Digitale Bilddiagnostik最新文献

60 patients with suspected lesion of the rotator cuff were examined by digital subtraction arthrography and the results were compared to ultrasound. The dynamic study of digital subtraction arthrography visualised in 22 of 23 complete or incomplete cuff tears the exact location of the extravasation of the contrast medium. All diagnoses were confirmed by surgery. Problems of conventional arthrography were not seen by the digital method.

The pedicled pelvic bone graft is a new operative technique for the treatment femoral head necrosis. 29 femoral head necroses were examined by i.a. DSA before a pedicled pelvic bone graft was implanted. 11 pedicled pelvic bone grafts were investigated postoperatively. The pre- and postoperative findings are presented. I. a. DSA is a valuable method for the evaluation of the vascularisation of the femoral head before and after surgery.

MR examinations of the extremities occupy the first place in whole body examinations via MR. Highest accuracy quotas in this area with an average of 93.8% were obtained for tumours, trauma and necroses of the bones. These high accuracy quotas, however, were achieved only if sufficient preliminary information was available. Other statistically significant factors were found to be the field strength, the combined use of spin echo and fast imaging sequences and the use of the multislice technique.

This paper provides an overview of the most important imaging properties of a high-resolution computed tomography system. Spatial and contrast resolution (inplane as well as crossplane) are described, while the trade-off between those two characteristics is pointed out. Furthermore, it is shown that extremely small structures are imaged, but not with realistic Hounsfield units. Finally, the noise is set into relation to the contrast resolution.

Due to the inhomogeneous and very variable structure of healthy tissue of the female breast it is often very difficult to detect a carcinoma via computer-aided sonography. The present study based on preoperative measurements in 29 woman patients with carcinoma of the breast aimed at finding out to what extent it would be possible to circumvent this problem by means of additional reference measurements in healthy tissue. For this purpose, relative image parameters were determined besides absolute ones from measurements in tumorous and healthy reference tissue. These relative image parameters are much more suitable for subsequent decision analysis on account of their narrower range of variation. The results obtained in this manner could be improved further by additional optimization or extension (such as analysis of other combinations of parameters, by enlarging the field of measurement and hence the data available per tissue sample, use of higher or even different ultrasound frequencies).

The CODEX method was employed for volume selective proton NMR spectroscopy with a whole body imager in order to control the quality of reproduction with phantoms. The spectral resolution and time stability during typical measuring times are almost better than 3.10(-8) and are usually sufficient for the requirements of high resolution in vivo proton spectroscopy.

102 polytraumatised patients with pelvic fractures were studied by conventional x-rays of the pelvis as well as by computed tomography to obtain detailed information on type and degree of the fractures. We paid particular attention to acetabular and sacral fractures and combinations thereof. We found that only computed tomography enabled us to precisely define type and degree of pelvic injury. We thus draw the conclusion that each patient with proven or suspected pelvic injury should be subjected to a CT study to enable the surgeon to plan his therapy-conservative or surgical-to the best benefit of the patient.

A case demonstrating the computertomographic appearance of entero-enteric intussusception in an adult patient is presented. Unlike conventional barium studies CT is able to demonstrate completely the intussusception complex. Its characteristic CT-appearance allows a definite diagnosis.

The knowledge of the exact spreading and location of a malignant bile duct tumor and the exclusion of differential diagnoses are the prior conditions for the development of an optimal therapy concept. All usual methods such as ERCP, PTC, ultrasound, CT and angiography have weak points in the diagnosis of Klatskin tumors. A new aspect for the solution of this problem is the ability to visualize these tumors by arterial angio-CT and MR.

CT scans of 54 patients with primary peritoneal soft tissue masses were studied retrospectively. All lesions were untreated at the time of the CT examinations and the nature of the lesions was subsequently proven histologically. Each scan was evaluated initially without knowledge of clinical and pathological information in respect of several criteria including size and number of lesions, delineation of the lesions, border definition, and internal structure of the lesions. The lesions were demonstrated in all patients and displayed with great anatomical detail. The presence of gas and attenuation values below -30 HU were the only singular signs specifically indicative of abscesses or lipomatous tumors, respectively. All other applied criteria were found both in sarcomas and benign masses, and no malignant neoplasm had CT characteristics specific enough to differentiate it from any other one. Considering all criteria, the benign or malignant nature of the lesions could be predicted in 43% of the patients studied based solely on CT morphology. In context with the clinical information provided on the study request form, 54% of the lesions were correctly classified into aetiological sub-groups (i.e. soft tissue sarcoma, abscess).