Biomedical subjects

P Hübsch

Publications and source records attributed to P Hübsch.

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

[Color-coded Doppler sonography of the thyroid: an advance in carcinoma diagnosis?].

There are several papers suggesting that colour-coded Doppler sonography is a useful diagnostic tool for the differentiation of malignant and benign lesions of the thyroid gland. This hypothesis (hypervascularization of malignant nodules) is reconsidered by preoperative examination of 65 patients by using colour-coded Doppler sonography and scintigraphy. Among these patients 21 carcinomas and 2 malignant lymphomas of the thyroid gland were found histologically. Colour-coded Doppler sonography was true positive in 10 cases, true negative in 28 cases, false positive in 14 cases and false negative in 13 cases. Our conclusion is that colour-coded Doppler sonography cannot be used unconditionally for the detection of carcinoma of the thyroid gland.

Adult↗

PubMed1992

[Noninvasive follow-up by color-coded Doppler sonography after surgical interventions on the extracranial cerebral arteries].

By means of colour-coded Doppler sonography we studied retrospectively the incidence of postoperative changes in 54 patients following 58 carotid endarterectomies. The interval between operation and ultrasound varied from one to 41 months. The overall incidence of recurrent carotid disease was 50% with a 31% (18 of 58) of hemodynamically insignificant restenoses, a 13.8% (8 of 58) incidence of haemodynamically significant restenoses, and a 5.2% (3 of 58) of occlusions. The segment that had been endarterectomized showed a bulbous dilatation in 24.1% (14 of 58). In all of these cases extensive flow reversal zones could be demonstrated, the possible importance of which is discussed. Examinations in 9 patients with reimplantation of subclavian artery to the common carotid artery and grafting technique between these arteries and in 11 patients with reimplantation of vertebral artery to the common carotid artery demonstrated one occlusion of the ipsilateral vertebral artery.

Carotid Artery Thrombosis↗

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

[Pseudo-stenosis of the renal artery: a possible defect of color Doppler sonography].

The diagnostic value of pulsed Doppler sonography for the detection of renal artery stenosis was questioned by recent studies. Until now, the diagnostic value of colour-coded Doppler sonography of the renal arteries is not clearly defined in relation to pulsed Doppler. This study deals with specific problems of colour-coded Doppler sonography in the examination of the renal arteries. Because of basic technical principles of colour-coded Doppler sonography a stenosis can be imitated especially at the origin of the right renal artery by using a ventral approach to the vessel. This pseudo-stenosis is due to a change of colour similar to an aliasing-phenomenon in a curved vessel. In order to avoid false positive results, a laterodorsal approach to the vessel should be applied additionally. A spectral waveform should be also registered routinely.

Adult↗

PubMed1992

Color Doppler imaging of inferior vena cava: identification of tumor thrombus.

Color-coded Doppler sonography (CCDS) was used for the examination of tumor thrombus (n = 7) and benign thrombosis (n = 6) of the inferior vena cava. Tumor thrombus was due to hepatocellular carcinoma in two cases and to renal cell carcinoma in five cases. Whereas no specific information about the nature of thrombus formation could be gained by gray scale sonography, a typical patchy vascularization pattern was noted within tumor thrombi in six of seven cases using CCDS. This ws due to marked neovascularization within the tumor thrombi, confirmed by histologic examination in all cases. In one patient no vascularization within the tumor thrombus could be observed by CCDS because the thrombus was relatively small. In patients with bland thrombosis, either no vascularization of the thrombus was seen (n = 5) or linear recanalization of the thrombus occurred (n = 1). Therefore, it might be possible to differentiate tumor from nontumor thrombus in the inferior vena cava by using CCDS. Further studies are needed to confirm this preliminary hypothesis.

Adult↗

PubMed1992

Comparison of dual energy X-ray absorptiometry of the proximal femur with morphologic data.

Measurements of bone mineral density (BMD) of the proximal femur (including femoral neck, Ward's triangle and trochanteric region) were compared with the Singh index grading in 40 normal subjects (20 male, 20 female) and in 116 patients (18 male, 98 female) referred for assessment of possible osteoporosis. Additionally, the BMD and the Singh index of 12 cadaver specimens (6 male, 6 female) of the proximal femur were compared with each other and with the histomorphology of the femoral necks of the specimens. Although there was a good correlation of Singh index with BMD in the group of male patients with suspected osteoporosis and in the series of bone specimens, there was a poor correlation in the group of female patients as well as in the normal controls and in the patient population as a whole. There was also poor correlation of Singh index values with histomorphologic data, whereas the BMD measurements correlated well with the amount of calcified bone found histologically in the femoral necks of the bone specimens. We conclude that the Singh index cannot be used to predict BMD of the proximal femur accurately.

Absorptiometry, Photon↗

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

[Correlation of the x-ray morphology with the histopathological staging and grading of colorectal cancer].

In a retrospective study stage grouping as well as histopathological grading (G category) of colorectal carcinomas was compared to radiographic findings at double contrast barium enema. A good correlation of tumour stage according to Dukes and the pT category and histopathological grading could be established to radiographic morphology. Apple core lesions and eccentrically obstructing neoplasms as well as saddle-like tumours exhibited worse staging and grading categories in comparison to polypoid lesions; plaque-like tumours are probably in between. It can therefore be assumed that the radiographic appearance of colorectal carcinomas may be a valuable tool to indicate stage group and G-category and thus offer information about patient prognosis.

Adult↗

PubMed1991

[Varicosis orbitalis. Its demonstration by color-coded Doppler sonography and computed tomography].

Three patients with intermittent exophthalmos were studied by computed tomography (CT) and colour-coded Doppler sonography (CCDS). By CT the possible diagnosis of an orbital varix was established. CCDS, however, with the dynamic evaluation and realtime direct imaging of flow and the possibility of examination in different positions facilitated the diagnosis of this orbital vascular disorder without the need for any contrast material. This technique may prove to be a useful adjunct to computed tomography for the evaluation of suspected vascular lesions of the orbit. Surgery confirmed the diagnosis in all patients.

Color↗

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↗

PubMed1991

Color-coded Doppler sonography of vertebral arteries.

Color-coded Doppler sonography of the vertebral arteries was performed in 86 patients who had a history of vertebrobasilar disease. The origin of the artery was visualized in 87.2% on the right and 70.9% on the left side. The inter-transverse portion of the vertebral artery was visualized in 95% on the right and 97% on the left side. The atlas loop could be visualized in 88.4% on the right and 84.9% on the left side. Pathologic findings were hypoplasia (n = 4), stenosis (n = 19), dissection (n = 2), occlusion (n = 7), kinking (n = 12), cervical tumors (n = 3), and subclavian steal syndrome (n = 3). Nine postoperative patients had subclavian and vertebral artery reimplantation to the common carotid artery. The characteristic color-coded Doppler sonographic features of these findings are presented and discussed.

Angiography↗

PubMed1991

[DEXA (dual-energy x-ray absorptiometry) and DPA (dual photon absorptiometry) in densitometry of the femoral neck: correlation of the measurements of three commercially available instruments].

The bone mineral density measurements of three different instruments at the femoral head were compared using 12 cadaver specimens. Two of these instruments were operated by x-rays (dual energy x-ray absorptiometry = DEXA), whereas one system was based on a gadolinium source (dual photon absorptiometry = DPA). Although excellent correlation between the measurements was obtained (r greater than 0,9), the measurements of one of the DEXA-instruments were significantly higher than the measurements of the two other systems. We conclude that a comparison of bone mineral density measurements obtained on different densitometry instruments may pose problems. Follow-up examinations should be done on one single densitometry unit.

Absorptiometry, Photon↗

PubMed1990

[Velocity variance function: additional information in color-coded Doppler sonography of the carotids].

A new software, called the velocity variance programme, by which flow disturbances are additionally colour-coded, was systematically applied with colour Doppler sonography in 59 patients with stenotic atheromatous lesions of different grades in the carotid bifurcation. A direct comparison with and without using this programme was made. In group 1 (n = 23) with stenosis of the internal carotid artery of more than 50% it could be demonstrated that flow disturbances were maximally in the region immediately downstream of the stenosis and complete dissipation of these effects occurred within 8-10 vessel diameters downstream. Moreover, a direct correlation between the size of the region of disturbed flow and the irregularity of the stenotic plaque surface within the stenosis could be demonstrated. Distal to the stenosis there was an inverse relationship between the extension of disturbed flow and the length of the stenosis and a direct relationship to the grade of the stenosis and the irregularity of the plaque surface. In patient group 2 (n = 36) with less than 50% diameter reduction, a local flow disturbance near the atheromatous plaque was shown in 27 patients. In eighteen of these patients the region of disturbed flow could be revealed only by using the velocity variance programme. The importance of this non-invasive in-vivo visualisation of flow disturbances in the carotid bifurcation is discussed.

Arteriosclerosis↗

PubMed1990

[Radiologic therapy of symptomatic lymphoceles following kidney transplantation].

During a four and a half year period ending in November 1988, we performed 13 percutaneous needle aspirations and 35 percutaneous drainages on 32 patients suffering from symptomatic lymphoceles (LC) following renal transplantation. Of 13 needle aspirations, 4 were therapeutic (31%); in 9 cases recurrent lymphoceles were observed within 3 days. 35 percutaneous catheter drainages were carried out on 29 patients. 16 of these (55%) did not require any additional therapy. In 8 cases recurrent lymphoceles were treated surgically by marsupialization, another 5 underwent repeated percutaneous drainage. One patient needed 3 percutaneous interventions until his symptoms ceased. In 8 patients 5 ml. of fibrinous glue was administered before the catheter was removed; nevertheless, 3 of them developed recurrent LC. In the group of patients without any symptoms after percutaneous drainage, 5 LC were infected, in the group of repeatedly drained LC, 2 had superinfection which was treated with antibiotics. All of the infected LC could be managed successfully by percutaneous drainage. The overall rate of success was 72%.

Adult↗

PubMed1990

Color-coded Doppler imaging of normal vertebral arteries.

Using color-coded Doppler sonography, we studied the vertebral arteries of 42 persons without history or physical signs of vertebrobasilar disease. The intertransverse portion of the vertebral artery was visualized in all persons on both sides. Its origin was visualized in 37 persons (88.1%) on the right side and in 28 (66.7%) on the left; the atlas loop was visualized in 32 persons (76.2%) on the right side and in 36 (85.7%) on the left. Four vertebral arteries were hypoplastic. Peak systolic blood velocity ranged from 19 to 98 (mean 56) cm/sec and peak diastolic blood velocity ranged from 6 to 30 (mean 17) cm/sec. Resistive indices ranged from 0.62 to 0.75 (mean 0.69). Thus, color-coded Doppler sonography seems to be a promising noninvasive method for the evaluation of hemodynamics in the extracranial portion of the vertebral arteries.

Blood Flow Velocity↗