[Acute spinal epidural hematoma--comments on MRI diagnosis using fluid-attenuated inversion recovery sequence (FLAIR)].
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Equipment Design↗
Biomedical subjects
D Pauleit
Publications and source records attributed to D Pauleit.
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.
Brain↗
[The pathological/MR tomographic correlation and differential diagnosis of malignant kidney tumors].
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.
Carcinoma, Renal Cell↗
[Portal contrast medium-enhanced spiral computed tomography of the liver--the correlation of radiological and intraoperative findings and the evaluation of resectability].
PURPOSE: To evaluate the accuracy of spiral computed tomography during arterial portography (SCTAP) in the detection, localization, and resectability of liver tumors in a correlative study between radiology and intraoperative findings. METHOD AND MATERIALS: Retrospectively, SCTAP images of 168 consecutive patients before liver tumor resection were analyzed. The SCTAP studies (100 ml lopromid 300 by automated injector with a flow of 3 ml/s; slice thickness, table feed and reconstruction index 5 mm each; scan-delay 30 s; 120 kV; 250 mAs) were evaluated for the detection, localization, and resectability of focal liver lesions by three experienced radiologists in consensus and were correlated with histopathological and intraoperative findings where available (59/168). RESULTS: The sensitivity of SCTAP for the detection of liver tumors was 91% for all lesions and 84% for lesions < 1 cm. The specificity was only 19% due to a high rate of false-positive lesions (30%) and preselection effects. Typical pitfalls in false positive lesions were inhomogeneous liver perfusion near the portal vein, the falciform ligament, and the gallbladder (19/42). In 30% of the patients SCTAP correctly diagnosed inoperability, in 23% the intraoperative tumor expansion was larger than expected from SCTAP images, which would have changed operability. CONCLUSION: The SCTAP has a high sensitivity in the detection and localization of liver tumors and is a valuable method in the preoperative diagnostic procedure. The method is limited by many false-positive lesions often due to inhomogeneous liver perfusion and the insufficient evaluation of local tumor spread. Therefore, SCTAP should be replaced by MRI in the near future.
Adult↗
Indirect MR arthrography: techniques and applications.
Indirect MR arthrography is a relatively new MR technique improving articular and periarticular contrast. It is achieved by injection of paramagnetic MR contrast media intravenously instead of intra-articular injection as in direct MR arthrography. After the injection exercising the joint results in considerable signal intensity increase within the joint cavity. Fat saturated MR sequences then yield arthrographic images. The method is less invasive than direct MR arthrography and first results showed comparable sensitivities and specificities for rotator cuff and glenoid labrum pathology. In this article the technique, established and potential future indications, drawbacks and limitations of the method are reviewed.
Contrast Media↗
[Improved diagnosis of early cerebral infarct by the combined use of diffusion and perfusion].
PURPOSE: To evaluate the feasibility and the diagnostic efficacy of multislice diffusion-weighted and perfusion imaging in addition to FLAIR-TSE, T2w-GraSE and MR-angiography in the diagnosis of acute stroke. METHODS: 18 patients with acute stroke were examined at 1.5 Tesla (Gyroscan ACS-NT, Philips Medical Systems) within 6 (n = 9) and 6-48 (n = 9) hours, respectively, and followed at regular intervals. For diffusion imaging we used a multislice multishot EPI-SE sequence with navigator echo correction and cardiac gating. Perfusion imaging was done by means of a FFE-EPI sequence after bolus injection of Gd-DTPA. RESULTS: The diagnostic value of diffusion-weighted and perfusion imaging was significantly higher compared with FLAIR-TSE (p = 0.0023) and GraSE (p = 0.0012) during the first 6 hours. With FLAIR-TSE and GraSE first pathologic changes were seen after 4 hours. We detected perfusion deficit (rCBV < 10%) and a corresponding drop of the ADC in all infarcts larger than 1 cm in diameter. Within the area of low rCBV the combined analysis of diffusion and perfusion imaging allows to identify an infarct region with characteristics of a penumbra and one with characteristics of the infarct core. TTP was increased in the surrounding tissue. However, parts of this area were rarely included in the infarct. The final extension of the untreated infarct, as revealed by computed tomography, corresponded well to the perfusion deficit. CONCLUSIONS: Early ischaemic cerebral infarcts can be diagnosed with diffusion and perfusion imaging before pathological changes are visualized with other imaging modalities. The combined use may allow to distinguish the infarct core from surrounding, potentially salvageable tissue.
Adult↗
[Spiral CT and MRT of the operated Stanford-type-A aortic dissection: its course and complications].
PURPOSE: To demonstrate normal postoperative spiral CT and MRI findings and typical complications in patients with aortic repair after Stanford type A aortic dissection. METHODS: 24 patients with aortic repair after Stanford type A aortic dissection were followed up by spiral CT and MRI (0.5 Tesla). Presence of persistent dissection, progressive or new dissection, proximal and distal anastomosis, periprosthetic space, supraaortic vessels, thrombosis and dilatation of the true and false lumen were evaluated. RESULTS: The following postoperative complications were seen: three pseudoaneurysms which developed at the proximal anastomoses of the Dacron prosthesis in two cases and at the insertion site of the reimplanted left coronary artery after implantation of a composite graft (Bentall procedure) in one case; one re-dissection; one perforation of the false lumen; periprosthetic flow in one patient after surgical repair of type A dissection by the graft inclusion technique; progressive dilatation of the false lumen in 4 cases; dilatation of the aortic root in a Marfan patient after replacement of the ascending aorta. CONCLUSION: Precise knowledge of the surgical technique performed is crucial to accurate postoperative imaging evaluation. MRI is the method of choice in the postoperative follow-up of clinically stable patients with aortic dissections.
Aortic Dissection↗
[An epidermoid of the sphenoid bone and a ruptured intracranial dermoid--a case report].
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Abnormalities, Multiple↗
[MRI diagnosis of right ventricular dysplasia].
PURPOSE: Right ventricular dysplasia (RVD) represents an important cause of sudden death and ventricular arrhythmias in young patients. The aim of this study was to describe diagnostic diagnostic criteria and the MR-tomographie aspects of the disease. METHODS: 34 patients with clinically suspected RVD were examined by 0.5-T MRI (cardiac-gated T1-weighted spin echo sequences and cine gradient echo sequences). RVD was confirmed in 16 patients and ruled out in 18 patients. MR images were evaluated for presence of: 1. right myocardial fatty infiltration, 2. dilatation of the right ventricle, 3. dilatation of the right ventricular outflow tract, and 4. localised right ventricular aneurysm. RESULTS: Right myocardial fatty infiltration was detected by MRI in 11 of 16 patients (69%) with RVD. Dilatation of the right ventricle was seen in 5 patients, dilatation of the right outflow tract in one patient, and localised right ventricular aneurysm in two patients with RVD. CONCLUSIONS: MRI is able to demonstrate fatty replacement of right ventricular myocardium in most cases and plays an important role in the diagnosis of RVD.
Adipose Tissue↗
[Indirect MR arthrography in the diagnosis of lesions of the labrum glenoidale].
PURPOSE: It has been shown that intravenous administration of contrast media produces an MR arthrographic effect without the need for intraarticular injection. This is the first study evaluating this new technique of indirect MR arthrography in the diagnosis of glenoid labrum tears. METHODS: 28 patients with clinically suspected labral injuries were prospectively investigated (1.5 Tesla, flexible surface coil). A plain MR examination of the shoulder (transverse and oblique-coronal orientation, T1-weighted spin- [TE/TR 15/675], proton density- and T2*-weighted gradient echo [TE/TR/Flip 14,32/600/30 degrees] sequences) and indirect MR arthrography (transverse and oblique-coronal orientation, fat-suppressed T1-weighted spin-echo sequences [TE/TR 15/675], intravenous injection of gadopentetate dimeglumine [0.1 mmol/kg], followed by 10-15 min of joint movement) were performed. Results were confirmed by arthroscopy and/or open surgery. RESULTS: Indirect MR arthrography significantly improved delineation of the glenoid labrum and hyaline cartilage (p < 0.05). Sensitivity and specificity of indirect MR arthrography in the diagnosis of labral injuries were 90% and 89%, compared to 79% and 67% of the native MR examination. CONCLUSION: Indirect MR arthrography is a promising non-invasive technique in the evaluation of the glenoid labrum.
Adult↗
[MR relaxation time measurements with and without selective fat suppression (SPIR) in endocrine orbitopathy].
PURPOSE: To determine the value and utility of relaxation time measurements with magnetic resonance (MR) imaging in patients with Graves' ophthalmopathy (G.O.). MATERIALS AND METHODS: 20 orbits were studied in control subjects and 58 orbits in patients with G.O. T2 relaxation times of extraocular muscles and retrobulbar fat tissue were calculated. The thickness of the eye muscles was correlated with the calculated T2 times. 18 orbits were measured before and after retro-orbital radiation therapy. RESULTS: Upper limits of determined normal T2 values were 60 ms in extraocular eye muscles and 40 ms in retrobulbar fat tissue. 89% (17/19) of the patients with G.O. had prolonged T2 times in extraocular eye muscles. The retrobulbar fat tissue in 5 of 38 orbits revealed minimal edema with the use of fat saturated sequences. T2 relaxation times decreased significantly (p < 10(-4)) after 10 Gy radiation therapy. No correlation was found between enlargement and T2 relaxation times in extraocular eye muscles (r = 0.44 in patients before radiation therapy). CONCLUSION: In patients with G.O. the determination of the enlargement of extraocular eye muscles in computed tomography is not a sufficient parameter for an antiinflammatory therapy, since CT cannot visualise eye muscle edema. T2 relaxation time measurements with MR imaging allow differentiation between edematous and fibrotic changes. This is the diagnostic method of choice in patients with Graves' ophthalmopathy.
Adipose Tissue↗
[Craniocervical dissections: study strategies in MR imaging and MR angiography].
PURPOSE: To define the diagnostic efficacy of MR imaging, "time of flight" (TOF) and phase contrast (PC) MR angiography in craniocervical arterial dissections. MATERIAL AND METHODS: The MR examinations of 16 patients with proven arterial dissections (n = 20) were retrospectively analysed by three independent readers. The MR protocol included T1w spin echo sequences with and without fat saturation (SPIR), T2w-turbo-spin echo, 2D- and 3D-TOF- and 3D-PC-MRA. The study was undertaken to assess the diagnostic sensitivity of each technique in detecting typical pathological features. RESULTS: The overall sensitivity was best in 3D-PC-MRA; reaching 88% of all possible points. Intramural haematoma could be easily detected with T1W spin echo with fat saturation (100%). Intimal flap and lumen narrowing was best defined with 3D-TOF-MRA in 86% resp. 96% and 3D-PC-MRA in 69% resp. 97%. 3D-PC-MRA was superior to all other sequences in 5 cases of aneurysmal dissection (100%). CONCLUSIONS: An accurate evaluation of craniocervical arterial dissections should rely on a combined protocol including T1w spin echo with fat saturation and an axial 3D-MR angiography (if possible 3D-phase contrast MRA).
Adolescent↗
[Percutaneous radiotherapy of bone metastases].
Bone metastases causing pain syndromes and imminent pathologic fractures are among the main reasons for radiotherapy in patients suffering from malignant tumors. The indication is much influenced by the radiologic findings. Surgical methods are to be chosen in the first place in cases of pathologic fractures or patients with a high risk of such fractures. Different authors recommend various therapeutic regimens. Effective pain control can be achieved with one single dose of radiation. Doses of 6 to 40 Gy applied in one to 19 days are also efficient. Side effects, especially nausea and vomiting occur in 25% of cases; this number rises to 50% in cases of half body irradiation. Visible changes of bone mineral density may be noticed about 6 weeks after termination of radiotherapy. About 70% of osteolytic metastases show progressive sclerosis whereas osteosclerotic lesions may show both increase or decline of bone mass. In spite many years of experience the optimal strategy for radiation therapy of bone metastasis has not been defined; further studies are needed.
Bone Density↗
[Pulmonary changes in high-resolution spiral CT in Williams-Campbell syndrome].
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Adult↗
[In-vivo 31P-NMR-spectroscopy in patients with dilated cardiomyopathy].
In vivo 31P-NMR spectra of heart muscle were obtained in 7 patients with dilating cardiomyopathies and in 10 normal subjects, using an ISIS technique with a 1.5 Tesla body scanner (Philips Gyroscan S15) and the results of the two groups were compared. These results were easily reproduced. In patients with cardiomyopathy there was a significant (p < 0.05) reduction of the PCr/ATP ratio as an expression of abnormal energy metabolism. Two patients with mild clinical symptoms and only slightly reduced functional measurements showed no significant changes in the 31P-NMR spectrum. The patients with the largest reduction of the PCr/ATP index also showed the most marked changes in functional measurements. The PCr/ATP ratio (as also suggested by animal experiments) appears to be a suitable non-invasive indicator for the diagnosis and staging of myocardial changes in dilating cardiomyopathies.
Adenosine Triphosphate↗
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.
Adolescent↗