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Biomedical subjects

M Heller

Publications and source records attributed to M Heller.

At least 235 records · Page 13Linked to original sources
PubMed1996

Spiral CT angiography and selective digital subtraction angiography of internal carotid artery stenosis.

PURPOSE: To determine whether spiral CT angiography allows accurate, quantitative evaluation of anatomic abnormalities, including detection of additional lesions, delineation of plaque morphology, and estimation of degree of internal carotid artery stenosis. METHODS: Spiral CT angiography with a maximum intensity projection technique was compared with selective digital subtraction angiography (DSA) in 92 carotid arteries. The category of stenosis was determined according to the North American Symptomatic Carotid Endarterectomy Trial: mild (0% to 29%), moderate (30% to 69%), severe (70% to 99%), and occlusion (100%). RESULTS: In 78 (85%) of the 92 cases, spiral CT angiography and selective DSA demonstrated the same degree of stenosis. All occlusions (n = 19) were diagnosed correctly with spiral CT angiography. Spiral CT angiography agreed with selective DSA in the classification of stenosis in 59% of the group with mild stenosis, in 82% of the group with moderate stenosis, and in 90% of the group with severe stenosis. In the groups with mild (n = 13), moderate (n = 9), and severe (n = 27) stenosis, correlation of spiral CT angiography with selective DSA was significant. Calcified plaques were readily diagnosed with the use of spiral CT angiography but delineation of ulcers was poor. Tandem lesions were not visible owing to the limited coverage. CONCLUSION: Spiral CT angiography is useful for the detection of proximal internal carotid stenoses that are greater than 30%. Depiction of mild stenoses appears to be limited. CT is superior for the detection of calcified plaques but it is not useful for the detection of ulcers.

Adult↗
PubMed1996

[CT-guided punctures: diagnostic value, therapeutic consequences and economic aspects].

PURPOSE: To evaluate the diagnostic and clinical relevance and therapeutic consequences of CT-guided biopsy with regard to economic aspects. METHODS: 213 CT-guided biopsies in 190 patients were evaluated. All information regarding patient referral, reason for request, body region, underlying diagnosis, and clinical consequences were registered over a period of 22.2 +/- 9.4 month. RESULTS: Patient referral to biopsy was mainly from the departments of surgery, internal medicine, and radiotherapy with the question of tumor and metastasis. Less than 5% of biopsies were performed in outpatients. Main regions were the lung (39%), the abdomen (35%), and the skeleton (11%). Biopsy and surgical histology corresponded in 73%. Largest diagnosis groups were benign unspecific tissues or other benign lesions in 24%. As a result of CTP no further procedures were necessary in 22.5%. Follow-up studies or conservative treatment were indicated in 11.3%. Surgical procedures were needed in only 15.5%. There was only one complication requiring therapy. CONCLUSION: CT-guided biopsy is a safe procedure, which helps to avoid unneccessary cost-intensive diagnostics and surgical treatment. If CTP is performed early and in outpatients residence time in the hospital is reduced and thus money is saved.

Adult↗
PubMed1996

[CT and PRI angiographic findings in dissection of the neck arteries].

PURPOSE: To determine the usefulness of CT angiography (CTA) and MR angiography (MRA) for evaluation of dissection in cervical vessels. MATERIAL AND METHODS: Dissection of cervical vessels was revealed by conventional angiography in 4 patients (two female, two male) of 30-62 years of age. Dissection was located in the carotid artery (n = 3) and in the vertebral artery (n = 1). In two patients CTA and in two patients MRA was performed. RESULTS: Diagnosis of dissection was possible by CTA (internal carotid artery: n = 2) and by MRA (internal carotid artery and vertebral artery). Imaging of the dissection membrane of the vessel wall was possible in one case with MRA. CONCLUSION: CT and MR angiography was successful for detection of typical morphology of dissection in all cases. If results in a greater number can be obtained it seems to be conceivable that both methods can be used in primary diagnosis.

Adult↗
PubMed1996

[Diving-associated pulmonary barotrauma as a rare differential diagnosis in internal medicine-pneumologic ambulatory care].

Arterial gas embolism due to pulmonary barotrauma (PBT) is a well known fatal complication in compressed air diving. Pulmonary damage is often missed in conventional diagnostic radiology. We present two cases of PBT in recreational divers, in which pre and post accidental chest x-rays were negative but chest-CT showed peripheral bullae in the lower lung lobes preferably responsible for PBT, Chest-CT is recommended in any case of suspected PBT to evaluate the possibility of preexisting pathology in order to predict further diving fitness.

Adult↗
PubMed1996

[Spiral CT angiography versus DSA in detection of carotid stenoses].

PURPOSE: To determine the value of spiral CT angiography for evaluation of internal carotid artery stenosis. METHODS: Spiral CT angiography was compared with selective intraarterial DSA in 40 patients with 72 internal carotid artery stenoses. Quantification of stenoses was performed according to the NASCET-study and categorized in mild (0-29%), moderate (30-69%), severe (70-99%) and occlusion (100%). RESULTS: The total agreement of spiral CT angiography with DSA in all stenoses was 78% (r = 0.933; p < 0.0001). In the mild stenoses group there was an agreement of 56% (r = 0.598; p = 138), in the moderate stenosis group there was an agreement of 59% (0.623; p = 0.0128) and in the group with severe stenosis the agreement was 97% (0.944; p < 0.0001). All occlusions were correctly interpreted by spiral CT angiography (r = 1; p = 0.0082). CONCLUSION: The agreement of spiral CT angiography with DSA is good. Especially SCTA allows a good correlation in the severe stenosis group and in the occlusion group. DSA remains the standard of reference, because of its ability to demonstrate tandem lesions and collateral flow.

Adult↗
PubMed1995

Cine MR imaging before and after realignment surgery for patellar maltracking -- comparison with axial radiographs.

OBJECTIVE: Comparison of motion-triggered cine magnetic resonance (MR) imaging and conventional radiographs for the assessment of operative results of patellar realignment. SUBJECTS AND METHODS: Fifteen patients with recurrent patellar dislocation or patellar subluxation were evaluated with conventional axial radiographs before and after realignment surgery by measuring the congruence angle (CA), lateral patellofemoral angle (LPFA), and lateral displacement (d). In eight patients the patellofemoral joint was additionally evaluated pre- and postoperatively with motion-triggered cine MR imaging by determining the bisect offset (BSO), lateral patellar displacement (LPD), and patellar tilt angle (PTA). RESULTS AND CONCLUSIONS: Significant differences between the pre- and postoperative measurements were found for all MR imaging parameters (BSO, LPD, PTA: p<0.01) but not for the conventional X-ray parameters (CA: p = 0.70, LPFA: p = 0.56; d: p = 0.04). Motion-triggered cine MR imaging was superior to conventional tangential radiographs for assessing the effectiveness of patellar realignment surgery.

Adolescent↗
PubMed1995

Emergency ultrasound services as perceived by directors of radiology and emergency departments.

Despite widespread concern that emergency ultrasound services are not widely available after regular business hours, data supporting or refuting this concern have not been reported. To determine the availability of emergency ultrasound services as perceived by directors of emergency departments (EDs) and radiology departments, direct mail survey was sent to both ED Directors and Directors of Radiology at 100 large teaching hospitals (more than 300 beds) and 100 smaller nonteaching hospitals (fewer than 300 beds) chosen at random from the American Heart Association Guide. Questions elicited the directors' perceptions of availability of emergency ultrasound services in their own institutions as well as their attitudes toward performance of ultrasound examinations by emergency physicians. The overall response rate was 53%. It was found that 24-hour in-house ultrasound services are rarely available even in large teaching hospitals, even as reported by Directors of Radiology. ED Directors and Directors of Radiology differ significantly in perceptions of ultrasound availability, clinical importance of emergency ultrasound, and desirability of ultrasound performance by ED physicians.

Attitude of Health Personnel↗
PubMed1995

[The initial results of spiral CT angiography in demonstrating stenoses of the a. carotis].

PURPOSE: To determine the value of spiral CT angiography in Maximum Intensity Projection (MIP)-technique for evaluation of carotid artery stenosis. METHODS: A comparison of the MIP technique with intraarterial DSA was done in 24 patients with 40 stenoses. Quantification of stenosis was determined according to the NASCET study: mild (0-29%), moderate (30-69%), severe (70-99%) and occlusion (100%). RESULTS: Totally the correlation of spiral CT angiography with DSA was 80% (r = 0.93; p = 0.0001). In the moderate stenosis group (r = 1; p = 0.1573), severe stenosis group (r = 0.89; p = 0.002) and the occlusion group (r = 1; p = 0.0009) there was a good correlation with DSA. In the mild stenosis group (r = 0.55; p = 0.0704) correlation of spiral CT angiography with DSA was poor. Spiral CT angiography allows an excellent delineation of calcifications. Tandem lesions and collateral flow cannot be shown with spiral CT angiography. CONCLUSION: Intraarterial DSA remains the gold standard for evaluation of carotid artery stenosis, because DSA is the modality which shows the whole length of the carotid artery and yields information on tandem lesions and collateral flow.

Adult↗
PubMed1995

[Quantitative computed tomography of the lung in the early diagnosis of asbestosis: initial results in asbestos-exposed navy personnel].

AIM: To evaluate the diagnostic role of respiratory gated quantitative CT of the lung with regard to the early detection of asbestos-induced lung fibrosis. MATERIAL AND METHODS: 29 navy personnel with a mean asbestos exposure of 21.3 years and exclusively low profusion stages with regard to plain film X-ray (0/1 and 1/0, ILO 1980) were examined using high resolution CT and respiratory gated quantitative CT of the lung. RESULTS: A low but significant increase of the global lung density with -816 HU (range -844 to -749 HU) was found in comparison with the age-matched reference values of -829.8 HU (range -834 to -819 HU). In individual cases the histogram analysis demonstrated a shift of the density distribution towards higher density intervals without corresponding findings in HRCT. No alterations in lung function were observed. There was no correlation between the latency period or length of exposure and density values. CONCLUSION: The respiratory gated quantitative CT of the lung may potentially develop into an accessory parameter for monitoring dust exposed personnel.

Adult↗
PubMed1995

[Venous stent application with a simultaneous cubitofemoral approach].

In 4 patients with superior inflow obstruction caused by stenosis or occlusion of the central veins it was not possible to pass the guide wire from transfemoral. An additional transbrachial access was applied to avoid the stenosis or occlusions. Patency of the veins from transbrachial was achieved in all cases. After pulling the extensively long guide wire through the still horizontal venous lock, successful Wallstent application was performed from transfemoral in all 4 patients. No peri-interventional or post-interventional complications were seen during 2 days follow-up.

Aged↗
PubMed1995

[Kinematic MRI in degenerative cervical spine changes].

AIM: To evaluate functional stenosis of the cervical spine, kinematic MRI was performed in 23 healthy volunteers and 23 patients with degenerative disease. MATERIAL AND METHOD: Kinematic MRI of the cervical spine was done from 50 degrees of inclination to 30 degrees of reclination. Depending on the maximum inclination and reclination the range of motion was divided into 9 equal angle positions. At each angle position sagittal T2* weighted gradient echo sequences were performed. RESULTS: In relation to the neutral position a physiological narrowing of the ventral epidural space was seen in healthy volunteers at inclination (50 degrees) in up to 50% and respectively widening at reclination (30 degrees) in up to 10%. An increase of spinal canal stenosis or even spinal cord compression was seen at inclination in 5 patients (22%) and in 15 patients (65%) at reclination. No change of spinal canal stenosis was found in three patients (13%). CONCLUSION: In patients with degenerative disease of the cervical spine kinematic MRI demonstrated in some patients functional spinal canal stenosis with myelon compression which was not seen in standard MRI. Therefore kinematic MR imaging can be recommended as a complementary examination in the early detection of functional myelon compression and in planning the further therapeutic work-up.

Adult↗
PubMed1995

[Double spiral CT angiography].

AIM: To evaluate the clinical value of CT angiography using double-spiral CT technique. METHOD: 7 patients with peripheral occlusive disease were examined after stent placement into iliac arteries (5/7) or prior surgery under the clinical suspicion of an occluded vascular graft (2/2). After a delay of 25 sec two spiral CT-scans, each of 32 sec duration, were started. The average interscan delay was between 12-15 sec. The total examination time was about 100 sec and the total range 36 cm using a slice thickness of 3 mm and a table feed of 6 mm/sec. 150 ml of contrast material were injected continuously with 3 ml/sec. RESULTS: All stents were exactly located and diagnosed as patent (6/6) in comparison to intraarterial angiography. Two occluded vascular grafts were diagnosed, confirmed by surgical findings (2/2). Density measurements showed enough of contrast material in the vessels to perform CT-angiography even in the second part of the examination. CONCLUSION: Double-spiral CT angiography is a clinical applicable and helpful method to examine patients with peripheral occlusive disease. It allows to double the examination range without losing the advantages of small slice thickness.

Aged↗
PubMed1995

[CT angiography in the follow-up after carotid endarterectomy].

PURPOSE: To prove the usefulness and clinical value of early CT angiography with maximum intensity projection after carotid endarterectomy: for demonstrating postoperative results. METHODS: In 16 patients with angiographically confirmed 20 high grade stenoses of internal carotid artery CT angiography was performed before and after carotid surgery within 7 days. The evaluation of successful surgery was related to complete plaque removal and patency of internal carotid artery after endarterectomy based on preoperative CT angiography. Classification of stenosis was performed according to the NASCET study. RESULTS: In 2/20 cases severe stenoses remained after surgery, which were demonstrated using CT angiography and confirmed by digital subtraction arteriography. 3/20 cases showed mild stenosis and 15/20 were normal. CONCLUSION: CT angiography is best suited to evaluate results after carotid surgery. The method enables delineation of complete removal of calcified plaque and patency of carotid artery.

Aged↗
PubMed1995

[Spiral CT angiography after the application of an iliac artery stent].

PURPOSE: To evaluate the diagnostic and clinical value of CT-A performing MIP- and SSD-reformations after intraarterial iliac stent application. METHODS: In a prospective study 32 patients underwent CT-A after stent placement in the iliac arteries. The vascular morphology was analyzed regarding neointimal hyperplasia and calcification pattern. The results were compared with those of clinical findings (walking distance), Doppler ultrasound (ankle-brachial index) and DSA. RESULTS: All 47 stents were visible and patent (100%). One misplacement was identified. A good correlation was found between an improved ankle-brachial index and CT-A (88.5%) and extension of the walking distance and CT-A (92.3%). Concerning location, number and grade of stenoses the results between CT-A and DSA matched in 42.1%. An exact mapping of calcified plaques was possible in all cases. CONCLUSIONS: CT-A as MIP is shown to be superior than DSA with regard to calcifications. Complementary to the indirect methods of the ankle-brachial index and walking distance, CT-A is useful for therapy control after vascular stent placement.

Aged↗
PubMed1995

[A modified technic for local rt-PA catheter-mediated lysis].

PURPOSE: To develop an economic and efficient concept for more time-saving local rt-PA thrombolysis therapy. METHOD: 40 patients with peripheral vascular occlusive disease stage IIb-III according to the Fontaine classification and with angiographically proven occluded segments of pelvic and lower limb arteries were treated by a modified concept of local rt-PA catheter thrombolysis. Via a thin guide wire the catheter for thrombolysis is slowly advanced through the thrombus without fluoroscopic control, outside the room in which angiography is performed. In 24 cases a short-term lysis and in 16 cases a long-term lysis was carried out. RESULTS: The initial success rate was 75%, the patency rate in six months' follow-up was 66.7%. The ankle-brachial index decreased from 0.4 +/- 0.3 to 0.8 +/- 0.2 on the average. There were no relevant clinical complications. The average occupancy time of the angiography room or table was 60 +/- 52 min, the average time of fluoroscopy was 17 +/- 13 min. CONCLUSION: In modified local rt-PA thrombolysis, short-term lysis and long-term lysis were mostly performed outside the angiography room, so that the exposure to radiation and there fore the radiation dose were reduced for both the patient and the attending staff. The angiography room is thus available for other patients and can therefore be used more efficiently.

Adult↗