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Biomedical subjects

J Link

Publications and source records attributed to J Link.

At least 91 records · Page 5Linked to original sources
PubMed1996

Influence of different fasting periods on P-31-MR-spectroscopy of the liver in normals and patients with liver metastases.

The purpose of this study was to determine the influence of different fasting periods on the in vivo P-31-MR spectroscopy of the healthy liver and patients with liver metastases. Image-guided localized P-31-MRS was performed in 24 patients with liver metastases and in 20 healthy volunteers. The spectra were obtained with a whole body scanner operating at 1.5 T using a surface coil. The P-31-MRS was performed after a fasting period of 3-5 h (group 1) and after overnight fasting (group 2). The PME/beta-NTP, PDE/beta-NTP and Pi/beta-NTP were calculated from P-31-MR spectra and were compared in relation to the nutrition status of the volunteers and patients. The PME/beta-NTP and PDE/beta-NTP were significantly increased in spectra of patients with metastases. There were no significant changes in the ratios of phosphorus metabolites in healthy liver tissue or in liver metastases after a fasting period of 3-5 h as compared with overnight fasting.

Adult↗
PubMed1996

[MR angiography in fibromuscular dysplasia of the cervical arteries].

PURPOSE: To determine 3-D time of flight MR angiography for evaluation of fibromuscular dysplasia in cervical vessels. MATERIAL AND METHODS: In 386 selective angiograms of cervical vessels fibromuscular dysplasia was revealed in 4 female patients in the age of 30-54 years. FMD was located in the carotid artery (n = 5) and in the vertebral artery (n = 2) with a total of 8 lesions. RESULTS: 6/8 of the lesions of the seven cervical vessels were located typically in the mid cervical portion of the vessels and 2/6 lesions were located in the atlas loop of the vertebral artery. 4 lesions showed moderate stenosis and 4 vessels showed only mild stenosis. These patterns which demonstrated the typical morphology of fibromuscular dysplasia with alternating irregular zones of widening and narrowing were evaluated well with MR angiography, the others were missed. CONCLUSION: MR angiography is suitable for detection of fibromuscular dysplasia when the characteristic pattern is combined with moderate stenosis of the vessel. Conventional angiography remains the standard of reference.

Adult↗
PubMed1996

[Technical modification of the rheolytic thrombectomy].

A 48-year-old male patient with acute occlusion (5 cm) of a leg artery was treated with the rheolytic thrombectomy (RT). As recommended the catheter is applied via a single coaxial running guide wire, which is removed later. If an additional wire has been placed in the occluded vessel segment, the occlusion can be passed repeatedly. A 30 degrees bent catheter tip improves the removal of wall-adherent thrombotic material. The occluded segment was successfully recanalized with the RTC, 270 ml of heparinised saline had been injected. The blood examinations showed mild haemolysis.

Arterial Occlusive Diseases↗
PubMed1996

[Results of percutaneous implantation of coated vascular prostheses in long-distance femoropopliteal occlusions].

PURPOSE: Evaluation of primary patency rate, complications and midterm follow-up after implantation of endoprostheses in femoropopliteal occlusions. MATERIAL AND METHODS: 25 patients suffering from femoropopliteal occlusion (average length 7 cm) underwent percutaneous femoropopliteal endoprosthesis treatment. A total of 34 endoprostheses were implanted. Clinical and Doppler follow-up was performed after 1, 3, 6 and 9 months. Mean follow-up is 6 months. RESULTS: Percutaneous placement of endoprostheses was successful primarily in 24/25 patients. In one patient an early occlusion of the endoprosthesis occurred, caused by an embolic complication. Primary patency was 64% after 6 months and secondary patency rate was 71%. Severe local pain at the application site and fever was observed in 40% of the patients. CONCLUSION: The occlusion rate of 36% after 6 months is high. Long-term follow-up must be awaited before a general recommendation can be made. The cause of the local pain and fever in the early postinterventional period remains unclear.

Adult↗
PubMed1996

[Mechanical thrombolysis with the Amplatz thrombectomy catheter].

PURPOSE: To determine the efficiency of the Amplatz thrombectomy device (ATD) in thromboembolic occlusions of lower limb arteries and haemodialysis shunts. PATIENTS AND METHODS: 9 patients (mean age 61 years) with either occluded native leg arteries (n = 7) or haemodialysis graft access (n = 2) were treated with the ATD. Mean length of occlusion was 10 +/- 4.47 cm. RESULTS: The occlusions were primarily successfully recanalized by ATD within 44 +/- 17 seconds. Remaining stenoses were treated with percutaneous transluminal angioplasty (PTA, n = 6) and an additional implantation of a vascular stent (n = 3). The ankle-brachial-index (ABI) increased from 0.46 +/- 0.37 to 0.81 +/- 0.2 within 24 hours after intervention. In the first month ABI measured 0.9 +/- 0.15 and decreased from 0.7 +/- 0.23 after three months to 0.72 +/- 0.26 within 6 months. After 5 months, a shunt occlusion and a native leq artery occlusion appeared. CONCLUSIONS: Thrombolysis by ATD is a safe, feasible and simple procedure. There are no contraindications. No complications were seen.

Adult↗
PubMed1996

[MR diagnosis after a Ross operation].

PURPOSE: To determine the ability of MRI to diagnose morphological and functional changes in patients after Ross procedure. MATERIAL AND METHODS: During one year, 5 patients after Ross procedure were studied by MRI. T1-weighted spin-echo sequences in different orientations as well as cine sequences and a VENC sequence were used. RESULTS: In all patients the morphology including the postoperative changes could be visualised by MRI. The cine sequences provided functional information on valvular and ventricular function. VENC-MR yielded an exact quantification of the regurgitant fraction. CONCLUSION: MRI is capable of providing all important diagnostic information in patients after Ross procedure such as valvular and ventricular function and valvular and outflow tract morphology in a single examination.

Adolescent↗
PubMed1996

[MR angiography of the carotid arteries using 3D TOF technique with sagittal double-volume acquisition using a new head-neck coil].

PURPOSE: The aim of the study was to assess the value of MR angiography (MRA) in sagittal technique compared to DSA in the evaluation of carotid artery stenosis. METHODS: 80 carotid arteries in 40 symptomatic patients were prospectively studied with DSA and MRA. MRA was carried out by means of 3 D time-of-flight technique with a FISP sequence (TE6 ms/TR80 ms, flip angle 25 degrees, FOV 240 x 210 mm, matrix 157 x 256 mm, in-plane resolution 1.34 x 0.94 mm, partition thickness 1.32 mm, slab thickness 45 mm, acquisition time 7 min) using a new head-neck coll. Data acquisition was performed in sagittal orientation with the "double-slab" technique. Imaging quality of the extracranial carotid arteries and correctness of quantification of stenosis was performed. RESULTS: Imaging quality was good at the origin of the carotid arteries in 65%, at the bifurcation region in 98% and near the skull base in 81%. The agreement of DSA and MRA was 96% of the normal arteries (24/25), 90% of the severe stenoses (28/31) and 100% of the occluded arteries (9/9). CONCLUSION: MRA in sagittal "double-slab" technique is a noninvasive technique allowing to detect normal arteries and candidates for surgery with a high degree of certainty.

Adult↗
PubMed1996

[Modified manual rt-PA pulse-spray lysis in occlusions of leg arteries and femoro-popliteal bypasses].

PURPOSE: The evaluation of local rt-PA pulse-spray-lysis (PSL) by the Katzen infusion wire for treatment of thrombosed leg arteries and bypass grafts. MATERIAL AND METHOD: 21 patients (mean age 64.4 years) with either occluded leg arteries (n = 19) or femorocrural bypass grafts (n = 2) were treated with PSL. Mean length of occlusion was 13.2 +/- 11.6 cm. Time of occlusion ranged from less than one week to 6 months. RESULTS: In 71.43% (15/21) the occlusions could be successfully recanalized with PSL. The mean rt-PA dose was 10.7 +/- 4.9 mg. Remaining stenoses were handled with PTA (n = 9) and additional stent implantation (n = 3). Additional long-time-lysis with 17.5 mg rt-PA was necessary in two cases, the success rate increased to 81% (17/21). The anlde-brachial-index increased from 0.38 +/- 0.29 to 0.83 +/- 0.32 within 24 hours after intervention. In 4 cases bleeding complications occurred. 5 patients showed reocclusions during 6 months follow-up. CONCLUSIONS: Local fibrinolysis with rt-PA in PSL technique using the Katzen infusion wire is a feasible and promising treatment of thrombosed leg arteries and grafts. Even careful and dosage-minimized rt-PA application cannot prevent bleeding complications.

Adult↗
PubMed1996

Augmented expression of tumour necrosis factor-alpha and lymphotoxin in mononuclear cells in multiple sclerosis and optic neuritis.

The involvement of proinflammatory cytokines tumour necrosis factor-alpha (TNF-alpha) and lymphotoxin (LT) in multiple sclerosis is suggested by the parallel occurrence of these proinflammatory cytokines in acute and chronic active multiple sclerosis brain lesions. We describe the use of in situ hybridization with radiolabelled cDNA oligonucleotide probes to detect and enumerate TNF-alpha and LT mRNA expressing mononuclear cells without culture, and after culture in the presence of myelin basic protein (MBP), control antigens or without antigen. Compared with patients with aseptic meningo-encephalitis, non-inflammatory neurological diseases and healthy controls, the multiple sclerosis patients had elevated numbers of TNF-alpha and LT mRNA expressing mononuclear cells in blood when enumerated without previous culture, and also after culture with MBP. The MBP-induced upregulation of TNF-alpha and LT was major histocompatibility complex (MHC) class II molecule dependent. Tumour necrosis factor-alpha mRNA expressing mononuclear cells were further enriched in the multiple sclerosis patients' CSF. Positive correlations were observed in multiple sclerosis between TNF-alpha and LT mRNA expressing blood mononuclear cells, MBP-reactive TNF-alpha and LT mRNA expressing cells, and TNF-alpha and interferon-gamma (INF-gamma) mRNA expressing mononuclear cells. Upregulation of TNF-alpha correlated positively with exacerbation, enhanced disability and the secondary progressive phase of multiple sclerosis. Patients with optic neuritis, in many instances representing very early multiple sclerosis, had TNF-alpha and LT positive blood mononuclear cells that were elevated to the same extent as patients with clinically definite multiple sclerosis. The findings support the hypothesis that TNF-alpha and LT play a harmful role in the development of multiple sclerosis and suggest that TNF-alpha could be useful as a disease activity marker in multiple sclerosis.

Adult↗
PubMed1996

Effect of intraarticular pressure on patellar position. Computed tomography study in cadaveric specimens.

RATIONALE AND OBJECTIVES: The purpose of the study was to evaluate the effect of articular fluid distention on patellar position at different degrees of knee angulation. METHODS: Patellar position in 10 cadaveric knee specimens was determined with 30, 100, and 200 mm Hg joint distention at 45, 20, and 5 degrees of knee flexion using computed tomography. Patellar tilting and lateromedial and anteroposterior displacement of the patellar position were analyzed. RESULTS: Lateral tilting increased with greater articular distention and decreasing knee flexion. At 5 degrees of flexion and 200 mm Hg of distention, change in lateral tilting ranged from -7 to +5 degrees. At 45 degrees of flexion and increased distention, the patellar shift ranged from 6 mm medialization to 1 mm lateralization for 200 mm Hg, but the patellar position was more variable at 5 degrees of flexion with increasing intraarticular pressure (range 7 mm medialization to 8 mm lateralization). With increasing articular pressure the patellae were increasingly displaced anteriorly with the most pressure-dependent changes at 45 and 20 degrees of knee flexion. CONCLUSIONS: Fluid distentions of the knee joint have unpredictable and varying effects on the patellar position and vary considerably among persons. When judging patellar position during arthroscopy and in patients with large joint effusions, the arthroscopist and radiologist should be aware of these effects.

Aged↗
PubMed1996

Iatrogenic vertebrojugular arteriovenous fistula.

Arteriovenous fistulae originating from the vertebral artery are rare. We report a patient in whom a vertebral artery-jugular venous fistula developed following insertion of a central venous catheter via the internal jugular vein. The fistula was successfully occluded surgically.

Aged↗
PubMed1996

Dacron-covered stent-grafts for the percutaneous treatment of carotid aneurysms: effectiveness and biocompatibility--experimental study in swine.

PURPOSE: To evaluate the short-term effectiveness and biocompatibility of Dacron-covered stent-grafts for percutaneous treatment of carotid aneurysms. MATERIALS AND METHODS: In eight swine, nine aneurysms were created surgically in the common carotid artery. Percutaneous treatment was performed with Dacron-covered stent-grafts. Seven of eight swine underwent follow-up angiography at 2, 3, 4, and 5 weeks after stent implantation. Histologic examinations of tissue from the site of stent implantation were performed at the same intervals. RESULTS: Initial closing off of the aneurysm was possible in all swine. Angiographic follow-up revealed patency of only one Dacron-covered stent-graft after 2 weeks. In six of seven swine, the stent was occluded on the follow-up angiogram. One of the swine died of unclear cause after 1 week. The stent-graft of this swine was not occluded. In all Dacron-covered stent-grafts, inflammatory reaction with granulocyte infiltration was found next to the Dacron material. CONCLUSION: Primary treatment of carotid aneurysms with Dacron-covered stent-grafts is effective. However, the short-term patency rate is poor, which probably can be attributed to the limited biocompatibility of the Dacron cover. An acute inflammatory reaction against Dacron seems responsible for the poor patency rate.

Angiography, Digital Subtraction↗
PubMed1996

[The initial results of percutaneous therapy of popliteal aneurysms with stents].

PURPOSE: Are percutaneous stents a therapeutic alternative to bypass surgery in the treatment of popliteal aneurysms? MATERIAL AND METHODS: Three patients with femoropopliteal occlusion related to popliteal aneurysms were treated percutaneously. In two cases coated stents were used. In the third patient who underwent prior bypass surgery due to local fibrinolysis a reperfusion of the aneurysm occurred. He was treated with a Wallstent. RESULTS: Primary stent treatment was successful in all cases. There were no complications. One patient was lost to follow-up. One of the two coated stents occluded after one month due to a poor run-off of only one lower limb artery. The other coated stent is still patent after 6 months proven by angiography. CONCLUSION: Percutaneous therapy with coated stents could be an alternative to surgical bypass therapy for popliteal aneurysms. Obviously long-time patency is related to sufficient run-off.

Aged↗
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↗