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Biomedical subjects

B Krug

Publications and source records attributed to B Krug.

At least 73 records · Page 4Linked to original sources
PubMed1996

Clinical outcome of patients with an uncomplicated myocardial infarction: effect of revascularization.

In 80 patients (pts) with an uncomplicated myocardial infarction (MI) the rate of major cardiac events (MACE) including cardiac death, non-fatal myocardial infarction and recurrent ischemia requiring hospitalization was prospectively assessed over a mean follow-up period of 17 +/- 9 months and related to clinical, angiographic and scintigraphic findings, the latter obtained from adenosine Tc-99m sestamibi SPECT imaging. Decision for revascularization was mainly based on angiographic data and was carried out in a total of 50 patients (angioplasty in 34 pts and cardiac surgery in 16 pts). The overall MACE rate was 24% with a mortality and myocardial infarction rate of 4% and 5%, respectively. Early (< 2 months) revascularization seemed to have a beneficial effect on clinical outcome as was suggested by the following findings: 1) Cardiac events (MACE) were not significantly different in patients with versus without revascularization (MACE 24% versus 23%) although the former constituted a subgroup at higher risk for ischemic events because of a more extensive coronary artery disease state. 2) In the subset of patients with at least one significant coronary artery stenosis the clinical outcome was significantly better in those who were revascularized than in those who underwent no revascularization (MACE 24% vs 47%, p < 0.05. Among a variety of factors, including the scintigraphic and angiographic extent of coronary artery disease and post-MI treatment strategy, multivariate analysis selected hypercholesterolemia (> 240 mg%) as the only independent predictor of MACE with a more than fourfold increase in risk for development of MACE. These data suggest that the natural history, especially the rate of recurrent ischemic events, can be favourably changed by an elective and early revascularization, strategically oriented by the results of the angio-graphic study. Furthermore, our data emphasized the deleterious role of hypercholesterolemia on clinical outcome in patients with a recent MI.

Angioplasty, Balloon, Coronary↗
PubMed1996

Renal milk of calcium: contraindication to extracorporeal shockwave lithotripsy.

Renal milk-of-calcium (MOC) cysts are rare findings, with only approximately 60 cases reported in the literature. The diagnosis depends on the demonstration of the typical "half-moon" configuration on horizontal beam radiography; classical ultrasound finding is a gravity-dependent, echogenic shadowy material in a renal cyst. The importance of the MOC syndrome lies in its recognition and differentiation from a renal stone in order to avoid unwarranted surgery or extracorporeal shock-wave lithotripsy (ESWL). We have encountered five patients with renal MOC and present the typical clinical and radiological features in order to facilitate differential diagnosis.

Adult↗
PubMed1995

MR pulsatility measurements in peripheral arteries: preliminary results.

Phase contrast flow velocity measurements were performed in six healthy volunteers and 30 patients with arteriosclerotic disease. The iliac arteries were investigated in 8 cases and the femoral arteries in 28 cases. In the first 24 patients, 16 evenly distributed data sets were acquired during one cardiac cycle. In the last 12 patients, a trigger pulse followed by the acquisition of 30 evenly distributed data sets was applied every second heart beat. This procedure allowed data to be acquired over a full heart cycle without any acquisition gap. The measured flow velocities were displayed as function of time. Systolic acceleration, postsystolic deceleration and pulsatility of flow velocity were calculated and compared with stenosis grades determined from DSA angiograms. Flattening of the flow velocity patterns was found to correlate with the local severity of arteriosclerotic disease.

Adult↗
PubMed1995

Diagnostic performance of digital subtraction angiography (DSA) and magnetic resonance angiography (MRA): preliminary results in vascular occlusive disease of the abdominal and lower-extremity arteries.

Fifty-nine patients with occlusive disease of the aorto-iliac and femoro-popliteal arteries were investigated prospectively by intravenous (IV) or intraarterial (IA) digital subtraction angiography (DSA) and magnetic resonance angiography (MRA). This was accomplished using a two-dimensional (2D) Inflow- (59 patients) and a 2D Phase Contrast- (RSE--rapid sequential excitation) sequence (29 patients). The spectrum of pathology included stenoses < 50%, stenoses 50-89%, stenoses 90-99%, occlusions, aneurysms and status following reconstructive surgery. MRA- and DSA-examinations were evaluated by four radiologists. The diagnoses were made by consent decisions of a radiologist and a vascular surgeon based on clinical and radiological findings. Diagnostic performance of IA-DSA was superior to all other imaging modalities. Vascular delineation of 2D Inflow-MRA was comparable to that of IV-DSA. The image quality of RSE-MRA was not adequate for diagnosis. In conclusion, 2D Inflow-MRA is a promising method for evaluating abdominal and peripheral arteriosclerotic disease. Interpretation of MR-angiograms, however, requires profound knowledge of MRA-techniques, X-ray angiography and hemodynamics.

Adult↗
PubMed1995

[Peripheral occlusive arterial diseases: comparison of diagnostic value of MRA and DSA].

MATERIAL AND METHODS: In 59 patients with arterial flow disturbances 2-D inflow sequence of the abdominal and lower leg arteries were prospectively obtained on a 1.5 T MR-imager and were compared with additional DSA examinations. Supplementary Phase Contraste RSE ("Rapid Sequential Excitation") sequences were carried out in 29 patients. MRA and DSA angiograms were evaluated in random order by 4 readers using a questionnaire. The assessment of image quality were evaluated by variance analysis. Diagnostic performance of MRA and DSA was assessed by comparison of the readers' diagnostic assessments with reference diagnoses established by a radiologist and a vascular surgeon with full knowledge of all data concerning a patient. Image quality of inflow MRA was considered inferior to i.a. DSA (p < 0.001) and comparable with i.v. DSA (p = 0.1361). Image quality of RSE-MRA was inadequate (p < 0.001). Correspondingly, i.a. DSA was the superior and RSE-MRA the inferior imaging technique. The accuracy of inflow MRA in determining stenosis grade was 66% and that of RSE-MRA 59%.

Aged↗
PubMed1995

Adenosine technetium-99m sestamibi (SPECT) for the early assessment of jeopardized myocardium after acute myocardial infarction.

The purpose of this study was to evaluate the accuracy of adenosine Tc-99m sestamibi single photon emission computed tomography (SPECT) in the detection of jeopardized myocardium early after acute myocardial infarction. Coronary arteriography and myocardial scintigraphy were performed in 50 consecutive patients with an uncomplicated myocardial infarction. Myocardium was considered jeopardized if a significant infarct-related vessel stenosis (> 50% diameter stenosis) supplied an infarct area with residual viable tissue. Perfusion reversibility in the infarct region occurred in 25 patients (50%) and was almost solely observed in the presence of jeopardized myocardium. Non-reversible perfusion defects in the infarct region were found in patients without jeopardized myocardium. This subgroup consisted of either patients without significant vessel stenosis or patients without significant residual viability in the infarct region. Adenosine Tc-99m sestamibi SPECT had an accuracy of 88% for the detection of jeopardized myocardium. Side effects during adenosine infusion were frequently observed but well tolerated. These results suggest that adenosine Tc-99m sestamibi SPECT is an accurate non-invasive method for detecting jeopardized myocardium after acute myocardial infarction and may be a valuable non-invasive test for the early selection of patients at risk for future ischaemic events.

Adenosine↗
PubMed1995

Metastases seen on SPECT imaging despite a normal planar bone scan.

Although bone scintigraphy is an extremely sensitive method for the detection of focal bone disease, small lesions below the resolution of planar imaging may be missed. This is a report of a patient with carcinoma of the breast who showed tumor progression 1 year after initial treatment. Complete evaluation was performed in order to detect the origin of increased level of a tumor marker. Although planar bone scintigraphy could not demonstrate any lesion in the spine, multiple metastases were detected in the lumbar and the thoracic spines on SPECT imaging. Only some of these lesions were seen with MRI. Repeat planar bone imaging 6 weeks later showed multiple bone lesions in the lumbar and thoracic areas.

Adenocarcinoma↗
PubMed1995

[Tuberculosis of the esophagus].

Tuberculosis of the esophagus is a rare disease, occurring in most cases secondary to tuberculous infection of other organs. There are neither characteristic symptoms or diagnostic signs, nor typical X-ray or laboratory findings. Histology, too, often fails to establish a reliable diagnosis, so that esophageal tuberculosis may be mistaken for esophageal carcinoma. Most cases can be successfully treated with antituberculous therapy, although patients with esophageal tuberculosis in the presence of AIDS do not respond as well to anti-tuberculous therapy.

AIDS-Related Opportunistic Infections↗
PubMed1995

Digital luminescence radiography and conventional radiography in abdominal contrast examinations.

In 326 patients abdominal contrast radiographs were compared to digital luminescence radiographs (DLR) and conventional screen-film system ones. The digital exposure dose was 50% of the conventional. In DLR, 2 different types of postprocessed images were obtained from each data set. A display with low spatial frequency enhancement filtered to look like a conventional radiograph was compared to a display with high spatial frequency enhancement. Conventional and DLR images were evaluated randomly and separately by 4 radiologists by means of a questionnaire. DLR proved to be diagnostically equivalent to the conventional technique with the exception of a slightly diminished visibility of the mucosal pattern. High spatial frequency enhancement did not provide additional diagnostic information and should be dispensed with in abdominal examinations.

Adult↗
PubMed1995

Esophageal tuberculosis: a differential diagnostic challenge.

Esophageal tuberculosis is a rare clinical picture. It is typically secondary to tuberculous infection of other organs. There are neither diagnostic signs or symptoms nor typical x-ray or laboratory findings. Histology, too, often fails to establish a reliable diagnosis, so that esophageal tuberculosis might be mistaken for esophageal carcinoma. We report the case of a woman with secondary esophageal tuberculosis to illustrate the clinical course and diagnostic problems of this condition.

Aged↗
PubMed1995

Cine phase contrast angiography of normal and diseased peripheral arteries. Preliminary results.

Cine phase contrast angiography (PCA) is a modified MR phase contrast sequence that acquires up to 22 coronal phase images per mean cardiac cycle. The ability of the sequence to visualise local haemodynamics was investigated in 7 normal volunteers and 9 patients with flow disturbances of the peripheral arteries using a 1.5 T imager. Functional flow information provided by coronal cine PCA was correlated with quantitative data obtained by MR flow measurements and vessel morphology confirmed by conventional angiograms. Due to the yet suboptimal image quality, an aortic dissection and 1 of 4 aneurysms could not be depicted morphologically. The temporal pattern of arterial perfusion in cine PCA corresponded with flow velocity versus time data provided by quantitative MR flow measurements. Accuracy and time resolution of cine PCA was thus sufficient to provide functional information on the severity of occlusive vascular disease.

Adult↗
PubMed1993

[X-ray studies of the peripheral joints: a comparison of digital luminescence radiography (DLR) and film-screen systems].

175 matched skeletal x-ray examinations were carried out by digital luminescent radiography (DLR) and conventional screen-film system combinations. In digital luminescent radiography (DLR) two differently postprocessed images were obtained from one x-ray exposure: A display with low spatial frequency enhancement was opposed to a second display with high edge enhancement. Conventional and digital images were evaluated randomly and separately by four radiologists using a questionnaire. DLR proved to be diagnostically equivalent to the conventional technique except for a diminished visibility of subtle erosions and fissures. As major advantages of DLR maybe pointed out that faulty exposures were avoided by the automatic adjustment of image brightness and that the soft tissue margins could be more easily delineated in displays with high edge enhancement than in conventional radiography. However, digital displays with high edge enhancement did not provide additional diagnostic information and led to artifacts at the edges of metal prostheses.

Adult↗
PubMed1992

[Digital cineradiography (DCR) of the act of swallowing. The initial clinical experiences].

Twenty-seven patients with different swallowing disorders were studied by employing digital cineradiography (DCR) for rapid imaging of the pharynx with a temporal resolution of up to 50 frames per second and a maximum spatial resolution of .8 per/mm. To facilitate therapy planning, the DCR study can be transferred to the otorhinolaryngologist via videotape. DCR is capable to substitute analog cine or video techniques in the pre- and postoperative examination of patients with swallowing disorders.

Cineradiography↗
PubMed1992

[Experimental studies on magnetic resonance tomographic and magnetic resonance angiographic imaging of poststenotic flow patterns].

A phantom has been developed, which permits the perfusion of defined stenosis with variable flow rates. The post-stenotic flow patterns were imaged by means of conventional MRI sequences and special angiographic sequences using a 1.5 total body scanner (Gyroscan S15, Philips). For conventional MRI images, spin-echo-sequences (TR 500 ms, TE 27 ms with reconstruction of the magnitude and phase images) and gradient-echo-sequences (TR 60 ms, TE 27 ms, flip angle 15 degrees with reconstruction of the magnitude images) were used. For MR angiography 2D inflow (multiple-single-slice-technique, TR 40 ms, TE 14 ms, flip angle 60 degrees) and flow-adjusted-gradient-sequences (TR 24 ms, TE 10 ms, flip angle 60 degrees) were performed. In addition to an analysis of the appearances, the length of the changed signal intensity beyond the stenosis was evaluated. For constant flow rates it increases with the severity of the stenosis. For a constant stenosis the length of the post-stenotic signal change alters with flow rate. The changes also depend on the direction of flow and the gradients of the chosen sequences. The comparison of magnitude and phase images allows the discrimination between turbulent and non-turbulent flow. It therefore appears possible to estimate the severity of arteriosclerotic occlusive disease by means of MRI in the future.

Blood Flow Velocity↗
PubMed1991

[Surgical therapy of bronchial cancer. Healing or palliation?].

In spite of the revolutionary innovations concerning diagnostic and intensive care techniques as well as better understanding of tumour biology during the last decade, rates of resection and long-term survival in bronchogenic carcinoma could not be improved. Nevertheless there is no reason for therapeutic nihilism. On the contrary all efforts are to be done in investigation on practicable, suitable, and supportable screening programmes to improve the patients outcome.

Carcinoma, Bronchogenic↗
PubMed1991

[Gastrointestinal amyloidosis: differential diagnosis and indications for surgical therapy].

The diagnosis of gastrointestinal amyloidosis may be difficult for both the radiologist and the examining surgeon because clinical symptoms are often uncharacteristic. Upper gastrointestinal series may show stenosing submucosal masses in the esophagus or gastric antrum with diminished peristalsis and pliability mimicking malignancies. With small bowel involvement, diminished motility and segmental or complete distension, a prolonged transit time, and eventually obstruction are common findings. In the present study, we report four cases of gastrointestinal amyloidosis and review the indications for operative treatment. Surgery should be avoided for abdominal pseudo-obstruction and but may be indicated in patients with gastrointestinal bleeding, perforation or other severe complications. The postoperative course is characterized by impaired wound healing, a high rate of heart and kidney failures, and considerable perioperative mortality. Thus, results are frequently unsatisfactory.

Aged↗
PubMed1990

[Colonic contrast enema in digital luminescent radiography (DLR) and conventional x-ray technic].

120 double-contrast barium enemas were obtained by both digital luminescent radiography (DLR) and conventional screen-film systems, the digital exposure dose being 50% of the conventional one. In DLR two differently post processed images were obtained from one x-ray exposure: a display with low spatial frequency enhancement was processed to look like a conventional radiograph and was complemented by a display with high spatial frequency enhancement. Analysing the results statistically DLR proved to be diagnostically equivalent to conventional radiography despite the reduction in exposure dose and a slightly diminished image quality. High spatial frequency enhancement did not provide further diagnostic information and is therefore superfluous in barium enemas.

Adult↗