Digitale Bilddiagnostik最新文献

Stress fractures can represent a diagnostic problem especially in their differentiation from bone tumours. 6 patients with 7 lesions were examined. MRI visualised the stress fractures and established the diagnosis of stress fracture vs. tumour in 6 cases. In the seventh, biopsy having been performed, a tumour was ruled out. MRI is more sensitive than radiography in the detection of stress fractures, showing the characteristic changes earlier. MRI, being a very sensitive method in the diagnosis of stress fractures and a reliable one in their differentiation from bone tumours, can be applied in cases of unusual clinical course and difficult radiological diagnosis prior to biopsy.

The contrast medium dose used in CT renal function analysis corresponds to about 1 ml/kg body weight at a measurement interval of 5 or 10 minutes. In the present study the dependence of "CT clearance" on dosage and time was examined in 12 healthy subjects. The amount of clearance was directly proportional to the employed contrast medium dose and to the length of the measurement interval. On account of the superior signal-to-noise ratio, the higher dose (1 ml/kg body weight) will continue to be preferred in future. The measurement interval can be limited to 10 minutes.

In a female patient suffering from renal insufficiency in whom angiography could not be performed, it was possible to confirm the diagnosis of a ductus arteriosus (Botallo's duct) by magnetic resonance imaging. The present case report shows that it is possible to visualise this congenital heart disease by MRI. This can be of importance especially if angiography cannot be performed (as in this case) because of renal insufficiency or because of contrast medium allergy.

106 patients with a stenosis of the carotid arteries or the common iliac arteries were examined by digital subtraction angiography. The haemodynamic effectiveness of a stenosis was supposed to be measured by time-density curves. Evaluation of time-density curves produced by videodensitometry did not allow to judge the degree of a stenosis of the carotid or the common iliac arteries. Causative for the insufficient accuracy of the results is a patient related change of examination quality. Disturbing factors are reduced cardiac output, moving artifacts, overshadowing of the examined region by air and reduced contrast due to obesity.

A new CT-sign as a pointer to the imminent rupture of an abdominal aortic aneurysm is described: the enhanced shell of the thrombus of the aneurysm. This sign is caused by bleeding into the thrombotic layer.

MR examinations of the elbow joint of three healthy subjects and a comparison with corresponding sections of anatomical preparations show that MR tomography enables not only an excellent differentiation of muscles, tendons and of the articular capsule, but will also visualise vessels and nerve tracts. MR tomography proved superior to the conventional methods in demonstration of separate fragments and inflammatory changes in the bone on examining 11 pathological elbow joints: congenital malformation, osteochondritis dissecans, ostitis, ulnar and radial nerve lesions, completely healed radius fracture and epicondylitis of the radial and ulnar humerus. Epicondylitis could not be demonstrated by MR. Magnetic resonance tomography seems to be the only method that enables direct visualisation of the nerve paths at the elbow joint.

The authors describe the computer tomographic findings in a patient with proven hereditary angioneurotic edema of the gastrointestinal tract with emphasis on differential diagnoses.

33 CT-studies of 26 patients with alloplastic vascular prostheses were evaluated and compared with postoperative digital subtraction-angiography in 16 cases. 13 patients had no pathologic findings confirmed by further clinical development. In 4 cases bypass infection was diagnosed, which CT findings were perigraft gas (2/4), perigraft fluid (4/4), cm-enhancement (4/4) and fistulas (2/4). 10-21 d. post.-op. sterile hematomas were found in 3 patients. Further 3 cases had 5 weeks-2 post.-op. perigraft seromas. CT was method of first choice for diagnostic of perivascular alterations after bypass surgery. DSA was complementary to CT and should be performed to detect vascular complications.

A case of cerebral AVM associated with Klippel-Trenaunay Syndrome is presented where Magnetic Resonance (MRI) flow measurement revealed details of the shunt from the cerebral arterial system. The AVM was supplied by two arteries, the main flow came from the left vertebral and internal carotid artery. The arterial blood supply of the AVM was about 268 ml/min, the av-shunt flow was about 18% of the whole carotid and vertebral upstream flow.

The use of digital image radiography in urographic diagnostics yields a high percentage of images that are useful in diagnosis, even at the present state of technical development which is rapidly improving. Our own results obtained in a prospective study on 75 patients supply proof of such diagnostically useful pointers. Clear improvements in demonstrating the details when employing a 28 cm image amplifier input format in place of the additionally used 40 cm are seen only with the system of the renal calices. However, we found that the 40 cm image amplifier input format proved satisfactory in respect of assessing renal contours, kidney pelvis and ureters as far as image quality was concerned. Enhance image quality can be expected in future from the use of wedge-shaped diaphragms as well as a selective influencing of the automatic exposure (several measurement chambers, weighting factors) and the transfer of monitor screen contents to hard copy without incurring any losses during transfer.