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Biomedical subjects

M D Rifkin

Publications and source records attributed to M D Rifkin.

At least 145 records · Page 8Linked to original sources
PubMed1983

Endoscopic ultrasonic evaluation of the prostate using a transrectal probe: prospective evaluation and acoustic characterization.

Transrectal sonography of the normal prostate demonstrates a gland that has low-level homogeneous echoes. Benign and malignant prostatic disease causes disruption of this normal texture. A prospective study was performed to determine the ability of ultrasound to detect focal defects accurately. The specific histologic diagnoses of the lesions were obtained by ultrasonically guided transperineal biopsy or prostatic resection. Acoustic characterization following pathologic evaluation demonstrated certain echogenic features to be highly suggestive of benign disease. These include hyperechoic lesions that are bright and thick, foci with shadowing, and, although uncommon, purely hypoechoic areas. Although in some instances differentiation of disease processes is difficult, this analysis suggests that in certain lesions, accurate prediction of benign and malignant disease can be made. At present, there is still enough overlap that biopsies are usually required.

Aged↗
PubMed1983

Sonographically guided transperineal prostatic biopsy: preliminary experience with a longitudinal linear-array transducer.

Transperineal prostate biopsy performed with continuous sonographic monitoring by a real-time rectal endoscopic probe, using a longitudinal linear array which offered complete visualization of the needle from the perineum into suspected abnormal areas within the prostate, was performed in 25 patients with clinically suspected prostate disease. Clinically suspected nodules in 13 patients were more accurately biopsied using sonographic guidance as opposed to conventional manual, digital guidance. Subclinical carcinomas in three patients and areas of atypical histology in three patients were also identified and biopsied using transrectal sonographic guidance.

Aged↗
PubMed1983

Abnormal echogenicity of the testicle caused by epididymal cysts.

Ultrasonography of the scrotum has proven to be highly accurate for the diagnosis of testicular and other scrotal abnormalities, particularly for defining focal lesions. False-positive examinations are unusual. Three cases are presented where large epididymal cysts compressed the testes and the remainder of the epididymis. This led to an abnormal echogenic area in testes of two patients and a hypoechoic defect of the testis suggesting malignancy in the thirds. The patients were sonographically and anatomically normal without testicular abnormality during and after operation, following removal of the epididymal fluid collections.

Adult↗
PubMed1983

Ultrasonography in the evaluation of muscular trauma.

Ultrasonography was performed to assess muscle injuries in 120 advanced-level athletes. Real-time sonography was chosen for evaluation since it allowed a comparison between the muscles at rest and during contraction. Pathologic patterns are reported and compared with the normal ultrasonic muscular anatomy. Twenty-five subjects were referred for surgery. All lesions had abnormal sonograms, and these were correctly described in 21 cases (84 per cent). Ultrasonic investigation is a reliable, useful method to confirm, locate and evaluate traumatic muscular lesions and to assess the need for surgical repair.

Athletic Injuries↗
PubMed1983

Polyorchidism diagnosed preoperatively by ultrasonography.

Polyorchidism, or multiple testes, is a rare condition that has been referred to in both medical literature and mythological folklore. Curious attributes have been ascribed to men with this condition, including supposed increased sexual prowess and virility. In the medical literature, the examples of supernumerary testicles have demonstrated only one additional testis. The first proven case of an extra testicle was by Lane, in 1895. Boggon reviewed 11 additional cases in 1933, and numerous other cases have been reported since then. To date, there has not been a preoperative ultrasonographic study that adequately describes this phenomenon.

Adolescent↗
PubMed1983

Ultrasonographic findings in placenta increta.

Placenta increta, invasion of the myometrium by normal placental (chorionic) villi, can be life-threatening to a mother at delivery. In two reported cases of pathologically proven placenta increta, the abnormal areas were retrospectively identified on ultrasonographic images. In both cases, there was consistent focal obliteration of the hypoechoic retroplacental zone by either tissue of echogenicity similar to that of the normal placenta or tissue of slightly decreased echogenicity. This was found to represent extension of the villi through the decidua basalis into the myometrium. The spectrum of non-malignant invasive placentas and the specific ultrasonographic findings that should allow prospective diagnosis are discussed.

Decidua↗
PubMed1983

Prostate biopsy utilizing transrectal ultrasound guidance: diagnosis of nonpalpable cancers.

A long-axis real-time ultrasonic transrectal probe was utilized in transperineal biopsies to detect three nonpalpable prostate cancers. It was found that ultrasonically guided percutaneous perineal biopsy allows for the accurate placement of the biopsy needle tip into suspicious areas of the prostate. Ultrasonographic examination prior to biopsy is recommended to provide confirmation of palpable masses and to reveal other suspicious but not clinically suspected areas.

Adenocarcinoma↗
PubMed1983

The role of diagnostic ultrasonography in varicocele evaluation.

Twenty-one patients with the clinical diagnosis of varicocele were evaluated with static and superficial organ scanners. The sonogram was able to image the dilated scrotal veins in all of these cases. The small, clinically subtle varicocele could be demonstrated only with high-resolution, dedicated real-time small-parts scanners, whereas larger lesions could also be imaged with B-mode contact equipment. Varicoceles are a well-documented cause of male infertility amenable to surgical treatment. From this study it is felt that ultrasonography can accurately detect varicoceles. It can be used as a screening procedure so that only those men requiring therapy need undergo more extensive and complicated diagnostic procedures.

Adult↗
PubMed1977

The normal contrast-enhanced computed axial tomogram of the brain.

Intravenous administration of iodinated contrast agents permits identification of the major cerebral arteries and veins; third, fourth, and lateral ventricular choroid plexuses; falx and tentorium on appropriate sections of contrast-enhanced computed axial tomographic (CECT) images. Combinations of these normal vascular structures into conglomerate densities may produce confusing contrast pseudotumors on CECT images.

Brain↗
PubMedDate not supplied

MR imaging of shoulder injuries in professional baseball players.

Magnetic resonance (MR) imaging was used to evaluate the shoulders of 10 symptomatic professional baseball players and one asymptomatic player, with surgical correlation in six cases and arthrographic correlation in two cases. Seven small rotator cuff tears measuring 0.5-1 cm were identified on MR images, with arthrographic and surgical confirmation of these findings in two patients and surgical confirmation only in three patients. Cortical irregularity and/or subchondral cyst formation at the posterior aspect of the greater tuberosity near the insertion site of the infraspinatus tendon was found in five of the seven players with rotator cuff tears. Similar findings were noted in the asymptomatic volunteer and in one of the three players without cuff tear, who also had irregular thickening of the posterior capsule. These findings are believed to represent chronic avulsive changes resulting from the deceleration stresses of the follow-through motion.

Adult↗
PubMedDate not supplied

MR imaging characteristics of noncancerous lesions of the prostate.

Radical prostatectomy specimens from 53 men with clinical stage A or B prostate cancer were retrospectively reviewed and compared with correlative axial T2-weighted magnetic resonance (MR) images obtained just before surgery. Non-cancerous lesions were evaluated for signal intensity and location. Focal high-signal-intensity areas (n = 72) were present in 81% of patients. The 26% of lesions seen in the central gland all correlated with cystic atrophy. Of the 53 lesions seen in the peripheral prostate, 47 (89%) were cystic atrophy without associated cancer, four (7.5%) cystic atrophy with cancer, and two (3.8%) focal inflammation. Focal low-signal-intensity areas (n = 42) were present in 60% of patients. Of the 31% of lesions in the central prostate, one-fifth correlated with benign prostatic hyperplasia (BPH) and four-fifths with fibrous tissue. Of the 69% of peripheral lesions, 83% corresponded to fibrous tissue, 10% to BPH, and 7% to normal tissue. Mixed lesions (n = 42) were present in 64% of patients; 86% of these were located centrally and 14% peripherally. All mixed central lesions were BPH; the peripheral lesions were areas of combined cystic atrophy and fibrosis. BPH of low or mixed signal intensity can extend into the peripheral prostate and mimic cancer. High-intensity cystic atrophy associated with cancer can mimic normal tissue.

Aged↗
PubMedDate not supplied

Chemical shift artifact along the section-select axis.

Chemical shift artifact (CSA), familiar to radiologists along the frequency-encoding axis, also occurs along the section-select axis. The authors observed a case in which CSA mimicked a renal mass. Subsequent retrospective analysis of 50 abdominal magnetic resonance (MR) imaging studies was performed to assess occurrence of CSA adjacent to the upper and lower renal poles. CSA along the section-select axis was observed in 76% of cases and adjacent to 39% of all renal poles imaged. CSA along the section-select axis is common in abdominal MR imaging and may occasionally mimic disease.

Abdomen↗
PubMedDate not supplied

MR imaging of hepatic iron overload in rat.

To investigate the relationship of hepatic signal intensity and T2 with histologic grading in an animal model of oral iron overload and to determine the duration of feeding necessary to produce abnormalities detectable on magnetic resonance (MR) images, hepatic iron overload was induced in 12 rats by feeding them a diet supplemented with 4% carbonyl iron for 2-11 weeks. Iron overload seen on MR images was graded independently and blindly by two radiologists as normal, mild, moderate, or severe. The rats were killed, and histologic findings were graded blindly by four pathologists using a similar subjective scale. Hepatic T2 values were estimated from spin-echo images. In the rats with iron overload, intracellular iron deposition was noted on histologic studies. On MR images, hepatic signal intensity and T2 decreased after only 2 weeks of dietary iron overload, and both continued to decrease with longer duration of feeding. There was significant correlation between iron overload duration and changes on MR images and between MR images and histologic grading (r = .92, P = .0001 for both). The mean T2 of hepatic iron overload decreased with longer duration of feeding.

Animals↗
PubMedDate not supplied

MR imaging of pelvic lymph nodes in primary pelvic carcinoma with ultrasmall superparamagnetic iron oxide (Combidex): preliminary observations.

The potential of ultrasmall superparamagnetic iron oxide (Combidex)-enhanced MRI of pelvic lymph nodes in patients with primary pelvic carcinoma is evaluated. Fifteen histologically classified lymph nodes in six patients with known primary pelvic cancer (four prostate; one rectum; one uterus) were evaluated with T2-weighted fast spin-echo (FSE) and T2*-weighted gradient-echo (GRE) MRI at 1.5T 12 to 48 hours after intravenous administration of Combidex at a dose of 1.7 mg Fe/kg. Quantitative image evaluation was performed by comparing signal intensity of individual nodes on pre- and postcontrast images. All patients proceeded to pelvic lymph-node biopsy or surgical dissection, where six were found to be benign and nine were malignant. Of the 15 lymph nodes, four nodes showed a decrease in signal intensity. Of these, three, in which signal loss was homogenous were benign, and one, in which the signal-intensity decrease was heterogeneous, was malignant (micrometastases). No signal change was noted in 11 of 15 lymph nodes of which three were benign (inflammatory) and eight were malignant. Combidex is a promising MR contrast agent for evaluating pelvic lymph nodes. Our preliminary observations suggest that the agent is most useful for classifying normal lymph nodes.

Adult↗
PubMedDate not supplied

Duplex Doppler examination in renal disease: evaluation of vascular involvement.

Evaluation of renal disease and transplant rejection has been limited to excretory urography, nuclear isotope flow studies and other more invasive procedures. The B-scan ultrasound findings are often nonspecific. The development of duplex pulsed Doppler sonography has permitted evaluation of both arterial and venous flow. Duplex ultrasound studies in patients with a suspected diminution in renal function demonstrated the ability to delineate normal and abnormal flow, limiting the differential diagnosis, and in some cases actually documented an abnormality before gross pathologic changes became evident.

Adult↗