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Biomedical subjects

F Frauscher

Publications and source records attributed to F Frauscher.

34 records · Page 2Linked to original sources
PubMed1999

Crossing vessels at the ureteropelvic junction: detection with contrast-enhanced color Doppler imaging.

PURPOSE: To investigate the feasibility of imaging crossing vessels at the ureteropelvic junction (UPJ) preoperatively by means of contrast agent-enhanced color Doppler imaging (CDI). MATERIALS AND METHODS: Twenty-nine patients (13 female patients, 16 male patients; age range, 17-76 years; mean age, 45 years) with symptomatic UPJ obstruction were examined with CDI before and after intravenous infusion of the contrast agent. The type (i.e., arterial or venous) and position of the vessel relative to the UPJ (i.e., anterior or posterior) were assessed. The CDI findings were correlated with the surgical findings at laparoscopic pyeloplasty. RESULTS: Among the 29 patients, crossing vessels were detected with nonenhanced CDI in 15 patients, with enhanced CDI in 22 patients, and with laparoscopy in 23 patients. Enhanced CDI depicted crossing vessels in 22 (96%) of the 23 laparoscopically confirmed cases compared with nonenhanced CDI, which depicted 15 (65%) of the 23 cases. The rate of detecting crossing vessels increased significantly with use of the contrast agent (P < .016, McNemar test). CONCLUSION: Compared with nonenhanced CDI, contrast-enhanced CDI significantly improves the detection of crossing vessels at the UPJ and is useful in the presurgical evaluation of UPJ obstruction.

Adolescent↗
PubMed1999

Importance of the renal resistive index in children suffering from vesicoureteral reflux.

OBJECTIVE: in our study, we wanted to assess changes and values of the renal resistive index (RI) in children with vesicoureteral reflux (VUR) using color Doppler ultrasound (CDUS) techniques. METHODS: We investigated 92 kidney units in 46 children (mean age 6 +/- 4 years) with VUR by means of CDUS. The RI was measured at the level of the interlobar and/or arcuate arteries using a color Doppler unit Acuson 128 XP/10. The CDUS findings were correlated with those obtained using standard renal scintigraphy. RESULTS: Children with VUR grades I-III showed a RI of 0.6 +/- 0.07, whereas patients suffering from VUR grades IV and V demonstrated a significantly increased RI of 0.77 +/- 0.07 (p < 0.0001). The correlation of the CDUS measurements with the scintigraphic findings revealed a positive correlation coefficient of r2 = 0.61. CONCLUSIONS: CDUS seems to be a helpful, radiation-free, noninvasive, and inexpensive tool in children with VUR, demonstrating a significant change in the RI especially in high-grade reflux. Moreover, the RI findings represent a good correlation with standard renal scintigraphy. Therefore, CDUS with assessment of the RI allows a perfect follow-up study of affected children.

Age Factors↗
PubMed1998

Intraurethral ultrasound: diagnostic evaluation of the striated urethral sphincter in incontinent females.

The aim of our study was to evaluate the striated urethral sphincter (rhabdosphincter) in incontinent females by means of intraurethral ultrasound (IUUS). Thirty-four incontinent and 11 continent female patients were examined by means of 12.5-MHz endoluminal ultrasound (US). The distance between the inner contour of the sphincter muscle and the US catheter was measured in the contracted and the non-contracted condition. The US findings were correlated with those obtained by urodynamic studies. Partial or complete loss of sphincter function was detected in patients with stress urinary incontinence (SUI). Reduced sphincter function was not observed in patients with urge incontinence and continent volunteers. The findings on US were found to correlate well with the grade of SUI. The IUUS technique offers the benefit of direct visualization of the sphincter mechanism. Therefore, endoluminal US may become an important adjunct in the diagnostic evaluation of SUI and will possibly provide new insights for a better therapeutic strategy.

Adult↗
PubMed1998

Transurethral ultrasound: evaluation of anatomy and function of the rhabdosphincter of the male urethra.

PURPOSE: A combined anatomic-sonographic study was undertaken to investigate whether the anatomical arrangement and the contractions of the rhabdosphincter of the male urethra could be visualized by transurethral ultrasound. Furthermore, this new technique was compared with standard urodynamic tests. MATERIALS AND METHODS: In 7 cadavers transurethral ultrasound was performed to define sono-morphological criteria of the rhabdosphincter, and the sonographic pictures were then compared to histological sections. In 48 patients the rhabdosphincter of the male urethra was investigated by transurethral ultrasound and urodynamic techniques. Of these patients 40 were completely continent after radical prostatectomy and 8 presented with urinary stress incontinence after transurethral resection of the prostate or radical prostatectomy. The decrease of the distance between the rhabdosphincter and the transducer during contraction served as quantitative parameter for the contractility of the muscle. RESULTS: The anatomical arrangement and contractions of the rhabdosphincter loop could be clearly visualized on transurethral ultrasound (during contraction the rhabdosphincter retracts the urethra, pulling it towards the rectum). Ultrasound showed scars in 3 patients with postoperative urinary stress incontinence, thinning of the muscle in 3 complete atrophy of the rhabdosphincter in 2 and minimal contractions of the rhabdosphincter in 1. Urethral closure pressures were decreased and decrease in rhabdosphincter-transducer distance was statistically significantly decreased in the incontinent patients. CONCLUSIONS: Our sono-morphological data and anatomical histological results strongly suggest that the rhabdosphincter constitutes the main component of the continence mechanism in post-prostatectomy patients. Unlike urethral pressure profiles, which can only reveal zones of higher intraluminal pressure between the bladder and the penile urethra, transurethral ultrasound is highly specific for measurement of the function of the rhabdosphincter.

Humans↗
PubMed1997

New onset hypertension after extracorporeal shock wave lithotripsy: age related incidence and prediction by intrarenal resistive index.

PURPOSE: In a recent study we found an increased resistive index immediately after extracorporeal shock wave lithotripsy (ESWL) in patients older than 60 years, which suggests renovascular disturbance. The present 26-month followup study was undertaken to investigate the relevance of elevated resistive index levels and the incidence of new onset hypertension. MATERIALS AND METHODS: Of the initial 76 patients 57, including 20 of the 23 at risk patients 60 or greater years, group 3), were followed for more than 26 +/- 6 months after ESWL. Followup included 2 resistive index measurements by Doppler ultrasound of the treated and the contralateral kidney, at least 2 blood pressure measurements 1 week apart and excretory urography as well as determination of plasma renin activity in 9 patients. RESULTS: With 1 exception, elevated resistive index levels and hypertension were observed exclusively in patients older than 60 years. In these patients the resistive index ranged between 0.65 and 0.86 (mean plus or minus standard deviation 0.74 +/- 0.05, normal less than 0.7). This increase in resistive index was statistically significant (p < 0.0001). Compared to the levels obtained immediately after ESWL, the resistive index continued to increase in all 9 patients older than 60 years who had hypertension (45%), whereas in the normotensive patients the resistive index was either stable or decreased. There was a strong positive correlation (0.903) between pathological resistive index levels and blood pressure. CONCLUSIONS: Patients older than 60 years are at risk for disturbances of renal perfusion as assessed by the resistive index, and 45% of these patients have new onset hypertension within 26 months of treatment.

Adolescent↗
PubMed1996

Blood pressure changes after extracorporeal shock wave nephrolithotripsy: prediction by intrarenal resistive index.

In order to identify a high-risk group for the development of arterial hypertension after extracorporeal shock wave nephrolithotripsy (ESWL), we correlated the increase in renovascular resistance induced by ESWL in 79 normotensive patients with changes in arterial blood pressure occurring 20 (+/- 3) months after therapy. Renal vascular resistance was measured as resistive index (RI) by duplex Doppler sonography in both kidneys. Mean RI before treatment was 0.620 +/- 0.035 (SD). After treatment, we observed a significant and age-dependent increase in the RI in the treated kidney to 0.673 +/- 0.06. Of the patients with a post-ESWL RI > 0.690, 39% developed hypertension. Posttherapy RI values surpassing 0.690 showed a 0.8 sensitivity and a 0.7 specificity in predicting arterial hypertension. Intrarenal Doppler ultrasound (US) is useful to find the high-risk group for arterial hypertension after ESWL.

Adolescent↗
PubMed1996

[Ultrasound diagnosis of the shoulder].

Sonography of the shoulder joint is a well-established technique in the hands of the experienced examiner, when using a standardized protocol. It has proved invaluable in assessing pathological soft tissue changes, especially after trauma. The static evaluation of anatomy and dynamic assessment of function are especially helpful in both preoperative staging and postoperative follow-up. The normal anatomy, examination techniques, including our own variations, and pathological conditions are discussed. The findings and various classifications of impingement syndrome, rotator cuff injuries, biceps tendon lesions and inflammatory changes are examined. Review of the major articles in the literature shows excellent correlation with our results, the overall sensitivity in the case of rotator cuff lesions being over 90%. A well-performed ultrasound examination in most cases obviates the need for the more invasive arthroscopy and the more cumbersome and expensive MRI examinations.

Adolescent↗
PubMed1996

Anatomy of the eustachian tube as demonstrated by endoluminal ultrasonography.

Using a new application of the endoluminal approach, we were able to demonstrate the sonographic anatomy of the eustachian tube in vitro and in vivo and correlate it with the plastic-embedded specimen. Five adult normocephalic cadavers, two patients, and one specimen especially prepared for embedding in plastic were examined. A specifically developed device was used to insert the ultrasound transducer employing an endo-oral approach. The investigation was performed using an intravascular ultrasound unit. In all cases the tube could be visualized in its entirety and relevant anatomic structures identified and compared with the specimen at the corresponding levels. The deeper layers, including the paratubal structures and the mucosa, could be distinguished for the first time by means of endoluminal ultrasonography. Now that endoluminal ultrasonography has revealed this anatomic information, further studies will be able to gauge the clinical efficacy of our method in cases of ventilatory, drainage, and clearance problems. The images showed no difference between the structures in vitro and in vivo, and the vivo examination was even easier than the in vitro one owing to better tissue turgor.

Adult↗
PubMed1995

Variability of Doppler parameters in the healthy kidney: an anatomic-physiologic correlation.

Contradictory results have been obtained in classifying various renal diseases when trying to use the resistive index measured by duplex Doppler technique in renoparenchymal arteries. These measurements may have been influenced by the lack of standardization of the anatomic site at which the renoparenchymal artery is sampled. To elucidate this influence, we measured the resistive index, peak systolic velocity, end diastolic velocity, and pulsatility index in 120 healthy kidneys at three different positions of the renal vasculature. The resistive index at the level of the interlobar-arcuate arteries proved to be the parameter with the most consistent results and should be preferred in clinical applications.

Adult↗
PubMed1995

Age-related changes in resistive index following extracorporeal shock wave lithotripsy.

PURPOSE: Changes in intrarenal vascular resistance after extracorporeal shock wave lithotripsy (ESWL*) were studied with Doppler ultrasound techniques. MATERIALS AND METHODS: In 76 patients the resistive index was measured at an interlobar artery before and after ESWL in the treated and contralateral kidneys. The resistive index levels were compared to N-acetyl-beta-D-glucosaminidase levels in 40 patients. RESULTS: We found an age-related positive linear correlation between post-therapeutic resistive index increases and patient age. N-acetyl-beta-D-glucosaminidase levels were also elevated after ESWL but these elevations were not age-related. CONCLUSIONS: Elderly patients have a higher risk of post-ESWL renal tissue damage.

Acetylglucosaminidase↗
PubMedDate not supplied

Finger injuries in extreme rock climbers. Assessment of high-resolution ultrasonography.

Dynamic high-resolution ultrasonography findings obtained in 34 extreme rock climbers with finger injuries were compared with those in 20 healthy volunteers. Thicknesses of the flexor tendon and A-2 flexor tendon pulley system were measured at the base of the proximal phalanx. The distance between the tendon and phalanx was evaluated with the finger in extension and in forced flexion as a measure of bowstringing. Gliding ability of the flexor tendons was assessed during active and passive motion. Compared with healthy volunteers, climbers showed a significantly increased thickness of the flexor tendons and the flexor tendon pulley system but no impairment of the gliding mechanism. Only in climbers did the distance between tendon and phalanx increase from 0.14 cm (+/-0.07) during extension to 0.30 cm (+/-0.09) during forced flexion. In three climbers with complete A-2 pulley ruptures this distance was up to 0.51 cm (+/-0.15) during forced flexion. Clinically unsuspected synovial cysts, thickened joint capsules, fibrous tissue, or fluid collection were found only in climbers. We concluded that dynamic ultrasonography is a valuable tool for accurate assessment of early changes in "climber's finger." It provides useful information, especially in cases where clinical evaluation is difficult, and should be performed to select appropriate therapeutic management.

Adult↗
PubMedDate not supplied

Contrast-enhanced transrectal color doppler ultrasonography (TRCDUS) for assessment of angiogenesis in prostate cancer.

BACKGROUND: The clinical relevance of tumor angiogenesis has been investigated in several human tumors, including prostate carcinoma (PC). Previously, we found angiogenesis, measured as microvessel density (MVD), to be an independent prognostic factor in PC. Therefore, we evaluated contrast-enhanced Transrectal Color Doppler Ultrasonography (TRCDUS) for assessment of angiogenesis in PC. MATERIALS AND METHODS: We investigated 15 patients with PC before radical prostatectomy (RP) and 3 control patients before radical cystoprostatectomy. TRCDUS was performed using a micro-bubble-based ultrasound enhancer Levovist for identifying hypervascularized areas within the prostate. Computer-assisted quantification of color pixel intensity (PI) was used to evaluate objectively the hypervascularized areas; resistive index (RI) measurements were also obtained in these areas. After histopathological examination of the entire prostate gland for tumor confirmation, immunohistochemical evaluation of MVD using a polyclonal antibody against factor VIII was performed as described by Weidner et al. (N Engl J Med 324: 1-8, 1991). TRCDUS findings were correlated with the immunohistochemical data. RESULTS: All patients showed hypervascularized areas (range: 1-9) on contrast-enhanced TRCDUS. Hypervascularized areas showed a sensitivity of 50.8% and a specificity of 95.2% for detecting PC. Analysis of TRCDUS data and immunohistochemistry revealed a significant correlation between PI and MVD in PC specimens, demonstrating a correlation coefficient of r2 = 0.977 (p<0.001). RI did not correlate with MVD. CONCLUSION: Contrast-enhanced TRCDUS showed a high specificity in identifying PC. PI correlated significantly with MVD. Therefore, quantification of color Doppler signals seems to be helpful for assessment of angiogenesis in PC.

Adenocarcinoma↗