Alexander Cavallaro - Academia.edu (original) (raw)
Papers by Alexander Cavallaro
Academic Radiology, Aug 1, 2018
Rationale and Objectives: To evaluate two-and three-dimensional (2D and 3D) image quality of sub-... more Rationale and Objectives: To evaluate two-and three-dimensional (2D and 3D) image quality of sub-milliSievert (mSv) computed tomography (CT) colonography utilizing a third-generation dual source CT scanner featuring a tin filter. Methods: We retrospectively evaluated 26 consecutive patients who underwent third-generation dual source CT colonography, nine with the standard-dose clinical-scan protocol (SDP) and 17 with a low-dose protocol (LDP) featuring a tin filter. Radiation dose was evaluated by volume computed tomography dose index (CTDIvol), dose length product (DLP), effective dose (E), and size-specific dose estimate. Objective image quality was evaluated utilizing signal-to-noise ratio (SNR) derived from standardized placed regions of interest on the transverse 2D images and the ratio of SNR/ CTDI vol (normalized SNR). Two radiologists in consensus assessed subjective image quality of the virtual 3D images. Results: There were no significant differences in subjective image quality (P = .661). All examinations were rated "excellent" or "good" for diagnostic confidence. The mean total for DLP/E was 143.4 ± 29.8 mGy/3.00 ± 0.40 mSv in the SDP and therefore significantly higher than in the LDP with 36.9 ± 8.7 mGy/0.75 ± 0.16 mSv (P < .001). The SNR was 8.9 ± 2.1 in the SDP and 4.9 ± 0.8 in the LDP. Conclusions: Third-generation dual source CT featuring a tin filter enables consistent sub-mSv colonography without substantially impairing image quality.
Radiologe, Apr 14, 2011
Die iPhone-Applikation "KM Helper" Radiologie im Internet Mobiltelefone haben in den letzten Jahr... more Die iPhone-Applikation "KM Helper" Radiologie im Internet Mobiltelefone haben in den letzten Jahren durch elektronische Innovationen ihre Einsatzgebiete deutlich erweitert. So genannte Smartphones, Mobiltelefone mit interaktiver Bedienung, wie z. B. das iPhone der Firma Apple, Cupertino, CA, USA, erfreuen sich größter Beliebtheit [1, 2, 3]. Im so genannten "app store", einer Handelsplattform von Apple, können Zusatzprogramme (apps) z. T. kostenlos, z. T. gegen Gebühr erworben und so die Standardfunktionen des Smartphones erweitert werden. Auch in der Untersparte Medizin existieren bereits zahlreiche Applikationen wie etwa anatomische Atlanten oder medizinische Enzyklopädien. Anhand der App "KM Helper" soll gezeigt werden, dass eine sinnvolle Anwendung dieser Technologie auch im radiologischen Alltag möglich ist.
Journal of Medical Case Reports, Mar 23, 2019
Background: Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarci... more Background: Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarcinomatous and neuroendocrine components. They can originate in any organ but are more common in the rectum. Due to their rarity, current treatment recommendations for mixed adenoneuroendocrine carcinoma are based on limited data and follow general guidelines for the management of adenocarcinomas and neuroendocrine neoplasms. Uncertainty regarding the efficacy of the available local and systemic treatment strategies is a compounding issue. Even those patients with locally limited disease have a relatively short life expectancy. In this report, we describe a case of deep rectal mixed adenoneuroendocrine carcinoma with long survival after chemoradiation. Case presentation: A 48-year-old Caucasian woman was diagnosed with a grade 3 rectal adenocarcinoma combined with a poorly differentiated large cell neuroendocrine carcinoma component and synchronous metastases (cT3cN1cM1) in both lobes of the liver in 2012. She received concomitant chemoradiotherapy followed by four additional cycles of cisplatin plus irinotecan. Initial treatment induced complete remission of the rectal tumor and liver metastases. Consequently, it was not necessary to surgically resect the primary tumor or any of the metastases. Three months after the end of treatment, one metastasis in the first segment of the liver showed regrowth, and stereotactic body radiotherapy of the metastasis and chemotherapy resulted in a clinical complete response. The patient has been recurrence-free for more than 5 years. Conclusions: Extended long-term control of a poorly differentiated metastatic (stage IV) mixed adenoneuroendocrine carcinoma is rare. The multimodal first-and second-line regimens of radiotherapy and chemotherapy described in this case report represent a new therapeutic approach. Encouraged by the results in this case, we compiled a review of the literature on mixed adenoneuroendocrine carcinoma.
Röntgenpraxis; Zeitschrift für radiologische Technik, 2004
We present the history of a woman suffering from an extensive gastrointestinal bleeding due to li... more We present the history of a woman suffering from an extensive gastrointestinal bleeding due to liver cirrhosis and chronic pancreatitis. Selective angiogram of the celiac artery revealed a pseudoaneurysm of the gastroduodenal artery caused by inflammatory wall penetration. The life-threatening hemorrhage was completely stopped by embolization with three stainless steel coils after microcatheter engagement of the gastroduodenal artery. The particularity of this case is the restricted embolization of the aneurysm vessel segment, so the collateral circulation of the gastroduodenal and pancreaticoduodenal artery could be preserved.
arXiv (Cornell University), Oct 15, 2017
Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be bene... more Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be beneficial for biomedical research and clinical applications. However, it is a challenging task. Recent advances in deep learning showed the feasibility to use 3-D fully convolutional networks (FCN) for voxel-wise dense predictions in single energy computed tomography (SECT). In this paper, we proposed a 3D FCN based method for automatic multi-organ segmentation in DECT. The work was based on a cascaded FCN and a general model for the major organs trained on a large set of SECT data. We preprocessed the DECT data by using linear weighting and fine-tuned the model for the DECT data. The method was evaluated using 42 torso DECT data acquired with a clinical dual-source CT system. Four abdominal organs (liver, spleen, left and right kidneys) were evaluated. Cross-validation was tested. Effect of the weight on the accuracy was researched. In all the tests, we achieved an average Dice coefficient of 93% for the liver, 90% for the spleen, 91% for the right kidney and 89% for the left kidney, respectively. The results show our method is feasible and promising.
Journal of Clinical Oncology, Jun 1, 2008
We determined the toxicity of nelfinavir chemoradiotherapy in borderline resectable and unresecta... more We determined the toxicity of nelfinavir chemoradiotherapy in borderline resectable and unresectable pancreatic cancer. Patients and Methods Oral nelfinavir (2 ϫ 1,250 mg) was started 3 days before and continued throughout chemoradiotherapy to 50.4 Gy (boost, 59.4 Gy) in 12 patients. Two gemcitabine dose levels (DL) were tested (200 mg/m 2 and 300 mg/m 2 on days 1, 8, 22, and 29). Cisplatin was administered on the same days at 30 mg/m 2. Phospho-Akt downregulation by nelfinavir was monitored by immunoblotting in patient leukocytes. Restaging positron emission tomography (PET)/computed tomography (CT) and CA19-9 levels served to assess response, and responding tumors were resected. Results At each DL, five of six patients completed chemoradiotherapy, and two of 12 patients had incomplete chemoradiotherapy because of clinical depression (DL1) and peritoneal metastasis (DL2). Grade 4 toxicities were a transaminase elevation (DL2) as a result of biliary stent occlusion and acute cholecystitis as a result of peritoneal metastasis (DL2). Stent occlusions led to dose-limiting toxicities of grade 3 liver enzyme and bilirubin elevations (two patients at DL1, one patient at DL2). Grade 3 nausea and vomiting occurred in a DL2 patient, and weight loss occurred in a DL1 patient who refused supportive feeding. Secondary complete resection was possible in six of 10 patients with complete chemoradiotherapy, including one tumor with pathologic sterilization. Partial CT responses were observed in five of 10 patients who completed chemoradiotherapy. Of nine patients assessable by PET,responses were complete in five patients and partial patients, and stable disease was observed in two patients. Conclusion The combination of nelfinavir and chemoradiotherapy showed acceptable toxicity and promising activity in patients with pancreatic cancer.
Nature Precedings, Jul 30, 2009
Formal knowledge about human anatomy, radiology or diseases is necessary to support clinical appl... more Formal knowledge about human anatomy, radiology or diseases is necessary to support clinical applications such as medical image search. This machine processable knowledge can be acquired from biomedical domain ontologies, which however, are typically very large and complex models. Thus, their straightforward incorporation into the software applications becomes difficult. In this paper we discuss first ideas on a statistical approach for modularizing large medical ontologies and we prioritize the practical applicability aspect. The underlying assumption is that the application relevant ontology fragments, i.e. modules, can be identified by the statistical analysis of the ontology concepts in the domain corpus. Accordingly, we argue that most frequently occurring concepts in the domain corpus define the application context and can therefore potentially yield the relevant ontology modules. We illustrate our approach on an example case that involves a large ontology on human anatomy and report on our first manual experiments.
Annals of the Rheumatic Diseases, Jun 1, 2016
Background: Several pro-inflammatory cytokines such as TNF-α, IL-1, IL-6, IL-8 and IL-15 are know... more Background: Several pro-inflammatory cytokines such as TNF-α, IL-1, IL-6, IL-8 and IL-15 are known to be critical in synovial inflammatory process in RA and successful results have been obtained in RA treatment with targeting pro-inflammatory cytokines including TNF-α, IL-1 and IL-6. Objectives: This study sought to investigate the role of IL-33 and IL-6 in RA patients receiving IL-6 receptor inhibition therapy. Methods: We analyzed the association of the IL-33 and IL-6 level with disease activity and serologic features in 83 patients with RA. We also measured the serum level of IL-33 and IL-6 before and after the administration of tocilizumab for 24 weeks in 40 patients. Results: Serum IL-33 level showed significant correlation with RF (rho =0.660, p<0.001) but did not correlate with DAS28, ESR, hsCRP or RA duration. IL-6 level was significantly correlated with hsCRP (rho =0.482, p<0.001) but not correlate with DAS28, ESR, RF or RA duration. There was no correlation between serum IL-6 and IL-33 levels. Serum IL-33 level significantly decreased after 24 weeks of IL-6 receptor inhibition in patients with RA (p<0.001). When comparing subgroups according to ACR20 response, serum IL-33 levels were significantly decreased after 24 weeks of IL-6 receptor inhibition therapy in ACR20 responders (p<0.001) but not in the non-responders (p=0.084). Baseline IL-33 levels were not significantly different between the two subgroups (p=0.765). Serum IL-6 levels were not significantly changed after 24 weeks of IL-6 receptor inhibition therapy (median 7.1 to 8.9 pg/mL, p=0.503). Changes of IL-6 levels were insignificant both in ACR20 responders and non-responders after 24 weeks of IL-6 receptor inhibition therapy. Baseline IL-6 levels were not different between ACR20 responders and non-responders. Conclusions: The use of IL-6 receptor inhibitor decreased the serum level of IL-33 and this effect seems to be led by the responder group. IL-33 could be a useful indicator to monitor the response in IL-6 receptor inhibition therapy.
Magnetic Resonance Materials in Physics Biology and Medicine, Dec 14, 1998
The aim of this study was to determine whether low-field magnetic resonance (MR) imaging can safe... more The aim of this study was to determine whether low-field magnetic resonance (MR) imaging can safely and accurately depict inflammatory changes in patients with anal dynamic graciloplasty, in whom high-field MR imaging is contraindicated and ultrasonography and computed tomography are inadequate. A 0.2-T field-strength MR examination was performed in six patients with anal dynamic graciloplasty malfunction in whom reoperation was contemplated. The following sequences were applied: T2-weighted turbo spinecho with fat saturation, T~-weighted conventional spin-echo, and contrastenhanced T~-weighted conventional spin-echo with fat saturation. Results indicated that none of the patients experienced relevant discomfort, pacemaker malfunction, or electrode dislocation with low-field MR imaging. Inflammatory pelvic changes were visualized in four patients and atrophy of the transposed gracilis muscle in another. Surgery was thus avoided in the four, who underwent conservative treatment for their pelvic inflammation. It was concluded that these preliminary results demonstrate the feasibility of MR imaging with a low field strength in patients with anal dynamic graciloplasty. In such patients, in whom diagnostic imaging had been problematic, the potential for safe and accurate visualization will be a boon to treatment planning.
Zeitschrift Fur Rheumatologie, Jul 5, 2017
ZusammenfassungHintergrundNichtinvasive bildgebende Verfahren werden für die morphologische wie a... more ZusammenfassungHintergrundNichtinvasive bildgebende Verfahren werden für die morphologische wie auch funktionelle Evaluierung und Diagnosestellung der Gicht eingesetzt. Keine dieser Methoden zeigte jedoch eine ausreichend hohe Sensitivität und Spezifität. Durch den Einsatz der Dual-Energy-Computertomographie(DECT)-Methode ist erstmalig die Direktdarstellung von Natriumuratablagerungen möglich. Zudem lassen sich damit verschiedene pathologische Zustände, Aktivitätsbewertung sowie ein Therapiemonitoring durchführen. Seit 2 Jahren stellt die positive DECT-Untersuchung auch ein Klassifikationskriterium im Rahmen der 2015 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR)-Klassifikationskriterien für Gicht dar.Material und MethodenBei der Literatursuche in PubMed mit dem Suchkriterium „Dual Energy CT and Gout“ erhält man insgesamt 77 Publikationen zur DECT-Methode.ErgebnisseDie DECT-Untersuchung hat eine sehr hohe Sensitivität (90–100 %) und hohe Spezifität (83–89 %) bei der Diagnosestellung der Gicht. Durch die zusätzliche Entwicklung einer semiquantitativen Scoringmethode wurde zudem die Möglichkeit geschaffen, lokalisationsbezogene Angaben in Bezug zum Schweregrad der Natriumuratablagerung zu machen.DiskussionDer Goldstandard zur Diagnosestellung der Gicht bleibt weiterhin der positive Nachweis von doppelbrechenden Kristallen im Polarisationsmikroskop im Rahmen einer Gelenkpunktion. Die DECT-Untersuchung ermöglicht aber als nichtinvasive Methode die direkte Visualisierung und genaue Volumenbestimmung von Natriumuratablagerung und ist damit zur Bestimmung des Schweregrads und zur Verlaufsbeurteilung geeignet. Obwohl die DECT hierfür klinisch nicht validiert wurde, lässt sich mittels DECT die Diagnose einer Gicht gelegentlich stellen. Weitere Studien sollten noch durchgeführt werden.AbstractBackgroundNon-invasive imaging modalities are used for the morphological and functional evaluation and diagnosis of gout; however, none of these methods are sufficiently sensitive or specific for the diagnosis of gout. By the use of dual-energy computed tomography (DECT) the direct visualization of sodium urate deposition is now possible. Moreover, it is possible to show the different pathological situations, disease activity and monitoring of tophaceous gout. The positive DECT scan became one of the 2015 ACR/EULAR classification criteria for gout 2 years ago.Material and methodsThe literature search from 2009–2017 in PubMed, with the search criteria “Dual Energy CT and Gout” revealed 77 publications on the DECT method.ResultsThe DECT technique has a high sensitivity (90–100%) and a high specificity (83–89%) for diagnosing gout. The development of a semiquantitative scoring method also enables measurement of the severity of urate deposits at specific sites.ConcusionThe gold standard for the diagnosis of gout is still the detection of monosodium urate monohydrate crystals by polarizing microscopy after a joint punction; however with the DECT it is possible to non-invasively visualize, measure and score urate deposition and is therefore suitable for estimating the severity and prognosis. Although not clinical validated, DECT may sometimes help to detect gout. More studies should be conducted.
Springer eBooks, 2010
Automatic segmentation of the esophagus from CT data is a challenging problem. Its wall consists ... more Automatic segmentation of the esophagus from CT data is a challenging problem. Its wall consists of muscle tissue, which has low contrast in CT. Sometimes it is filled with air or remains of orally given contrast agent. While air holes are a clear hint to a human when searching for the esophagus, we found that they are rather distracting to discriminative models of the appearance because of their similarity to the trachea and to lung tissue. However, air inside the respiratory organs can be segmented easily. In this paper, we propose to combine a model based segmentation algorithm of the esophagus with a spatial probability map generated from detected air. Threefold cross-validation on 144 datasets showed that this probability map, combined with a technique that puts more focus on hard cases, increases accuracy by 22%. In contrast to prior work, our method is not only automatic on a manually selected region of interest, but on a whole thoracic CT scan, while our mean segmentation error of 1.80mm is even better.
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2014
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2013
ArXiv, 2017
Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be bene... more Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be beneficial for biomedical research and clinical applications. However, it is a challenging task. Recent advances in deep learning showed the feasibility to use 3-D fully convolutional networks (FCN) for voxel-wise dense predictions in single energy computed tomography (SECT). In this paper, we proposed a 3D FCN based method for automatic multi-organ segmentation in DECT. The work was based on a cascaded FCN and a general model for the major organs trained on a large set of SECT data. We preprocessed the DECT data by using linear weighting and fine-tuned the model for the DECT data. The method was evaluated using 42 torso DECT data acquired with a clinical dual-source CT system. Four abdominal organs (liver, spleen, left and right kidneys) were evaluated. Cross-validation was tested. Effect of the weight on the accuracy was researched. In all the tests, we achieved an average Dice coefficient...
European Radiology, 2018
ObjectivesWe compared the interobserver agreement for the recently introduced contrast-enhanced u... more ObjectivesWe compared the interobserver agreement for the recently introduced contrast-enhanced ultrasound (CEUS)-based algorithm CEUS-LI-RADS (Liver Imaging Reporting and Data System) versus the well-established magnetic resonance imaging (MRI)-LI-RADS for non-invasive diagnosis of hepatocellular carcinoma (HCC) in high-risk patients.MethodsFocal liver lesions in 50 high-risk patients (mean age 66.2 ± 11.8 years; 39 male) were assessed retrospectively with CEUS and MRI. Two independent observers reviewed CEUS and MRI examinations, separately, classifying observations according to CEUS-LI-RADSv.2016 and MRI-LI-RADSv.2014. Interobserver agreement was assessed with Cohen’s kappa.ResultsForty-three lesions were HCCs; two were intrahepatic cholangiocarcinomas; five were benign lesions. Arterial phase hyperenhancement was perceived less frequently with CEUS than with MRI (37/50 / 38/50 lesions = 74%/78% [CEUS; observer 1/observer 2] versus 46/50 / 44/50 lesions = 92%/88% [MRI; observer 1/observer 2]). Washout appearance was observed in 34/50 / 20/50 lesions = 68%/40% with CEUS and 31/50 / 31/50 lesions = 62%/62%) with MRI. Interobserver agreement was moderate for arterial hyperenhancement (ĸ = 0.511/0.565 [CEUS/MRI]) and “washout” (ĸ = 0.490/0.582 [CEUS/MRI]), fair for CEUS-LI-RADS category (ĸ = 0.309) and substantial for MRI-LI-RADS category (ĸ = 0.609). Intermodality agreement was fair for arterial hyperenhancement (ĸ = 0.329), slight to fair for “washout” (ĸ = 0.202) and LI-RADS category (ĸ = 0.218)ConclusionInterobserver agreement is substantial for MRI-LI-RADS and only fair for CEUS-LI-RADS. This is mostly because interobserver agreement in the perception of washout appearance is better in MRI than in CEUS. Further refinement of the LI-RADS algorithms and increasing education and practice may be necessary to improve the concordance between CEUS and MRI for the final LI-RADS categorization.Key Points• CEUS-LI-RADS and MRI-LIRADS enable standardized non-invasive diagnosis of HCC in high-risk patients.• With CEUS, interobserver agreement is better for arterial hyperenhancement than for “washout”.• Interobserver agreement for major features is moderate for both CEUS and MRI.• Interobserver agreement for LI-RADS category is substantial for MRI, and fair for CEUS.• Interobserver-agreement for CEUS-LI-RADS will presumably improve with ongoing use of the algorithm.
European Journal of Nuclear Medicine and Molecular Imaging, 2018
Purpose We aimed at evaluating the role of 68 Ga-PSMA-11 PET/CT-derived metabolic parameters for ... more Purpose We aimed at evaluating the role of 68 Ga-PSMA-11 PET/CT-derived metabolic parameters for assessment of wholebody tumor burden and its capability to determine therapeutic response in patients with prostate cancer. Methods A total of 142 patients with biochemical recurrence of prostate cancer underwent PET/CT with [ 68 Ga]Ga-PSMA-HBED-CC (68 Ga-PSMA-11). Quantitative assessment of all 641 68 Ga-PSMA-11-positive lesions in the field of view was performed to calculate PSMA-derived parameters, including whole-body PSMA tumor volume (PSMA-TV) and whole-body total lesion PSMA (TL-PSMA), as well as the established SUVmax and SUVmean values. All PET-derived parameters were tested for correlation with serum PSA levels and for association with Gleason scores. In 23 patients who underwent 68 Ga-PSMA-11 PET/CT before and after therapy with either external beam radiation, androgen deprivation, or docetaxel chemotherapy, SUVmax and TL-PSMA were compared to radiographic response assessment of CT images based on RECIST 1.1 criteria and to biochemical response determined by changes of serum PSA levels. Results PSMA-TV and TL-PSMA demonstrated a significant correlation with serum PSA levels (P < 0.0001) and TL-PSMA was significantly different for different Gleason scores. The agreement rate between TL-PSMA derived from PET and biochemical response was 87% (95% confidence interval, 0.66-0.97; Cohen's κ = 0.78; P < 0.01) and, thus, higher than for SUVmax, which was 74% (95% CI, 0.52-0.90; κ = 0.55; P < 0.01). Furthermore, agreement with PSA was higher for TL-PSMA and SUVmax than for CT-based response evaluation. Discordant findings between PET and CT were most likely due to limitations of CT and RECIST in rating small lymph nodes as metastases, as well as bone involvement, which was sometimes not detectable in CT. Conclusion 68 Ga-PSMA-11 PET/CT-derived metabolic tumor parameters showed promising results for evaluation of treatment response. Especially, TL-PSMA demonstrated higher agreement rates with biochemical response compared to SUVmax. Larger, ideally prospective trials are needed to help to reveal the full potential of metabolic parameters derived from PET imaging with 68 Ga-PSMA-11.
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2012
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2006
Röntgenpraxis; Zeitschrift für radiologische Technik, 2001
Academic Radiology, Aug 1, 2018
Rationale and Objectives: To evaluate two-and three-dimensional (2D and 3D) image quality of sub-... more Rationale and Objectives: To evaluate two-and three-dimensional (2D and 3D) image quality of sub-milliSievert (mSv) computed tomography (CT) colonography utilizing a third-generation dual source CT scanner featuring a tin filter. Methods: We retrospectively evaluated 26 consecutive patients who underwent third-generation dual source CT colonography, nine with the standard-dose clinical-scan protocol (SDP) and 17 with a low-dose protocol (LDP) featuring a tin filter. Radiation dose was evaluated by volume computed tomography dose index (CTDIvol), dose length product (DLP), effective dose (E), and size-specific dose estimate. Objective image quality was evaluated utilizing signal-to-noise ratio (SNR) derived from standardized placed regions of interest on the transverse 2D images and the ratio of SNR/ CTDI vol (normalized SNR). Two radiologists in consensus assessed subjective image quality of the virtual 3D images. Results: There were no significant differences in subjective image quality (P = .661). All examinations were rated "excellent" or "good" for diagnostic confidence. The mean total for DLP/E was 143.4 ± 29.8 mGy/3.00 ± 0.40 mSv in the SDP and therefore significantly higher than in the LDP with 36.9 ± 8.7 mGy/0.75 ± 0.16 mSv (P < .001). The SNR was 8.9 ± 2.1 in the SDP and 4.9 ± 0.8 in the LDP. Conclusions: Third-generation dual source CT featuring a tin filter enables consistent sub-mSv colonography without substantially impairing image quality.
Radiologe, Apr 14, 2011
Die iPhone-Applikation "KM Helper" Radiologie im Internet Mobiltelefone haben in den letzten Jahr... more Die iPhone-Applikation "KM Helper" Radiologie im Internet Mobiltelefone haben in den letzten Jahren durch elektronische Innovationen ihre Einsatzgebiete deutlich erweitert. So genannte Smartphones, Mobiltelefone mit interaktiver Bedienung, wie z. B. das iPhone der Firma Apple, Cupertino, CA, USA, erfreuen sich größter Beliebtheit [1, 2, 3]. Im so genannten "app store", einer Handelsplattform von Apple, können Zusatzprogramme (apps) z. T. kostenlos, z. T. gegen Gebühr erworben und so die Standardfunktionen des Smartphones erweitert werden. Auch in der Untersparte Medizin existieren bereits zahlreiche Applikationen wie etwa anatomische Atlanten oder medizinische Enzyklopädien. Anhand der App "KM Helper" soll gezeigt werden, dass eine sinnvolle Anwendung dieser Technologie auch im radiologischen Alltag möglich ist.
Journal of Medical Case Reports, Mar 23, 2019
Background: Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarci... more Background: Mixed adenoneuroendocrine carcinomas are highly malignant tumors with both adenocarcinomatous and neuroendocrine components. They can originate in any organ but are more common in the rectum. Due to their rarity, current treatment recommendations for mixed adenoneuroendocrine carcinoma are based on limited data and follow general guidelines for the management of adenocarcinomas and neuroendocrine neoplasms. Uncertainty regarding the efficacy of the available local and systemic treatment strategies is a compounding issue. Even those patients with locally limited disease have a relatively short life expectancy. In this report, we describe a case of deep rectal mixed adenoneuroendocrine carcinoma with long survival after chemoradiation. Case presentation: A 48-year-old Caucasian woman was diagnosed with a grade 3 rectal adenocarcinoma combined with a poorly differentiated large cell neuroendocrine carcinoma component and synchronous metastases (cT3cN1cM1) in both lobes of the liver in 2012. She received concomitant chemoradiotherapy followed by four additional cycles of cisplatin plus irinotecan. Initial treatment induced complete remission of the rectal tumor and liver metastases. Consequently, it was not necessary to surgically resect the primary tumor or any of the metastases. Three months after the end of treatment, one metastasis in the first segment of the liver showed regrowth, and stereotactic body radiotherapy of the metastasis and chemotherapy resulted in a clinical complete response. The patient has been recurrence-free for more than 5 years. Conclusions: Extended long-term control of a poorly differentiated metastatic (stage IV) mixed adenoneuroendocrine carcinoma is rare. The multimodal first-and second-line regimens of radiotherapy and chemotherapy described in this case report represent a new therapeutic approach. Encouraged by the results in this case, we compiled a review of the literature on mixed adenoneuroendocrine carcinoma.
Röntgenpraxis; Zeitschrift für radiologische Technik, 2004
We present the history of a woman suffering from an extensive gastrointestinal bleeding due to li... more We present the history of a woman suffering from an extensive gastrointestinal bleeding due to liver cirrhosis and chronic pancreatitis. Selective angiogram of the celiac artery revealed a pseudoaneurysm of the gastroduodenal artery caused by inflammatory wall penetration. The life-threatening hemorrhage was completely stopped by embolization with three stainless steel coils after microcatheter engagement of the gastroduodenal artery. The particularity of this case is the restricted embolization of the aneurysm vessel segment, so the collateral circulation of the gastroduodenal and pancreaticoduodenal artery could be preserved.
arXiv (Cornell University), Oct 15, 2017
Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be bene... more Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be beneficial for biomedical research and clinical applications. However, it is a challenging task. Recent advances in deep learning showed the feasibility to use 3-D fully convolutional networks (FCN) for voxel-wise dense predictions in single energy computed tomography (SECT). In this paper, we proposed a 3D FCN based method for automatic multi-organ segmentation in DECT. The work was based on a cascaded FCN and a general model for the major organs trained on a large set of SECT data. We preprocessed the DECT data by using linear weighting and fine-tuned the model for the DECT data. The method was evaluated using 42 torso DECT data acquired with a clinical dual-source CT system. Four abdominal organs (liver, spleen, left and right kidneys) were evaluated. Cross-validation was tested. Effect of the weight on the accuracy was researched. In all the tests, we achieved an average Dice coefficient of 93% for the liver, 90% for the spleen, 91% for the right kidney and 89% for the left kidney, respectively. The results show our method is feasible and promising.
Journal of Clinical Oncology, Jun 1, 2008
We determined the toxicity of nelfinavir chemoradiotherapy in borderline resectable and unresecta... more We determined the toxicity of nelfinavir chemoradiotherapy in borderline resectable and unresectable pancreatic cancer. Patients and Methods Oral nelfinavir (2 ϫ 1,250 mg) was started 3 days before and continued throughout chemoradiotherapy to 50.4 Gy (boost, 59.4 Gy) in 12 patients. Two gemcitabine dose levels (DL) were tested (200 mg/m 2 and 300 mg/m 2 on days 1, 8, 22, and 29). Cisplatin was administered on the same days at 30 mg/m 2. Phospho-Akt downregulation by nelfinavir was monitored by immunoblotting in patient leukocytes. Restaging positron emission tomography (PET)/computed tomography (CT) and CA19-9 levels served to assess response, and responding tumors were resected. Results At each DL, five of six patients completed chemoradiotherapy, and two of 12 patients had incomplete chemoradiotherapy because of clinical depression (DL1) and peritoneal metastasis (DL2). Grade 4 toxicities were a transaminase elevation (DL2) as a result of biliary stent occlusion and acute cholecystitis as a result of peritoneal metastasis (DL2). Stent occlusions led to dose-limiting toxicities of grade 3 liver enzyme and bilirubin elevations (two patients at DL1, one patient at DL2). Grade 3 nausea and vomiting occurred in a DL2 patient, and weight loss occurred in a DL1 patient who refused supportive feeding. Secondary complete resection was possible in six of 10 patients with complete chemoradiotherapy, including one tumor with pathologic sterilization. Partial CT responses were observed in five of 10 patients who completed chemoradiotherapy. Of nine patients assessable by PET,responses were complete in five patients and partial patients, and stable disease was observed in two patients. Conclusion The combination of nelfinavir and chemoradiotherapy showed acceptable toxicity and promising activity in patients with pancreatic cancer.
Nature Precedings, Jul 30, 2009
Formal knowledge about human anatomy, radiology or diseases is necessary to support clinical appl... more Formal knowledge about human anatomy, radiology or diseases is necessary to support clinical applications such as medical image search. This machine processable knowledge can be acquired from biomedical domain ontologies, which however, are typically very large and complex models. Thus, their straightforward incorporation into the software applications becomes difficult. In this paper we discuss first ideas on a statistical approach for modularizing large medical ontologies and we prioritize the practical applicability aspect. The underlying assumption is that the application relevant ontology fragments, i.e. modules, can be identified by the statistical analysis of the ontology concepts in the domain corpus. Accordingly, we argue that most frequently occurring concepts in the domain corpus define the application context and can therefore potentially yield the relevant ontology modules. We illustrate our approach on an example case that involves a large ontology on human anatomy and report on our first manual experiments.
Annals of the Rheumatic Diseases, Jun 1, 2016
Background: Several pro-inflammatory cytokines such as TNF-α, IL-1, IL-6, IL-8 and IL-15 are know... more Background: Several pro-inflammatory cytokines such as TNF-α, IL-1, IL-6, IL-8 and IL-15 are known to be critical in synovial inflammatory process in RA and successful results have been obtained in RA treatment with targeting pro-inflammatory cytokines including TNF-α, IL-1 and IL-6. Objectives: This study sought to investigate the role of IL-33 and IL-6 in RA patients receiving IL-6 receptor inhibition therapy. Methods: We analyzed the association of the IL-33 and IL-6 level with disease activity and serologic features in 83 patients with RA. We also measured the serum level of IL-33 and IL-6 before and after the administration of tocilizumab for 24 weeks in 40 patients. Results: Serum IL-33 level showed significant correlation with RF (rho =0.660, p<0.001) but did not correlate with DAS28, ESR, hsCRP or RA duration. IL-6 level was significantly correlated with hsCRP (rho =0.482, p<0.001) but not correlate with DAS28, ESR, RF or RA duration. There was no correlation between serum IL-6 and IL-33 levels. Serum IL-33 level significantly decreased after 24 weeks of IL-6 receptor inhibition in patients with RA (p<0.001). When comparing subgroups according to ACR20 response, serum IL-33 levels were significantly decreased after 24 weeks of IL-6 receptor inhibition therapy in ACR20 responders (p<0.001) but not in the non-responders (p=0.084). Baseline IL-33 levels were not significantly different between the two subgroups (p=0.765). Serum IL-6 levels were not significantly changed after 24 weeks of IL-6 receptor inhibition therapy (median 7.1 to 8.9 pg/mL, p=0.503). Changes of IL-6 levels were insignificant both in ACR20 responders and non-responders after 24 weeks of IL-6 receptor inhibition therapy. Baseline IL-6 levels were not different between ACR20 responders and non-responders. Conclusions: The use of IL-6 receptor inhibitor decreased the serum level of IL-33 and this effect seems to be led by the responder group. IL-33 could be a useful indicator to monitor the response in IL-6 receptor inhibition therapy.
Magnetic Resonance Materials in Physics Biology and Medicine, Dec 14, 1998
The aim of this study was to determine whether low-field magnetic resonance (MR) imaging can safe... more The aim of this study was to determine whether low-field magnetic resonance (MR) imaging can safely and accurately depict inflammatory changes in patients with anal dynamic graciloplasty, in whom high-field MR imaging is contraindicated and ultrasonography and computed tomography are inadequate. A 0.2-T field-strength MR examination was performed in six patients with anal dynamic graciloplasty malfunction in whom reoperation was contemplated. The following sequences were applied: T2-weighted turbo spinecho with fat saturation, T~-weighted conventional spin-echo, and contrastenhanced T~-weighted conventional spin-echo with fat saturation. Results indicated that none of the patients experienced relevant discomfort, pacemaker malfunction, or electrode dislocation with low-field MR imaging. Inflammatory pelvic changes were visualized in four patients and atrophy of the transposed gracilis muscle in another. Surgery was thus avoided in the four, who underwent conservative treatment for their pelvic inflammation. It was concluded that these preliminary results demonstrate the feasibility of MR imaging with a low field strength in patients with anal dynamic graciloplasty. In such patients, in whom diagnostic imaging had been problematic, the potential for safe and accurate visualization will be a boon to treatment planning.
Zeitschrift Fur Rheumatologie, Jul 5, 2017
ZusammenfassungHintergrundNichtinvasive bildgebende Verfahren werden für die morphologische wie a... more ZusammenfassungHintergrundNichtinvasive bildgebende Verfahren werden für die morphologische wie auch funktionelle Evaluierung und Diagnosestellung der Gicht eingesetzt. Keine dieser Methoden zeigte jedoch eine ausreichend hohe Sensitivität und Spezifität. Durch den Einsatz der Dual-Energy-Computertomographie(DECT)-Methode ist erstmalig die Direktdarstellung von Natriumuratablagerungen möglich. Zudem lassen sich damit verschiedene pathologische Zustände, Aktivitätsbewertung sowie ein Therapiemonitoring durchführen. Seit 2 Jahren stellt die positive DECT-Untersuchung auch ein Klassifikationskriterium im Rahmen der 2015 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR)-Klassifikationskriterien für Gicht dar.Material und MethodenBei der Literatursuche in PubMed mit dem Suchkriterium „Dual Energy CT and Gout“ erhält man insgesamt 77 Publikationen zur DECT-Methode.ErgebnisseDie DECT-Untersuchung hat eine sehr hohe Sensitivität (90–100 %) und hohe Spezifität (83–89 %) bei der Diagnosestellung der Gicht. Durch die zusätzliche Entwicklung einer semiquantitativen Scoringmethode wurde zudem die Möglichkeit geschaffen, lokalisationsbezogene Angaben in Bezug zum Schweregrad der Natriumuratablagerung zu machen.DiskussionDer Goldstandard zur Diagnosestellung der Gicht bleibt weiterhin der positive Nachweis von doppelbrechenden Kristallen im Polarisationsmikroskop im Rahmen einer Gelenkpunktion. Die DECT-Untersuchung ermöglicht aber als nichtinvasive Methode die direkte Visualisierung und genaue Volumenbestimmung von Natriumuratablagerung und ist damit zur Bestimmung des Schweregrads und zur Verlaufsbeurteilung geeignet. Obwohl die DECT hierfür klinisch nicht validiert wurde, lässt sich mittels DECT die Diagnose einer Gicht gelegentlich stellen. Weitere Studien sollten noch durchgeführt werden.AbstractBackgroundNon-invasive imaging modalities are used for the morphological and functional evaluation and diagnosis of gout; however, none of these methods are sufficiently sensitive or specific for the diagnosis of gout. By the use of dual-energy computed tomography (DECT) the direct visualization of sodium urate deposition is now possible. Moreover, it is possible to show the different pathological situations, disease activity and monitoring of tophaceous gout. The positive DECT scan became one of the 2015 ACR/EULAR classification criteria for gout 2 years ago.Material and methodsThe literature search from 2009–2017 in PubMed, with the search criteria “Dual Energy CT and Gout” revealed 77 publications on the DECT method.ResultsThe DECT technique has a high sensitivity (90–100%) and a high specificity (83–89%) for diagnosing gout. The development of a semiquantitative scoring method also enables measurement of the severity of urate deposits at specific sites.ConcusionThe gold standard for the diagnosis of gout is still the detection of monosodium urate monohydrate crystals by polarizing microscopy after a joint punction; however with the DECT it is possible to non-invasively visualize, measure and score urate deposition and is therefore suitable for estimating the severity and prognosis. Although not clinical validated, DECT may sometimes help to detect gout. More studies should be conducted.
Springer eBooks, 2010
Automatic segmentation of the esophagus from CT data is a challenging problem. Its wall consists ... more Automatic segmentation of the esophagus from CT data is a challenging problem. Its wall consists of muscle tissue, which has low contrast in CT. Sometimes it is filled with air or remains of orally given contrast agent. While air holes are a clear hint to a human when searching for the esophagus, we found that they are rather distracting to discriminative models of the appearance because of their similarity to the trachea and to lung tissue. However, air inside the respiratory organs can be segmented easily. In this paper, we propose to combine a model based segmentation algorithm of the esophagus with a spatial probability map generated from detected air. Threefold cross-validation on 144 datasets showed that this probability map, combined with a technique that puts more focus on hard cases, increases accuracy by 22%. In contrast to prior work, our method is not only automatic on a manually selected region of interest, but on a whole thoracic CT scan, while our mean segmentation error of 1.80mm is even better.
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2014
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2013
ArXiv, 2017
Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be bene... more Automatic multi-organ segmentation of the dual energy computed tomography (DECT) data can be beneficial for biomedical research and clinical applications. However, it is a challenging task. Recent advances in deep learning showed the feasibility to use 3-D fully convolutional networks (FCN) for voxel-wise dense predictions in single energy computed tomography (SECT). In this paper, we proposed a 3D FCN based method for automatic multi-organ segmentation in DECT. The work was based on a cascaded FCN and a general model for the major organs trained on a large set of SECT data. We preprocessed the DECT data by using linear weighting and fine-tuned the model for the DECT data. The method was evaluated using 42 torso DECT data acquired with a clinical dual-source CT system. Four abdominal organs (liver, spleen, left and right kidneys) were evaluated. Cross-validation was tested. Effect of the weight on the accuracy was researched. In all the tests, we achieved an average Dice coefficient...
European Radiology, 2018
ObjectivesWe compared the interobserver agreement for the recently introduced contrast-enhanced u... more ObjectivesWe compared the interobserver agreement for the recently introduced contrast-enhanced ultrasound (CEUS)-based algorithm CEUS-LI-RADS (Liver Imaging Reporting and Data System) versus the well-established magnetic resonance imaging (MRI)-LI-RADS for non-invasive diagnosis of hepatocellular carcinoma (HCC) in high-risk patients.MethodsFocal liver lesions in 50 high-risk patients (mean age 66.2 ± 11.8 years; 39 male) were assessed retrospectively with CEUS and MRI. Two independent observers reviewed CEUS and MRI examinations, separately, classifying observations according to CEUS-LI-RADSv.2016 and MRI-LI-RADSv.2014. Interobserver agreement was assessed with Cohen’s kappa.ResultsForty-three lesions were HCCs; two were intrahepatic cholangiocarcinomas; five were benign lesions. Arterial phase hyperenhancement was perceived less frequently with CEUS than with MRI (37/50 / 38/50 lesions = 74%/78% [CEUS; observer 1/observer 2] versus 46/50 / 44/50 lesions = 92%/88% [MRI; observer 1/observer 2]). Washout appearance was observed in 34/50 / 20/50 lesions = 68%/40% with CEUS and 31/50 / 31/50 lesions = 62%/62%) with MRI. Interobserver agreement was moderate for arterial hyperenhancement (ĸ = 0.511/0.565 [CEUS/MRI]) and “washout” (ĸ = 0.490/0.582 [CEUS/MRI]), fair for CEUS-LI-RADS category (ĸ = 0.309) and substantial for MRI-LI-RADS category (ĸ = 0.609). Intermodality agreement was fair for arterial hyperenhancement (ĸ = 0.329), slight to fair for “washout” (ĸ = 0.202) and LI-RADS category (ĸ = 0.218)ConclusionInterobserver agreement is substantial for MRI-LI-RADS and only fair for CEUS-LI-RADS. This is mostly because interobserver agreement in the perception of washout appearance is better in MRI than in CEUS. Further refinement of the LI-RADS algorithms and increasing education and practice may be necessary to improve the concordance between CEUS and MRI for the final LI-RADS categorization.Key Points• CEUS-LI-RADS and MRI-LIRADS enable standardized non-invasive diagnosis of HCC in high-risk patients.• With CEUS, interobserver agreement is better for arterial hyperenhancement than for “washout”.• Interobserver agreement for major features is moderate for both CEUS and MRI.• Interobserver agreement for LI-RADS category is substantial for MRI, and fair for CEUS.• Interobserver-agreement for CEUS-LI-RADS will presumably improve with ongoing use of the algorithm.
European Journal of Nuclear Medicine and Molecular Imaging, 2018
Purpose We aimed at evaluating the role of 68 Ga-PSMA-11 PET/CT-derived metabolic parameters for ... more Purpose We aimed at evaluating the role of 68 Ga-PSMA-11 PET/CT-derived metabolic parameters for assessment of wholebody tumor burden and its capability to determine therapeutic response in patients with prostate cancer. Methods A total of 142 patients with biochemical recurrence of prostate cancer underwent PET/CT with [ 68 Ga]Ga-PSMA-HBED-CC (68 Ga-PSMA-11). Quantitative assessment of all 641 68 Ga-PSMA-11-positive lesions in the field of view was performed to calculate PSMA-derived parameters, including whole-body PSMA tumor volume (PSMA-TV) and whole-body total lesion PSMA (TL-PSMA), as well as the established SUVmax and SUVmean values. All PET-derived parameters were tested for correlation with serum PSA levels and for association with Gleason scores. In 23 patients who underwent 68 Ga-PSMA-11 PET/CT before and after therapy with either external beam radiation, androgen deprivation, or docetaxel chemotherapy, SUVmax and TL-PSMA were compared to radiographic response assessment of CT images based on RECIST 1.1 criteria and to biochemical response determined by changes of serum PSA levels. Results PSMA-TV and TL-PSMA demonstrated a significant correlation with serum PSA levels (P < 0.0001) and TL-PSMA was significantly different for different Gleason scores. The agreement rate between TL-PSMA derived from PET and biochemical response was 87% (95% confidence interval, 0.66-0.97; Cohen's κ = 0.78; P < 0.01) and, thus, higher than for SUVmax, which was 74% (95% CI, 0.52-0.90; κ = 0.55; P < 0.01). Furthermore, agreement with PSA was higher for TL-PSMA and SUVmax than for CT-based response evaluation. Discordant findings between PET and CT were most likely due to limitations of CT and RECIST in rating small lymph nodes as metastases, as well as bone involvement, which was sometimes not detectable in CT. Conclusion 68 Ga-PSMA-11 PET/CT-derived metabolic tumor parameters showed promising results for evaluation of treatment response. Especially, TL-PSMA demonstrated higher agreement rates with biochemical response compared to SUVmax. Larger, ideally prospective trials are needed to help to reveal the full potential of metabolic parameters derived from PET imaging with 68 Ga-PSMA-11.
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2012
RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren, 2006
Röntgenpraxis; Zeitschrift für radiologische Technik, 2001