Sacral pseudomeningocele and Marfan's disease. One case.

The authors report a case of sacral pseudomeningocele discovered by chance in a 29-year old male patient presenting with Marfan's disease. In this disease, such abnormalities are common and due to excessive fragility. of the dura mater. CT and MRI provide an accurate morphological analysis and a complete evaluation of lumbosacral osteomeningeal abnormalities.

Contribution of MR-angiography to the diagnosis and the therapeutic indication and follow-up of intracranial aneurysms.

The purpose of this study was to evaluate MR-Angiography (MRA) in comparison with digital angiography in the diagnosis, therapeutic indication and therapeutic follow-up of cerebral aneurysms. Out of 27 patients explored by angiography and MRA, 17 had aneurysm, 5 had an aneurysm excluded by a detachable balloon, and 5 without aneurysm were used as controls. MRA, performed by the paradoxical enhancement technique, required a 3 DFT acquisition with short TR and TE (40-8 ms) in gradient echo, with a 15 degrees flip angle. Analysis of angiograms and partitions was compared with that of angiography. Sixteen of the 17 aneurysms were found by a study of both angiograms and partitions. The result was doubtful in 1 patient. No false-negative result was recorded. Spasm was always detected, but the neck of the aneurysm was never sufficiently well defined. The quality of angiogram depends on the type of balloon used in the patients treated: only the balloon without metallic index did not induce an artefact. Thus, MRA seems to be useful in the detection of cerebral aneurysms, and the absence of artefact induced by detachable balloons without metallic index could allow a therapeutic follow-up. But for the moment, arteriography remains the reference for pretherapeutic evaluation.

How does iliac crest bone marrow biopsy compare with imaging in the detection of bone metastases in small cell lung cancer?

Iliac crest bone marrow biopsy (BMB) has often been used as the gold standard for the detection of bone marrow metastases in small cell lung cancer (SCLC). However, it is likely to lead to numerous false-negative results. For this reason, we compared the results of bone scintigraphy (BS), magnetic resonance imaging (MRI), and BMB in 48 sequential patients affected with pathologically confirmed SCLC (47 were evaluable; mean age, 58.4 years). The three procedures were carried out within 1 week, no treatment being performed during this period. Whole-body scans and spot views were obtained in the anterior and posterior projections. For MRI, only the thoracolumbar spine, the sternum and the pelvis were scanned, using spin-echo T1-weighted sequences, resulting in an acquisition time of less than 45 min. Only five BMBs were rated as positive. In these cases, both BS and MRI were also positive. The other 42 biopsies were negative. Among them, in ten cases both BS and MRI were positive. In 21 cases, both BS and MRI were negative. In five cases MRI was positive while BS was negative. Finally, in six cases MRI was negative whilst BS was positive. In most cases in which either BS or MRI was positive, follow-up scans confirmed the initial findings. This study suggests that BMB is more invasive and less sensitive than BS or MRI in detecting bone metastases. MRI seems to be more sensitive than BS in detecting small spinal or pelvic metastases. Whole-body bone scintigraphy is more sensitive in detecting skull, costal or peripheral metastases.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemochromatosis: diagnosis and quantification of liver iron with gradient-echo MR imaging.

PURPOSE: To assess the role of magnetic resonance (MR) imaging in detection and quantification of liver iron overload. MATERIALS AND METHODS: MR imaging at 0.5 T was prospectively performed on 77 patients (67 with liver iron overload and 10 without) who underwent a liver biopsy with biochemical determination of the liver iron concentration (LIC) (normal, < 36 mumol per gram of liver tissue [dry weight]). Ratios of signal intensities and liver T2 relaxation time were calculated from images obtained with spin-echo and breath-hold gradient-echo (GRE) sequences. RESULTS: Liver-to-tissue signal intensity ratios were better correlated with LIC than T2 relaxation time. Long-echo-time GRE sequences were the most sensitive for detection of slight overload. Thus, high sensitivity (94%) and specificity (90%) were obtained with a liver-to-fat ratio threshold of 1. The quantification of iron with MR imaging was accurate when the LIC was 80-300 mumol/g. For heavy overload, above 300 mumol/g, quantification was impossible owing to complete signal loss. Pancreatic and splenic signal intensity were unchanged in most cases. CONCLUSION: This method, which can be improved by using more sensitive sequences with a high-field-strength system, should be competitive with biopsy for the diagnosis of substantial liver iron overload.