: MR findings

AJNR. American journal of neuroradiology, 1994

PURPOSE To study MR patterns of venous sinus occlusive disease and to relate them to the underlyi... more PURPOSE To study MR patterns of venous sinus occlusive disease and to relate them to the underlying pathophysiology by comparing the appearance and pathophysiologic features of venous sinus occlusive disease with those of arterial ischemic disease. METHODS The clinical data and MR examinations of 26 patients with venous sinus occlusive disease were retrospectively reviewed with special attention to mass effect, hemorrhage, and T2-weighted image abnormalities as well as to abnormal parenchymal, venous, or arterial enhancement after intravenous gadopentetate dimeglumine administration. Follow-up studies when available were evaluated for atrophy, infarction, chronic mass effect, and hemorrhage. RESULTS Mass effect was present in 25 of 26 patients. Eleven of the 26 had mass effect without abnormal signal on T2-weighted images. Fifteen patients had abnormal signal on T2-weighted images, but this was much less extensive than the degree of brain swelling in all cases. No patient showed abn...

Research paper thumbnail of T2-weighted vs. intrathecal contrast-enhanced MR cisternography in the evaluation of CSF rhinorrhea

Acta Radiologica, 2013

Background Endoscopic surgical approach is being more widely used in the treatment of cerebrospin... more Background Endoscopic surgical approach is being more widely used in the treatment of cerebrospinal fluid (CSF) rhinorrhea. Accurate localization of CSF fistulas prior to surgery is essential in increasing the success of dural repair and in decreasing negative or recurrent explorations. Purpose To evaluate and compare intrathecal contrast medium-enhanced magnetic resonance cisternography (CEMRC) with T2-weighted MR cisternography (T2MRC) in identifying the presence and site of CSF rhinorrhea. Material and Methods Sixty patients with suspected CSF rhinorrhea underwent MR cisternography including intrathecally enhanced fat-suppressed T1WI in three orthogonal planes and T2WI in the coronal plane. Both set of images were reviewed by two blinded radiologists for the presence and location of CSF leakage. Imaging data were compared with surgical findings and/or beta-2 transferrin testing. Results With surgery proven CSF leakage in 20 instances as reference, CEMRC detected 18 (90%), whereas...