[Show abstract][Hide abstract]ABSTRACT: An experimental study was performed on joint specimens of the knee to assess the advantages and disadvantages of 14 generally available sequences in cartilage imaging.
Each of the 50 surgically exposed cadaveric joints of the knee was examined by the following sequences: T1, proton- and T2 weighted spin echo(SE) sequences, proton- and T2 weighted Turbo-SE, T1 weighted SE with fat suppression, MTC combined with T1-weighted SE and T2 weighted FLASH-2 D, STIR, FISP-3 D, FLASH-3 D (with fat suppression), and MR arthrography. We assessed the image quality by a scale, signal to noise-ratio of cartilage and joint fluid, and the accuracy in detection of cartilage lesions. Pathology and arthroscopy were reference methods to MRI, and demonstrated grade 1-4 lesions on 186 of 300 joint facettes.
Advanced stages of cartilage lesions (65 grade 3 and 4 lesions) were detected by standard SE sequences in 67-94%. Application of volume techniques (FISP-3 D, FLASH-3 D), high definition matrix (512 pixel), MTC with FLASH-2 D and MR-arthrography improved the sensitivity up to 82-100%. Superficial lesions (65 grade 2 lesions) were demonstrated in 3-38%, and on MR arthrography in 45%. Structural changes (56 Grade 1 lesions) were recorded on MR) in only 10%.
With regard to standard SE sequences, the detectability of cartilage lesions can be improved by techniques that use 512 matrices, selective cartilage imaging, and volume acquisition.
Article · Jun 1997 · RöFo - Fortschritte auf dem Gebiet der R
[Show abstract][Hide abstract]ABSTRACT: An experimental study was performed on cadaveric joint specimens of the shoulder to determine the accuracy of US and MRI in diagnosis of abnormalities of the rotator cuff. The value of different morphological criteria was evaluated for discrimination of degeneration as well as partial and complete disruption. A total of 38 surgically exposed specimens of the shoulder joint were examined by US, MRI and pathological methods visualising the tendons of the rotator cuff in same axial and longitudinal orientations. The three imaging modalities were reviewed separately by experienced examiners, respectively, who were blind to other results. Evaluation criteria consisted of signs of shape (thinning, thickening, discontinuity and absence of rotator cuff) and structure (changes in echogenicity in US, increased signal intensity in MRI, tissue changes in pathology). Findings in US and MRI were finally compared with pathology to assess sensitivity and specificity. Pathology demonstrated 4 full-thickness tears, 6 partial-thickness tears, 16 cases with degeneration and 12 normal rotator cuffs. Ultrasound showed pathological signs in all abnormal cuffs, and one MRI report was false negative. Specificity was 67 % in US (4 of 12 cases were false positive) and 100 % in MRI (no abnormal findings in healthy tendons). Discrimination of different pathological disorders of the rotator cuff was reduced in both methods. Using US only 10 of 16 cases of degeneration, 2 of 6 partial tears and 3 of 4 complete tears were correctly defined. Using MRI 13 of 16 degenerations, 3 of 6 partial tears and 3 of 4 complete tears were detected. The MRI technique failed to visualise intratendinous calcifications in all 3 cases. We conclude that MRI and US are both sensitive in detection of abnormalities of the rotator cuff. Ultrasound should be the primary diagnostic method in screening of shoulder pain because it is economic and fast. The MRI technique should be used secondary because it provides more information about extent of tendons and has lower risk of artefacts.
[Show abstract][Hide abstract]ABSTRACT: We report about two cases of tumor dissemination after thoracoscopic wedge resection of malignant nodules of the lung. In the first case, a metastasis at the extraction site was observed after thoracoscopic resection of a metastasis of the lung. In the second case we diagnosed a pleural carcinosis after thoracoscopic wedge resection (and additional open lobectomy and lymph node dissection) of a pT2 N0 lung cancer. The patient died 12 months after the operation. The indication for thoracoscopic resection of malignant nodules of the lung should be restricted for peripheral tumors smaller than 2 centimetres.
[Show abstract][Hide abstract]ABSTRACT: A 66-year-old woman was known to have had cholecystolithiasis for at least 4 years. Laparoscopic cholecystectomy was performed at another hospital where histological examination surprisingly revealed middle-grade differentiated carcinoma of the gall-bladder (pT2, G2). A nodular metastasis of the gall-bladder carcinoma was noted on the abdominal wall 3 months later and excised. Lymph-vessel carcinomatosis was already present. The patient again noticed a tumour in the right mid-abdomen and a further tumour was palpated in the epigastrium 5 months after the operation.
Laboratory and tumour-marker (CEA, CA 19-9) tests were unremarkable, while sonography and computed tomography were highly suspicious for abdominal wall metastases in the epigastrium and right mid-abdomen.
Both metastases were excised. Laparotomy revealed tumour recurrence in the old gall-bladder bed, as well as extensive peritoneal carcinoma. Two months after the operation she developed jaundice, caused by tumour compression of the choledochal duct. An expanding stent was inserted into the stenosed section of the duct. The patient died 13 months after the first operation from the underlying malignancy with multiple liver metastases and malignant ascites.
Indications for minimally invasive surgery in malignant tumour should be narrowly defined. Because tumour seeding is possible after laparoscopic cholecystectomy with incidentally found carcinoma extensive re-excision should be performed.
Article · Feb 1996 · DMW - Deutsche Medizinische Wochenschrift
[Show abstract][Hide abstract]ABSTRACT: In a prospective study, 153 MRI examinations were performed on 74 patients following reconstruction of a ruptured anterior cruciate ligament with a semitendinosus graft. MRI examinations were performed at three defined intervals (3 months, 4 to 12 months, and 1 to 2 years postoperatively), and the findings were compared to simultaneous clinical tests to define stability criteria. This permitted reliable assessment of the integrity of the ligament graft; in three cases we correctly diagnosed a ruptured graft. A well-defined tendon graft with recognizable fibrous structures correlated with a clinically stable ligament in 98% of the cases. Due to physiological transformation occurring from three months to one year postoperatively, that graft temporarily appears less distinct. Complete integration of the graft with full stability of the knee is visualized in the MRI scan as a tendon with low signal intensity. Postoperative complications and the desire to participate in sports activities are indications for MRI examination.
Article · Dec 1994 · RöFo - Fortschritte auf dem Gebiet der R
[Show abstract][Hide abstract]ABSTRACT: A 62-year-old man presented with chest pain was admitted to the hospital. Coronary artery disease and pulmonary emboli were ruled out. Chest X-ray showed a left upper lobe nodule; differential diagnosis included a tumor and a scar. Computed tomography (CT) of the chest revealed a pericardial effusion. Serial echocardiograms, a second CT and Magnetic resonance imaging could not differentiate between pericardial adhesions resulting from pericarditis and a solid mass. Within two months, the patient developed severe congestive heart failure and had an anterior myocardial infarction despite having had normal coronary arteries on arteriogram 4 weeks previously. He died shortly thereafter. On autopsy, the left upper lobe nodule was found to be an adenocarcinoma, atypically metastatic to the pericardium with involvement of the myocardium and the left anterior descending artery.