[Use of SPIO-enhanced T1- and T2-weighted images for the differentiation of liver lesions: an ROC analysis]. / Differenzierung von Leberläsionen mit SPIO-gestützten T1-w und T2-w MRT-Aufnahmen: Eine ROC-Analyse.

PURPOSE: The superparamagnetic iron oxide (SPIO) Resovist is a contrast media with shortening of both T(1) and T(2) relaxation time. This study evaluates the impact of SPIO-enhanced T(1)- and T(2)-weighted images for the differentiation of liver lesions. MATERIALS AND METHODS: SPIO-enhanced MRI examinations (1.5 T, Symphony Quantum) of 61 patients were analyzed. Thirty-seven patients had malignant liver lesions (metastases n = 32, HCC n = 5) proven by biopsy or laparotomy, 11 patients had benign liver lesions (FNH n = 2, hemangiomas n = 4, benign cysts n = 5, normal liver on laparoscopy n = 13). After unenhanced T(1)- and T (2)-weighted imaging, a bolus injection of 1.4 ml SPIO (Resovist) was given, followed by T(1)-weighted imaging at 20 s, 60 s, and 5 min and T(2)-weighted imaging at 10 min post injection. A score from 1 (benign) to 5 (malignant) was used by three blinded radiologist for the ROC analysis of the unenhanced T(1)-/T(2)-weighted images (set 1) and of the combinations of unenhanced T(1)/T(2)-weighted and SPIO T(1)-weighted images (set 2), unenhanced T(1)/T(2) and SPIO T(2)-w images (set 3) and all images (set 4). RESULTS: The accuracy of plain MRI (set 1: 56 %) was increased by SPIO-enhanced T(1)-weighted images (set 2: 81 %) and SPIO-enhanced T(2)-weighted images (set 3: 90 %). Best results were obtained using unenhanced T(1)-weighted, unenhanced T(2)-weighted and both SPIO T(1)-weighted and T(2)-weighted images (set 4: 93%). The accuracy of predicting histopathologic diagnosis was 91%. CONCLUSION: For the differentiation of liver lesions, SPIO-enhanced T(2)-weighted images had a greater impact on the accuracy of MRI than T (1)-weighted images, but SPIO-enhanced T(1)-weighted images provided additional information in some patients and should not be deleted.

[Morphology of gastrointestinal stromal tumors in advanced stages of the disease: baseline findings before chemotherapy with imatinib]. / Morphologie gastrointestinaler Stromatumoren im fortgeschrittenen Stadium der Erkrankung: Ausgangsbefunde vor Chemotherapie mit Imatinib.

PURPOSE: Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract with an increasing detection rate due to improved differentiating methods in current diagnostic pathology. This study evaluates the radiologic characteristics of these neoplasms to discover specific signs leading to an earlier diagnosis. MATERIALS AND METHODS: As part of a randomized phase III clinical trial of the European Organization for Research and Treatment of Cancer (EORTC), 72 patients with advanced stage GIST were treated with the selective tyrosine-kinase-inhibitor imatinib (Glivec, Novartis, Switzerland). For initial staging, 60 patients underwent MRI and 12 patients underwent CT. RESULTS: GISTs are mesenchymal tumors that grow submucosally and exophytically and become multiple, nodular or ovoid in the advanced stage. The predominant findings are peripheral solid structures with strong contrast enhancement and a central necrosis. Metastases are primarily located in the liver, where they appear as oval or round, sharply delineated solitary lesions with central necrosis. CT demonstrates the primary tumors and local recurrences as nearly isodense with the liver. On MRI, the lesions are hypointense on T 1 -weighted sequences and hyperintense on T 2 -weighted sequences, compared to the liver. CONCLUSION: Immunopathology now enables the exact histologic separation of GISTs from other mesenchymal tumors. The radiological morphology is not sufficiently specific to differentiate GISTs from other mesenchymal tumors. In view of new therapeutic options, cognizance of their typical manifestations is of increasing importance for radiologists.

[MRI in the diagnosis of tumors of the shoulder girdle area]. / Diagnostik von Tumoren des Schultergürtelbereichs in der MRT.

The aim of the study was to estimate the value of MRI for evaluation tumors of the shoulder girdle. We diagnosed respectively 13 patients with lesions in the shoulder region. The imaging has been done with a "Magnetom SP 63" (Siemens, Erlangen, Germany). The protocol consisted of T1- and T2-based SE-sequences in axial slice orientation, T1-based imaging in coronary respectively in sagittal slice orientation as well as T1-based sequences after application of contrast medium. The evaluation of the tumor expansion within the soft tissue was possible. The exact diagnosis in some individual cases--neurinoma, cyst of the synovia--could be found by MRI. Estimation of the dignity in the case of infiltrative growth was possible in most cases. To assess the exact type of tumor was often difficult. Especially the dignity of the cartilaginous tumors could not be precisely described.

High-resolution magnetic resonance imaging in patients with facial haemiatrophy.

The aim of this clinical study was to evaluate the use of high-resolution magnetic resonance imaging (MRI) in the diagnosis of facial haemiatrophy. A total of 14 patients with clinically suspected facial haemiatrophy were investigated using high-resolution MRI. The T1- (500/25) and T2- (2200/50) weighted images were analysed visually and numerically. The results of the affected skin portions were compared with the contralateral skin and correlated with the clinical results. The subcutis could not be delineated by high-resolution MRI in 9 patients with facial haemiatrophy. The dermis was not discernible in 6 cases and was "smooth" in a further 6 patients. The signal-to-noise ratio of affected skin portions and contralateral skin or clinical severity did not correlate. The higher the clinical severity, the more pronounced was the magnetic resonance ratio between dermis and subcutis thickness. Thus high-resolution MRI is a useful method for objective description of pathological changes in clinically suspected facial haemiatrophy.

[How can Romberg disease be evaluated by means of MRI?]. / Was bringt die Magnetresonanztomographie in der Beurteilung der Romberg-Erkrankung?

Romberg disease, also known as progressive facial hemiatrophy (PFH), is an uncommon disease with progressive facial asymmetry as the major symptom. It is a atrophic process of the subcutaneous fatty tissue whose etiology is unknown. Skin, muscles and bones can be secondarily afflicted. With MRI evaluation we were able to show in 14 patients with PFH thinner subcutaneous fat, as well as flattening of the dermis in 12 of the 14. We divided the patients into three stages by the means of the MRI findings and found tendency towards concurrence between the MRI stage and the clinical stage.

An experimental high-resolution MR coil for the imaging of pathological findings in the post mortem brain stem.

PURPOSE: The purpose of this study was to evaluate the potential of an experimental coil using a whole-body MR unit to delineate pathological changes within formalin-fixed human brain stems. MATERIAL, METHODS, AND RESULTS: The MR images of 9 brain stems were compared with gross anatomy and corresponding histological sections. The resolution of the images was high enough to depict areas of clinically relevant pathological alterations.

[Ultrasound detection of breast cancer with normal mammogram]. / Sonographischer Nachweis des Mammakarzinoms bei unauffälliger Mammographie.

In eleven patients with breast cancer the diagnosis was made by using ultrasound as the only method. In none of the patients could mammography show the malignoma. Although six of the patients underwent additional tube X-ray investigation, no radiological criteria of malignancy were found on the mammograms. In ten patients a lump of the breast was palpable and/or retraction of the skin was visible. In one woman, neither the clinical investigation nor the mammography could reveal the tumor. The ultrasound of the breast is a indispensable and useful method for diagnosing breast cancer.