MEDICAL STUDIES: From 09/1992 until 06/1995: Medical education at the University of Diepenbeek.
From 09/1995 until 06/1999: Medical education at the Catholic University of Leuven.
From 08/1999 until 08/2001: 1st and 2nd year of training in Radiology in the AZ St.-Jan AV Hospital in Bruges, Belgium, under the supervision of Dr. H. Rigauts (Bruges) and Prof. Dr. G. Marchal (Leuven).
From 08/2001 until 08/2004: 3rd, 4th and 5th year of training in Radiology at the University Hospitals, Catholic University of Leuven, under the supervision of Prof. Dr. G. Marchal.
From 01/08/2004: Staff member in the department of Radiology in the AZ St.-Jan AV Hospital in Bruges, Belgium.
From 25/02/2009: Doctorate (PhD) in Medical Sciences; PhD (http://dare.uva.nl/record/292150) at the faculty of medicine at University of Amsterdam (UvA/AMC), The Netherlands; promotor: Prof. Dr. J. Stoker.
FURTHER EDUCATION: *Foreign education in the Department of Interventional Radiology at the Institut Gustave-Roussy, Comprehensive Cancer Center in Villejuif (France). Head of the Department of Radiology: Prof.dr.R.Sigal; Head of the Department of Interventional Radiology: Prof.dr.T.de Baere. (April 2005) *Management training at the Vlerick School of Management, Ghent, Belgium: General Management for the hospital physician. (March-November 2005) *Course on Statistics: Department of Postacademic Education of K.U.Leuven Campus Kortrijk (KULAK): Statistical basic methods in practice; Prof.dr. An Carbonez and Prof.dr. Lea Vermeire. (April-June 2006) *Foreign education in the Institute for Diagnostic and Interventional Radiology at the JW Goethe University in Frankfurt am Main (Germany). Director of the Institute for Diagnostic and Interventional Radiology: Prof.dr.TJ.Vogl. (October 2006) *Foreign education in the Department of Medical Imaging (Hôpital St.-André ; Head of Department of Medical Imaging: Prof.dr.H.Trillaud) and in the Laboratory for Molecular and Functional Imaging (Laboratory CNRS ; Director of the Laboratory CNRS: Prof.dr.C.Moonen) of the University of Bordeaux (France). (October 2007)
ADDITIONAL ACTIVITIES: *Member of the Editorial Board of AZlink, hospital magazine of the AZ St.-Jan AV Hospital, Bruges (2004-present). *President of the Medical Audit of the AZ St.-Jan AV Hospital, Bruges (2006-present). *Member of Strategic Management Planning for the AZ St.-Jan AV Hospital, Bruges: project coordinator dr.H.Rigauts, Chief Medical Officer; February 2006 - Spring 2007. *Member of International Management Planning (external/international management cell) for the AZ St.-Jan AV Hospital, Bruges: project coordinator dr.H.Rigauts, Chief Medical Officer; June 2006 – January 2008. *President of International Management Planning (external/international management cell) for the AZ St.-Jan AV Hospital, Bruges: project coordinator dr.H.Rigauts, Chief Medical Officer; January 2008 - present. *Member of the Editorial Board of the AZ St.-Jan AV Hospital Website, Bruges (2006-present). *Member of the Quality Management Board of the AZ St.-Jan AV Hospital, Bruges (March 2008-present).
MEMBERSHIP: Titular member of the Royal Belgian Society of Radiology; Member of the European Congress of Radiology; Member of the European Society of Gastrointestinal and Abdominal Radiologists; Member of the American Roentgen Ray Society. Member of the Société Française de Radiologie. Member of the International Society for Magnetic Resonance in Medicine.
LANGUAGES: -Native language: Dutch. -Excellent knowledge of English and French. -Good knowledge of German.
Abstract: OBJECTIVE: The purpose of this study was to evaluate the diagnostic performance of digital tomosynthesis in comparison with digital radiography in the detection of urinary stones with MDCT as the reference standard. SUBJECTS AND METHODS: Fifty consecutively enrolled patients (32 men, 18 women; mean age, 51.5 years; range, 19-83 years) referred for unenhanced MDCT of the abdomen with suspicion of urinary stones also underwent digital tomosynthesis and digital radiography (anteroposterior and bladder inlet views). Images from all examinations were randomly read by three blinded radiologists. The mean effective doses for digital tomosynthesis, digital radiography, and low- and high-dose MDCT were measured on a male phantom. Free-response receiver operating characteristics and receiver operating characteristics analyses were used to compare the diagnostic performance of digital radiography with that of digital tomosynthesis. RESULTS: Both types of analysis showed significantly better performance of tomosynthesis over digital radiography for all urinary stones (p < 0.05). No such improvement was found for ureteral stones. The gain in sensitivity with tomosynthesis was largest for stones between 2 and 5 mm in diameter. The mean effective dose was 0.5 mSv for digital radiography, 0.85 mSv for tomosynthesis, 2.5 mSv for low-dose MDCT, and 12.6 mSv for high-dose MDCT. CONCLUSION: Use of digital tomosynthesis of the abdomen results in improved detection of urinary stones in general over digital radiography with only a slight increase in effective dose. Use of tomosynthesis, however, was not associated with major improvement in the diagnosis of ureteral stones. The technique has potential as an alternative imaging technique in the detection and follow-up of urinary stones.
Abstract: BACKGROUND: Magnetoliposomes have pronounced signal-enhancing effect on T1-weighted (T1w) images of the liver using qualitative analysis which may be benefical for demonstrating peritumoral vasculature. PURPOSE: To correlate peri-tumoral vasculature (ring-enhancement) surrounding colorectal liver metastases after injection of magnetoliposomes using T1-weighted (T1w) imaging with histopathology in a rat model. MATERIAL AND METHODS: All experiments were approved by the responsible Animal Care Committee. Three rats injected with CC531 coloncarcinoma cells in the portal vein were imaged at 3T using a small diameter four channel coil. The presence of liver metastases, signal intensity changes within intrahepatic vessels, peri-tumoral vasculature (ring-enhancement) surrounding liver metastases on T1w imaging and histopathology, and the histopathological distribution of iron particles were evaluated. SS SE-EPI and T1w GE sequences were used. Images were evaluated qualitatively and MRI findings were correlated with histopathology. RESULTS: Fifteen liver metastases were present which were all detected at MRI (mean diameter 2.4 mm (SD 0.8 mm, range 1.5-4.7 mm)). Ring-enhancement surrounding liver metastases at contrast-enhanced T1w GE sequences was present in all liver metastases. Correlation with histopathology showed the corresponding presence of dilated sinusoids filled with iron particles surrounding the liver metastases. CONCLUSION: Blood-pooling of iron oxide particles within magnetoliposomes was demonstrated with increased and hyperintensity of vessels after injection of magnetoliposomes. Qualitatively, ring-enhancement surrounding the liver metastases was seen on T1w imaging and corresponded histopathologically with the presence of iron particles (magnetoliposomes) within the dilated sinusoids surrounding the liver metastases.
Abstract: To prospectively evaluate a new imaging sequence (4D THRIVE) for whole liver perfusion in high temporal and spatial resolution. Feasibility of parametric mapping and its potential for characterizing focal liver lesions (FLLs) are investigated.
Abstract: The early detection of focal liver lesions, particularly those which are malignant, is of utmost importance. The resection of liver metastases of some malignancies (including colorectal cancer) has been shown to improve the survival of patients. Exact knowledge of the number, size, and regional distribution of liver metastases is essential to determine their resectability. Almost all focal liver lesions larger than 10 mm are demonstrated with current imaging techniques but the detection of smaller focal liver lesions is still relatively poor. One of the advantages of magnetic resonance imaging (MRI) of the liver is better soft tissue contrast (compared to other radiologic modalities), which allows better detection and characterization of the focal liver lesions in question. Developments in MRI hardware and software and the availability of novel MRI contrast agents have further improved the diagnostic yield of MRI in lesion detection and characterization. Although the primary modalities for liver imaging are ultrasound and computed tomography, recent studies have suggested that MRI is the most sensitive method for detecting small liver metastatic lesions, and MRI is now considered the pre-operative standard method for diagnosis. Two recent developments in MRI sequences for the upper abdomen comprise unenhanced diffusion-weighted imaging (DWI), and keyhole-based dynamic contrast-enhanced (DCE) MRI (4D THRIVE). DWI allows improved detection (b = 10 s/mm(2)) of small (< 10 mm) focal liver lesions in particular, and is useful as a road map sequence. Also, using higher b-values, the calculation of the apparent diffusion coefficient value, true diffusion coefficient, D, and the perfusion fraction, f, has been used for the characterization of focal liver lesions. DCE 4D THRIVE enables MRI of the liver with high temporal and spatial resolution and full liver coverage. 4D THRIVE improves evaluation of focal liver lesions, providing multiple arterial and venous phases, and allows the calculation of perfusion parameters using pharmacokinetic models. 4D THRIVE has potential benefits in terms of detection, characterization and staging of focal liver lesions and in monitoring therapy.
Abstract: Fluoro-18-deoxyglucose positron emission tomography computed tomography (FDG-PET/CT) and magnetic resonance imaging (MRI), including unenhanced single-shot spin-echo echo planar imaging (SS SE-EPI) and small paramagnetic iron oxide (SPIO) enhancement, were compared prospectively for detecting colorectal liver metastases. Twenty-four consecutive patients suspected for metastases underwent MRI and FDG-PET/CT. Fourteen patients (58%) had previously received chemotherapy, including seven patients whose chemotherapy was still continuing to within 1 month of the PET/CT study. The mean interval between PET/CT and MRI was 10.2+/-5.2 days. Histopathology (n=18) or follow-up imaging (n=6) were used as reference. Seventy-seven metastases were detected. In nine patients, MRI and PET/CT gave concordant results. Sensitivities for unenhanced SS SE-EPI, MRI without SS SE-EPI and FDG-PET/CT were, respectively, 100% (p=9 x 10(-10) vs PET, p=8 x 10(-3) vs MRI without SS SE-EPI), 90% (p=2 x 10(-7) vs PET) and 60%. PET/CT sensitivity dropped significantly with decreasing size, from 100% in lesions larger than 20 mm (identical to MRI), over 54% in lesions between 10 and 20 mm (p=3 x 10(5) versus unenhanced SS SE-EPI), to 32% in lesions under 10 mm (p=6 x 10(-5) versus unenhanced SS SE-EPI). Positive predictive value of PET was 100% (identical to MRI). MRI, particularly unenhanced SS SE-EPI, has good sensitivity and positive predictive value for detecting liver metastases from colorectal carcinoma. Its sensitivity is better than that of FDG-PET/CT, especially for small lesions.
Abstract: PURPOSE: To assess the added value of true diffusion (D), perfusion factor (f) and apparent diffusion coefficient at low b-values (ADC(low)) for differentiation between liver metastases and hemangiomas based on respiratory-triggered high-resolution Black-Blood Single-Shot SpinEcho Echo Planar Imaging (BB SS SE-EPI). MATERIALS AND METHODS: Twenty-five patients suspected for malignant colorectal liver lesions were included in this study. A total of 106 lesions were examined. Different b-value images were compared for lesion conspicuity, image quality and artifacts using rank order statistic (RIDIT) and Student's t-test. D, f, and ADC(low) values were calculated. Pearson correlation coefficient is used for comparison of interobserver variability. RESULTS: Best lesion conspicuity (p<0.05) was achieved with BB SS SE-EPI (b=0 and 10s/mm(2)); best image quality (p<0.05) with b=10s/mm(2). Image artifacts were lowest (p<0.05) with b=0s/mm(2). Over the whole sample, D in metastases (D(met)) was significantly (p<0.05) lower than D in hemangiomas (D(hem)); f and ADC(low) of metastases (f(met), respectively, ADC(lowmet)) were significantly (p<0.05) higher than f and ADC(low) of hemangiomas (f(hem), respectively, ADC(lowhem)). All Pearson correlations were statistically significant at a 0.01 level. CONCLUSIONS: This preliminary study shows the potential of BB SS SE-EPI as a useful technique to aid in differentiating between liver metastasis and hemangioma. The calculation of D, f and ADC(low) provides useful additional information for differentiating metastases from hemangiomas.
Abstract: PURPOSE: To compare lesion conspicuity and image quality between single-shot spin echo echo planar imaging (SS SE-EPI) before, immediately and 5min after intravenous (IV) injection of superparamagnetic iron oxide (SPIO) for detecting and characterizing focal liver lesions (FLLs). MATERIALS AND METHODS: Twenty-five patients suspected for colorectal liver metastases were prospectively included. Lesion detection and characterization were compared between all SS SE-EPI and T2-weighted turbo spin echo (T2w TSE) sets (two-sided Fisher's exact test). Image quality and lesion conspicuity were compared for SS SE-EPI sets using rank order statistic (RIDIT). Reference standard comprised of surgery, biopsy and/or follow-up. RESULTS: Reference standard demonstrated 18 benign and 43 malignant FLLs. Best lesion detection (p<0.05) was achieved with non-contrast-enhanced SS SE-EPI. Lesion characterization was best using all T2w TSE sequences. Best image quality and lesion conspicuity (p<0.05) was achieved with non-contrast-enhanced SS SE-EPI. CONCLUSION: Non-contrast-enhanced SS SE-EPI was best for lesion detection. SS SE-EPI sequences were not useful for lesion characterization (differentiation between benign and malignant lesions). Unenhanced SS SE-EPI did not allow differentiation especially as many benign FLLs were hyperintense on the highest b-value images. Combining unenhanced and SPIO-enhanced SS SE-EPI performed better but still was not clinically useful due to variable degree of uptake and vascular pooling of SPIO for (especially) benign FLLs. T2w TSE with SPIO-enhancement was needed for characterization.
Abstract: T2-weighted turbo spin echo sequences are being used as a first sequence for abdominal magnetic resonance imaging in many cases. For oncological patients breath-hold imaging can be difficult. T2-weighted turbo spin echo sequences can be used during breath-hold or during respiratory-triggering. The purpose of our study is to compare a respiratory-triggered fat-suppressed and breath-hold T2-weighted Turbo Spin Echo (RT and BH FS T2w TSE) sequence for focal liver lesions. Prospectively, both T2w TSE sequences were acquired in 40 patients using 1.5T MRI. Qualitatively analysis was performed for image quality, lesion conspicuity, diagnostic confidence, artifacts using two-tailed Wilcoxon signed-ranks test. Quantitative analysis was performed for lesion-to-liver Contrast-to-Noise Ratio (CNR) using two-tailed Student's t-test. Qualitatively, RT FST2wTSE performed significantly (p < 0.05) better than BH FST2wTSE concerning image quality, lesion conspicuity, diagnostic confidence and artifacts. Seventy-eight metastases and 47 hemangiomas were detected on both FST2wTSE sequences. Seven liver metastases and 2 hemangiomas < 10 mm and 3 metastases between 10-20 mm detected on RT FS T2wTSE were only retrospectively detected on BH FS T2wTSE. Diagnostic confidence scores were best using RT FS T2w TSE compared with BH FS T2w TSE. Mean CNR of all lesions, mean CNR of all lesions < 10 mm and mean CNR between hemangiomas and metastases was significantly better using the RT sequence compared with the BH sequence. RT FST2wTSE might perform better than BH FST2wTSE for lesion detection and characterization in this study.
Abstract: PURPOSE: To prospectively compare single-shot spin-echo echo-planar imaging (SSSE-EPI) using b = 0, 10, 150, and 400 seconds/mm(2) with standard MRI techniques after intravenous super paramagnetic iron oxide (SPIO) in the detection and characterization of focal liver lesions with focus on small (<10 mm) focal liver lesions. MATERIALS AND METHODS: A total of 25 patients suspected for colorectal liver metastases were included. Number of detected lesions was evaluated. Image quality was compared between SSSE-EPI sequence and post-SPIO (fat-suppressed T1-weighted [T1w] gradient echo [GE], T2-weighted [T2w] turbo spin echo [TSE] and T2* GE) sequences using rank order statistic (RIDIT). Lesion characterization was performed for SSSE-EPI and for all remaining sequences pre- and post-SPIO. Reference standard comprised surgery, biopsy, and/or follow-up. RESULTS: Reference standard demonstrated 25 hemangiomas and 70 metastases. Best lesion detection respectively best image quality (P < 0.05) was achieved with SSSE-EPI (b = 10 seconds/mm(2)) post-SPIO T1w GE and T2w turbo spin echo. Lesion characterization using all sequences pre- and post-SPIO performed best for lesion characterization compared with SSSE-EPI. CONCLUSION: This preliminary study shows the potential of SSSE-EPI as a stand-alone sequence for the detection of liver hemangiomas and metastases when compared with SPIO-enhanced imaging. Sequences pre- and post-SPIO are needed for qualitative lesion characterization.
Abstract: Magnetic resonance (MR) imaging is the method of choice to evaluate the cranial nerves. Although the skull base foramina can be seen on CT, the nerves themselves can only be visualized in detail on MR. To see the different segments of nerves I to XII, the right sequences must be used. Detailed clinical information is needed by the radiologist so that a tailored MR study can be performed. In this article, MR principles for imaging of the cranial nerves are discussed. The basic anatomy of the cranial nerves and the cranial nerve nuclei as well as their central connections are discussed and illustrated briefly. The emphasis is on less known or more advanced extra-axial anatomy, illustrated with high-resolution MR images.
Abstract: Pancreatic serous cystadenomas are benign cystic lesions without complication risks. They can be discovered after investigations for upper abdominal discomfort because of mass effect or incidentally. In rare cases they are detected because of biliary obstruction. Hemorrhagic complication is very unusual.
Abstract: Small unilamellar phospholipid vesicles containing the phosphatidylethanolamine-diethylene triamine pentaacetic acid (PE-DTPA) conjugate as one of the building stones were constructed. The ability of these colloids to complex gadolinium(III) ions at the surface of both the inner and outer bilayer shells was verified using a colorimetric method with Arsenazo III as a dye indicator. On incubation of these functionalized vesicles with magnetoliposomes (MLs, nanometer-sized magnetite cores encapsulated in a phospholipid bilayer), PE-DTPA percolates into the ML coat. The PE-DTPA content could be fine-tuned by varying the conjugate concentration in the donor vesicles. In the experimental conditions applied, up to 500 Gd(3+) ions were immobilized per ML colloid. The resulting ML-Gd(3+) complexes might have great potential, for example, as a novel magnetic resonance imaging contrast agent.
Abstract: We report a case of splenic hamartoma that was occasionally detected. Ultrasonography performed as a screening examination revealed a hypoechoic splenic lesion. A computed tomography and magnetic resonance examination were performed in order to characterize the lesion but failed to make a final diagnosis. An elective laparoscopic splenectomy with consecutive histologic examination revealed a splenic hamartoma. Splenectomy may be required for definite characterization of this type of splenic lesion.
Abstract: The purpose of this study was to compare diffusion-weighted respiratory-triggered single-shot spin echo echoplanar imaging (SS SE-EPI) sequence using four b-values (b = 0, b = 20, b = 300, b = 800 s mm(-2)) and single-shot T2 weighted turbo spin echo (T2W SS TSE) in patients with focal liver lesions, with special interest in small (<10 mm) lesions. Twenty-four patients underwent routine MRI. The five sequences were compared qualitatively for image quality, lesion conspicuity and artefacts. Quantitative analysis was performed for lesion identification and lesion-to-liver contrast-to-noise ratio (CNR). Subgroup analyses were performed for different types of lesions with different sizes. Sequences were compared by rank order statistic (RIDIT) and Kruskal-Wallis test. The best image quality (p<0.05) was achieved with T2W TSE and the best lesion conspicuity (p<0.05) with T2W TSE for biliary cysts and SE-EPI diffusion-weighted imaging (DWI) (b = 20 s mm(-2)) for haemangiomas and metastases. Image artefacts were lowest (p<0.05) with T2W TSE. T2W TSE was found to be the best protocol (p<0.05) for the identification of biliary cysts and SE-EPI DWI (b = 20 s mm(-2)) for haemangiomas and metastases. The lesion-to-liver CNRs were highest on T2W TSE for biliary cysts and on SE-EPI diffusion-weighted imaging (DWI) for haemangiomas and metastases (p<0.05). This study shows the potential of SS SE-EPI DWI (especially with a b-value of 20 s mm(-2)) as a promising technique for detecting small (<10 mm) focal liver lesions.
Abstract: Steroid-resistant sarcoidosis has conventionally been treated with various drugs, including methotrexate, azathioprine, cyclophosphamide, cyclosporine, antimalarial drugs and thalidomide, with variable success. There is a compelling need for more efficient and safer alternatives to these agents. Several lines of evidence suggest a critical role of TNF-alpha (tumour necrosis factor-alpha) in the initiation and organization of sarcoid granulomas. Inhibition of TNF-alpha with monoclonal antibodies has therefore received attention as a potential treatment option in therapy-resistant sarcoidosis. A number of case reports and small case series describe successful treatment of refractory disease with infliximab. Preliminary evidence from an RCT (randomized controlled trial) with infliximab in pulmonary sarcoidosis suggests a modest improvement in functional and radiological parameters. In contrast, the results with etanercept have been disappointing, perhaps related to differences in the mechanism of TNF-alpha blockade. The experience with adalimumab in sarcoidosis is too limited to draw conclusions. An open-label study and an RCT evaluating the efficacy of adalimumab in sarcoidosis with pulmonary and cutaneous involvement respectively, have been initiated. Although TNF-alpha antagonists appear relatively safe, especially when compared with conventional agents, caution is warranted in view of the increased incidence of tuberculosis, which may be a particular diagnostic challenge in patients with sarcoidosis. Pending publication of the RCTs, the use of TNF-alpha blockade in sarcoidosis should remain in the realm of experimental treatment.
Abstract: We present a case of right-sided omental infarction in a child documented with ultrasound and multislice computed tomography and confirmed by surgery and pathologic examination. Omental infarction is a rare cause of right-sided acute abdominal pain in a child. Differential diagnosis includes appendicitis. With different imaging modalities a diagnosis can be made and avoid unnecessary appendectomy.
Abstract: We present a case of a rare small bowel tumor. A 73-year-old female patient presented at our department with vague abdominal pain. Ultrasound examination discovered an inhomogeneous vascularised mass originating from a small bowel loop, mesenteric enlarged lymph nodes and a nodule in the liver. Multislice Computed Tomography of the abdomen confirmed the ultrasonographic findings and found omental implants together with a left-sided ovarian mass. Surgery was performed. Pathology revealed a rare ileal collision tumor consisting of an adenocarcinoma and a small cell neuroendocrine tumor with peritoneal metastasis of neuroendocrine origin and coincidental benign lesions on both ovaries.
Abstract: Gastro-intestinal stromal tumors can present with gastro-intestinal hemorrhage, often with an acute episode of abdominal pain, weight loss, nausea and vomiting. We present a case of a young man who presented with gastrointestinal bleeding. The patient previously presented with gastro-intestinal bleeding but several investigations like gastroscopy, coloscopy, Ectopic gastric mucosa-scan, and computed tomography were reported as negative. A well-circumscribed submucosal tumoral mass in the duodenum with maximal thickness of 15 mm was however detected by CT-enteroclysis. Microscopic examination confirmed the presence of a gastro-intestinal stromal tumor.
Abstract: We present a case of giant aneurysm in the superficial temporal artery. A 59-year-old male was admitted to our hospital with a slowly growing swelling just in front of his right ear. Diagnosis was made by US and CT. CTA was able to provide accurate anatomic information and to eliminate the risks associated with diagnostic conventional angiography. A superselective embolization of the giant temporal aneurysm was performed.
Abstract: Primary lymphoma of the liver is a very rare malignancy. Most often, these lesions consist of diffuse large B-cell non-Hodgkin's lymphoma that occurs mostly in immunodeficient patients. To prove the primary nature of a hepatic lesion, a systemic lymphoproliferative disease should be ruled out. Secondary liver involvement during Hodgkin's and non-Hodgkin's lymphoma is frequent. In advanced cases the incidence varies from 25% to 50%.The present case describes the MRI features of a primary lymphoma of the liver presenting as a solitary nodule. The primary lymphoma presents as a T2-hyperintense homogeneous nodule, with a signal intensity comparable with the signal intensity of the spleen. Signal intensity is comparable on in and out of phase imaging. The nodule is slightly T1-hypointense and doesn't show any arterial contrast uptake. In the late venous phase a slight increase in signal intensity is noted. Two and a half minutes after the administration of contrast agent, the lesion is iso-attenuating with the liver parenchyma.This case is rare because of the concomitant presence of heterozygous sickle cell anaemia and the presence of Gamna-Gandy bodies in the splenic parenchyma. It remains uncertain whether the presence of the Gamna-Gandy bodies is associated with the liver lymphoma or with the underlying sickle cell anaemia, or with a combination of both.
Abstract: An 80-year-old female patient with arterial hypertension and slowly progressive deterioration of renal function was referred to our department for investigation of the renal arteries. Imaging of the renal arteries with ultrasound was inconclusive, due to obesity. Subsequently, imaging was performed with balanced turbo field echo which is a newly developed technique in our department. This new technique for the moment is still combined with contrast-enhanced magnetic resonance angiography. A therapeutic digital subtraction angiography was performed for stent placement.
Abstract: PURPOSE: To compare a multislab balanced turbo field-echo magnetic resonance (MR) angiographic technique, without the use of a contrast agent, with digital subtraction angiography (DSA) for imaging of the renal arteries. MATERIALS AND METHODS: Twenty-five randomly selected patients (eight women and 17 men; age range, 27-88 years; mean age, 72 years) suspected of having renal artery stenosis underwent both DSA and balanced turbo field-echo MR angiography. A consensus result was obtained among three radiologists in evaluation of main renal arteries on balanced turbo field-echo images and DSA images. Sensitivity, specificity, and negative and positive predictive values of the balanced turbo field-echo technique were calculated, and receiver operating characteristic analysis was performed for depiction of hemodynamically significant stenosis. Cohen kappa analysis was used to assess agreement between the two imaging methods in grading of stenoses and depiction of significant stenosis. Accessory renal arteries also were evaluated. RESULTS: Fifty main renal arteries and 11 accessory arteries were fully depicted with DSA. DSA depicted 11 stenotic lesions in the main renal arteries. In comparison, balanced turbo field-echo MR angiography enabled visualization of 46 of 50 main renal arteries to their first branching points and depicted 10 of 11 accessory arteries. Sensitivity, specificity, negative predictive value, and positive predictive value of this technique for depiction of significant stenosis were 100% (four of four), 98% (41 of 42), 100% (41 of 41), and 80% (four of five), respectively. The area under the receiver operating characteristic curve was 0.988. kappa was 0.782 for grading of stenoses and 0.877 for depiction of significant stenosis. CONCLUSION: Multislab balanced turbo field-echo imaging has potential as an MR angiography technique for depiction of normal and diseased renal arteries.
Abstract: PURPOSE: To characterize pancreatic perfusion in volunteers and patients with chronic pancreatitis (CP) by dynamic contrast-enhanced (DCE) MRI. MATERIALS AND METHODS: Pancreatic enhancement after bolus injection of Gd-DTPA with a three-dimensional ultrafast partial-Fourier radiofrequency (RF) spoiled gradient-echo (GE) acquisition was examined prospectively. An acquisition volume of the pancreatic parenchyma was obtained every 4.2 seconds during a single breath-hold in 31 volunteers and 19 patients with CP. We calculated the wash-in rate and a newly defined parameter, the "time-to-inflow deceleration" (TID). A statistical analysis of the differences between both groups was performed with the use of Student's t-test. RESULTS: Significant differences in the TID and wash-in rate were found for the head and body of the pancreas: the TID was 22.4 sec +/- 4.4 sec and 23.5 sec +/- 6.1 sec in the pancreatic head and body of the healthy volunteers, and 29.8 sec +/- 8.6 sec and 29.4 sec +/- 3.8 sec in patients with CP. The wash-in rate was 96 +/- 37 sec(-1) and 101 +/- 27 sec(-1) in controls, and 62 +/- 17 sec(-1) and 75 +/- 27 sec(-1) in CP. CONCLUSION: CP can be identified by semiquantitative changes on DCE-MRI. Whether DCE-MRI of the pancreas can be used to detect early CP remains to be validated.
Abstract: This experiment was conducted in compliance with the guidelines of the International Committee on Thrombosis and Hemostasis and the current institutional regulations for use and care of laboratory animals. The purpose of the present study was to report the feasibility of using clinical magnetic resonance (MR) imaging devices for depiction of stroke in a rat model. Twenty-four rats with photochemically induced thrombosis of the middle cerebral artery were examined at superacute (1 hour, n = 24), acute (12 hours, n = 12), and subacute (24 hours, n = 12) phases with 1.5-T MR imaging weighted for T1, T2, diffusion, and gadopentetate dimeglumine-enhanced perfusion. With reasonable signal-to-noise ratio and imaging times, ischemic lesions were well distinguished on MR images as validated qualitatively and quantitatively with postmortem standard-of-reference techniques, including volume-rendered computed tomography, microangiography, and histochemistry. In the superacute phase, the perfusion defect at perfusion-weighted MR imaging was well matched with microangiographic and pathologic findings (P > .05). There was no difference in lesion size at perfusion-weighted MR imaging between superacute and subacute phases (P > .05). Performance of certain stroke-related research in rats is feasible with clinical MR imagers.
Abstract: OBJECTIVE: The aim of this study is to compare multislice computed tomography (MSCT) in combination with a newly developed semiautomated software program with calibrated aortography in patients who are scheduled for endovascular aortic stent graft placement. METHODS: From November 2000 until December 2001, seven patients with an abdominal aortic aneurysm (AAA) underwent both calibrated aortography and MSCT for preoperative endovascular stent graft planning. Both studies were performed within 14 days. Further, length measurements were performed with a semiautomated computerized tomographic angiography (CTA) calibration method and a conventional calibrated aortography technique using three differently configured tubes with variable tortuosity. The AAA length measurements of the semiautomated CTA calibration method and the calibrated aortography were compared. RESULTS: Statistical analysis included linear regression analysis and revealed a probability value of 0.000381 and an r2 value of 0.93. Using phantoms, it is proven by the authors that the accuracy of the semiautomated CTA calibration method increases with increasing tortuosity when compared with the conventional calibrated aortography technique. CONCLUSIONS: Our preliminary results show that the semiautomated CTA calibration method has a potentially advantageous role in preoperative stent graft planning regarding the aortic length measurements and seems to be more accurate than calibrated aortography, especially in extremely tortuous vessels. Further studies have to be performed, however.
Abstract: As compared to single slice helical CT, multislice helical CT does not only improve the quality of the individual images (in terms of slice sensitivity profile and image artifacts) and the range of scan coverage, it also enforces the CT postprocessing possibilities. The advantage of post-processing thin collimation bowel CT images with overlap and cine-viewing or paging is reported. The case report illustrates that cine-viewing of overlapping thin collimation images obtained with multislice helical CT, allows an excellent evaluation of the bowel loops resulting in the diagnosis of a perforated sigmoid carcinoma and its complications.
Abstract: A case of traumatic pseudo-aneurysm and dissection of the proximal descending thoracic aorta in association with an aberrant right subclavian artery and a common trunk for both common carotid arteries is presented. The diagnosis of this traumatic pseudo-aneurysm and dissection in association with these congenital anomalies by means of a multi-slice helical CT is discussed. To our knowledge, this is the first such case reported in the literature.
Abstract: This article presents a case of appendicitis 7 years after open appendectomy. Together with the apparent CT findings we discuss the current literature of this issue.
