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Biomedical subjects

G Mostbeck

Publications and source records attributed to G Mostbeck.

At least 37 records · Page 2Linked to original sources
PubMed1995

Response of untreated stage IV Wilms' tumor to single dose carboplatin assessed by "up front" window therapy.

A total of nine children with previously untreated stage IV Wilms' tumor of favorable histology were treated according to the Austrian/Hungarian Wilms' Tumor Protocol 89 and received a preoperative single dose of carboplatin as an "up front" window therapy. The treatment consisted of carboplatin as a single-dose of 600 mg/m2 over 30 minutes on day 1. Response evaluation by chest X-ray, serial CT scans, and sonography was performed on day 22. Investigation of the abdominal tumors revealed seven partial responses (78%), one nonresponse, and one progressive disease with a median tumor volume reduction of 62%. Response of metastases evaluated by CT scans was as follows: four complete remission, four partial response, and one nonresponse. Thrombocytopenia (WHO grade III 1, grade II 2, grade I 2) and leukocytopenia (WHO grade II 1, grade I 5) were the main side effects. No renal or liver toxicity were observed. The overall response rate after a preoperative single-dose of 600 mg/m2 carboplatin in untreated patients with stage IV Wilms' tumor is encouraging and the toxicity acceptable. This data indicate that carboplatin seems to be an additional effective drug in patients with previously untreated Wilms' tumor of favorable histology.

Austria↗
PubMed1994

MR-appearance of the pituitary gland before and after resection of pituitary macroadenomas.

Pituitary macroadenomas can cause severe compression and displacement of the pituitary gland. This study was undertaken to determine the value of contrast administration for the detection of the pituitary gland in patients with pituitary macroadenomas, to evaluate the preoperative location and configuration of the pituitary gland and to describe its postoperative changes after tumour resection. Preoperative and postoperative MR imaging examinations of 30 patients with histologically proven pituitary macroadenomas were retrospectively evaluated. The examinations were performed on a 1.5 T unit, by obtaining T1-weighted sagittal and coronal images after administration of gadopentetate dimeglumine. On preoperative MR images, contrast administration increased the detectability of the anterior lobe from 30% to 80%. Depending on the size and extension of the adenoma, the pituitary gland was displaced to the suprasellar space (53%) and/or deformed to a club-shaped (27%) or sickle-shaped (47%) configuration. In six patients, the sickle-shaped pituitary gland was interposed between the cavernous sinus and the adenoma ('rim-sign'), which was seen only on gadopentetate dimeglumine-enhanced images. In these cases, there was no infiltration of the cavernous sinus at surgery. Postoperatively, descent of the pituitary gland was found in 63%, and reexpansion in 54%. We conclude that contrast administration improves the detectability of the pituitary gland on preoperative MR images, and that the displacement and deformation of the pituitary gland depend on the size, location and extension of the adenoma. Preoperatively, demonstration of the pituitary gland interposed between the cavernous sinus and the adenoma ('rim-sign') is a very useful sign for exclusion of cavernous sinus infiltration, best seen on contrast-enhanced coronal MR images. The normal postoperative changes of the pituitary gland after tumour resection include repositioning and re-expansion.

Adenoma↗
PubMed1994

[Color Doppler ultrasound of kidney transplants. Does the resistance index facilitate diagnosis of chronic kidney failure?].

The retrospective study under report assessed the diagnostic capability of colour Doppler sonography (CDS) with measurement of the resistive index (RI) in the long-term follow-up of patients with renal allografts. 210 CDS examinations were performed in 115 patients. The time since transplantation ranged from 6 months to 22 years. The RI was correlated to laboratory parameters of renal allograft function (serum creatinine, urinary protein levels and serum-cyclosporine). In 97 of 210 examinations, serum creatinine was elevated (> 1.5 mg% or an increase of more then 0.3 mg% within the last 6 months). In 35 out of these examinations RI was > 70%, in 62 RI was < or = 70%. Thus, with a threshold RI of 70%, sensitivity of the RI in the diagnosis of renal allograft dysfunction is 36% and specificity 62%, respectively. There was no significant difference in the RI between examinations of allografts with normal function (68.2% +/- 7.5%) and those with dysfunction (68.5% +/- 8.5%). Furthermore, there was no significant correlation between the RI and any of the laboratory parameters. CDS with calculation of the RI cannot differentiate in the long-term follow-up between allografts with normal function and those with dysfunction.

Adolescent↗
PubMed1992

Quantification of left to right atrial shunts with velocity-encoded cine nuclear magnetic resonance imaging.

OBJECTIVES: The purpose of this study was to evaluate the ability of velocity-encoded nuclear magnetic resonance (NMR) imaging to quantify left to right intracardiac shunts in patients with an atrial septal defect. BACKGROUND: Quantification of intracardiac shunts is clinically important in planning therapy. METHODS: Velocity-encoded NMR imaging was used to quantify stroke flow in the aorta and in the main pulmonary artery in a group of patients who were known to have an increased pulmonary to systemic flow ratio (Qp/Qs). The velocity-encoded NMR flow data were used to calculate Qp/Qs, and these values were compared with measurements of Qp/Qs obtained with oximetric data derived from cardiac catheterization and from stroke volume measurements of the two ventricles by using volumetric data from biphasic spin echo and cine NMR images obtained at end-diastole and end-systole. RESULTS: Two independent observers measured Qp/Qs by using velocity-encoded NMR imaging in 11 patients and found Qp/Qs ranging from 1.4:1 to 3.9:1. These measurements correlated well with both oximetric data (r = 0.91, SEE = 0.35) and ventricular volumetric data (r = 0.94, SEE = 0.30). Interobserver reproducibility for Qp/Qs by velocity-encoded NMR imaging was good (r = 0.97, SEE = 0.20). CONCLUSIONS: Velocity-encoded NMR imaging is an accurate and reproducible method for measuring Qp/Qs in left to right shunts. Because it is completely noninvasive, it can be used to monitor shunt volume over time.

Adolescent↗
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

[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

CT in pancreatic involvement of non-Hodgkin lymphoma.

In an attempt to evaluate characteristic CT features of primary pancreatic involvement in non-Hodgkin lymphoma (NHL), scans of 10 patients were reviewed retrospectively and compared to 50 patients with histologically proved different neoplasms of the pancreas. Setting the correct diagnosis of NHL would be essential for planning of treatment and prognosis. CT findings of NHL were characteristic but not specific. Nevertheless, the presence of a homogeneous pancreatic mass with a diameter of 7 cm or more, infiltrating surrounding tissue accompanied by retroperitoneal and/or mesenteric lymphadenopathy strongly suggests NHL. CT-guided needle biopsy can help to establish the diagnosis of pancreatic NHL.

Adult↗
PubMed1992

[Duplex ultrasound and color-coded Doppler ultrasound of visceral blood vessels in abdominal diseases].

Duplex Doppler sonography (DS) and color-flow Doppler sonography (FDS) are noninvasive diagnostic methods for the evaluation of a patient with suspected vascular disease of the abdomen. They represent a useful adjunct to realtime sonography in the identification of normal and variant visceral vascular anatomy. Aneurysms and pseudo-aneurysms of visceral arteries are readily differentiated from other cystic lesions. DS and FDS have a high sensitivity in the detection of portal vein thrombosis and stenosis. Both methods allow the observation and measurement of splanchnic hemodynamics in patients with chronic liver disease and portal hypertension. Hence, DS and FDS already play an important role in the pre- and postoperative assessment of patients undergoing liver or pancreas transplantation. The possibility that DS and FDS may enable discrimination between hypovascular and hypervascular tumors is under clinical investigation. FDS facilitates an excellent anatomic display of the abdominal vasculature and allows easy placement of the Doppler sample volume. Consequently, quantitative data acquired with DS are accomplished within short scanning times. However, the diagnostic impact of both modalities depends to a great extent on the experience of the investigator.

Abdominal Pain↗
PubMed1991

Hepatic and splenic abscesses--a common complication of intensive chemotherapy of acute myeloid leukemia (AML). A prospective study.

In order to determine the frequency of hepatosplenic abscesses in AML patients during chemotherapy and to evaluate the clinical and laboratory characteristics of this complication we performed a prospective study over a 28-month period. Fifty-five consecutive patients with de novo AML or relapse who received intensive chemotherapy underwent regular ultrasound examinations. In 16 patients (29.1%) hepatic and/or splenic abscesses were detected sonographically. Histopathological evidence for abscess formation was obtained in five of these 16 patients. In three patients granulation tissue and in one patient necrotizing granulomas were found. Causative micro-organisms were proven in only three patients: Candida hyphae were demonstrated in one patient, gram-positive cocci in another. Bacteria and fungi were seen in the tissue specimen of the third patient. Patients with hepatosplenic abscesses had significantly prolonged fever after neutrophil recovery but did not differ from patients without abscesses in any other laboratory or clinical features. Due to the absence of specific alerting clinical and laboratory signs and symptoms of hepatosplenic abscesses, routine ultrasound examination is required for detection of this complication. The presence of hepatic and/or splenic abscesses does not necessarily worsen the prognosis, but it may influence the decision on further chemotherapy and antimicrobial treatment.

Abscess↗
PubMed1991

[Sonographic detection of gas in the vascular system of the liver: an image essay].

Gas within the vascular system of the liver was demonstrated sonographically in 5 patients. In contrast, plain films of the abdomen in these patients failed to demonstrate this serious finding. 3 patients presented with gas within the hepatic portal venous system, 1 patient with gas in the liver veins. In these patients, gas formation was probably caused by sepsis with gas-producing bacteria. In the last patient, air within the hepatic arterial system was caused by insufflation of air thru a port-a-cath catheter located in the main hepatic artery. The characteristic sonographic appearance of intravascular gas are highly echogenic particles flowing within the vessels. Different pathophysiologic mechanisms of gas formation in the hepatic portal venous system include sepsis with gas forming organisms, gastrointestinal necrosis of various origin in combination with elevation of intramural pressure and alteration of gas solubility of blood. The significance of sonography as a very sensitive and specific modality is outlined.

Adult↗
PubMed1990

[Invasive pulmonary aspergillosis: radiologic and magnetic resonance tomographic characteristics].

46 patients with invasive pulmonary aspergillosis (IPA) were investigated by chest radiographs (n = 46), plain film tomograms (n = 16), CT (n = 8) and MRI (n = 13). Radiologic characteristics of early IPA were nodular or patchy infiltrates in the upper lobes of all patients. Enlargement of the infiltrates and/or development of segmental/lobar consolidations were typical for fully developing IPA. Air crescent signs were seen in 40% of patients during or after bone marrow restitution. CT added additional information by visualisation of small pleural based infiltrates, demonstration of air crescents and identification of halo phenomena. MRI revealed the target character of nodular aspergillomas with hypointense centres and rims of higher signal intensity. A gadolinium-DTPA rim enhancement could be observed in almost all nodular lesions. Hyperintense areas in nodular and segmental infiltrates on T1-weighted images were interpreted as aging haemorrhage (methemoglobin) in aspergillus-induced haemorrhagic infarcts or in focal parenchymal bleeding.

Aspergillosis↗
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

[Vascular kidney transplant rejection--is a duplex sonographic diagnosis possible?].

The diagnostic value of quantitative Duplex Doppler sonography (DS) in renal allograft evaluation is being viewed increasingly critically. We undertook a retrospective analysis of DS in 51 consecutive patients to assess the capability of DS in the diagnosis of vascular rejection. At the time of renal allograft biopsy, a mean resistive index (RI) was calculated from Doppler measurements within main, segmental, interlobar and arcuate arteries and correlated with histological diagnosis. Our results indicate a low specificity (36% for RI greater than 0.7), low sensitivity (35% for RI greater than 0.9) as well as a low positive predictive value (54% for RI greater than 0.7) for the diagnosis of vascular rejection. Therefore, elevation of the RI is an unspecific finding in different causes of allograft dysfunction. Thus, renal biopsy to establish specific histologic diagnosis of allograft dysfunction remains mandatory.

Adolescent↗
PubMed1990

Evaluation of arteriovenous fistulas and pseudoaneurysms in renal allografts following percutaneous needle biopsy. Color-coded Doppler sonography versus duplex Doppler sonography.

One hundred one patients with renal allografts were studied by two independent observers using duplex Doppler sonography (DDS) and color-coded Doppler sonography (CCDS). In all patients, single or multiple percutaneous needle biopsies of the transplant had been performed 1 to 30 days before. In 6 patients CCDS following the biopsy demonstrated an area of combined red and blue color-coded blood flow within the renal parenchyma (n = 5) or within the sinus (n = 1); the Doppler waveform was abnormal in these areas with signals above and below the zero line indicating turbulent blood flow. Consecutive intraarterial digital subtraction angiography (DSA) revealed the presence of an arteriovenous fistula (n = 4) or of a pseudoaneurysm (n = 2). In one patient, gross hematuria with obstruction of the bladder occurred as a complication of a pseudoaneurysm within the renal sinus; the bleeding could not be stopped by embolization of the lesion and the kidney had to be removed. DDS demonstrated the lesion in only one of the six patients. Thus, CCDS is the method of choice for noninvasive detection of vascular lesions due to percutaneous biopsy.

Adolescent↗
PubMed1990

[A posttraumatic pseudoaneurysm of the hepatic artery. Duplex sonographic diagnosis and follow-up in spontaneous thrombosis].

Guided percutaneous biopsy represents a standard procedure in establishing specific diagnosis of focal liver lesions. We report a case of left hepatic artery pseudoaneurysm diagnosed by means of Duplex Doppler sonography (DS) immediately before percutaneous biopsy should be performed. Selective hepatic artery embolization was planned, but spontaneous thrombosis of the pseudoaneurysm was documented by DS and angiography, respectively. DS is able to identify the vascular nature of a lesion and is helpful to avoid puncture of an aneurysm.

Abdominal Injuries↗