PubMed Health⌕ Search

Biomedical subjects

G H Mostbeck

Publications and source records attributed to G H Mostbeck.

At least 55 records · Page 3Linked to original sources
PubMed1994

[Extensive intraductal components of invasive ductal breast carcinoma--value of mammography].

The presence of an extensive intraductal component (EIC) in patients with infiltrating ductal carcinoma is a major factor for predicting local recurrence after breast-conserving surgery and radiotherapy. A retrospective study including 67 consecutive cases of stage I and II infiltrating ductal carcinomas of the breast was conducted to determine the predictive values of mammographic features associated with the presence or absence of EIC. 43% of the lesions contained a pathologically verified EIC. 63% (25/40) of lesions showing mammographic evidence of calcifications with or without a mass were associated with an EIC. In contrast, only 17% (4/24) of carcinomas without calcifications demonstrated an EIC. This difference was statistically significant (p < 0.001). Lesions with calcifications greater than 3 cm in extent were significantly (p < 0.01) more likely to have an EIC (8/9; 89%) than those with calcifications less than 3 cm in extent (17/31; 55%). Furthermore, no patient with a palpable mass who had normal findings on mammograms was diagnosed to have an EIC.

Adult↗
PubMed1994

Hypoechoic perirenal fat in renal transplant recipients.

PURPOSE: To evaluate ultrasonographic (US) findings of morphologies, anatomic locations, and causes of hypoechoic rims that mimic disease and appear around native kidneys of asymptomatic renal allograft recipients. MATERIALS AND METHODS: Annual, routine abdominal US examinations of 170 renal allograft recipients were performed. US scans of 23 (13.5%) of these patients showed a hypoechoic rim. CT examination of the perirenal space was performed for 18 of these 23 patients to confirm the US findings. RESULTS: For 11 of these 18 patients, the hypoechoic rims on US scans corresponded to low-attenuation, septated perirenal fat on CT scans; for seven, the perirenal space appeared to be a homogeneous, fat-filled compartment. Low-attenuation fat in the perirenal space was separated by bridging septa. Patients with hypoechoic rims were significantly older than those without (57 years +/- 10 vs 48 years +/- 12, P = .001). CONCLUSION: Hypoechoic rims are frequently found in asymptomatic renal allograft recipients. They correspond not to disease but to low-attenuation perirenal fat divided into compartments by bridging septa.

Adipose Tissue↗
PubMed1993

Velocity-encoded cine MRI in the evaluation of left ventricular diastolic function: measurement of mitral valve and pulmonary vein flow velocities and flow volume across the mitral valve.

Left ventricular diastolic function has been evaluated by means of analysis of the flow pattern through the mitral valve. Velocity-encoded cine magnetic resonance imaging (VEC-MR) is a new method for characterizing flow patterns in the heart. The feasibility of using VEC-MR to measure early diastolic (E) and atrial systolic (A) peak flow velocities and E/A ratios in the mitral inflow, as well as systolic (X), early diastolic (Y), and atrial systolic (Z) peak flow velocities and X/Y ratios in the pulmonary vein, was evaluated in 10 normal volunteers. The VEC-MR-derived velocities and indexes were compared with Doppler-derived results. Volumetric flow across the mitral valve was also used to measure stroke volume, cardiac output, and the left atrial contribution of left ventricular filling. VEC-MR yielded lower peak velocities than Doppler echocardiography. The velocities of the two measurements showed a significant linear correlation (Doppler E velocity = 1.30 x VEC-MR + 1.6 cm/sec, r = 0.68; Doppler A velocity = 1.83 x VEC-MR - 5.2 cm/sec, r = 0.83; and Doppler X velocity = 0.45 x VEC-MR + 0.09 cm/sec, r = 0.74). Consequently the E/A and X/Y ratios measured by these two methods showed statistically significant linear correlations with r values of 0.94 and 0.83. The volume of blood flow across the mitral valve measured by VEC-MR (5610 +/- 620 ml/min) was not statistically different from the cardiac output measured from the ascending aorta by VEC-MR (5670 +/- 590 ml/min) or by left ventricular cine magnetic resonance imaging (5440 +/- 614 ml/min). The left atrial contribution to left ventricular filling was 25.9 +/- 7.5%. Our results indicate that VEC-MR can be used not only for evaluation of left ventricular diastolic filling from the mitral valve and pulmonary vein flow velocities but also for quantitative measurement of the volume of blood flow across the mitral valve.

Adult↗
PubMed1993

Renal biopsy: in vitro and in vivo comparison of a new automatic biopsy device and conventional biopsy systems. Work in progress.

A nondisposable full-cut biopsy gun with a disposable needle (system 1, prototype of system 2) and a disposable gun-needle combination (system 2) were compared with conventional needles and Tru-Cut-type biopsy systems in renal parenchymal biopsy procedures. In cadaveric kidneys, more glomeruli were harvested with system 1 than with four other biopsy systems. In native kidneys, more glomeruli were harvested and core quality was better with system 2 than with a Tru-Cut-type biopsy gun.

Adult↗
PubMed1993

Quantification of the left ventricular volumes and function with cine MR imaging: comparison of geometric models with three-dimensional data.

Acquisition and measurement of left ventricular (LV) volumes with a three-dimensional data set of cine magnetic resonance (MR) images from apex to base is a time-consuming process. Results of a study with 10 healthy volunteers and 10 patients with LV hypertrophy were prospectively evaluated. The heart was shown in the anatomic short- and horizontal long-axis planes with cine MR imaging. LV volumes were measured with various geometric models, and ejection fractions were calculated. In both groups, the values of LV stroke volume obtained with a modified Simpson rule and biplane ellipsoid models correlated well to the analysis of the three-dimensional data set of cine MR images. There were no significant differences for the calculated ejection fraction between values obtained with the modified Simpson rule or the biplane ellipsoid model versus the three-dimensional data set. A high inter-observer reproducibility of cine MR measurements with the two former models was found. Therefore, modified Simpson rule and biplane ellipsoid models, with their shorter acquisition and processing times, may increase the clinical utility of cine MR imaging.

Adult↗
PubMed1993

Duplex Doppler sonography of celiac trunk and superior mesenteric artery: comparison with intra-arterial angiography.

DDS was compared to intra-arterial angiography for the diagnosis of significant (> 50%) stenoses of the celiac trunk and the SMA in 38 consecutive patients referred for angiographic evaluation of peripheral arterial occlusive disease. Celiac trunk occlusion was correctly identified by DDS in three of three patients. In patients with significant celiac trunk stenoses, mean peak systolic velocity was 246 (+/- 154) cm/sec and differed significantly (P < 0.05) from the peak systolic velocity (101 +/- 22 cm/sec) of 22 patients with no angiographic evidence of significant stenosis. Five false-negative DDS examinations in patients with > 50% celiac trunk stenoses were noted. Using a peak systolic velocity of > 160 cm/sec (mean value in normal vessels plus 3 standard deviations) to diagnose > 50% celiac trunk stenosis, sensitivity of DDS was 57% and specificity was 100%. However, considering celiac trunk stenoses and occlusions as a single group, the sensitivity rate of DDS in diagnosing significant stenosis and occlusion of celiac trunk was 70%.

Adult↗
PubMed1993

[Imaging procedures in varicosities].

A prospective study was performed to compare the diagnostic potential of color-coded duplex sonography (CCDS) and that of ascending pressure phlebography (APP) in 61 patients before venous stripping. Varicosis of the long saphenous vein was correctly diagnosed and graded by CCDS in 87% of cases, and varicosis of the short saphenous vein in 97%. CCDS was inaccurate in 3 of 4 cases of recurrent varicosis of the long saphenous vein. Anterior femoral cutaneous varicosis (n = 3), mild postthrombotic syndrome (n = 1) and variant venous anatomy (n = 1) were not diagnosed on CCDS. One Baker cyst was diagnosed by CCDS. In the assessment of venous reflux CCDS seems to be superior to APP. Our results suggest that CCDS is a valuable diagnostic tool for routine imaging before venous stripping. However, patients with ambiguous or inconclusive CCDS results (eg. recurrent varicosis, venous variants) should be examined by APP.

Adult↗
PubMed1993

[A comparison of sonography and phlebography in the diagnosis of deep venous thrombosis of the lower extremities].

In recent years, non-invasive sonographic techniques [real-time ultrasound (US), duplex ultrasonography (DU) and color-coded duplex sonography (CCDS)] have increased in importance for the diagnosis of lower extremity deep venous thrombosis. To ascertain the accuracy and limitations of these techniques prospectively, various studies have been performed to compare sonography with venography. This review deals with basic methodologic considerations when two imaging methods are compared and describes the features of deep venous thrombosis seen on US, DU and CCDS. Reports comparing sonography and phlebography for the diagnosis of deep venous thrombosis are presented and discussed. The advantages and limitations of US, DU and CCDS for the diagnosis of iliac, femoral, popliteal and infrapopliteal venous thrombosis are compared with those of venography, and controversial areas are touched on.

Humans↗
PubMed1993

[Possibilities of error and pitfalls in sonography of the gallbladder and bile ducts].

Ultrasound has a primary role in the imaging of biliary disease. Often the diagnosis is straightforward, but in this article the emphasis is placed on unusual and uncommon diseases, variant anatomy and artifacts that may present diagnostic challenges. The pitfalls and differential diagnosis in sonographic imaging of cholecystolithiasis, intraluminal gallbladder echoes, gallbladder wall thickening, artifacts of the gallbladder wall, pericholecystic fluid collections, bile duct dilatation and intraluminal bile duct echoes are discussed.

Artifacts↗
PubMed1993

[Possibilities of error in sonography of the pancreas and spleen].

Sonography plays an essential role in imaging suspected disease in the pancreas and spleen. A variety of different factors, such as artifacts, the close anatomical relationship of the pancreas to other intestinal organs, variant anatomy, and the well-known effect of the skill and experience of the sonographer may cause diagnostic difficulties. In this article, we discuss potential pitfalls and differential diagnoses in ultrasonographic imaging of the pancreas and spleen.

Artifacts↗
PubMed1992

Severity of aortic regurgitation: interstudy reproducibility of measurements with velocity-encoded cine MR imaging.

The interstudy reproducibility of velocity-encoded cine (VEC) magnetic resonance (MR) imaging for quantification of regurgitant volume (RV) and regurgitant fraction (RF) was studied in 10 patients with chronic aortic regurgitation. Each patient underwent two VEC MR imaging studies. RV and RF were measured on the aortic flow curve by quantifying antegrade and retrograde flow per cardiac cycle. VEC MR imaging measurements for RV and RF correlated closely with volumetric measurements for both studies (r greater than .97). Interstudy reproducibility for VEC MR imaging measurement of RV and RF was high (r greater than .97), and the interstudy variability for VEC MR imaging measurements was low. These results demonstrate a high accuracy of VEC MR imaging for measurement of RV and RF in patients with chronic aortic regurgitation. The level of interstudy reproducibility of VEC MR imaging for quantitative assessment of RV and RF indicates the potential of this technique for follow-up and monitoring of response to therapy.

Adult↗
PubMed1992

MR measurement of blood flow in the cardiovascular system.

Methods for measurement of blood flow with MR were devised many years ago but have been used for diagnosis in only the past few years. The two methods of measurement that have been used most extensively are based on the principles of time of flight and phase shift. A number of factors can influence the accuracy of MR measurements of blood flow. In vitro studies using flow phantoms have verified the accuracy of the phase-shift technique for measuring flow velocities exceeding 5 m/sec, which for practical purposes, encompasses the peak flow encountered in cardiovascular disorders. The flow measurements have been used to quantify valvular heart disease, congenital heart disease, pulmonary arterial disease, thoracic aortic disease, and peripheral vascular disease.

Blood Flow Velocity↗
PubMed1992

Polyetiology of renal allograft dysfunction. Does calculation of the resistive index still make sense?

In 101 consecutive patients with renal allograft dysfunction a correlation of Duplex Doppler sonography (DDS) with histopathologic reports of simultaneously performed biopsies was made. Renal vascular impedance was estimated by calculating the resistive index (RI). A total of 290 different specific histologic diagnoses (mean 2.1 +/- 0.84 diagnoses/biopsy) was noted. With increasing time interval to transplantation, single diagnoses as cause of allograft dysfunction decreased. DDS could not reliably differentiate, exclude, or grade any of the common causes of renal allograft dysfunction like vascular and/or cellular rejection, chronic rejection, acute tubular necrosis, cyclosporin nephrotoxicity, relapse of glomerulonephritis and infection. Follow-up studies after established histologic diagnosis in 19 patients with persisting allograft dysfunction demonstrated a lack of sensitivity of DDS to significant superimposed causes of transplant malfunction. We conclude that biopsy is still necessary to direct proper therapy of renal allograft dysfunction.

Adolescent↗
PubMed1991

[Papillary process of the caudate lobe--erroneous sonography interpretation as a space-occupying lesion].

The sonographic appearance of the papillary process separated from the caudate lobe of the liver by a fissure is reported. In 2 out of 5 patients, this variant anatomy mimicked a mass lesion. The papillary process is located dorsal to the left lobe of the liver and in front of the portal vein and common hepatic artery. The echogenicity of the papillary process is identical to liver parenchyma. Knowledge of the sonographic appearance and vascular relationship may help to avoid errors in diagnosis.

Aged↗
PubMed1991

[The percutaneous ultrasonic-guided fluoroscopy-controlled drainage of pericardial fluids].

The results of 25 ultrasonographically guided percutaneous pericardial drainage procedures and of one pericardiocentesis performed in 25 patients with pericardial fluid collections are reported. After initial puncture of the pericardial cavity under sonographic guidance, dilatation and placement of 5F to 8.3F catheters in Seldinger technique was controlled fluoroscopically in 22 procedures. Clinical indications were emergency treatment of tamponade (n = 6) or urgent treatment of large (n = 14) pericardial effusions. The remaining 6 procedures were performed to establish specific diagnoses of small effusions. Puncture sites were subxiphoid in 23 and left parasternal in 3 cases. The volume of aspirated fluid ranged from 20 to 1710 ml (median: 615 ml). Median duration of pericardial drainage was 3 days (range less than 1 day to 21 days). A specific diagnosis was obtained in 48% of patients. 4 patients had subsequent elective surgical intervention for recurrent effusion or for pericardial biopsy. Three minor complications included one vasovagal reaction and two asymptomatic pneumothoraces. Percutaneous ultrasonically guided and fluoroscopically controlled placement of a pericardial catheter is safe and effective for treatment and diagnosis of pericardial effusions.

Adolescent↗
PubMed1991

Duplex Doppler sonography in renal parenchymal disease. Histopathologic correlation.

To evaluate the histopathologic changes influencing Doppler measurements of the resistive index (RI) in renal arteries in renal parenchymal diseases, 68 kidneys in 34 consecutive patients with various forms of renal parenchymal diseases were studied by duplex Doppler ultrasound (duplex US) immediately before percutaneous renal biopsy. The RI, renal length, and renal cortical echogenicity were correlated with the amount of glomerular, interstitial, and vascular changes graded on a scale from 0 to 100. The renal vascular resistance and therefore the RI are significantly correlated with the prevalence of arteriolosclerosis, glomerular sclerosis, arteriosclerosis, edema, and focal interstitial fibrosis. There was no significant difference of the RI in five groups of different renal parenchymal diseases. Of 34 patients, 24 presented with an RI less than 0.7, which was thought to be within the normal range so far. Additionally, the RI increases as the patient's age increases, due to higher incidence of arteriosclerosis. Of our patients, 44% presented with normal cortical echogenicity. Quantitative duplex US using the RI does not reliably distinguish different types of renal medical disorders.

Adult↗