[Rare differential diagnosis on suspected liver tumor]. / Seltene Differenzialdiagnose bei Verdacht auf Lebertumor.

This case report describes a 77-year old woman with a leiomyosarcoma of subhepatic inferior caval vein. The presented symptom was unspecific abdominal pain. Ultrasound and CT suggested a primary liver tumor. MRI revealed retroperitoneal location of the neoplasm. The tumor was resected completely and ICV was replaced by a PTF-graft. Vascular leiomyosarcoma is a rare tumor entity, which often is diagnosed in advanced stage. Depending on location it can be mistaken for neoplasms of other organs.

Therapy of hepatocellular carcinoma with 131I-lipiodol: patient dosimetry.

AIM: Dosimetry in (131)I-lipiodol therapy for hepatocellular carcinoma (HCC) in the hitherto largest existing patient cohort. PATIENTS, METHODS: 38 courses of intra-arterial (131)I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC. Liver and tumour volume were measured by computed tomography (CT) and (131)I-activity by scintigraphy on day 3, 6, 14, 28 and 42 after injection. Lipiodol deposition in tumour nodules as shown by CT rendered definite attachment to scintigraphic data possible. The radiation dose in tumour nodules, liver and lungs was calculated according to the MIRD concept and the tumour dose related to pre-therapeutic tumour volume, response and survival. RESULTS: Mean tumour dose was 23.6 +/- 3.6 Gy (14.2 +/- 2.1 mGy/MBq) with maximal 162 Gy (90.1 mGy/MBq) after one and 274 Gy after three courses. The dose to nontumourous liver was 1.9 +/- 0.2 Gy (1.2 +/- 0.1 mGy/MBq) and the mean dose ratio of tumour / nontumourous liver 11.1 +/- 1.7 (max. 82). The pulmonary dose was 25.9 +/- 1.8 mGy (16.3 +/- 1.2 microGy/MBq) and therefore much lower. There was a reciprocal relation between tumour dose and pretherapeutic tumour volume. Tumour dose had no effect on response or survival. CONCLUSION: High radiation doses are particularly in small tumour nodes achievable but not necessarily related to tumour response. The dose of non-tumourous liver and lungs is much lower.

Therapy of hepatocellular carcinoma with iodine-131-lipiodol. Results in a large German cohort.

AIM: To evaluate the efficacy and tolerance of iodine-131-lipiodol ((131)I-lipiodol) for hepatocellular carcinoma (HCC) in German long term patients and comparison with medically treated controls. PATIENTS, METHODS: 38 courses of intra-arterial (131)I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC (6 with portal vein thrombosis). Liver and tumour volume and lipiodol deposition were measured by computed tomography and (131)I activity by scintigraphy. Therapeutic efficacy was determined by tumour volume change and matched-pairs analysis in comparison to medically (i.e. tamoxifen or medical support) treated patients. RESULTS: Tumour volume decreased in 20/32 index nodules (63%) after the first course. Repeated therapy frequently resulted in further tumour reduction. Overall response to treatment was partial in 11 nodules, minor response in 4 nodules, and disease was stable in 12 and progressive in 5. Significant response was associated with pretherapeutic nodule volume up to 150 ml (diameter of 6.6 cm). Survival rate after 3, 6, 9, 12, 24 and 36 months was 78, 61, 50, 39, 17, and 6%. Matched-pairs analysis of survival revealed (131)I-lipiodol to be superior to medical treatment. The most important side effect was a pancreatitis-like syndrome whereas overall tolerance was good. CONCLUSION: The long term results confirm that HCC therapy with (131)I-lipiodol is effective and probably superior to medical treatment. Tumour nodules of up to 6 cm diameter are well suited for this therapy even in the presence of portal vein thrombosis.

[Ruptured aortoiliac aneurysm with AV-fistula]. / Rupturiertes aortoiliakales Aneurysma mit AV-Fistel -- Seltene Ursache einer akuten einseitigen Beinschwellung.

HISTORY AND ADMISSION FINDINGS: A 65-year-old man presented an acute swelling of the left leg as the main sign. A pulsatile bruit could be auscultated over the abdomen. INVESTIGATIONS: Doppler ultrasound suggested an aortic aneurysm with fistula. Dynamic bolus-triggered computed tomography demonstrated an aortoiliac aneurysm with a fistula into the confluence of the common iliac veins. TREATMENT AND COURSE: An aorto-iliac graft was inserted surgically and and the patient recovered well. CONCLUSION: In patients with an acute swelling of a lower limb an aorto-iliac aneurysm, though a rare cause, should be considered.

Magnetic resonance imaging analysis of anterior and posterior eye segment displacement during ocular gaze shifts.

PURPOSE: To determine the relationship between movements of the posterior and anterior eye segments during arbitrary gaze shifts and to obtain information for monitoring fixation during radiotherapy for ocular diseases. METHODS: We examined eye movements of ten emmetropic volunteers in a 1.5 T magnetic resonance system. Using a T2-weighted ultrafast turbo-spin echo sequence (UTSE), the eyes were examined within 21 seconds. Sagittal and transversal eye slices were obtained in five passages in five gaze directions (straight ahead, 15 degrees above, 15 degrees below, 15 degrees right and 15 degrees left of the primary position). Displacement of the posterior eye segment was analyzed in relation to the movement of the anterior segment in all directions. RESULTS: The relationship between the movements of the anterior and posterior eye segment was 1:0.8 (+/- 0.06 SD) during horizontal gaze shifts and 1:1.16 (+/- 0.11 SD) during vertical gaze shifts. CONCLUSIONS: Magnetic resonance imaging showed that the relationship between anterior and posterior eye segments was different during horizontal and vertical eye movements, indicating the presence of more than one center of rotation. Compared to the anterior eye segment, there was less displacement of the posterior eye segment during horizontal eye movements and more displacement during vertical eye movements.

Three-dimensional magnetic resonance cholangiopancreatography with respiratory triggering in the diagnosis of primary sclerosing cholangitis: comparison with endoscopic retrograde cholangiography.

BACKGROUND AND STUDY AIMS: The purpose of this study was to evaluate the accuracy of respiratory-triggered three-dimensional magnetic resonance cholangiopancreatography (3D-MRCP) for the detection of primary sclerosing cholangitis (PSC) and to compare the specific findings of magnetic resonance cholangiography and endoscopic retrograde cholangiography in patients with PSC. PATIENTS AND METHODS: The MRCP findings were evaluated in 150 patients with clinical symptoms (progressive fatigue, pruritus followed by icterus) and/or elevated values for alkaline phosphatase and serum aspartate transaminase, and occasionally an elevated serum concentration of bilirubin as a sign of cholestasis, who were consecutively referred for magnetic resonance imaging. Two observers independently classified bile duct abnormalities and established the MRCP diagnosis in a consensus reading. The results of MRCP were compared with the definitive diagnosis, which was based on the clinical history and laboratory and histological data, as well as on endoscopic retrograde cholangio-pancreatography (ERCP) findings. In a second step, the observers compared the delineation of the biliary system and morphological findings using MRCP and ERCP in patients with confirmed PSC. RESULTS: Diagnostic examinations were obtained in 146 of the 150 MRCPs (97 %). The diagnosis of PSC was confirmed by clinical data and ERCP in 34 of these 150 patients (23 %). The sensitivity and specificity of MRCP for diagnosing PSC were 88 % (29 of 33) and 99 % (108 of 109), respectively. MRCP and ERCP yielded similar scores for the delineation of the biliary system (P = 0.2) in patients with PSC. However, different bile duct abnormalities leading to the diagnosis of PSC were depicted by MRCP and ERCP; more bile duct stenoses and pruning were seen with ERCP and more skip dilatation with MRCP (P < 10(-4)). CONCLUSION: In patients with PSC, MRCP is a highly sensitive method and its diagnostic accuracy is comparable to that of ERCP.

Multimodal target point assessment for stereotactic biopsy in children with diffuse bithalamic astrocytomas.

INTRODUCTION: Diffuse glial tumors with bithalamic involvement are rare in children. Diagnostic assessment can be difficult as the radiological findings can be unspecific. MATERIALS AND METHODS: In order to enhance the diagnostic yield metabolic imaging with MRS and PET using FET ( O-(2-[(18)F]fluoroethyl)- L-tyrosine) was performed in two children (2 and 10 years of age). Co-registered images were used for image-guided biopsy, which was planned with neuronavigation and stereotaxy simultaneously. RESULTS: Biopsies from the right thalamus were planned, but locations were changed in both cases after metabolic imaging was available. MRS (thalamic voxel) was typical for a glial tumor in one child. In the older girl FET-PET revealed an unexpected lesion in the left cerebellar hemisphere, with a tumor-to-cortex ratio of 3.8, as against 1.7 in the thalamus. Accordingly, a stereotactic biopsy specimen was taken from the left cerebellar hemisphere, and a final diagnosis of anaplastic astrocytoma was made. The other patient showed a higher uptake (tumor-to-cortex ratio 1.6) in the left dorsal thalamus, compared with bilateral homogeneous hyperintensity of the thalamus structures on MRI. Stereotactic biopsy revealed a low-grade diffuse astrocytoma. CONCLUSION: Stereotactic biopsy using metabolic imaging and image fusion can enhance the diagnostic yield in cases of diffuse pediatric gliomas disclosing unexpected 'hot spots'.

Improving the detectability of focal liver lesions on T2-weighted MR images: ultrafast breath-hold or respiratory-triggered thin-section MRI?

The purpose of this study was to determine whether a respiratory-triggered (RT) T2-weighted turbo spin-echo (TSE) sequence with thin section can improve the detectability of focal liver lesions compared to a breath-hold (BH) T2-weighted TSE sequence. In 25 patients an RT TSE with 8-mm sections (8-TSE RT) and 5-mm sections (5-TSE RT) and a BH TSE sequence with 8-mm sections (8-TSE BH) were performed. Forty-one focal liver lesions (mean: 1.8 +/- 1.2 cm; 14 lesions < or =1 cm; 27 lesions >1 cm) were evaluated. The 5-TSE RT was significantly better in lesion detection compared to the 8-TSE BH sequence for all sizes of lesions (40/41 vs. 33/41; P = 0.014). For lesions >1 cm no relevant differences in the detection rate of the sequences were found (8-TSE RT, 26/27; 5-TSE RT, 26/27; 8-TSE BH, 25/27), for lesions < or =1 cm the 5-TSE RT provided significantly better sensitivity than the 8-TSE BH (14/14 vs. 8/14, P = 0.015). The results of this study suggest that lesion detection could be significantly improved by using an RT TSE sequence with thin sections compared with a BH TSE sequence.

Fibrinolytic preflush upon liver retrieval from non-heart beating donors to enhance postpreservation viability and energetic recovery upon reperfusion.

BACKGROUND: Our objective was to evaluate graft equilibration with high viscosity (University of Wisconsin solution [UW]) or low viscosity (Bretschneider's histidine-tryptophan-ketoglutarate [HTK]) during liver procurement from non-heart beating donors (NHBD) and the potential impact of a preceding fibrinolysis with streptokinase on postpreservation viability. METHODS: After 60 min of cardiac arrest, rat livers were perfused by gravity (60 cm H2O) via the portal vein with either 60 ml of HTK, 20 ml of UW, or 20 ml of Ringer's solution (22 degrees C including 7500U of streptokinase) and, subsequently, 20 ml of UW. After 24 h of storage at 4 degrees C, viability of the livers was assessed upon isolated reperfusion in vitro. RESULTS: Magnetic resonance imaging revealed severe perfusion deficits, which were mildly attenuated with HTK, upon flush-out with UW. After preflush with streptokinase, a mostly homogenous distribution of the preservation solution was observed throughout the liver tissue. The choice of the flush-out solution (UW or HTK) had no influence on parenchymal enzyme leakage, hepatic bile production, or tissue levels of ATP after reperfusion of the livers. Fibrinolytic preflush, however, resulted in a relevant and significant improvement of structural integrity as well as functional and metabolic recovery. CONCLUSIONS: Compromised vascular tissue perfusion upon organ harvest in NHBD triggers graft dysfunction after cold storage and can easily be circumvented by temporary fibrinolysis before graft retrieval.

[Incidence and significance of small focal liver lesions in MRI]. / Häufigkeit und Bedeutung von kleinen fokalen Leberläsionen in der MRT.

PURPOSE: Analysis of the frequency and significance of small focal liver lesions (< or = 2 cm) detected on MRI in the presence or absence of a history of malignancy. METHODS: 628 MRI examinations of the liver performed during 1994-1996 were evaluated. The inclusion criterion into the study was the detection of a focal liver lesion with a size < or = 2 cm. The frequency, the size, the diagnostic proof, and the differential diagnosis of the focal liver lesions were analysed with regard to the patients history of a known malignant tumor. RESULTS: Overall, 179 of the 628 patients (28.5%) had focal liver lesions < or = 2 cm (n = 338). 58.9% of the lesions could be classified based upon follow-up studies by ultrasound, CT or MRI, or by biopsy. The remaining 41.1% of the lesions could not be classified due to the absence of follow-up examinations. 57.3% of all proven lesions were benign and 42.7% were malignant. A history of a malignant tumor was present in 76.7% of all patients with small liver lesions; however, lesions were benign in these patients in 50.6% of the cases. In patients with no known history of a malignancy, 75% of the lesions were benign and 25% were malignant. However, these malignant lesions were in 10/11 cases hepatocellular carcinomas in patients with liver cirrhosis. CONCLUSION: Even in the presence of a history of a malignant tumor, about 50% of the detected small liver lesions on MRI are benign. In the absence of a tumor history the probability of a small malignant liver lesion is very low, if the patients does not have liver cirrhosis where small hepatocellular carcinomas can be present.

[Pulse triggering for improved diffusion-weighted MR imaging of the abdomen]. / Kardiale Triggerung zur verbesserten abdominellen MR-Diffusionsbildgebung.

PURPOSE: The aim of this work was to reduce the influence of motion on diffusion-weighted MR images of the abdomen by pulse triggering of single-shot sequences. METHODS: Five healthy volunteers were examined both without and with finger pulse-triggering of a diffusion-weighted single-shot echo planar MR imaging sequence at 1.5 T. Series of diffusion-weighted images were acquired at different phases of the cardiac cycle by varying the time delay between finger pulse and sequence acquisition. The measurements were repeated three times. The diffusion weighted images were analysed by measuring the signal intensities and by determining the ADC values within the spleen, kidney and liver. RESULTS: The magnitude of motion artifacts on diffusion weighted images shows a strong dependence on the trigger delay. The optimum trigger delay is found to be between 500 and 600 ms. For these values the abdominal organs appear homogeneous on all diffusion weighted images and the strongest signal intensities are detected. At optimum triggering the accuracy of the apparent diffusion coefficients is up to 10 times better than without triggering. Moreover, the standard deviation of the repeated measurements is smaller than 12% for all volunteers and for all organs. Without triggering the standard deviation is larger by a factor of 4 on average. CONCLUSION: Pulse triggering of single-shot sequences leads to significant reduction of motion related artifacts on diffusion weighted images of the abdomen and provides more accurate and reproducible ADC values.

Detection of thrombosis in the portal venous system: comparison of contrast-enhanced MR angiography with intraarterial digital subtraction angiography.

PURPOSE: To determine whether intraarterial digital subtraction angiography (DSA) can be replaced by contrast material-enhanced magnetic resonance (MR) angiography in the assessment of patency or thrombosis of the portal venous system in patients with portal hypertension. MATERIALS AND METHODS: Thirty-six patients with portal hypertension underwent contrast-enhanced MR angiography and intraarterial DSA for assessment of the portal venous system. The images were evaluated for vessel patency or thrombosis of the portal, splenic, or superior mesenteric vein. RESULTS: Of the 101 vessels evaluated, 42 were thrombosed. Overall sensitivity, specificity, and accuracy for the detection of thrombosis were 100%, 98%, and 99%, respectively, for MR angiography and 91%, 100%, and 96%, respectively, for DSA; differences between the imaging methods were not statistically significant. Only in four patients with six vessels (6%) were there discordant findings between MR angiography and DSA. CONCLUSION: Noninvasive contrast-enhanced MR angiography has the potential to replace intraarterial DSA as the standard method to assess the whole portal venous system.

Multiple macroregenerative nodules in liver cirrhosis due to Budd-Chiari syndrome. Case reports and review of the literature.

Clinical, radiological, histological and immunohistochemical methods were used to define the nature of multiple rapidly growing hepatic nodules in 2 young patients with Budd-Chiari syndrome due to myeloproliferative diseases. In one patient, the arterial hyperperfusion of large nodules was demonstrated by dynamic computed tomography and angiography. The explanted livers of these patients showed multiple well-demarcated nodules up to 3 cm in diameter on the background of liver cirrhosis resulting from chronic hepatic congestion. Histologically, these nodules covered a spectrum ranging from adenoma-like lesions to nodules resembling focal nodular hyperplasia. They consisted of essentially normal hepatocytes, and variably contained fibrous septa including neoductules and large, mostly dysmorphic arteries. Sometimes, they were located close to still patent or recanalized veins. These rapidly growing hepatic nodules are best defined as macroregenerative nodules. The knowledge of this entity may help the physician to avoid misinterpretation of such nodules as carcinomas.

[The pathological/MR tomographic correlation and differential diagnosis of malignant kidney tumors]. / Pathologisch/MR-tomographische Korrelation und Differentialdiagnose von malignen Nierentumoren.

PURPOSE: Evaluation of malignancy criteria in MRT of kidney tumors in correlation with the histopathological findings. MATERIALS AND METHODS: 41 patients with suspected malignant kidney tumors were examined using a T1 SE sequence (TR/TE 300/10 ms) before and after i.v. administration of 0.1 mmol/kg Gd-DTPA and a T2 SE sequence (TR/TE 5500/150 ms). The results were correlated with the pathological findings. RESULTS: 38 malignant tumors were found: 29 renal cell carcinomas (RCC), 13 with solid growth, 11 with tubulopapillary growth, and three with mixed growth forms, one cystic RCC, and one chromophobic RCC, in addition, 6 urothelial carcinomas and three other malignomas. Typical MRT criteria for RCC were an inhomogeneity of the tumor with regions of slightly increased signal intensity on the T1-weighted image (59%) and regions with reduced signal intensity on the T2-weighted image (96%) as compared with renal parenchyma; these were due to histomorphological hemorrhage and hemosiderin deposits, respectively. A further criterion for RCC was a hypointense pseudocapsule in the T2 TSE sequence in 79% of the cases. CONCLUSIONS: The low-signal nature of RCC in the T2-weighted image correlates with hemorrhage and hemosiderin deposits. The detection of a pseudocapsule is useful in the differential diagnosis of solid tumors in the kidney.

[Spiral CT of the head-neck area: the advantages of the early arterial phase in the detection of squamous-cell carcinomas]. / Spiral-CT der Kopf-Hals-Region: Vorteile der arteriellen Frühphase bei der Detektion von Plattenepithelkarzinomen.

PURPOSE: To determine if scanning in the arterial phase improves detection of squamous cell carcinomas in the pharynx and larynx. METHODS: In a prospective clinical study 20 patients with a pharyngeal or laryngeal carcinoma were examined with by spiral CT. 80 ml lopromid were intravenously injected as a bolus with a rate of 3 ml/sec. Two consecutive spiral CT scans were performed with start-delay times of 20 and 70 seconds respectively. Delineation and contrast enhancement of tumours, cervical lymph nodes and vessels were evaluated. The radiodensities (HU) of tumors, lymph nodes vessels, pharyngeal wall and muscle were measured. RESULTS: Comparing early and late start delay time scans tumor assessment in the early phase was better in 58%, less in 16% and equal in both scans in 26%. 82% of the pathologic lymph nodes had more peripheral enhancement than surrounding muscle tissue. During the arterial phase the measured radiodensities of the common carotid artery and jugular vein were significantly higher than in the second phase. CONCLUSION: Contrast-enhanced special CT permits accurate morphologic assessment (size, infiltration) of pharyngeal and supraglottic laryngeal squamous cell carcinoma, while pathologic lymph nodes already have a sufficient contrast enhancement for the detection.

[3D-TSE MR cholangiopancreatography with breath triggering to clarify unclear hepatopathies in children]. / 3D-TSE MR-Cholangiopankreatikographie mit Atemtriggerung zur Abklärung von unklaren Hepatopathien bei Kindern.

PURPOSE: Evaluation of 3D-TSE MR-cholangiography with respiratory triggering in the work up of hepatopathies in infants and young children. PATIENTS AND METHOD: 16 infants (4-16 years) with increased transaminases, two with recurrent pancreatitis, were examined at 1.5 T (ACS-NT II, Philips Medical Systems) using a 3D-TSE MRCP with respiratory triggering in addition to a regular MRI of the liver. The MRCP was compared to ERCP. Two radiologists and one gastroenterologist evaluated the technical quality, visualization of the pancreaticobiliary system, and the diagnostic value of the examinations. RESULTS: Technically feasible were 14/16 MRCPs and 13/16 ERCPs. Two MRCP were not of diagnostic value due to motion artifacts and in three ERCP cannulation of the papilla was not possible. 14/16 ERCP required general anaesthesia, while MRCP needed i.v. sedation in two patients only. Extrahepatic ducts/cystic duct/pancreatic duct were visualized in 14/12/8 patients using MRCP, and in 13/10/3 patients using ERCP, both without adverse effects or complications. Intrahepatic ducts were better delineated with MRCP. In 10 patients with histologically proven periportal fibrosis (n = 7) and liver fibrosis (n = 1) or antineutrophil cytoplasmatic antibodies and associated inflammatory bowel disease, MRCP and ERCP revealed pathological results. CONCLUSION: MRCP using a 3D-TSE sequence with respiratory triggering is a good non-invasive technique for delineation of the biliary tract in infants and young children for the work up to hepatopathies.

Infantile fibromatosis of the neck with intracranial involvement: MR and CT findings.

CT and MR imaging studies were performed in a 3-year-old boy with infantile fibromatosis arising from the infratemporal fossa and extending into the middle cranial fossa. On CT scans, the lesion was hyperattenuating (44-49 Hounsfield units [HU]), enhancing significantly after application of contrast material (63-66 HU). The MR images showed a multilobulated lesion of heterogeneous signal intensity. The tumor was markedly hypointense on T2-weighted images and slightly hypointense on T1-weighted images relative to brain tissue, iso- or slightly hyperintense relative to tongue muscle on both T2- and T1-weighted images, and enhanced strongly after administration of gadopentetate dimeglumine.