Stellenwert der MR-Tomographie bei traumatischen Patellaluxationen

PURPOSE To describe the MR imaging findings in patients with lateral patellar dislocation. MATERIAL AND METHODS The MRIs of 31 patients with patellar dislocation were evaluated retrospectively. Arthroscopic surgery was performed in 23 cases. RESULTS Hemarthrosis was found in 30/31, contusions of the lateral femoral condyle in 30/31 and of the medial patellar facet in 26/31 cases. Injury of the medial patellar retinaculum was seen in 28/31 cases. Osteochondral fractures were found in 18 patients; compared to arthroscopy there were one false-positive and 5 false-negative findings concerning loose cartilage bodies. In 7 cases, patellar dislocation was not suspected before MR imaging. CONCLUSIO…

Stellenwert der MR-Tomographie bei akuten Schulterluxationen

24 patients up to two weeks after primary traumatic shoulder dislocation were examined at 0.5 and 1.5 T. Surgical and/or arthroscopic correlation was available in 13, CT-arthrographic correlation in 16 patients. A joint effusion allowing sufficient evaluation of the capsulolabral complex was present in 21/24 (87.5%) cases. 11/14 patients with combined dislocated detachments of the glenoid labrum and capsular lesions were subsequently operated upon. Marrow edema of the humeral head was found in 16/19 Hill-Sachs lesions and in 4/5 fractures of the greater tuberosity. Two patients presented with a lesion of the long biceps tendon associated with rotator cuff tears and were also subsequently op…

Gadolinium-DTPA (Magnevist®) als Kontrastmittel für die arterielle DSA

16 DSA investigations using intra-arterial Gd-DTPA were performed on 12 patients. The contrast medium was administered either as a 0.5 molar gadolinium solution (commercially available) or diluted with distilled water to a 0.2-0.4 molar gadolinium solution. The injection was made either by pressure injector or by hand. The aortic arch, abdominal aorta and pelvic and lower limb arteries were examined. 14 of the 16 procedures were diagnostically adequate, but compared with iodinated contrast materials, contrast was less marked. There were no cardiovascular, neurological or allergic side effects. Three patients suffered a feeling of heat and one patient had mild pain during the injection. Even…

MR-tomographische Funktionsanalyse des linken Ventrikels

The following contribution presents a continuous MRT analysis of the contraction and relaxation processes of healthy left ventricles giving reference values for contraction and relaxation velocities. For the total ventricle we have Vsyst. r. total = 342 +/- 47% LVEDV/sec and Vdiast. r. total = 303 +/- 59% LVEDV/sec. In relation to the end-diastolic (tomographic) volume (EDSV) significantly greater changes in volume per unit of time were measured apically compared to basal (systolic: 411 +/- 89% EDSV/sec apical vs 261 +/- 35% EDSV/sec basal; diastolic: 810 +/- 145% EDSV/sec apical vs 245 +/- 70% EDSV/sec basal). Occurrence of the end-systolic minimal volumes of apical tomographic layers was …

MR-Tomographie bei Hodenprozessen

The value of T1-weighted sequences after intravenous administration of Gd-DTPA and of T2-weighted sequences was compared in 43 patients suspected of having scrotal abnormalities. T2-weighted sequences gave better demonstration of the tunica albuginea and better contrast between tumor and parenchyma. The two techniques were equally sensitive for demonstrating testicular tumors but orchitis was better demonstrated on the contrast enhanced sequences. Motion artifacts were less marked in the T1-weighted sequences with contrast enhancement. In selected cases, contrast enhancement may be a valuable addition to native protocols. Our experience has indicated that MRI provides specific findings in c…

MRT des Kniegelenkes: Fehleranalyse bezüglich der Meniskus- und Kreuzbanddiagnostik an einem arthroskopisch kontrollierten Patientenkollektiv

PURPOSE To categorise discrepancies in findings of the menisci and anterior cruciate ligament (ACL) between arthroscopy and MRI. MATERIALS AND METHODS The MRIs of 236 patients were retrospectively analysed by an experienced radiologist without knowledge of clinical and/or operative findings. Discrepancies in arthroscopic findings were reevaluated together with the arthroscopist to determine their cause of error. RESULTS The diagnostic accuracies for injuries of the medial and lateral meniscus and the ACL were 92.4%, 92.4%, and 94.1%, respectively. For the menisci, causes for discrepancies in findings (n = 31) were: overinterpretation of central signal intensities with contact to the menisca…

Parosteal osteosarcoma of the talus.

A case of parosteal osteosarcoma in the very rare location of the talus is presented. The radiological, pathological, and clinical characteristics of parosteal osteosarcoma are described and the differential diagnosis discussed.

Diagnostik der primär sklerosierenden Cholangitis: prospektiver Vergleich von MR-Cholangiographie mit endoskopisch retrograder Cholangiographie

PURPOSE To assess the accuracy of MR cholangiography (MRC) in the diagnosis of primary sclerosing cholangitis (PSC) in comparison to endoscopic retrograde cholangiography (ERC). METHOD 20 patients with PSC were examined by ERC and MRC (1.0 T, HASTE sequence). Visualization and pathologic changes of the extra- and intrahepatic bile ducts were evaluated with both methods. RESULTS Mural irregularities of the common bile duct were seen with MRC in 6/7 cases, stenoses and dilatation of the common bile duct were detected correctly in all patients. Diffuse, multifocal strictures of the intrahepatic bile ducts were the most common intrahepatic findings and correctly diagnosed in almost all patients…

Magnetresonanztomographische Befunde nach Resektionsarthroplastik des Humeruskopfes

PURPOSE The resection of the humeral head is normally carried out only with respect to four-part and dislocation fractures in elderly patients. The purpose of this study was to examine whether there is a correlation between the clinical results and the MRI findings. MATERIAL AND METHODS 8 patients underwent clinical and MR examination two to 6 years after resection. RESULTS A cartilage-like tissue formation between the remaining humeral head and the glenoid fossa, with signal intensities comparable to hyalin cartilage was found in all patients. CONCLUSION The good functional results following resectional surgery of the humeral head can partially be related to new substitute cartilage result…

Meßfehlerschätzung bei der MR-tomographischen Volumetrie des linken Ventrikels mit Mehrschicht-Technik

A multi-slice technique for MRT measurements of the left ventricular volume is much faster than the use of single-slice methods and is therefore better tolerated, leaving time for additional measurements. The end-diastolic left ventricular volume can be reliably measured by this method (123.3 +/- 13.5 ml vs. 124.1 +/- ml). The end-systolic volume is consistently overestimated by 23.7 +/- 18.3% compared with the reference value obtained by single slice measurements (47.9 +/- 8.9 ml vs 39.1 +/- 7.9 ml). Correspondingly, stroke volume and ejection fraction is underestimated on average by 10.6 +/- 9.7% and 10.6 +/- 7.6% respectively).

MR-Tomographie bei Innenbandverletzungen des Kniegelenkes

Frequency and characteristics of lesions of the medial collateral ligaments (MCL) were studied by MRI in 155 patients with trauma to the knee. There were abnormalities of the MCL in 38% of cases with ligamentous injuries and in 27% these were combined with meniscal tears. 11% of these patients showed isolated rupture of MCL and as a result of the MRI findings were treated conservatively. By means of T2*-weighted images the individual lesions could be accurately localised. Characteristic findings have been defined.

Injuries of the lateral collateral ligaments of the ankle: assessment with MR imaging.

The aim of this study was to evaluate the ability of MRI to display injuries of the lateral collateral ligamentous complex in patients with an acute ankle distorsion trauma. The MR examinations of 36 patients with ankle pain after ankle distorsion were evaluated retrospectively without knowledge of clinical history, outcome and/or operative findings. The examinations were performed on a 1. 5-T whole-body imager using a flexible surface coil. The signs for ligamentous abnormality were as follows: complete or partial discontinuity, increased signal within, and irregularity and waviness of the ligament. The results were compared with operative findings in 18 patients with subsequent surgical r…

Magnetresonanztomographie bei chronischer Aortendissektion

17 patients with chronic aortic dissection were examined by MRI. In 12 patients, comparison between gradient echo sequences and SE sequences was possible. Gradient echo sequences, unlike SE sequences, permitted evaluation of flow in the true and false lumen, reliable differentiation between thrombus and flowing blood and clear delineation of the intimal flap. An additional comparison between transoesophageal ultrasound and MRT in 15 patients showed significant advantages in favour of MRI. In three patients MRI was able to detect more proximal origins of the dissection. Moreover, MRI allowed evaluation of the major aortic branches and their relation to the dissection; this was not possible w…

Transvaskuläre Fensterung eines dissektierenden Aortenaneurysmas

Einsatzmöglichkeiten der MR-Arthrographie bei Erkrankungen des Schultergelenkes

In a prospective study possible indications for MR arthrography of the shoulder were evaluated. 37 patients were examined before and after intraarticular administration of a 2-mmolar solution of Gd-DTPA. MR arthrography was performed if there was no joint effusion and/or an uncertain finding concerning the rotator cuff or the capsulolabral complex on plain MR images. MR arthrography leads to a better demonstration of labrum pathology in 11/22 patients and to a superior delineation of the capsuloligamentous apparatus in 20/22 cases. In 9/15 patients with impingement lesions MR arthrography allowed a differentiation of severe tendinitis from partial and small full-thickness tears of the rotat…

MR-Tomographie versus CT-Arthrographie bei glenohumeralen Instabilitäten

In a prospective study the diagnostic value of MRI compared to CT arthrography (CT-A) was evaluated in 26 patients with 27 instable shoulder joints. Surgical and/or arthroscopic correlation was available in all cases. Both methods showed a high accuracy (96% CT-A, 94% MRI) in the evaluation of the glenoid labrum. CT-A was significantly superior to MRI in the detection of capsular lesions (sensitivity 96% vs. 44%, accuracy 96% vs. 72%, negative predictive value 96% vs. 67%). CT-A and MRI results regarding humeral head fractures were similar; fractures of the glenoid rim were better detected by CT-A, the difference, however, was statistically not significant. Overall, CT-A proved to be superi…

Eine Mannitollösung als orales Kontrastmittel in der pelvinen MRT

PURPOSE Improvement of pelvic MRI using peroral administration of an aqueous mannitol solution. METHODS We retrospectively evaluated magnetic resonance examinations of 72 patients with suspected or proven pelvic abnormalities: In 36 patients, no bowel marking was carried out. In further 36 patients, we performed a contrast enhancement of the bowel by oral application of 1000 ml of an aqueous mannitol solution. RESULTS 8/36 (22%) patients suffered from diarrhoea, nausea or meteorism as a result of mannitol application. In group 2, an excellent bowel marking of the small intestine could be obtained in 36/36 (100%) patients. Contrast enhancement of the bowel significantly improved delineation …