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Biomedical subjects

W F Dahnert

Publications and source records attributed to W F Dahnert.

7 recordsLinked to original sources
PubMed1991

Bladder exstrophy-epispadias complex: prostatic evaluation by transrectal ultrasonography.

Seven patients with bladder-exstrophy-epispadias complex underwent high resolution prostatic ultrasonography in order to establish the presence and appearance of their prostate gland and seminal vesicles. Six patients had been born with classic bladder exstrophy, and one patient with complete epispadias. The size of the prostate gland was in the normal range in three patients. Three patients had small glands, and in one patient no prostatic tissue could be identified. Two patients showed an unusual position or echoappearance of their glands. The seminal vesicles in five patients were relatively large, contained multiple cystic spaces, and/or extended posteriorly and inferiorly to the prostate gland proper. Our study demonstrates that the prostate gland and seminal vesicles are present in patients with bladder exstrophy. The unusual appearance, position, and size in most patients, however, suggests faulty embryologic development or changes secondary to surgery reflecting the complex nature of the condition. Likewise, the enlarged seminal vesicles may indicate impaired drainage of these structures secondary to the initial bladder closure or subsequent bladder neck reconstruction.

Adolescent↗
PubMed1989

Determination of canine prostatic size in situ: comparison of direct caliper measurement with radiologic and transrectal ultrasonographic measurements.

The use of transrectal ultrasonography to estimate canine prostatic size in situ was evaluated and compared to that of direct measurement via calipers and an in situ radiologic procedure. The length, width, and depth of prostates were measured by transrectal ultrasound in both the transverse and sagittal planes from which prostatic volume was calculated. Prostatic volumes were subsequently transformed into prostatic weights using the following nomogram: prostatic Weight (g) = 0.602 x prostatic Volume (cm3) + 1.16. Prostatic weights estimated by ultrasound as well as by direct measurement with caliper were similar (P greater than 0.10) to the true gravimetric weight; however, prostate weights estimated by the radiological X-ray procedure were significantly (P less than 0.01) lower. The relationship between true gravimetric prostate weight and that estimated by ultrasound was described by the following regression equation: estimated weight (g) = 1.127 gravimetric weight (g) - 1.665; r = 0.900; P less than 0.001; n = 23. In summary, the results of this study demonstrate that transrectal ultrasonography can be used to accurately predict canine prostatic weight.

Animals↗
PubMed1988

Renal involvement in AIDS: sonographic-pathologic correlation.

Renal sonography was performed in 36 patients with clinical and/or laboratory evidence of AIDS, usually because of deteriorating renal function. In 15 patients, histopathologic specimens were reviewed to characterize renal pathologic changes underlying the sonographic findings. Sonographic evaluation included determination of renal size and cortical echogenicity according to a standard grading system. Pathologic specimens were evaluated for tubular and glomerular abnormalities. Sonography showed either normal-sized or enlarged kidneys with grade I cortical echogenicity in 13 patients (36%), grade II in three patients (8%), and grade III in five patients (14%). Fifteen patients (42%) had normal renal echogenicity. In addition to focal segmental glomerulosclerosis the pathologic examination showed different degrees of tubular abnormalities. Striking, irregularly dilated, infolded tubules with flattened epithelium and intratubular deposits of proteinaceous material, and sometimes cystlike formation involving the medulla and cortex, were seen in two patients with grade III kidneys, and mild dilatation of the tubules was seen in four patients with grade I disease. Moderate tubular dilatation was observed in one patient with grade I disease. No significant tubular abnormality was seen in one patient with grade I disease or in seven patients with normal renal echogenicity. Although glomerular changes contribute to the increase in renal echogenicity, we postulate that the main factors responsible for the increased echogenicity in AIDS nephropathy are the striking tubular abnormalities seen in these patients.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Update on prostatic ultrasound.

Although there is good evidence that carcinomas of the prostate are usually seen as echopenic masses within the external zone of the prostate, it is unclear how often an echopenic mass has an origin other than carcinoma of the prostate. Technical problems at the periphery of the gland not uncommonly create echopenic areas on an artifactual basis. Whether ultrasound will prove to be a satisfactory screening method for the detection of carcinoma of the prostate is yet to be decided. Prospective studies are in progress, but it has not yet been established whether prostate screening is a worthwhile procedure. The best possible equipment is required to detect these subtle lesions; cheap equipment will probably not give adequate results.

Aged↗
PubMed1986

Ultrasonography of prostatic carcinoma employing amplitude-enveloped (AM) and frequency-demodulated (FM) imaging: in vivo, in vitro, and pathologic correlation.

Thirty patients with biopsy proven carcinoma of the prostate were examined with transrectal (TR) (5-MHz linear array transducer) and transabdominal (TA) (3-MHz sector scanner) ultrasonography prior to prostatectomy. All patients had clinical stage A (n = 5) or B (n = 25) disease. Following retropubic radical prostatectomy, in vitro waterbath studies of the resected specimens were performed obtaining both conventional amplitude-enveloped (AM) images and frequency-demodulated (FM) images. The ability of each imaging modality (TR, TA, AM, FM) to detect the cancerous lesion was determined, and in all cases correlation with pathology was obtained. Transabdominal suprapubic ultrasonography did not prove helpful in detecting early carcinoma. Longitudinally oriented linear array transrectal ultrasonography was positive in nearly two thirds of the patients. Insignificantly lower positive correlation with pathologic findings was obtained from in vitro AM images; the lesions were often better visualized on transverse than on longitudinal images. The highest correlation with pathology was obtained from the in vitro frequency-demodulated images.

Aged↗