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Biomedical subjects

D M Paushter

Publications and source records attributed to D M Paushter.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of iohexol-240 versus iohexol-300 in abdominal CT.

Forty patients without evidence of liver, kidney, or significant cardiac disease were prospectively divided into two groups of 20, receiving either iohexol-240 or iohexol-300. A contrast load of 150 ml was administered in conjunction with a rapid scanning technique at a preselected, fixed level to include liver, renal cortex, and aorta. Peak enhancement was calculated as change in Hounsfield units (HU) over baseline for each area of interest. Mean peak enhancement and standard deviation were calculated for each organ, and the difference between the means for the two contrast agents was compared using the Student's t test. Differences were not statistically significant with all p values greater than 0.05. Our results suggest iohexol-240 is preferred to iohexol-300 for body computed tomography (CT) due to its lower cost and iodine load without statistically significant change in diagnostic quality of the examination.

Evaluation Studies as Topic↗
PubMed1992

Hypoechoic renal pyramids: sonographic visualization in older children and young adults.

The frequency and degree of visualization of medullary pyramids in a normal population, aged 10-29 years, was analyzed. Hypoechoic pyramids were visualized in 42% of right kidneys in subjects aged 10-18 years and in 27% of subjects aged 19-29 years. Prominently hypoechoic pyramids, mimicking the appearance of neonatal kidneys, were seen in an additional 34% of subjects aged 10-18 years and in 16% aged 19-29 years. Prominent pyramids were present in 50% of subjects with renal cortical echogenicity (RCE) equal to liver, but also in 21% of subjects with RCE less than liver. Our study expands the age at which prominently hypoechoic medullary pyramids can be considered a normal finding. This may relate to recent improvements in ultrasound technology.

Adolescent↗
PubMed1992

Fibrotic lesions of the testicle: sonographic patterns mimicking malignancy.

All testicular sonograms performed over a 2.5-year period were retrospectively reviewed, yielding eight patients with pathologically proven lesions consisting primarily of tubular sclerosis and interstitial fibrosis. Only two patients (25%) had a palpable abnormality. A variety of sonographic patterns was found, including focal hypoechoic or hyperechoic lesions and diffuse heterogeneity of the testicular parenchyma. The clinical and sonographic findings prompted open biopsy or orchiectomy in all cases. In the same time period, nine pathologically proven testicular malignancies were evaluated sonographically and displayed either well-defined hypoechoic or diffusely heterogeneous echo patterns. All but two of these patients (78%) had palpable abnormalities. This study demonstrates a significant overlap in the sonographic appearance of benign fibrotic lesions and testicular malignancies. When careful palpation of a sonographically heterogeneous or focal hypoechoic lesion fails to reveal a mass and serum tumor markers are negative, an open biopsy with frozen section analysis should be considered rather than proceeding directly to orchiectomy. Homogeneously hyperechoic masses can be considered benign and do not require surgery.

Adult↗
PubMed1992

Doppler color imaging. Scrotum, breast, thyroid, and extremities.

DCI, when coupled with small-parts gray-scale imaging, has demonstrated great utility in the evaluation of superficial body abnormalities. This technique has rapidly become a primary method of evaluation of suspected testicular torsion, and its results are competitive with those of standard nuclear medicine examinations. DCI evaluation of male impotence, coupled with intracavernous injection of vasoactive substances, is now a leading, noninvasive technique for diagnosis of both arteriogenic and venogenic causes. DCI may provide invaluable information in the evaluation of palpable masses, particularly in the diagnosis of vascular abnormalities such as false aneurysm and arteriovenous fistula. Further studies are needed to corroborate the utility of DCI in the evaluation of focal thyroid and parathyroid abnormalities, breast carcinoma, nodal cancer, and the orbit. Because this technique is applicable to superficial, high-frequency examinations, DCI is rapidly becoming an accepted and frequently necessary part of any small-parts ultrasound study.

Color↗
PubMed1990

Comparison of magnetic resonance imaging and ultrasonography in staging early prostate cancer. Results of a multi-institutional cooperative trial.

BACKGROUND: In 1987, a cooperative study group consisting of five institutions was formed to determine the relative benefits of magnetic resonance imaging (MRI) and endorectal (transrectal) ultrasonography in evaluating patients with clinically localized prostate cancer (stage Ta or Tb). METHODS: Over a period of 15 months, 230 patients were entered into the study and evaluated with identical imaging techniques. We compared imaging results with information obtained at the time of surgery and on pathological analysis. RESULTS: MRI correctly staged 77 percent of cases of advanced disease and 57 percent of cases of localized disease; the corresponding figures for ultrasonography were 66 and 46 percent (P not significant). These figures did not vary significantly between readers; moreover, simultaneous interpretation of MRI and ultrasound scans did not improve accuracy. In terms of detecting and localizing lesions, MRI identified only 60 percent of all malignant tumors measuring more than 5 mm on pathological analysis and ultrasonography identified only 59 percent. CONCLUSIONS: The MRI and ultrasonography equipment that is currently available is not highly accurate in staging early prostate cancer, mainly because neither technique has the ability to identify microscopic spread of disease. Further evaluation with improved equipment may improve the accuracy of these techniques.

Adult↗
PubMed1990

Renal artery stenosis: evaluation with color Doppler flow imaging.

Renal artery stenosis (RAS) is the most common correctable cause of hypertension. The current study was undertaken to evaluate the usefulness of color Doppler flow imaging as a screening examination in the detection of significant RAS. Fifty-five kidneys in 30 patients were examined with aortography and color Doppler flow imaging in a double-blind fashion. The peak systolic velocity (PSV) in the renal artery, the renal-aortic ratio (RAR) (ie, the ratio of the PSV in the renal artery to the PSV in the aorta), and the renal artery resistive index were determined and compared with the percentage of stenosis as determined with angiography. Ultrasound (US) criteria used to diagnose RAS were (a) an RAR of 3.5 or greater and/or (b) a renal artery PSV of greater than 100 cm/sec. Doppler tracings were obtained in 25 (69%) of 36 kidneys with a patent single renal artery. RAR and PSV each yielded a sensitivity of 0% in the diagnosis of RAS. Doppler tracings were obtained in three (50%) of six occluded renal arteries. Accessory arteries were present in 13 (24%) of 55 kidneys, but none were visualized with color Doppler flow imaging. The authors conclude that with current technical capability, color duplex US is not an adequate screening method for the detection of RAS.

Angiography, Digital Subtraction↗
PubMed1989

CT evaluation of suspected hepatic metastases: comparison of techniques for i.v. contrast enhancement.

Although IV injection of contrast material is widely used for detection and follow-up of hepatic metastases on CT, the optimal method of contrast enhancement has not yet been defined. A prospective study was performed in 50 consecutive patients with suspected hepatic metastases. Lesion size and detectability were compared on unenhanced CT scans, scans obtained during a bolus injection of contrast material (early bolus phase), and scans obtained during a rapid infusion after the loading bolus. A total of 60 hepatic lesions were evaluated in 26 patients, 19 with histologic confirmation of metastases and seven with strong supportive evidence. The bolus phase allowed detection of 15% more lesions than did examination during the rapid-infusion phase. Lesion size varied, depending on the timing and method of contrast administration; the largest measurements were obtained during bolus injection of contrast material. In addition, bolus administration of contrast material subjectively resulted in the best lesion detection. Because the three techniques of IV contrast enhancement may produce different size measurements, sequential examinations must be tailored appropriately. Scanning during the bolus phase is technically possible with current CT equipment and is recommended as the primary CT screening examination for hepatic metastases.

Contrast Media↗
PubMed1988

Follicular aspiration: a comparison of an ultrasonic endovaginal transducer with fixed needle guide and other retrieval methods.

Ultrasonic techniques have been developed as alternatives to conventional laparoscopic aspiration for oocyte retrieval for in vitro fertilization (IVF). Given the advantages (less risk, lower cost, and greater patient acceptance) of these alternative techniques, it is appropriate to assess their efficacy compared with traditional laparoscopic retrieval. This article examines the recovery rate of oocytes and their subsequent fertilization rate with the use of an ultrasonic endovaginal transducer with fixed needle guide and compares these results with other retrieval methods. Comparisons were made between laparoscopic harvesting (n = 71, group I), ultrasonic transabdominal transvesical (n = 21, group II), and ultrasonic vaginal transducer (n = 76, group III). The data demonstrate comparable success using an ultrasonic endovaginal transducer with fixed needle guide. The authors believe this technique to be the procedure of choice for all routine oocyte retrievals during IVF treatment.

Female↗
PubMed1988

Peripheral pseudoaneurysms: evaluation with duplex US.

The prospectively generated results of 64 duplex sonographic examinations in 59 patients being evaluated for peripheral pseudoaneurysms over a 2-year period were reviewed. Subsequently, two groups of patients were identified. Group 1 (45 examinations) presented with relatively acute symptoms after arterial puncture, and group 2 (19 examinations) had undergone previous vascular surgical procedures and were usually asymptomatic. Duplex sonography demonstrated high sensitivity (94%) and specificity (97%) for the diagnosis of pseudoaneurysm in group 1. Of the 19 studies in group 2, duplex sonography allowed correct identification of pseudoaneurysms in four studies and exclusion of this entity in six examinations. The duplex sonographic findings in nine studies in this group did not allow differentiation of pseudoaneurysm from true aneurysm or oversize graft anastomosis. Duplex sonography is suggested as a primary radiologic method for evaluating possible pseudoaneurysms after arterial puncture, and it may provide valuable information and a means of postsurgical follow-up of selected patients as well.

Adult↗
PubMed1988

Breast specimen radiography: evaluation of a compression device.

The irregular shape and uneven tissue thickness of excised breast specimens makes radiographic evaluation difficult, especially when calcifications are not present. Xeroradiographs before and after compression of 20 separate excised breast specimens were compared, and 17 of the same specimens were compared after compression combined with immersion in water. Specimen compression improved visibility of the lesion on average in 88% of cases, and visibility was equal in 12%. Combined compression/immersion further improved visibility of the lesion on average in 37% of cases. More significantly, evaluation of the compressed specimen led to a change in interpretation of the radiographs in 45% of cases. Compression of the specimen in specimen radiography is recommended in all cases in which pre-biopsy localization is performed.

Biopsy↗
PubMed1988

CT of the liver: a survey of prevailing methods for administration of contrast material.

The members of the Society of Body Computed Tomography were surveyed to determine the most frequently used method of administering contrast material in CT studies of the liver. The respondents represented CT departments performing liver examinations in 22 institutions. No department relied solely on noncontrast scans. In 12 (54%) of 22 institutions, only contrast-enhanced scans were performed. The preferred dose for enhancement was 150 ml of 60% contrast material. Eight (36%) of the 22 respondents obtained images during the administration of a bolus of contrast material, whereas nine (41%) obtained images during the administration of a sustained drip infusion given after a loading bolus. Follow-up in 1987 revealed that two departments had switched to obtaining images during the administration of a bolus. The availability of CT power injectors and refinements in the rapid-scanning capabilities of CT scanners have increased the popularity of obtaining images of the liver during the administration of a bolus of contrast material. Despite this, in many departments, contrast material is still administered via drip infusion in CT studies of the liver.

Contrast Media↗
PubMed1986

Tracheobronchial tree and pulmonary arteries: MR imaging using electronic axial rotation.

Standard coronal magnetic resonance (MR) imaging cannot depict long segments of the tracheobronchial tree and left pulmonary artery owing to the normal thoracic kyphosis and posteriorly angled course of these structures. By the use of electronic axial rotation (EAR), however, MR is capable of imaging any plane. We used EAR in 25 patients undergoing MR examinations of the thorax. This technique allowed superior definition of the longitudinal axis of the tracheobronchial tree and left pulmonary artery. The right pulmonary artery was satisfactorily imaged by the standard coronal plane.

Bronchi↗
PubMed1986

Computed tomography appearance of a right cervical aortic arch.

The clinical diagnosis of cervical aortic arch rests on the detection of a pulsatile mass in the supraclavicular fossa. Unfortunately, clinical differentiation of a cervical arch from an aneurysm of the great vessels can be difficult. Dynamic computed tomography (CT) can aid in this differentiation and avert the need for angiography.

Adult↗