[Percutaneous thermoablation of pulmonary metastases. Experience with the application of laser-induced thermotherapy (LITT) and radiofrequency ablation (RFA), and a literature review]. / Perkutane Thermoablation von Lungenmetastasen - Erfahrungen mit dem Einsatz der LITT, der Radiofrequenzablation (RFA) und Literaturübersicht.

PURPOSE: Evaluation of technical aspects, local efficiency and complications of thermoablative procedures, such as radiofrequency ablation (RFA) and laser-induced thermotherapy (LITT), in percutaneous lung metastases. MATERIALS AND METHODS: Techniques of thermal ablative procedures of RFA and LITT are presented. For primary positioning, monitoring and therapy control, computed tomography (CT) or magnetic resonance imaging (MRI) was performed. Different monopolar systems and one bipolar system were available for RFA and two different cooling systems for LITT. Percutaneous CT-guided RFA was performed on 32 metastases in 20 patients and percutaneous LITT on 34 metastases in 24 patients. Inclusion criteria were metastases < or = 5 cm in diameter in unresectable patients with up to 3 metastases per lung. All treatments were performed on outpatient basis using analgosedation. RESULTS: In our patient group, all patients tolerated both the RFA and LITT procedures well with mild sedation. The pneumothorax rate was 15 % (5/32 procedures) for the RFA group and 12 % (4/34 procedures) for the LITT group, without insertion of a chest tube. In all RF ablations, a complete "roll off" (increase in impedance) was achieved. Local tumor control rate in the 6-month follow-up was 85 % for RFA and 91 % for LITT. Nineteen of the 20 patients treated are still alive, one patient died from tumor progression. CONCLUSION: Both pulmonary RFA and LITT allow safe thermal ablation of pulmon arg metastases with a low complication rate and an acceptable tumor control rate.

[MRI staging of prostate cancer with the combined endorectal body phased-array coil and histologic correlation]. / Kernspintomographisches Staging des Prostatakarzinoms mittels kombinierter Endorektal-Body-Phased-Array-Spule und histopathologische Korrelation.

PURPOSE: Evaluation of the diagnostic value of the combined endorectal body-phased array technique regarding the staging of prostate cancers, especially in the differentiation between stages T2 and T3. MATERIALS AND METHODS: Forty-two patients with biopsy-proven or clinically suspected prostate cancer were examined on a 1.5 T scanner (Siemens, Symphony) prior to radical prostatectomy. T (2)-weighted TSE (axial, coronal) and T (2)-weighted FSE (axial) sequences were obtained with and without fat suppression. After application of 0.2 mmol/kg body-weight Gd-DTPA, T (1)-weighted GRE sequences were obtained using dynamic MRI. All images were prospectively interpreted by two observers. The MR images were correlated with the histopathological findings of wide-area sections of prostatectomy specimens. RESULTS: For the detection of extracapsular growth and seminal vesicle infiltration (T2 versus T3) the accuracy was between 94 % and 97 % (sensitivity 100 %, specificity between 87 % and 93 %, observer 1 and 2). In two cases with a histologically proven stadium pT2b, observer 1 had diagnosed stadium pT3a. The results of observer 2 were marginally better in only one case, which was histologically proven to be pT2b and overstaged as pT3a. MRI did not lead to under-staging of a single tumor with regard to the differentiation between T2 and T3. Overall, the staging of the tumor stages (T1 - T4) was correct in 25 of 33 cases (75 %). The dynamic MRI showed no improvement regarding sensitivity (100 %) and specificity (62 %) and achieved a staging accuracy of only 75 %. CONCLUSION: MRI performed with a combination of a pelvic phased-array coil (PPA) and integrated endorectal coil plays a significant role in the preoperative staging of prostate cancer. However, differentiation between capsular infiltration (T2) and penetration (T3) as well as evaluation of the seminal bladder (T3b) seem to be difficult.

Encephalomyelitis due to Cryptococcus neoformans var gattii presenting as spinal tumour: case report and review of the literature.

A 24 year old immunocompetent German resident is described who developed multifocal encephalomyelitis due to infection with Cryptococcus neoformans var gatti, commonly considered a disease of tropical regions. In the light of current knowledge on the epidemiology of C neoformans var gatti and the travel history of the patient it is assumed that the infection was acquired outside Europe. As exclusive intramedullary involvement is an outstandingly rare manifestation in spinal cryptococcosis, the particular diagnostic procedure and the therapeutic strategies are discussed

Muscle metabolism of professional athletes using 31P-spectroscopy.

PURPOSE: The aim of the study was to examine muscle metabolism in athletes by 31P-spectroscopy (MRS) and to evaluate to what degree the respective resonance spectrum correlates with the kind of muscle exercise. MATERIAL AND METHODS: Twelve runners and 12 young ice skaters were studied by 31P-spectroscopy of the gastrocnemic medialis muscle and the vastus medialis muscle using a surface coil at 1.5 T. RESULTS: Sprinters displayed a higher phosphocreatinine/inorganic phosphate (PCr/Pi) and PCr/beta-ATP ratios than marathon runners. The respective parameters for middle distance runners were in between. Ice skaters could prospectively be divided into sprint- and long-distance runners by our results which correlated with the athletes' training performance. CONCLUSION: 31P-spectroscopy can evaluate the distribution of muscle fiber types. Thus, the athlete's potential for sprint- or long-distance running can be determined. Additional studies will have to demonstrate to what extent training may change muscle fiber distribution.

Magnetic resonance imaging in the diagnosis of acute injured distal tibiofibular syndesmosis.

RATIONALE AND OBJECTIVES: This study assessed the diagnostic potential of magnetic resonance imaging for the evaluation of the tibiofibular syndesmosis. METHODS: A total of 38 patients with an acute ankle trauma and clinical suspicion of a syndesmotic tear were prospectively studied with conventional plain film radiography and magnetic resonance imaging. Magnetic resonance imaging studies included plain T1-weighted (T1-w) and T2-weighted (T2-w) sequences and contrast-enhanced T1-w sequences 0 to 3 days after trauma. All images were read by two independent radiologists before surgical intervention. Sensitivity and specificity were determined for the two observers and the concordance of the two observers were calculated using the interobserver analysis (Kappa-Test). Intraoperative inspection (n = 21) revealed rupture of the anterior tibiofibular ligament (ATIF) in 15 patients, intact ATIF in 6 patients, and intact posterior tibiofibular ligament (PTIF) in 21 cases. Clinical and follow-up examinations revealed an intact syndesmotic complex in another 17 patients. RESULTS: Primary diagnostic criteria for diagnosing a ligamentous tear included tibiofibular diastasis in conventional plain films; nonvisualization of the ATIF; an abnormal course, a wavy, irregular contour of the ligament; increased signal intensity of the ligament in T2-w sequences, in plain T1-w sequence, and marked enhancement in T1-w after contrast. Important secondary signs were defined as joint fluid in the tibiofibular space and prolapse of interspace fat. Highest diagnostic accuracy was achieved if three or more diagnostic criteria could be visualized. Both readers performed best with the enhanced T1-weighted and the T2-weighted images in transverse orientation. The interobserver analysis resulted in high concordance: Kappa = 0.9 (confidence interval: 0.76 to 1.00) for all patients, and in Kappa = 0.76 (confidence interval: 0.45 to 1.0) for surgically treated patients. CONCLUSIONS: Magnetic resonance imaging of the syndesmotic complex is a highly sensitive and specific tool for the pretherapeutic-evaluation of syndesmotic injury.

Liver tumors: comparison of MR imaging with Gd-EOB-DTPA and Gd-DTPA.

PURPOSE: To compare the usefulness of gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) and gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) in the diagnosis of focal liver lesions. MATERIALS AND METHODS: Thirty-one patients with focal liver lesions underwent T2- and T1-weighted spin-echo magnetic resonance (MR) imaging and fast low-angle shot two-dimensional MR imaging before, during, and after intravenous administration of three different doses of Gd-EOB-DTPA (12.5, 25, and 50 mumol per kilogram body weight). Gd-DTPA-enhanced imaging (dose, 0.1 mmol per kilogram body weight) was performed in the same patients within 1 week of Gd-EOB-DTPA imaging. RESULTS: During the perfusion phase (the 3 minutes after injection of contrast material), the dynamic enhancement characteristics seen after injection of 25 and 50 mumol of Gd-EOB-DTPA were similar to those seen with Gd-DTPA. At the lowest dose of Gd-EOB-DTPA (12.5 mumol), the dynamic enhancement characteristics were not comparable to those seen with Gd-DTPA. During the hepatobiliary phase (1.5 minutes to 4 hours after injection), Gd-EOB-DTPA-enhanced images yielded a dose-independent, statistically significant improvement in the detection rate of additional metastases, hepatocellular carcinomas, and hemangiomas compared with unenhanced and Gd-DTPA-enhanced images (P < .05). CONCLUSION: Gd-EOB-DTPA-enhanced MR imaging enables improved detection of hepatic lesions over Gd-DTPA-enhanced MR imaging while providing comparable differential diagnostic information.

[High-resolution magnetic resonance tomography by means of an endorectal coil--the results in rectal tumors]. / Hochauflösende Magnetresonanztomographie mittels Endorektalspule--Ergebnisse bei Tumoren des Rektums.

PURPOSE: To assess the value of high-resolution MRI of the rectum using an endorectal coil. METHODS: 10 volunteers and in 31 patients with suspected rectal tumors were examined. In 17 patients (n = 17) with rectal carcinoma, of which 15 subsequently underwent radical surgery, the preoperatively obtained tumor stage was compared with histology. In 12 patients (n = 12) with rectal adenoma (severe and medium graded epithelial dysplasias according to the WHO) who underwent endoscopy the results of the endorectal surface coil examination were compared with endoscopy and histology. In 4 patients (n = 4) with large rectal adenomas the surface coil was used before and as follow-up after endoscopic electro laser resection and the absence of adenoma after therapy also in the deeper layers of the rectal wall could be confirmed. RESULTS: Visualization of anatomical structures of rectum and adjacent structures is improved by the use of the endorectal surface coil. The diagnosis of carcinoma and adenoma of the rectum and the documentation of the exact extension can be reached with high accuracy (85%). CONCLUSION: MRI with an endorectal surface coil may play an important role in the preoperative diagnosis of rectal carcinoma. This method is useful for primary diagnosis and follow-up of large rectal adenoma after endoscopic electro laser resection.

[The value of in-vivo 31-phosphorus spectroscopy in the diagnosis of generalized muscular diseases. The clinical results and the differential diagnostic aspects]. / Wertigkeit der In-vivo-31Phosphorspektroskopie bei der Diagnostik generalisierter Muskelerkrankungen. Klinische Ergebnisse und differentialdiagnostische Aspekte.

PURPOSE: In a prospective study, characteristics and the diagnostic potential of in vivo 31-phosphorus spectroscopy in cases of generalised muscle diseases were analysed. METHOD: 41 patients with myogenic and neurogenic muscle diseases and 11 healthy volunteers were examined using MRI and in vivo 31-phosphorus spectroscopy by means of a 50 mm double-tuned surface coil. RESULTS: The spectra showed significant changes of the metabolite ratios depending on the degree of the disease. Inflammatory muscle diseases were characterised by increased PME and PDE peaks, which indicates that there is a higher conversion of the cell membrane. The spectra of muscular dystrophy showed a slight increase of PDE and Pi. A strongly reduced PCr and an increased Pi peak were demonstrated in cases of muscle atrophy depending on their degree of markedness. The pH values were minimally increased in comparison to the volunteers. In other muscle diseases, such as glycogenosis or myotonia, no significant changes were detected. CONCLUSION: Standardised in vivo 31-phosphorus spectroscopy of generalised muscle diseases provides noninvasive prognostic information on the type and behaviour of the disease and is complementary to clinical and histological findings.

[The proton MR spectroscopy of intracranial tumors. The differential diagnostic aspects for gliomas, metastases and meningiomas]. / Protonen-MR-Spektroskopie intrakranieller Tumoren. Differentialdiagnostische Aspekte für Gliome, Metastasen und Meningeome.

Twenty-two patients with intracranial tumours were examined by MR images and in vivo proton-MR-spectroscopy. The changes of relative concentrations of NAA, PCr/Cr, Cho, and Ins were measured spectroscopically and the amount of these metabolites were related to different tumour groups. Analysis of the results has shown that the spectra from all the tumours differed from normal spectra. All cerebral tumours showed marked reduction of the Pcr/Cho quotient and the NAA/Cho quotient was also reduced. The Ins/Cho quotient for meningiomas and metastases was also lower than in normals; in gliomas of low malignancy the quotient was slightly raised and in gliomas of greater malignancy it was significantly higher than normal. The spectra of cerebral metastases showed unusual high lipid signals of 0.9 ppm and 1.25 ppm. The only common feature for meningiomas was marked reduction of NAA concentration. In summary, localised in vivo proton-MR-spectroscopy can be used clinically to obtain valuable information for the differential diagnosis of gliomas and intracerebral metastases.