H.-J. Brambs

MRI in the diagnosis of small bowel disease: use of positive and negative oral contrast media in combination with enteroclysis.

Abstract. The aim of the study was to evaluate the additional findings of MRI following small bowel enteroclysis and to compare the efficacy of negative and positive intraluminal contrast agents. Fifty patients with inflammatory or tumorous small bowel disease were investigated by small bowel enteroclysis and consecutive MRI using breathhold protocol (T1-weighted fast low-angle shot, T2-weighted turbo spin echo). Patients were randomly assigned to either receiving a positive oral (Magnevist, Schering, Berlin, Germany) or a negative oral MR contrast media (Abdoscan, Nycomed, Oslo, Norway). The pattern of contrast distribution, the contrast effect, presence of artifacts, as well as bowel wall and extraluminal changes, were determined and compared between the contrast type using Fischers exact test. Sensitivity, specificity, and diagnostic accuracy for MRI and enteroclysis were calculated. Twenty-seven patients had clinically proven Crohns disease and two patients surgically proven small bowel tumours. Magnetic resonance imaging had important additional findings as abscesses and fistulae in 20 patients. Surgically compared sensitivities were 100 and 0 % for MRI and enteroclysis, for the detection of abscesses, and 83.3 and 17 % for the diagnosis of fistulae, respectively. Bowel wall thickening was more reliably detected with use of positive oral contrast media without intravenous enhancement (p < 0.001), whereas postcontrast negative oral contrast media allow for a superior detection (p < 0.001). T2-weighted sequences were necessary with use of negative oral contrast media, because loop abscesses may be masked. Magnetic resonance imaging should be performed in all patients with suspicion of extraintestinal complications, because the complications are more reliably detected by MRI. Negative oral contrast media show advantages with the use of intravenous contrast but can mask loop abscesses using only T1-weighted imaging.

Diagnostic imaging in Crohn's disease: comparison of magnetic resonance imaging and conventional imaging methods.

Abstract Conventional enteroclysis remains the method of choice in the diagnosis of inflammatory small bowel disease. The reported sensitivity rates, however, for the diagnosis of extraintestinal processes, such as fistulae and abscesses, are moderate. Computed tomography (CT) is the method of choice for the diagnosis of extraintestinal complications. The anatomical designation of the affected bowel segment may, however, prove difficult due to axial slices, and the applied radiation dose is high. The use of magnetic resonance imaging (MRI) in the diagnosis of inflammatory small bowel disease is a relatively new indication for the method; prerequisites were the development of breathhold sequences and phased array coils. Optimized magnetic resonance tomographic imaging requires a combined method of enteroclysis and MRI, which guarantees an optimal filling and distension of the small bowel. The high filling volume leads to a secondary paralysis of the small bowel and avoids motion artifacts. In a trial of 84 patients with histological and endoscopic correlation the sensitivity in diagnosing inflammatory bowel disease was 85.4% for enteroclysis and 95.2% for MRI, and the specificity was 76.9% for enteroclysis and 92.6% for MRI. As none of the abscesses was diagnosed with enteroclysis, the sensitivity was 0% for enteroclysis, but 77.8% for MRI. The sensitivity in diagnosing fistulae was 17.7% for enteroclysis and 70.6% for MRI. In summary, MRI can detect the most relevant findings in patients with inflammatory small bowel disease with an accuracy superior to that of enteroclysis.

MRI of histologically confirmed mammary carcinoma : Clinical relevance of diagnostic procedures for detection of multifocal or contralateral secondary carcinoma

PURPOSE MR mammography (MRM) is a sensitive diagnostic method for the detection of mammary carcinomas. The present study evaluates whether MRM can yield additional relevant data in cases of histologically confirmed mammary carcinoma. METHOD Thirty-four patients with histologically confirmed mammary carcinoma were examined at MRM using a T1-weighted GE sequence and a T2-weighted SE sequence. Morphologic criteria and the dynamic contrast medium behavior of the tumors were evaluated. RESULTS MRM showed a 100% sensitivity and diagnostic accuracy in the detection of mammary carcinomas. Additionally, three unexpected contralateral carcinomas were discovered. In 26 patients, there was a multifocal or multicentric tumor process. In 24 patients, peritumoral edema was visualized, which corresponded histologically in 21 patients with lymphangiosis and in 3 with an inflammatory peritumoral reaction. CONCLUSION Because of its high sensitivity in the diagnosis of multifocal disease and of contralateral carcinomas, MRM would seem to represent a useful addition to preoperative diagnostic procedures. The potential benefit to the patient and its cost efficiency, however, remain to be clarified.

Embolization for gastrointestinal hemorrhages

Abstract. Retrospective evaluation of interventional embolization therapy in the treatment of gastrointestinal hemorrhage over a long-term observation period from 1989 to 1997. Included in the study were 35 patients (age range 18–89 years) with gastrointestinal bleeding (GI) referred for radiological intervention either primarily or following unsuccessful endoscopy or surgery. Sources of GI bleeding included gastric and duodenal ulcers (n = 7), diverticula (n = 3), erosion of the intestinal wall secondary to malignancy (n = 6), vascular malformations (n = 4), and hemorrhoids (n = 2), as well as from postoperative (n = 6), posttraumatic (n = 2), postinflammatory (n = 4) or unknown (n = 1) causes. Ethibloc (12 cases) or metal coils (14 cases) were predominantly used as embolisates. In addition, combinations of tissue adhesive and gelfoam particles and of coils and Ethibloc were used (six cases). Finally, polyvinyl alcohol particles, a coated stent, and an arterial wire dissection were utilized in one case each. Bleeding was stopped completely in 29 of 35 cases (83 %). In one case (3 %) the source of bleeding was recognized but the corresponding vessel could not be catheterized. In five other cases (14 %) there was partial success with reduced, though still persistent, bleeding. The rate of complications was 14 %, including four instances of intestinal ischemia with fatal outcome in the first years, and, later, one partial infarction of the spleen without serious consequences. Gastrointestinal hemorrhage can be controlled in a high percentage of patients, including the seriously ill and those who had previously undergone surgery, with the use of minimally invasive interventional techniques. The availability of minicoils instead of fluid embolization agents has reduced the risk of serious complications.

Is a preoperative multidiagnostic approach to predict surgical resectability of periampullary tumors still effective

BACKGROUND Multimodality staging is recommended in patients with periampullary tumors to optimize preoperative determination of resectability. We investigated the potency of currently used diagnostic procedures in order to determine resectability. METHODS Ninety-five consecutive patients with periampullary tumors prehospitally staged resectable underwent preoperative diagnostic tests: helical-computed tomography (CT) with maximum intensity projection of arterial vessels (MIP), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreaticography (MRCP), endoscopic ultrasonography (EUS), endoscopic retrograde cholangiopancreaticography (ERCP), digital subtraction angiography (DSA), and positron emission tomography (PET). Diagnoses were verified by surgery and histopathology. RESULTS In 45 patients with benign and 50 patients with malignant periampullary tumors sensitivity for tumor diagnosis was 89% to 96% in CT, MRI, EUS, and PET. Small tumors were best diagnosed by EUS (100%). Diagnosis of malignancy was made with 85% (EUS), 83% (CT), 82% (PET), and 72% (MRI) accuracy. Arterial vessel infiltration was best predicted by CT/MIP with an accuracy of 85%. For venous vessel infiltration MRI reached 85% accuracy. Accuracy rates for local nonresectability were 93% (EUS), 92% (MRI), and 90% (CT). Two and 4 of 8 patients with distant metastases were identified by CT and PET, respectively. The correct diagnosis of malignancy and determination of resectability was made by CT in 71% and by MRI in 70%. Biliary stenting reduced accuracy of CT diagnosis of malignancy from 88% to 73%. CONCLUSIONS CT obtained before stenting was the single most useful test, providing correct diagnosis in 88% and resectability in 71% of patients. If no tumor is depicted in CT, EUS should be added. Uncertain venous vessel infiltration can be verified by MRI or EUS. Angiography should no longer be a routine diagnostic procedure. Equivocal tumors or possible metastasis may be further examined with PET.

Solid-pseudopapilläre Tumoren des Pankreas

Summary. We report on three female patients with solid pseudopapillary tumors of the pancreas. The histogenetic origin of this entity is still unclear. The tumor, usually occurring in young women, forms large masses (up to 10 cm in diameter) before becoming symptomatic. Metastases have very rarely been reported. In contrast to other pancreatic tumors, the main pancreatic duct was displaced, but of normal caliber without stenosis, in all our patients. Despite the large size of the tumors, they were curatively resected in all three cases. Two of the tumors infiltrated the parenchyma or adipose tissue of the pancreas but did not spread into the lymph nodes or other organs. All of the patients are alive and without signs of tumor recurrence up to 8 years after surgical resection.Zusammenfassung. Wir berichten über unsere Erfahrungen an 3 Patientinnen mit einem solid-pseudopapillären Tumor des Pankreas. Charakteristisch für diesen semimalignen Tumor sind das Vorkommen bei jungen Frauen, die auffallende Größe (bis 10 cm) und das seltene Auftreten von Metastasen. Trotz erheblicher Größe der Tumoren war in allen Fällen eine kurative Resektion möglich. Präoperatives Hauptunterscheidungsmerkmal zum duktalen Adenocarcinom war in allen Fällen die normale Weite des Pankreasgangs ohne Gangabbruch. Im Gegensatz zu den meisten anderen Tumoren des Pankreas hat dieser Tumor eine gute Prognose. Alle unsere Patientinnen sind z. Z. (bis zu 8 Jahren nach der Operation) rezidivfrei.Schlüsselwörter: Solid-pseudopapillärer Tumor – Pankreas – papillär-cystischer Tumor

Relevant imaging findings of cerebral aspergillosis on MRI: a retrospective case‐based study in immunocompromised patients

The aim of the study was to assess neuroimaging patterns of cerebral aspergillosis with magnetic resonance imaging (1.5 T). The clinical and imaging data of nine patients were reviewed. Patients were included in the study if the diagnosis of aspergillosis was confirmed by either biopsy, autopsy, aspergillus antigen determination and/or neuroradiological and clinical response to specific treatment. Four patients had single or multiple abscesses presenting as ring‐enhancing lesions on T1‐weighted images, hypointensity of the ring on T2‐weighted MR images and low to high signal intensity on diffusion‐weighted imaging. Four patients had single or multiple infarctions affecting all compartments of the brain with hyperintensities on T2‐weighted images in three of four patients, irregular parenchymal contrast enhancement in all patients and hemorrhagic transformation of the infarcted parenchyma in one patient. Diffusion‐weighted images were positive in all ischemic areas. One patient with paranasal sinusitis developed a mycotic aneurysm of the internal carotid artery. Cerebral aspergillosis presents three principal neuroimaging findings: areas consistent with infarction; ring lesions consistent with abscess formation following infarction; and dural or vascular infiltration originating from paranasal sinusitis or orbital infiltration. Recognition of these patterns in cerebral aspergillosis may lead to more timely and effective diagnosis and treatment.

Short-term Results with Use of the Amplatz Thrombectomy Device in the Treatment of Acute Lower Limb Occlusions☆

PURPOSE To evaluate the clinical efficacy of the Amplatz device for the treatment of acute occlusions of the lower limb arteries. MATERIALS AND METHODS Forty patients with acute occlusion of the lower limb arteries (3 hours to 8 days; mean, 2 days) were treated using the Amplatz clot macerator. Acute thrombotic lower limb occlusion was due to an embolic event in 32 patients and to atherosclerotic disease in eight patients. RESULTS Complete success, with complete clearing of thrombotic material without an adjunctive procedure, was achieved in 75% (30 of 40) of the patients. Mean thrombectomy time in these patients was 75 seconds. Partial success, with incomplete clearing of the thrombus, requiring additional procedures such as local thrombolysis, angioplasty, or atherectomy, was achieved in 20% (eight of 40) of the patients. The Doppler index increased significantly (P < .001) from .45 before intervention to .96 after intervention. There were two failures (5%). No major complications occurred. CONCLUSION Mechanical thrombectomy with use of the Amplatz device is a promising approach for quick recanalization of acute peripheral thromboembolic occlusions. Further studies are needed to prove the long-term patency after mechanical thrombectomy with use of this device.

Value of Mr Mammography in the Detection and Exclusion of Recurrent Breast Carcinoma

PURPOSE This is a study of 140 patients undergoing MR mammography (MRM) for evaluation of possible local recurrent disease following breast-conserving surgical treatment of mammary carcinoma. MRI was performed 1-228 months (mean 28.3 months) postoperatively. METHOD MRM and interpretation of the dynamic measurements were performed in a standardized manner after positioning the patient in a double breast coil. A GRE sequence (Flash 3D, TE 5 ms, TR 12 ms, FA 25 degrees) was acquired before and 1, 2, 3, and 8 min after intravenous injection of Gd-DTPA in a dose of 0.15 mmol/kg body wt. RESULTS Recurrent disease was excluded in 82.8% of cases with MRM. In another 13.6% of patients, MRM was able to reliably detect recurrence of malignancy. In five cases (3.6%), MRM returned false-positive results. CONCLUSION MRM is a sensitive method for detecting or excluding recurrence of malignant disease. It remains to be determined whether early detection of recurrent disease can contribute significantly to improving the prognosis in these patients.

MRI of the abdomen with positive oral contrast agents for the diagnosis of inflammatory small bowel disease.

Magnetic resonance imaging (MRI) is being used more often in the evaluation of inflammatory bowel diseases. A prerequisite for adequate image quality is the oral application of contrast medium, which can be administered with different modalities. Positive and negative oral contrast media can be used; in terms of diagnostic efficacy, there appears to be no relevant differences between them. Sequences usually are acquired using breath-hold or respiration-triggered protocols. The underlying principle is visualization of circumscribed thickening of the intestinal wall, which shows a pathologic pattern of contrast medium uptake. The available data suggest that MRI is equally as effective as enteroclysis in the primary diagnosis of Crohns disease and actually more sensitive in the detection of extraintestinal manifestations such as fistulae or abscesses. Supporters of the method predict that MRI will replace enteroclysis in the long term.