Epithelioid angiosarcoma of the scapula.

Epithelioid angiosarcoma is a rare variation of an angiosarcoma and its localization in the bone is exceptionally infrequent. This report presents the case of a 48-year-old male with an epithelioid angiosarcoma of the scapula. In CT and MRI scans an inhomogeneous tumour with osseous destructions, lytic areas, central necrosis and marginal hyperperfusion was observed. The bordering skeletal muscles were already infiltrated. The tumour was treated initially with neoadjuvant chemotherapy, followed by dose escalation, peripheral blood stem cell transplantation and resection of the lesion. Despite advanced local tumour stage at initial presentation, the patient is in complete remission.

[Pulmonary embolism as a cause of a reduced performance capacity of endurance trained men - report of 2 cases]. / Lungenembolie als Ursache einer Leistungsminderung bei Ausdauersportlern - 2 Kasuistiken.

HISTORY AND ADMISSION FINDINGS: Two trained long-distance runners, aged 53 and 58 years, respectively, presented (independently) at our outpatient department because of an acute reduction in physical performance after considerable exertion. Neither had specific clinical symptoms, particularly no dyspnea. INVESTIGATIONS: Neither patient had abnormal findings on physical examination, such as signs for deep venous thrombosis. The electrocardiogram and echocardiography were normal. Exercise tests revealed a significant limitation in physical performance and, in one patient, a reduction in arterial blood oxygen and elevated d-dimers as the only abnormal laboratory test result. DIAGNOSIS, TREATMENT AND COURSE: The diagnosis of pulmonary embolism was made by computed tomography, which showed the typical changes. In both patients venous phlebography revealed deep vein thrombosis and signs of post-thrombotic changes. Laboratory tests were unremarkable, with normal blood coagulation and no factor II mutations. Anticoagulants were administered to each patient and they slowly resumed their training program. At a subsequent examination physical performance had improved, but there was still a reduction in arterial oxygen during exercise. CONCLUSION: Even endurance-trained sportspersons without thrombophilic risk factors may develop deep vein thrombosis. Even when there are no symptoms, pulmonary embolism should always be included in the differential diagnosis of a sudden and significant reduction in physical performance.

High resolution 3 Tesla contrast-enhanced MR angiography of the hands in Raynaud's disease.

Raynaud's disease is associated with disorders in blood circulation of the hands. The gold standard to visualise pathology of digital arteries is catheter angiography. Contrast-enhanced MR angiography (CE MRA) has developed even more as an alternative non-invasive method to digital subtraction angiography, mostly for pelvic or lower limb vessels. We report a case of primary Raynaud's disease with high-grade stenosis and an occlusion of the digital arteries. This case illustrates the benefit and efficiency of CE MRA at high fields in depicting location and extension of peripheral arterial alterations.

Detection and characterization of benign focal liver lesions with multislice CT.

MDCT is a rapidly evolving technique that significantly improves CT imaging for several indications including depiction of focal benign lesions. Imaging mainly profits from improved longitudinal spatial resolution allowing high-quality non-axial reformations and 3D reconstructions and CT angiography as well as rapid accurate multiphase imaging with short breath-holding periods. This review provides an overview of the current status of MDCT with respect to liver imaging and the implications for characterizing benign focal liver lesions. MDCT currently allows the acquisition of thin slices in daily routine diagnostics providing an improved detection rate of small liver lesions. Whereas large benign focal liver lesions exhibit typical patterns of morphology, attenuation and perfusion, which also may be assessed with single-slice scanners, small lesions remain challenging even with MDCT, since the specific criteria for confident diagnosis become more ambiguous. Here, MR imaging provides more detailed information about tissue components and the availability of liver-specific contrast agents, adding further impact to this technique. With respect to dose considerations, the number of necessary multiphase scans as well as the application of very thin collimation should be strictly checked for each patient undergoing MDCT based on the individual clinical situation and question.

Whole-body MRI in comparison to skeletal scintigraphy in detection of skeletal metastases in patients with solid tumors.

AIM: To evaluate the diagnostic value of whole-body magnetic resonance imaging (MRI) and skeletal scintigraphy in the detection of skeletal metastases in patients with solid tumors. MATERIALS AND METHODS: One hundred and twenty-nine tumor patients were examined with whole-body MRI using coronal TIRM sequences for the different anatomical regions. Skeletal scintigraphy was performed with 99mTc-DPD. RESULTS: In 105/129 (81%) patients, the whole-body MRI and skeletal scintigraphy findings were concordant. In 56/129 (43%) patients, both imaging modalities excluded skeletal metastases. In 49/129 (38%) patients, whole-body MRI and skeletal scintigraphy revealed metastases, however whole-body MRI demonstrated more extensive disease in 22/49 (45%) cases. In 6/49 (12%) cases, skeletal scintigraphy was superior to whole-body MRI in detecting more skeletal metastases. In 24/129 (19%) cases, the imaging findings were discordant. In 15 cases, skeletal scintigraphy was negative, whereas whole-body MRI revealed skeletal metastases. In 9 cases, skeletal scintigraphy was positive, whereas whole-body MRI failed to detect these metastases. In 77/129 (60%) patients, whole-body MRI revealed additional tumor-related findings. CONCLUSION: Whole-body MRI, as a new staging method, is superior to skeletal scintigraphy with respect to the detection of skeletal metastases and the extent of metastastic disease. Furthermore, whole-body MRI yields additional tumor-related findings. Therefore, whole-body MRI should be performed as an alternative to skeletal scintigraphy for the assessment of skeletal metastases.

Endovascular treatment of superficial femoral artery occlusive disease with stents coated with diamond-like carbon.

A major consideration in the reduction of early stent thrombosis and in-stent restenosis is the improvement of biocompatibility of the devices. Diamond-like carbon is a novel material for coating stent surfaces in order to increase biocompatibility. The authors report on the endovascular treatment of two individuals with superficial femoral artery occlusions, using stents coated with diamond-like carbon. Technical and clinical success was achieved in both cases, with primary patency rates of 100% 12 months after intervention.

[Whole-body MRI in comparison to skeletal scintigraphy for detection of skeletal metastases in patients with solid tumors]. / Ganzkörper-MRT vs. Skelettszintigraphie bei der Detektion ossärer Metastasen solider Tumoren.

PURPOSE: The aim of this study was to compare the diagnostic efficacy of whole-body magnetic resonance imaging (WB-MRI) as a new and rapid examination technique with skeletal scintigraphy for detection of skeletal metastases from solid tumors. MATERIAL AND METHODS: In 129 patients with solid malignant tumors, WB-MRI was performed for individual comparison with skeletal scintigraphy. Examinations were performed with the innovative AngioSURF rolling table with integrated phased array surface coil and coronary TIRM sequences for different body regions. RESULTS: The results for WB-MRI and skeletal scintigraphy were concordant in 81% of the cases, whereby both procedures excluded skeletal metastases in 43%. WB-MRI and skeletal scintigraphy demonstrated skeletal metastases in 38% of the cases, whereby WB-MRI provided more comprehensive findings in 45%. In 12% of the cases, skeletal scintigraphy was superior to WB-MRI and in 19% the findings were discordant, whereby WB-MRI detected skeletal metastases in 15 cases which had not been found on skeletal scintigraphy. In nine cases, skeletal scintigraphy was positive when the WB-MRI was negative. In 60% of the cases, WB-MRI evidenced tumor-associated findings. CONCLUSION: WB-MRI represents a promising new staging technique for detection of skeletal metastases, which is more sensitive in many cases than skeletal scintigraphy in detecting and assessing the extent of skeletal metastases-and tumor-associated findings that are relevant for treatment strategy.

[Electronic distribution of patient records and images through PACS: implementation of data protection at the University Hospital in Freiburg]. / Elektronische Befund- und Bildverteilung aus einem PACS: Umsetzung der datenschutzrechtlichen Aspekte am Beispiel des Universitätsklinikums Freiburg.

In large installations of a Picture Archiving and Communication System (PACS), data protection becomes an issue. Above all, not every employee should have access to all data stored in the system. At the Freiburg University Hospital, we developed a concept of dynamic assignment of authorization, assuring that every physician is authorized to the data of all patients under his care. We describe the technical implementation of data protection developed for the integration of PACS and electronic patient records in Freiburg. The system was installed in January 2001 and the experience of its two years in operation is reported.

Background suppression using magnetization preparation for contrast-enhanced 3D MR angiography of the pelvic and lower leg arteries.

PURPOSE: To develop and evaluate non-slab-selective magnetization preparation in contrast-enhanced 3D-MR angiography. METHODS: An ultrafast spoiled mr angiography sequence (FLASH) with non-selective inversion prepulses for background suppression was implemented on a 1.5 T MR system. In 11 patients gadobenate dimeglumine-enhanced mr-angiography of the pelvic and lower leg arteries was performed using the AngioSURF device. Source data was evaluated for contrast-to-noise-ratio, image quality and the extent of background suppression. RESULTS: Background suppression and selective vessel contrast was excellent in all vascular levels. The mr protocol was comfortable and easy-to-handle. Abandonment of precontrast-series acquisition simplified the examination procedure markedly. CONCLUSIONS: Magnetization preparation provides efficient suppression of the background signal in contrast-enhanced 3D mr angiography of the pelvic and lower leg arteries. Since no subtraction technique is needed, moving-bed and whole body MRA-protocols can be simplified significantly.

Diagnosis of the hypothenar hammer syndrome by high-resolution contrast-enhanced MR angiography.

Our objective was to describe the imaging features of hypothenar hammer syndrome using minimally invasive contrast-enhanced MR angiography in comparison with oscillography study. In five patients with hypothenar hammer syndrome Gd-BOPTA-enhanced elliptically reordered 3D pulse sequence MR was compared with oscillography findings and clinical symptoms focusing on angiographic appearance of vessel injury, distribution pattern of hand vasculature and joining branches between the radial and ulnar artery supply. All patients showed segmental occlusion at the site of trauma impact with varying involvement of the superficial palmar arch, common volar digital arteries. Embolic disease was present in 50% of patients and could be clearly identified with MRA. Good correspondence was found between angiographic appearance including the presence of collaterals, clinical symptoms and oscillography. Bilateral comparison was helpful in distinguishing between vessel variants and pathology. Bilateral Gd-BOPTA-enhanced MR angiography is a minimally invasive method to depict clearly the localization and extent of vessel injury in hypothenar hammer syndrome providing valuable information about distribution pattern of hand vasculature and presence of collaterals; however, no flow data can be obtained.

Gadolinium-enhanced elliptically reordered three-dimensional MR angiography in the assessment of hand vascularization before radial artery harvest for coronary artery bypass grafting: first experience.

RATIONALE AND OBJECTIVES: To assess the suitability of contrast-enhanced magnetic resonance angiography (MRA) in the preoperative evaluation of hand vasculature in potential candidates for radial artery bypass grafting. METHODS: In 21 patients, gadobenate dimeglumine-enhanced, three-dimensional gradient-echo sequences of both hands were performed, as well as a Doppler ultrasound study with radial artery compression. Doppler findings were correlated with MRA, focusing on the assessment of anastomoses between the vascular bed of the ulnar and radial arteries. RESULTS: One individual had to be excluded because of accidentally disclosed metal foreign bodies. Sufficient depiction of the hand vasculature was achieved in the remainder. Seventeen patients had evidence of adequate collateral flow between the ulnar and radial artery supply on Doppler ultrasound. Three patients exhibited inadequate collateral flow, with angiographic signs of vessel occlusion or missing collaterals between the palmar arches. Two patients presented with stenosis or occlusion of the radial artery. Magnetic resonance angiograms displayed great variations in hand vasculature and collateral formation, with no mismatch compared with Doppler ultrasound results. CONCLUSIONS: Contrast-enhanced MRA displays vascularization of the hand in detail and supplies ultrasound flow measurements for radial artery harvest, with high-resolution angiographic data about possible vessel variations and the presence of anastomoses between the radial or ulnar artery supply.

Cardiac phase contrast gradient echo MRI: characterization of abnormal left ventricular wall motion in patients with ischemic heart disease.

PURPOSE: In our patient study, we examined the clinical usefulness of phase contrast velocity mapping for the detection and characterization of localized abnormalities of left ventricular motion. MATERIALS AND METHODS: Velocity encoding is based on the fact that motion in the presence of a magnetic field gradient causes a change of the phase of the MRI signal that is proportional to the velocity of tissue motion. Left ventricular motion was characterized by parameters describing rotation and contraction/dilatation, respectively. We examined 34 patients with localized abnormalities of left ventricular motion due to ischemic heart disease. RESULTS: Three patients could not be sufficiently evaluated due to technical problems including varying positions of the heart during successive breathhold periods. In 27 of the remaining 31 patients, MRI could demonstrate abnormal radial velocities that corresponded fully or partly with perfusion deficits in single photon emission computed tomography or positron emission tomography. The abnormalities were most pronounced in early diastole. Rotational velocities did not show any regional changes. CONCLUSION: Our study showed that our technique is suitable for the detection and characterization of localized abnormalities of left ventricular motion in patients with ischemic heart disease.

Diamondback moth compensatory consumption of protease inhibitor-transformed plants.

Prior study of the effect of protease inhibitors (PIs) on diamondback moths suggests that moths are resistant to them, so PIs represent an ineffective defence against moths. However, our data suggest that diamondback moths do suffer lower growth rates when they consume plants transformed with potato protease inhibitor (PI2), but that effect is hidden by compensatory consumption. Plants, instead of gaining an advantage by lowering the insect growth rate, suffer a disadvantage as moths consume more tissue to mitigate the effect. Furthermore, PI2, when used in conjunction with another transgenic pesticidal protein, Bt (from Bacillus thuringiensis) counteracts the effectiveness of Bt at protecting plant tissue. Thus, transgenic PIs are not only less effective than previously thought in protecting Brassica plants from diamondback moths, they may actually lead to increased plant damage by the moths.

Neurovascular contact of the brain stem in hypertensive and normotensive subjects: MR findings and clinical significance.

BACKGROUND AND PURPOSE: About 20 years ago, a theory was put forward that neurovascular contact of the root entry zone (REZ) of the ninth and 10th cranial nerve is responsible for elevated blood pressure in patients with essential hypertension. To test this hypothesis, we used MR tomography and MR angiography to evaluate the presence and degree of neurovascular contact of the REZ of the ninth and 10th cranial nerves in patients with essential hypertension as compared with patients with renal parenchymal hypertension and normotensive healthy volunteers. METHODS: Patients with essential hypertension (group 1; n = 33), renal parenchymal hypertension (group 2; n = 30), and normotensive healthy volunteers (group 3; n = 25) underwent high-resolution (axial and coronal) brain stem MR imaging and MR angiography. The images were interpreted consensually by two radiologists who were blinded to the patients' hypertensive status. Neurovascular contact was graded as vessel contact without associated brain stem deformity (grade I), vessel contact with associated brain stem deformity (grade II), or vessel contact with associated deformity and displacement of the brain stem (grade III). RESULTS: Neurovascular contact of the REZ of the ninth and 10th cranial nerve on the left side was found in 48.5% in group 1, in 26.7% in group 2, and in 48.0% in group 3. The rate of neurovascular contact on the right side was 24.2%, 13.3%, and 40.0%, respectively. chi(2) analysis showed no statistical difference between the groups. CONCLUSION: Neurovascular contact is not more frequent in patients with essential hypertension than in normotensive control subjects or in those with secondary hypertension; therefore, MR imaging cannot aid patient selection for neurosurgical vascular decompression.

Optimization of contrast-enhanced MR angiography of the hands with a timing bolus and elliptically reordered 3D pulse sequence.

Our objective was to optimize bolus administration and sequence setting in gadolinium-enhanced magnetic resonance (MR) angiography of the hands. Elliptically reordered three-dimensional (3D) spoiled gradient-echo sequence with non-slab-selective radio frequency excitation was optimized according to the measurements of arterial and venous time-signal curves in 21 patients. Great variations in bolus arrival time and arterio-venous transit time could be observed. In most patients high-quality arterial depiction could be obtained with minor venous contamination. Contrast-to-noise, spatial resolution, and selective arterial filling is still a challenge for 3D MR angiography of the hand but can be optimized using Gadolinium-BOPTA and a dedicated pulse sequence setting with exact bolus timing.

[Preoperative examination of potential kidney transplantation donors: value of gadolinium-enhanced 3D MR angiography in comparison with DSA and urography]. / Präoperative Untersuchung potentieller Nierenlebendspender: Wertigkeit der Gadoliniumverstärkten 3D-MR-Angiographie im Vergleich mit der DSA und Urographie.

PURPOSE: To assess a contrast-enhanced standardized MRA protocol for the presurgical evaluation of potential renal transplant donors. METHODS: Twenty-three potential donors for renal transplantations were examined with gadolinium-enhanced, two-phase MR angiograms (1.5 T) and DSA/urography for the number of renal arteries, the presence of aberrant arterial and venous branches, renal artery stenoses and anatomy of the renal collecting system and ureters. The diagnostic value was assessed by evaluating different image processing modalities and interobserver variability. RESULTS: Using maximum intensity projections (MIP) together with multiplanar reformatting (MPR), accessory arteries were detected with a sensitivity/specificity of 100%/98%. Depending on diagnostic experience, exclusive evaluation of MIP yielded a sensitivity/specificity of 67-100%/95-100%. Using MIP/MPR, venous depiction was good in 80%, with MIP solely in 30-40%. At least the proximal third of the ureter was visible in 67%. CONCLUSION: MPR/MIP evaluation of two-phase, contrast-enhanced MRA provides an excellent depiction of renal vessel anatomy for presurgical evaluation of renal transplant donors. Exclusive MIP assessment is less reliable and depends strongly on the examiner's experience. For sufficient visualization of the ureters, either additional measurements or low-dose diuretic injection have to performed.

Real-time interactive virtual endoscopy of the tracheo-bronchial system: influence of CT imaging protocols and observer ability.

OBJECTIVE: To evaluate the influence of different spiral CT examination protocols suitable for clinical use on image quality and to assess the observer dependence in interactive real-time virtual bronchoscopy. METHODS AND PATIENTS: Real-time perspective volume rendering of the airways in twenty normal patients based on four different spiral CT examination protocols was evaluated by four observers in regard to the order of depictable bronchi. RESULTS: Best results were obtained using an examination protocol with a small beam collimation and a maximum pitch. Depending on the observer's ability to control the fly path and the orientation of the bronchi with respect to the slice plane up to sixth order bronchi could be depicted. Inter-observer variability was up to two branching orders. CONCLUSION: The performance of virtual bronchoscopy strongly depends on the applied CT examination protocol and the observers experience with perspective volume rendering. Both of which have to be taken into account when virtual bronchoscopy is compared with fiberoptic bronchoscopy.

Fast functional MRA using time-resolved projection MR angiography with correlation analysis.

Most recently, time-resolved 2D MRA after injection of a contrast agent bolus for various applications has been proposed. Similar to conventional digital subtraction angiography (DSA), 2D MR DSA offers the ability to observe the dilution of the bolus in the vascular system during the passage with a temporal resolution considerably below 1 sec. The purpose of this paper is to present strategies to improve the inherent low signal-to-noise ratio of 2D angiograms while retaining some temporal resolution. This can be achieved by applying algorithms for time series analysis as used in functional MRI. The significantly improved image quality is demonstrated on examples from clinical studies from bronchial MRA as well as cardiovascular MRA. In addition to the increased signal-to-noise ratio, correlation analysis leads to suppression of background signals and to a better discrimination of overlapping vessels. Further improvements in the temporal discrimination of vessels is afforded by the use of consecutive multiple contrast agent boli as demonstrated by numerical simulations and experiments.

Pelvic imaging with a selenium-based detector (Thoravision). Comparison with screen-film radiography in 75 patients.

OBJECTIVE: To evaluate whether the selenium detector (Thoravision) provides sufficient diagnostic confidence in digital pelvic imaging compared with a conventional screen-film combination. METHODS: In 75 patients, pelvic imaging with conventional screen-film and isodose selenium radiography using a dedicated postprocessing mode was compared independently by three radiologists. The depiction of cortical and cancellous bone was evaluated in the iliac wings, sacral and pubic bones, acetabulum, femoral head, and trochanter. Demarcation of soft tissue was assessed in the iliac and trochanteric region. RESULTS: Visualization of cortical bone and soft tissue in the iliac area as well as soft tissue and cortical and cancellous bone in the trochanteric region was significantly superior with the selenium detector. However, conventional imaging was better in the trabecular bone of the sacral region, where results with the selenium system were particularly poor. CONCLUSIONS: The selenium detector (Thoravision) is advantageous in imaging soft tissue adjacent to the iliac wings and the trochanter, but results for the cancellous sacral bone are poor. Further modifications of postprocessing modes may lead to improved depiction of this critical pelvic area.

MRI of heart morphology. Comparison of nongradient echo sequences with single- and multislice acquisition.

RATIONALE AND OBJECTIVES: A large variety of cardiac MRI sequences have been introduced for heart morphology evaluation. The aim of this study was to establish a practicable and robust examination protocol for standard high-field systems applying nongradient echo sequences with single- and multi-slice acquisition. METHODS: Fifty-one patients received electrocardiogramgated MRI of the heart with "black-blood" preparation, comparing three single-slice and three multislice sequences with a T1-weighted turbo spin echo reference sequence. Demarcation of the left ventricular myocardium and cavity and the extent of flow and motion artifacts were assessed. RESULTS: The myocardium and left ventricular cavity were depicted best with the single-slice T1- and T2-weighted turbo spin echo sequence. The nonbreath-hold multislice sequences produced marked artifacts and therefore were of poor diagnostic value. The TIRM haste sequence was best suited for fat suppression. The T2-weighted breath-hold single-shot sequence with half-Fourier imaging proved to be most appropriate for multislice imaging. CONCLUSIONS: Sufficient depiction of heart morphology with comprehensive evaluation of signal changes can be achieved using nongradient spin echo and turbo spin echo sequences with breath-holding. For rational imaging of myocardial and heart chamber morphology, multislice and single-slice sequences should be combined.