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Biomedical subjects

F Karnel

Publications and source records attributed to F Karnel.

At least 19 recordsLinked to original sources
PubMed1992

Renal transplant hemodynamics in children: prospective analysis of colour coded versus pulsed Doppler sonography.

In 30 children with renal allografts the diagnostic validity of pulsed Doppler (PD) versus colour coded Doppler (CD) sonography was assessed prospectively. 46 PD examinations were performed calculating the resistive index (RI) in the segmental arteries in comparison to 46 CD scans, where renal blood flow throughout the grey-scale image was displayed. In addition, point-spectral analysis with calculation of the RI was also performed on the CD scans. The time for examination ranged from five to ten minutes for the PD and from three to five minutes for the CD study. Concordant findings for the PD and CD technique were generally obtained (normal blood flow pattern on PD-excellent visualization of renal blood flow on CD, reduced or reversed diastolic flow on PD-poor visualization of renal blood flow on CD). There was close correlation of the RI values obtained by the PD and CD scans. CD sonography facilitated point-spectral analysis in shortening the time for examination. The ability to visualize focal hemodynamic alterations provided a higher diagnostic accuracy in comparison to PD sonography.

Adolescent↗
PubMed1992

[Saphenous vein bypass stenoses, early diagnosis with color coded Doppler sonography].

In a prospective study 54 patients with 62 saphenous vein arterial bypass grafts were examined by colour-coded Doppler sonography and angiography. Five cases of graft occlusion were diagnosed by colour-coded Doppler sonography and confirmed by angiography. In comparison with angiography, colour-coded Doppler sonography showed a sensitivity of 92% and a specificity of 100% in the detection of focal graft stenosis. Only two stenoses in the region of the distal anastomosis could not be detected by colour-coded Doppler sonography. In 28 cases a marked dilatation of the proximal anastomosis was found corresponding to the surgically used patch angioplasty. Within this dilated bypass segment, turbulence and flow reversal zones were demonstrated, which might be predisposing factors for graft stenosis. Colour-coded Doppler sonography can accurately detect saphenous vein arterial bypass graft stenoses and should be routinely used in postoperative screening.

Adult↗
PubMed1992

[Percutaneous CT-guided catheter drainage of intrathoracic fluid accumulations].

To verify the value of percutaneous CT-guided drainage of thoracic fluid collections we studied the outcome in 39 patients retrospectively. 24 (61.5%) of the fluid collections were located in the pleural space, 10 (25.6%) in the lungs and 5 (12.8%) in the mediastinum. 11 CT-guided drainages after a previous attempt were necessary in 9 patients, because of recurrent (n = 6) or residual (n = 5) fluid collections. 70% of the drainage procedures were done using Seldinger's, 30% using trocar technique, mainly with 8.3-12 F catheters. The mean duration of drainage was 10.7 days. In 28 patients (71.8%) the percutaneous CT-guided drainage was curative. In 9 cases (23.1%) the patient's course was stabilised and surgery could be applied electively. 2 patients (5.1%) died because of their underlying end-stage malignancy. None of the drainage procedures changed the patient's course to the worse. There was only 1 pneumothorax with no need of any treatment; no other complication occurred. Our results suggest that percutaneous CT-guided drainage of thoracic fluid collections is a safe and straightforward alternative to surgical treatment.

Adult↗
PubMed1992

[The screening of renal artery stenoses. The initial results with the value of color Doppler sonography].

The value of colour Doppler sonography in the diagnosis of renal artery stenosis has been studied retrospectively. 17 patients were examined (34 main renal arteries and 7 accessory renal arteries; ages 37 to 84 years; 7 males and 10 females). We studied 1) ability to study the main renal arteries, 2) visibility of accessory renal arteries and 3) the sensitivity and specificity of colour Doppler sonography for the diagnosis of renal artery stenosis. The results were compared with intraarterial angiography. Demonstration of the main renal arteries with colour Doppler sonography was possible in 23 of the 34 vessels. Not a single of the 7 accessory renal arteries was demonstrated by colour Doppler sonography. Of 8 angiographically demonstrated stenoses (more than 50% narrowing) 2 were missed by colour Doppler sonography. One stenosis was correctly diagnosed and 5 were incorrectly evaluated by sonography. 16 out of 18 angiographically normal main renal arteries were correctly evaluated by colour Doppler sonography but 2 showed a false positive finding. This results in a sensitivity of 17% and a specificity of 89% per kidney. Colour Doppler sonography cannot be recommended as a screening method for renal artery stenosis in view of its limited accuracy.

Adult↗
PubMed1992

[The technic of adrenal biopsy. Ultrasound versus CT as the guidance method].

Forty-seven needle biopsies of the adrenal glands have been performed under ultrasound or CT guidance. The aim was to clarify the best guidance method, the best approach, the choice of biopsy needle and possible complications. Analysis of the results provided the following answers: 1. A mass in the right adrenal can be biopsied under ultrasound control by a transhepatic approach. Small lesions of the left adrenal are best approached under CT guidance. In these cases a subcostal angled approach is advised. 2. Cutting biopsy needles provide better results than aspiration biopsy needles. 3. The complication rate of adrenal biopsies is very low if thin cutting needles are used.

Adrenal Glands↗
PubMed1992

Do telangiectases communicate with the deep venous system?

Telangiectases of the legs occur frequently, with most patients seeking treatment for cosmetic reasons. Sclerotherapy continues to gain popularity as a safe and valuable therapeutic approach; however, deep vein thrombosis as well as pulmonary embolism have been reported even after sclerotherapy of small intradermal venectases. Hoping to uncover anatomic risk factors predisposing a patient to iatrogenic thrombosis, we investigated 15 patients with telangiectases of the legs applying ascending venography concomitantly with direct injection of the telangiectases. A digital radiographic technique was used as an imaging system. In two patients an unrestrained flow of the contrast medium into the venae femorales was noticed. As far as we know this is the first in vivo demonstration of venae communicantes connecting intradermal venectases to the deep veins. That means that particular anatomic conditions favor the spillage of sclerosant into the deep veins, which might contribute to the development of iatrogenic deep vein thromboses in compression sclerotherapy.

Adult↗
PubMed1992

[Documentation of digital dacryocystography using video technique].

Digital dacryocystography is considered the optimal radiodiagnostic method in obstructions of the lacrimal pathways. The examination is carried out by a computer-controlled X-ray unit with a C-arc attached to an image-intensifying TV system. In this way the advantages of this technique and of modern video recording are linked. The bilateral filling process of the contrast medium is recorded and the findings simultaneously recorded on videotape. Consequently, pictures of the dynamic flow are retrievable at any time. This provides good diagnostic documentation and an outstanding basis for any scientific analysis.

Diagnosis, Differential↗
PubMed1992

CT-guided percutaneous drainage and fluid aspiration in intensive care patients.

Fifty-two intensive care unit (ICU) patients with clinical signs of sepsis who were considered to be at extremely high risk for operation were subjected to CT-guided interventions. Bedside ultrasound (US) had been performed prior to CT in all patients but diagnoses were equivocal or US-guided interventions had failed. Nineteen patients solely underwent CT-guided diagnostic aspiration of fluid collections to rule out infection. Eighteen patients (72%) with abscess formations after surgery or trauma were cured by catheter drainage alone; 4 patients required additional surgery. Out of 8 patients suffering from acute pancreatitis (after several necrosectomies), abscesses could be cured in 5 (62.5%). Three patients with acute necrotizing pancreatitis (no surgery) were not cured by the interventional procedure and all required surgical debridement. Even patients who required additional surgery after drainage improved clinically after the interventional radiologic procedure. Our overall success rate was 64%, emphasizing the need for CT in the case of equivocal US results or if US-guided procedures have failed in ICU patients with signs of sepsis.

Abscess↗
PubMed1991

Videodocumentation in digital dacryocystography.

The digital dacryocystography proved to be the optimum method of X-ray diagnostics in obstructions of the lacrimal pathways. The examination was performed with a computer controlled X-ray unit with a C-arc coupled to an image intensifier tv-system. In the study the advantages of this technique were combined with the advantages of modern videotechnique. A nonionic water soluble contrast medium was used. The bilateral contrast medium filling process was registrated and the findings were recorded on videotape concurrently. The videocassettes, marked with the data of the patients and the date of examination, are stored in a video-tape library. This provides an always repeatable diagnostic documentation and it is also an excellent base for scientific analyses. The technique and the results of the examinations, performed with 18 patients, are described.

Adult↗
PubMed1991

[Imaging of peripheral arteriovenous malformations using color-coded Doppler sonography].

By using colour coded Doppler sonography and duplex Doppler sonography, the presence of AV-shunts could be demonstrated correctly in 15 patients with arteriovenous malformations (angiographic correlation was obtained in 10 cases). The feeding vessels could not be identified exactly in all cases by using duplex Doppler sonography; correct identification of the feeding vessels was possible in only 2 patients by using colour coded Doppler sonography. In one patient, a soft tissue tumour could be diagnosed sonographically (histology: malignant synovialoma). Therefore, colour coded Doppler sonography serves as an important supplement to angiography in the diagnostic evaluation of arteriovenous malformations, but cannot replace it.

Adolescent↗
PubMed1991

[Vascular space-occupying lesions of the carotid artery--detection with color-coded Doppler sonography. Comparison with duplex sonography and angiography].

Nine patients with a cervical tumour, diagnosed by duplex Doppler sonography were additionally evaluated by colour-coded Doppler sonography (CCDS). The duplex Doppler diagnosis of three internal carotid artery aneurysm was confirmed by CCDS in only one patient. In the remaining two cases CCDS identified a marked coiling of the internal carotid artery. Three low echogenic lesions, interpreted as cervical lymphomas by conventional Doppler sonography were identified as two internal carotid aneurysm with partial thrombosis and a carotid body tumour in the third patient by CCDS. Duplex-Doppler sonography and CCDS agreed in the diagnosis of two AV-malformations and one carotid body tumour. Angiography confirmed the CCDS-diagnosis in 7 patients. In the two patients with coiling of the ICA angiographic evaluation was not performed. Thus, CCDS was superior to duplex Doppler sonography in the evaluation of vascular lesions of the extracranial section of the carotid artery and provided additional diagnostic information.

Aneurysm↗
PubMed1991

[The patency of the external and internal carotid arteries in patients with occlusion of the common carotid: detection using color-coded Doppler sonography].

Common carotid artery occlusion is not necessarily associated with thrombosis of the ipsilateral internal carotid artery. Noninvasive imaging of the carotid bifurcation with colour-coded Doppler sonography demonstrated patency of the external and internal carotid arteries distal to a common carotid occlusion in 4 patients which could be proven surgically. Identification of internal carotid artery patency could be demonstrated by angiography in two of the patients while in the other two cases angiography was inconclusive. Thus, CCDS provided a correct diagnosis of the internal carotid patency in these patients with common carotid occlusion.

Adult↗
PubMed1991

[Balloon dilatation of benign esophageal stenoses].

Benign stenoses of the oesophagus have been conventionally treated by endoscopic bougienage and were operated on in case of failure. Now that balloon catheters with large balloon diameters are available, interventional radiological dilatation of enteric strictures can be easily performed. In case of eccentric high-grade stenosis with or without blind loop, stenosis is often easier to manage and associated with less risk with an angiographic guide wire and catheter than by endoscopy. 53.3% of the patients were referred to balloon dilatation after failed endoscopic bougienage. The indications for balloon dilatation were anastomotic stenosis (66.2%), peptic stenosis (16.9%), achalasia (7%), pylorospasm (5.6%) and stenosis due to pemphigus vulgaris, acid ingestion and (in one case) a Schatzki ring. The complication rate was low at 1%. The experience collected with 297 dilatations in 71 patients with benign oesophageal stenosis, is reported.

Adult↗
PubMed1991

[The percutaneous catheter drainage of pancreatic pseudocysts].

The results of CT/US-guided percutaneous drainage in 35 patients with pancreatic pseudocysts are reported. 27 patients recovered without surgery and no further treatment was required. 8 patients required a subsequent surgery due to recurrence. The role of CT/US-guided percutaneous drainage in pancreatic pseudocysts as well as an analysis of the technical aspects associated with a successful procedure are discussed. Although US may be used, we believe CT is safer and allows more precise localisation and guidance in the treatment of pseudocysts.

Adult↗
PubMed1991

Laser angioplasty: results of a prospective, multicenter study at 3-year follow-up.

A prospective multicenter trial was initiated to evaluate the efficacy and safety of laser angioplasty. Laser recanalization was performed in 338 patients with arteriosclerotic femoropopliteal artery occlusions (average length, 8.5 cm). Neodymium-yttrium-aluminum-garnet lasers were used in combination with sapphire probe catheters. The initial recanalization rate was 85%. Complications were observed in 14% of the patients. Emergency surgery was required in 1.5%. The cumulative long-term patency rate of the successfully recanalized arteries was 80%, 70%, 62%, and 57% at 6 months, 1 year, and 2 and 3 years, respectively. The patency rates were not affected by the length of the occlusion and the long-term medication (platelet inhibition vs anticoagulation), but patients with a normal runoff had significantly better patency rates than those with reduced runoff (63% vs 52%, P less than .01). The study has shown that laser-assisted angioplasty is safe and at least as effective as conventional angioplasty.

Adult↗
PubMed1991

Renal allograft arteriovenous fistula due to needle biopsy with late onset of symptoms--diagnosis and treatment.

A post-biopsy arteriovenous (AV) fistula in a renal allograft was diagnosed using color-coded Doppler sonography. Because the patient was asymptomatic, no specific treatment was initiated. 15 months after the diagnosis was established, severe hematuria with obstruction of the bladder occurred. Angiography revealed a connection of the fistula to the renal pelvis. The patient was treated successfully by transarterial embolization of the fistula. As a conclusion, we suggest periodical follow-up examinations of asymptomatic AV fistulas in renal allografts using color-coded Doppler sonography during 3-6 months. When no spontaneous regression of the fistula can be observed, embolization therapy should be performed even when the fistula is asymptomatic, in order to prevent late onset of complications.

Adult↗