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Biomedical subjects

U M Hamper

Publications and source records attributed to U M Hamper.

At least 37 records · Page 2Linked to original sources
PubMed1994

Three-dimensional US: preliminary clinical experience.

PURPOSE: To evaluate applications of three-dimensional (3D) ultrasound (US) in a clinical setting. MATERIALS AND METHODS: Sixty-two patients were examined with experimental 3D US transducers coupled to a commercially available US unit and a computer workstation. Images were acquired in either the sagittal or transverse plane and were reconstructed in two orthogonal planes, transverse and sagittal; the C-plane, parallel to the transducer surface; and a volumetric rotational transparency display. RESULTS: A variety of normal and diseased abdominal and superficial organs and selected fetal anatomy, and pathologic conditions were imaged. 3D US allowed display of anatomy and pathologic conditions in planes usually not possible with conventional two-dimensional (2D) US. CONCLUSION: Preliminary data suggest that 3D US may become a valuable clinical tool and adjunct to 2D US. 3D US allows depiction of normal and abnormal structures in previously unattainable planes, thus facilitating diagnosis and increasing operator diagnostic confidence.

Abdomen↗
PubMed1994

Color Doppler flow mapping of abdominal wall perforating arteries for transverse rectus abdominis myocutaneous flap in breast reconstruction: method and preliminary results.

PURPOSE: To describe the use of color Doppler flow ultrasound (US) in preoperative mapping of small perforating arteries in the abdominal wall that supply the transverse rectus abdominis myocutaneous (TRAM) flap used primarily for breast reconstruction. MATERIALS AND METHODS: With a grid (clear x-ray film) and a high-frequency linear-array transducer, the size and position of perforating arteries as they exit the rectus abdominis muscle were mapped preoperatively in 35 patients. Twenty-three of these patients had previously undergone abdominal surgery; 26 underwent reconstruction and clinical follow-up. RESULTS: Operating time was decreased and flap design was planned to include the largest perforating arteries and minimize the overall abdominal wall defect. Two of the 26 patients who underwent TRAM flap reconstruction had partial flap loss: One continued to smoke, which may have caused microvascular compromise; and a paucity of perforating arteries was seen in the second patient. CONCLUSION: Preoperative mapping of perforating arteries for TRAM flap reconstruction provides a rational basis for flap design and patient selection, which may affect flap survival.

Abdominal Muscles↗
PubMed1993

Endovaginal sonography of the nongravid uterus.

Endovaginal sonography allows excellent visualization of the endometrium, including the cyclic changes seen in premenopausal women and the normal postmenopausal endometrium. The spectrum of abnormalities affecting the endometrium and myometrium, including foreign bodies, infection, fluid collections, hyperplasia, and neoplasia, is also best assessed with endovaginal sonography. It has also become the imaging modality of choice for examining women with postmenopausal bleeding. In these patients, analysis of the sonographic appearance of the endometrium, combined with duplex and color Doppler evaluation of the endometrial vasculature, may allow differentiation of benign from malignant processes.

Adult↗
PubMed1993

Diagnosing breast implant rupture with MR imaging, US, and mammography.

A total of 135 symptomatic women with 262 breast implants were examined with magnetic resonance (MR) imaging performed with a body coil, ultrasound (US), or both to determine imaging features of implant rupture. Surgical proof was available for 33 women with 62 implants; 24 were ruptured and 38 were intact. Complicated internal structure was the most reliable predictor of implant rupture: Diffuse low-level echoes were seen on sonograms in 56% of ruptured implants; internal membranes (which correspond to the collapsed implant shell) were seen on MR images in 58% of ruptured implants. Fluid droplets were seen within the silicone in 26% of ruptured implants on MR images. Irregular implant contour can be a sign of rupture but is unreliable. Fluid collections around silicone implants are not a sign of rupture. At present, neither US nor conventional MR imaging with a body coil is sufficiently reliable to advocate routine screening of asymptomatic women with breast implants. Evaluation with MR imaging performed with a surface coil is more reliable.

Breast↗
PubMed1993

Thickened endometrium in the postmenopausal woman: sonographic-pathologic correlation.

A correlative sonographic and histopathologic analysis was performed in 35 postmenopausal women with greater than 5-mm thickening of the endometrium at pelvic sonography. Women undergoing estrogen replacement were excluded from study. Four distinct sonographic patterns were encountered. Pattern 1 consisted of echogenic endometrium with small cysts (endometrial polyp with cystic hyperplasia [n = 9], atrophic endometrium with cystically dilated glands [n = 5], and atrophic endometrium [n = 3] at microscopic examination). Pattern 2 was homogeneous echogenic endometrium (proliferative endometrium [n = 3] and adenomyomatous polyp [n = 1]). Pattern 3 was irregular, inhomogeneous endometrium with ill-defined hypoechoic areas (endometrial carcinoma [n = 5], complex hyperplasia with atypia [n = 1], blood clots [n = 1], and atrophic endometrium with eosinophilic metaplasia [n = 1]). Pattern 4 was thin endometrium with fluid in the endometrial cavity (scant atrophic endometrium [n = 6]). Thus, an endometrial thickness of greater than 5 mm in postmenopausal women is associated with a variety of pathologic conditions. Subclassification of sonographic patterns may be helpful in differentiating benign cystic atrophy or cystic endometrial hyperplasia from malignant endometrial lesions.

Aged↗
PubMed1993

Transvaginal color Doppler sonography of adnexal masses: differences in blood flow impedance in benign and malignant lesions.

OBJECTIVE: The purpose of this study was to assess the blood flow characteristics of adnexal masses before surgical excision and to determine whether color flow Doppler sonography is useful for distinguishing benign from malignant masses. SUBJECTS AND METHODS: Thirty-one adnexal masses were evaluated with color flow Doppler transvaginal sonography. The pulsatility index and resistive index were calculated from the waveforms generated from blood flow within the ovary. Twenty-five lesions were benign and six were malignant on pathologic examination. Benign lesions included six endometriomas, six mesothelial cysts, three serous and one mucinous cystadenoma, three mature cystic teratomas, two hemorrhagic corpus luteum cysts, one cystadenofibroma, one sclerosing stromal cell tumor, one paratubal cyst, and one ovary that had undergone torsion with infarction. The malignant lesions consisted of three papillary serous cystadenocarcinomas, one granulosatheca cell tumor, one immature teratoma, and one metastasis of colon cancer to the ovaries. RESULTS: Benign tumors and cysts had a significantly higher pulsatility index (mean, 1.93 +/- 1.02; range, 0.23-3.99) and resistive index (mean, 0.77 +/- 0.22; range, 0.2-1.0) than did malignant tumors (pulsatility index: mean, 0.77 +/- 0.33; range, 0.31-1.09; resistive index: mean, 0.5 +/- 0.17; range, 0.27-0.67). However, some overlap in individual values for benign and malignant lesions was found. CONCLUSION: Our preliminary data suggest that high pulsatility and resistive indexes indicate benign adnexal processes; however, considerable overlap in pulsatility and resistive indexes between benign and malignant lesions was noted, and further work is needed before the validity of these factors is proved.

Adnexal Diseases↗
PubMed1992

Intraoperative sonography of renal tumors.

Intraoperative sonography (7.5 MHz. transducer with Doppler probe) was used to evaluate renal masses in 41 kidneys to determine its correlation with pathological findings. This intraoperative determination of the extent of the renal lesion prompted occasional changes in surgical management. We conclude that intraoperative sonography is most useful in partial nephrectomy, and helps to determine the extent of tumor, multicentricity, venous extension and associated cysts. These findings may not be appreciated with intraoperative, visual inspection of the kidney.

Humans↗
PubMed1992

Fine-needle aspiration biopsy of abdominal lesions: diagnostic yield for different needle tip configurations.

Four fine-needle aspiration biopsy needles with different tip configurations were used in 133 patients with abdominal lesions. The 20-gauge needles were used in random sequence by several physicians. The specimen from each of the 522 needle passes was evaluated by two cytopathologists for adequacy to render a diagnosis and for the presence of cell block material. The Franseen needle produced a 16% and 9% better yield for diagnostic material than did the cut biopsy and spinal needles (P less than .05), respectively. The Westcott needle was better than the cut biopsy needle by 13%, and the spinal needle produced an 11% better yield than did the cut biopsy needle. Differences did not exist in liver biopsies but were present in pancreatic biopsies. The spinal needle was the least successful in yielding cell block material. Use of the cut biopsy needle resulted in the largest proportion of inadequate specimens, except its yield in cell blocks in the liver was 25% higher than that of the Westcott needle. The authors conclude that not all unusual designs for 20-gauge needle tips render results superior to those of the simple spinal needle.

Adolescent↗
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↗
PubMed1991

Retroperitoneal and pelvic CT of patients with AIDS: primary and secondary involvement of the genitourinary tract.

Although genitourinary tract disorders are common in acquired immunodeficiency syndrome (AIDS), little attention has been paid to their manifestations on computed tomographic (CT) scans. The authors reviewed the CT scans of 86 patients infected with the human immunodeficiency virus for CT manifestations of primary or secondary involvement of the genitourinary tract. Genitourinary tract abnormalities identified in the 86 patients included nephromegaly in 34 (40%), hilar adenopathy in 30 (35%), bladder wall thickening in 19 (22%), medullary hyperattenuation in 12 (14%), renal calcifications in seven (8%), adnexal masses in five (6%), hydronephrosis in four (5%), pyelonephritis in three (3%), renal abscesses in three (3%), and solid renal masses in three (3%). Although these abnormalities are seen on CT scans in many other diseases, in the AIDS patient they often indicate the presence of an AIDS-related renal disease or involvement of the genitourinary tract by an AIDS-related neoplasm or infection.

AIDS-Associated Nephropathy↗
PubMed1991

Capsular transgression of prostatic carcinoma: evaluation with transrectal US with pathologic correlation.

One hundred twenty-five patients with biopsy proved clinical stage A or B prostatic carcinoma were evaluated with biplane transrectal ultrasonography (US) prior to radical prostatectomy. Sonograms were evaluated for capsular transgression of the tumor into the posterior and posterolateral aspects of the glands as manifested by local contour deformity and irregularity or interruption of the periprostatic fat echoes. Correlation of the findings at US with the findings at pathologic examination of the step sections was obtained, and the presence and depth of capsular penetration were assessed. Of the 250 halves or hemispheres of the prostate gland that were evaluated, capsular penetration was seen at pathologic examination in 86. US enabled correct identification of pericapsular tumor spread in 59 of the 86 hemispheres but did not depict pericapsular tumor spread in 27 hemispheres. Absence of pericapsular tumor spread was verified at pathologic examination in 149 of the 164 hemispheres that either did not have tumor or did not show pericapsular tumor spread. Pericapsular tumor spread was incorrectly diagnosed in 15 hemispheres. A positive US diagnosis of pericapsular tumor spread correlated moderately well with the depth of penetration demonstrated at pathologic examination. Transrectal US is an effective noninvasive procedure that demonstrates the presence of prostatic cancer.

Biopsy↗
PubMed1991

Stage A adenocarcinoma of the prostate: transrectal US and sonographic-pathologic correlation.

Results of transrectal ultrasound (TRUS) of the prostate and pathologic examination of specimens obtained at transurethral resection of the prostate (TURP) were compared in 29 patients with clinical stage A adenocarcinoma. Ten specimens contained no residual tumors larger than 5 mm in diameter; in the remaining 19 glands, 20 discrete cancers were found. At TRUS, 30 peripheral hypoechoic lesions were demonstrated, of which 11 corresponded to carcinoma at pathologic examination. Other hypoechoic peripheral zone lesions included a focal area of dilated acinar glands in 10 cases, post-TURP scarring with fingerlike projections of fibrosis in seven, dysplasia in one, and no correlation in one. Of nine tumors that were not detected prospectively at TRUS, eight were predominantly in the anterior zone and one was in the posterior peripheral zone but was isoechoic. Overall, the sensitivity of TRUS in the evaluation of clinical stage A lesions was 55% and the specificity was 37%. Clinical stage A carcinomas may be difficult to detect at US, and findings are often nonspecific. Any suspicious peripheral zone lesion should undergo biopsy with TRUS guidance before being diagnosed as malignant.

Adenocarcinoma↗
PubMed1991

Stage B adenocarcinoma of the prostate: transrectal US and pathologic correlation of nonmalignant hypoechoic peripheral zone lesions.

Various benign conditions have been found to cause hypoechoic lesions in the prostate gland, thus mimicking the sonographic appearance of early prostatic cancer. Transrectal sonograms in a large series of patients with biopsy-proved clinical stage B prostatic cancer were retrospectively reviewed to determine the pathologic correlate to benign hypoechoic peripheral zone lesions. Transrectal sonograms demonstrated hypoechoic lesions that did not represent cancer in 25 of 160 patients examined. All lesions were contralateral to the carcinoma. Pathologic correlation was found in 24 of the 25 lesions. The results of this study show that contralateral hypoechoic lesions in patients with pathologically proved prostatic cancer do not necessarily imply bilateral tumor involvement; they accounted for benign lesions that mimicked the sonographic appearance of malignant tumors and thus produced a false-positive rate for cancer in the contralateral lobe of 16% of patients (25 of 160) with clinical stage B cancer.

Adenocarcinoma↗
PubMed1990

Bright echogenic foci in early prostatic carcinoma: sonographic and pathologic correlation.

One hundred sixty patients with biopsy-proved clinical stage A or B prostatic carcinoma were examined with high-resolution transrectal ultrasonography prior to radical prostatectomy. All tumors showed either a hypoechoic or isoechoic echo pattern. However, 11 patients demonstrated evidence of focal bright echogenic areas at the periphery or within the center of a hypoechoic tumor. Coarse echogenic foci seen in seven patients corresponded pathologically to calcified corpora amylacea in benign tumors of the prostate gland either at the edge of the tumor or scattered throughout the tumor. Seven patients showed a fine, stippled echogenic pattern within the lesion. On a pathologic level, this pattern represented high-grade tumors with extensive central comedonecrosis and calcifications in five patients and an unusual deposit of small intraluminal crystalloid deposits in two patients. Combinations of echo patterns were observed in three patients. This study demonstrates that echogenic foci can be seen within predominantly hypoechoic tumor nodules. Coarse bright echoes, usually at the periphery of the tumor, suggest calcifications in benign prostate glands. Tumor calcifications and intraluminal prostatic crystalloid deposits were located more centrally and had a finer stippled sonographic appearance.

Adenocarcinoma↗
PubMed1990

Pelvic masses: aspiration biopsy with transrectal US guidance.

Biplanar, transrectal ultrasound guidance was used in the transrectal aspiration of two pelvic abscesses, one recurrent tumor, and one sterile, nonmalignant fluid collection. This method provides an alternative path that allows precise localization for aspiration biopsy of pelvic masses.

Abscess↗