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J Link

Publications and source records attributed to J Link.

At least 73 records · Page 4Linked to original sources
PubMed1998

The utility of contrast-enhanced MR-angiography for posterior fossa giant cerebral aneurysm management.

The utility of magnetic resonance angiography is sometimes limited in the diagnostic workup of cerebral aneurysms with low flow and/or partial thrombosis when weighed against digital subtraction angiography. We present the case of a rare superior cerebellar artery giant, partially thrombosed aneurysm in which additional i.v. contrast-enhanced MRA sequences were comparable to digital subtraction angiography. It demonstrated not only the exact spatial resolution and correct anatomical relation but also the hemodynamics which were confirmed by intraoperative Doppler ultrasound. This report supports the feasibility and utility of i.v. contrast-enhanced MRA for posterior fossa giant cerebral aneurysm management.

Cerebellum↗
PubMed1998

[PTA of the brachiocephalic arteries].

PURPOSE: Assessment of the technical success and mid-term success of PTA of brachiocephalic occlusive disease. MATERIAL AND METHODS: 24 patients, who were treated interventionally because of stenoses of the brachiocephalic arteries were enrolled into this prospective study. In total there were 27 lesions (26 arteriosclerotic lesions and one dissection with pseudoaneurysma). 18 lesions were located in the subclavian artery (extending into the axillar artery in one case), 4 in the brachiocephalic trunk, three in the common carotid artery and two in the vertebral artery. As adjunctive to balloon dilatation 8 stents were implanted. RESULTS: Technical success was achieved in 24/27 lesions. There was an embolic complication in one of 27 interventions. 15/24 patients with 17 treated lesions underwent control angiography with a mean follow-up of 14 months. Follow-up angiography revealed one occlusion and three significant restenoses. 5/24 patients agreed only to clinical follow-up and Doppler examinations, three were lost and one patient died. CONCLUSION: PTA of brachiocephalic occlusive disease showed good technical success. Additional implantation of stents may be useful. Midterm success is satisfactory.

Aged↗
PubMed1997

[MR angiography of pelvic arteries].

During the last years, magnetic resonance angiography (MRA) has become a widely used modality for intracerebral and carotid artery imaging. Due to technical limitations, the clinical impact of MRA in the iliofemoral arteries has been rather poor. New developments in MRA like ECG-triggered sequences and the occurrence of contrast-enhanced MRA has overcome most of these limitations. Therefore, a major advance in clinical use of these diagnostic tools can be predicted. This paper discussed the advantages of ECG-gated 2D-Phase contrast, ECG-gated 2D-Time-of-Flight and contrast enhanced FLASH 3D angiography sequences from a clinical point of view. 2D-PC-MRA is a robust technique, which provides an overview of the iliofemoral artery system in less than 5 minutes. Limitations are the true 2D impression of the sequence and the partial venous overlay. 2D-TOF-MRA on the other hand is time consuming, however it enables 3D reconstruction and effective venous suppression can be applied. Contrast enhanced MRA as the third sequence discussed provides high resolution images in less than 30 sec. However contrast bolus timing might be a problem. In conclusion the authors suggest a combination of 2D-PC-MRA and additional 2D-TOF sequences at questionable vascular areas as the modality of choice, due to the fact, that MRA of the iliofemoral arteries ist mostly only one step of a complete lower limb examination. Contrast MRA might become the method of choice in the future however problems with multiple contrast injections and upper limits of contrast dose have to be solved.

Adult↗
PubMed1997

Distinct central anticholinergic syndrome following general anaesthesia.

The purpose of this prospective study was to identify the incidence of a distinct central anticholinergic syndrome following routine anaesthesia. For 2 months, all inpatients aged more than 15 years scheduled for elective procedures and cared for in the recovery room were investigated for symptoms of the syndrome. Patients with neuropsychiatric disease or other disorders that could alter consciousness were excluded. Prolonged action of anaesthetics or relaxants, respiratory depression and metabolic disorder were ruled out before making the diagnosis. Out of 962 patients (366 men, 596 women), 18 (4 men, 14 women) developed the syndrome. The difference between men and women was not statistically significant. Six out of 60 women developed the syndrome after a hysterectomy with or without adnectomy/oophorectomy, and this high incidence was significantly different from that observed after all other procedures in women (P = 0.003) or all other gynaecological procedures (P = 0.013). The reason for this is unknown. In six of the 18 cases, untreated prolonged somnolence lasted for more than 2 h. All patients woke up after an injection of physostigmine, but six of them relapsed into somnolence and needed a second, and in one case a third, injection. The findings of the study emphasize that, when there is delayed recovery from anaesthesia, the diagnosis of central anticholinergic syndrome should be considered if other accessible causes for that condition have been excluded.

Adolescent↗
PubMed1997

[3D-CT angiography and duplex sonography compared to arteriography in carotid stenoses].

PURPOSE: To determine the value of 3D-CT angiography, duplex sonography in comparison to selective digital subtraction angiography for evaluation of carotid artery stenoses. METHODS: 30 patients with 51 stenoses of carotid artery underwent 3D-CT angiography, duplex sonography and angiography. Quantification of stenosis was determined according to the NASCET study and categorized into mild (0-29%), moderate (30-69%), severe (70-99%) and occluded (100%). RESULTS: The agreement of 3D-CT angiography with intraarterial digital subtraction angiography (DSA) was 62% (r = 0.89; p < 0.0001) and of duplex sonography with DSA was 77% (r = 0.94; p < 0.0001). Both modalities underestimated one occlusion as stenosed. In the evaluation of moderate and severe stenoses 3D-CT angiography showed an agreement with DSA in 50% (duplex: 88%) and 55% (duplex: 89%) respectively and was inferior to duplex sonography. CONCLUSION: 3D-CT angiography is inferior to duplex sonography in the evaluation of carotid stenosis and not useful as a screening or reference examination.

Aged↗
PubMed1997

[Midterm follow-up after Cragg stent placement in iliac arteries].

PURPOSE: Evaluation of midterm success and patency rates after placement of Cragg stents in iliac arteries. MATERIAL AND METHODS: During a period of 26 months 16 patients, with a total of 19 iliac lesions were treated percutaneously by placement of 20 stents. Indications of stent placement were iliac occlusion in 4 cases and high-grade iliac stenoses in 15 cases. Indication for stent placement in the stenotic lesions were insufficient results following balloon angioplasty in 11 cases and extensive dissection in 4 cases. RESULTS: The ankle-brachial index was improved from 0.53 +/- 0.28 to 0.85 +/- 0.26 immediately after the intervention and was 0.80 +/- 0.15 at 16 months follow-up. Cumulative patency rate was 71% after 12 months. CONCLUSION: The occlusion and restenosis rates are high. Disadvantages of Cragg stents are low flexibility and a large bore introducer system. The radiopacity of the Cragg stent is advantageous for fluoroscopic positioning.

Aged↗
PubMed1997

The total entropy for evaluating 31P-magnetic resonance spectra of the liver in healthy volunteers and patients with metastases.

RATIONALE AND OBJECTIVES: The authors describe the clinical status of liver tissue with only a single numerical quantity (total entropy) derived from spectroscopic data of 31P-magnetic resonance (MR) spectra. METHODS: Twenty-four patients with liver metastases and 20 volunteers were investigated with image-guided volume selective 31P-MR spectroscopy on a 1.5-T whole body scanner. From each in vivo 31P-MR spectrum, the ratios of phosphomonoester (PME)/beta-adenosine triphosphate (ATP), inorganic phosphate (Pi)/beta-ATP and phosphodiester (PDE)/ beta-ATP and the total entropy (H*) were calculated. Mean values and standard deviations were determined and significance of the differences were tested with Student's t test. RESULTS: For patients, the H* = 4.7 +/- 4.3, PME/beta-ATP 0.72 +/- 0.28, Pi/beta-ATP = 1.00 +/- 0.39, PDE/beta-ATP = 1.68 +/- 0.59. For the volunteers, H* = 7.6 +/- 2.5, PME/beta-ATP = 0.39 +/- 0.15, Pi/beta-ATP = 0.90 +/- 0.19, PDE/beta-ATP = 1.25 +/- 0.28. The total entropy of patients' spectra showed significantly lower values compared with those of volunteers. PME/beta-ATP and PDE/beta-ATP of the patients increased and differed significantly from volunteer data. CONCLUSIONS: It was demonstrated that the results of in vivo 31P-MR spectroscopy may be described with a single criterion by means of the total entropy.

Adenosine Triphosphate↗
PubMed1997

Effects of selective angiography of the carotid artery with carbon dioxide on electroencephalogram somatosensory evoked potentials and histopathologic findings. A pilot study in pigs.

RATIONALE AND OBJECTIVES: The authors investigate the cerebral effects of selective carotid angiography with carbon dioxide (CO2). METHODS: In 6 pigs, CO2 was injected into the carotid artery with consecutively increasing doses. Cerebral function was monitored with two-channel electroencephalography and somatosensory evoked potentials (SEPs). After the experiment the brains were investigated histopathologically. RESULTS: Initial doses led to reversible decreases in electroencephalograph power by 40% to 80%. Further doses result in partly nonreversible electroencephalographic changes. Somatosensory evoked potential latencies (n = 5) were not changed. Amplitudes were not affected in low dose ranges up to 40 mL CO2. Higher CO2 doses led to different changes. There were no SEP amplitude reductions (n = 1), as well as reversible (n = 2) and nonreversible (n = 2) SEP amplitude reductions. Histopathologically, edema (n = 6), edema necrosis (n = 2), and destroyed cells as a sign of ischemia (n = 2) were found. CONCLUSIONS: Administering CO2 in brain supplying arteries impairs the cerebral function. Consecutive, increasing doses lead to partly nonreversible electroencephalographic and SEP changes and brain tissue damages.

Angiography↗
PubMed1997

Common carotid artery bifurcation: preliminary results of CT angiography and color-coded duplex sonography compared with digital subtraction angiography.

OBJECTIVE: The purpose of this study was to compare the abilities of color-coded duplex sonography, CT angiography, and selective digital subtraction angiography to reveal disease requiring surgery in patients with occlusive disease of the carotid bifurcation. MATERIALS AND METHODS: Fifty-six carotid arteries in 28 patients who had 48 carotid stenoses and symptomatic cerebrovascular disease were prospectively studied by selective digital subtraction angiography, color-coded duplex sonography, and CT angiography. CT data were displayed in maximum intensity projection. The degree of stenoses revealed were graded as mild, moderate, severe, and occluded according to North American Symptomatic Carotid Endarterectomy Trial criteria. The results of CT angiography and color-coded duplex sonography were correlated with the gold standard of digital subtraction angiography. RESULTS: Grading of stenoses on CT angiography agreed with grading of stenoses on digital subtraction angiography in 89% of cases. All high-grade stenoses and occlusions revealed on CT angiography were correctly interpreted by all observers. For stenoses revealed by color-coded duplex sonography and digital subtraction angiography, observers' agreement was 75%. Two severe stenoses were incorrectly graded as occluded by the interpreter of the color-coded duplex sonograms. Also, one occluded carotid artery was misdiagnosed as moderate stenosis. CONCLUSION: Our results indicate that CT angiography is superior to color-coded duplex sonography for evaluating carotid disease and determining disease requiring surgery. CT angiography warrants further investigation in a larger group of patients.

Angiography, Digital Subtraction↗
PubMed1997

MR imaging signal-intensity abnormalities after placement of arterial endoprostheses.

OBJECTIVE: Our objectives were to describe changes in T2-weighted MR images of patients who had undergone implantation of an endoluminal stent-graft and determine the rate of early reocclusion in patients with abnormal MR findings. SUBJECTS AND METHODS: Twenty-nine patients with 26 occlusions (average length, 8.7 +/- 5.6 cm) and three dissections of the superficial femoral artery were treated with 45 endoluminal stent-grafts. T2-weighted gradient-echo and T2-weighted turbo spin-echo MR images were obtained for all patients at 48 hr and at 4 weeks after stent-graft placement. We reviewed the MR imaging studies to assess the extent and severity of tissue alteration at the site of stent-graft implantation. RESULTS: Technical success rate of stent-graft placement was 100%. Three signal-intensity patterns were seen on MR images obtained at 48 hr: normal signal intensity (n = 8), subtle perivascular signal-intensity abnormalities at the site of stent-graft implantation (n = 11), and extensive signal-intensity abnormalities from the adductor canal to the subcutis (n = 10). Twenty of 21 patients with abnormal signal intensity on MR images had fevers and pain at the implantation site. Clinical signs of deep vein thrombosis, a diagnosis excluded on the basis of phlebography, were seen in the 10 patients with extensive signal-intensity abnormalities. In two of these 10 patients, the superficial femoral artery reoccluded within 4 weeks of implantation. MR images obtained at 4 weeks showed no signal-intensity abnormalities in any of the 29 patients. CONCLUSION: MR findings of perivascular signal-intensity abnormalities after implantation of endoluminal stent-grafts are associated with clinical complications such as local pain and fever. Care should be taken to avoid confusing the clinical signs of the postimplantation syndrome at 48 hr with deep vein thrombosis.

Aged↗
PubMed1997

Cardiac-gated two-dimensional phase-contrast MR angiography of lower extremity occlusive disease.

OBJECTIVE: The purpose of this study was to evaluate our capability to use coronally acquired, cardiac-gated two-dimensional phase-contrast MR angiography (MRA) to correctly detect and grade arteriosclerotic lesions from the aortic bifurcation to the popliteal artery. SUBJECTS AND METHODS: One hundred fifteen patients with a total of 253 arteriosclerotic lesions proven by intraarterial digital subtraction angiography were examined prospectively by two-dimensional phase-contrast MRA. MRA was performed from the aortic bifurcation to the popliteal trifurcation. Imaging parameters were TR/TE, 83/9 msec; flip angle, 11 degrees; matrix, 256 x 192; acquisitions, two; slice thickness, 80 mm; and field of view, 320 mm. ECG gating was used routinely and eight to 10 phases were acquired during the cardiac cycle. Velocity encoding was set to 30 cm/sec in the iliac arteries and to 20 cm/sec in the femoral and popliteal arteries. Detected stenoses were graded in the following manner: 1% to less than 50% stenosis, group 1; 50% to less than 75% stenosis, group 2; 75% to less than 100% stenosis, group 3; and total occlusion, group 4. RESULTS: All arteriosclerotic lesions were revealed by MRA. Two hundred seventeen of 253 lesions were also graded correctly. Sensitivity was 95%, specificity was 90%, positive predictive value was 90%, and negative predictive value was 96%. The weighted kappa index was (.92). Sensitivity and specificity for occlusions were both 100%; for high-grade stenoses, 94% and 91%, respectively; for moderate stenoses, 84% and 94%, respectively; and for mild stenoses, 79% and 100%, respectively. CONCLUSION: Two-dimensional phase-contrast MRA can provide MR angiograms with high sensitivity and specificity for high-grade stenoses in a reasonable amount of time in patients with peripheral artery occlusive disease.

Adult↗
PubMed1997

[Minimal invasive therapy of aneurysms of the superficial femoral artery and the popliteal artery].

Percutaneous stent placement has been described for treatment of aneurysms as an alternative to surgical therapy. Literature reports of percutaneous minimal invasive therapy of peripheral aneurysms shall be reviewed and compared with our own results. Six male patients (51-69 years) with femoropopliteal occlusions related to aneurysms were treated percutaneously. In two cases Wallstents and in four cases polyester-covered nitinol stents were applicated. A clinical investigation including doppler-ultrasound was performed 24 hrs, 1, 3, 6, 12 and 24 months after the intervention. Stent placement succeeded in all cases. No adjunctive surgical treatment was necessary. Ankle-brachial-index (ABI) improved from 0.22 +/- 0.2 before to 0.74 +/- 0.2 24 hours after the intervention. One patient was lost for follow-up (Wallstent). A decrease of ABI and additional intraarterial angiography revealed stent-graft occlusion within one month (n = 2) and within three months (n = 1). One of these cases was successfully recanalized with local fibrinolysis therapy. In three patients patency of the stent persisted for 24 (+/- 2) months follow-up with three-vessel-supply of the calf. These results warrant further investigations for this minimal invasive method of percutaneous stent deployment as an alternative to surgical bypass treatment of femoropopliteal aneurysms. Time of hospitalization was reduced. At this time, surgical treatment of peripheral vascular aneurysms is gold standard.

Aged↗
PubMed1996

[Therapy of venous stenosis using wall stents].

OBJECTIVE: To evaluate the patency of Wallstents implanted for the treatment of venous stenoses in patients with benign or malignant disease. PATIENTS AND METHODS: 22 Wallstents (20 central venous; two peripheral) were implanted during a period of two years in 12 patients (nine men, three women; mean age 57.8 [26-76] years) with malignant venous stenoses (n = 9) or stenosed dialysis shunts (n = 3). Stent diameter ranged from 8-16 mm, length from 32-91 mm. Introduction of the stents were by percutaneous transfemoral catheterisation, in six patients with simultaneous wire placement from a cubital to the femoral vein. The superior vena cava was the involved vessel in six patients (in two each also the subclavian or brachiocephalic veins), in three only the subclavian vein, twice only the inferior vena cava and once the cephalic vein. RESULTS: The patency of the stents was checked after 4.7 +/- 3.6 (1-14) months, in seven patients clinically, by digital subtraction phlebography in three, by computed tomography in two. In nine patients there was no evidence of obstruction to flow or flow was normal. Stent occlusion had occurred in three patients, 4, 9 and 14 months after placement. There were no complications. Five patients died after a mean period of 4.8 +/- 3.6 (1-6.5) months from the underlying disease, without symptoms of obstruction to flow. CONCLUSION: Stent placement should be considered early, as it is a well-tolerated and effective palliative procedure for central venous stenoses associated with malignant disease or stenosis of dialysis shunts.

Adult↗
PubMed1996

Mucosal tolerance to experimental autoimmune myasthenia gravis is associated with down-regulation of AChR-specific IFN-gamma-expressing Th1-like cells and up-regulation of TGF-beta mRNA in mononuclear cells.

Oral and nasal administration of nicotinic acetylcholine receptor (AChR) to Lewis rats prior to myasthenogenic immunization with AChR and complete Freund's adjuvant (CFA) resulted in prevention or marked decrease of the severity of experimental autoimmune myasthenia gravis (EAMG) and suppression of AChR-specific B-cell responses and of AChR-reactive T-cell function. To examine the involvement of immunoregulatory cytokines and the underlying mechanisms involved in tolerance induction, in situ hybridization with radiolabeled cDNA oligonucleotide proves was adopted to enumerate mononuclear cells (MNC) expressing mRNA for the proinflammatory cytokine interferon-gamma (IFN-gamma), the B cell-stimulating interleukin-4 (IL-4), and the immunosuppressive transforming growth factor-beta (TGF-beta). Popliteal and inguinal lymph nodes from EAMG rats contained elevated numbers of AChR-reactive IFN-gamma, IL-4, and TGF-beta mRNA-expressing cells, compared to control rats receiving PBS orally or nasally and injected with CFA only. Oral and nasal tolerance was accompanied by decreased numbers of AChR-reactive IFN-gamma and IL-4 mRNA-expressing cells and strong up-regulation of TGF-beta mRNA-positive cells in lymphoid organs when compared to nontolerized EAMG control rats. The results suggest that IFN-gamma and IL-4 are central effector molecules in the development of EAMG and that TGF-beta plays an important role in tolerance induction to EAMG.

Administration, Intranasal↗