Biomedical subjects

A L Feyock

Publications and source records attributed to A L Feyock.

3 recordsLinked to original sources

PubMed1990

Pseudogestational sacs: Doppler US differentiation from normal or abnormal intrauterine pregnancies.

Doppler ultrasound (US) evaluation of 40 empty intrauterine sac-like structures was performed to evaluate the ability of this technique to permit distinction between intrauterine pregnancy and pseudogestational sac associated with ectopic pregnancy. Proof of the location of the pregnancy was available in all cases. There were 31 intrauterine pregnancies, of which 23 were missed or incomplete abortions and eight were early normal pregnancies. With an insonating frequency of 3 MHz, the average frequency shift detected from these intrauterine pregnancies was 1.7/1.0 kHz (peak systolic/end diastolic ratio). Nine pseudogestational sacs were evaluated, of which seven demonstrated no flow and two demonstrated minimal flow that averaged 0.4/0.1 kHz. Defining intrauterine peritrophoblastic flow as a peak systolic frequency shift of 0.8 kHz or greater (equivalent to 21 cm/sec with an angle of 0 degree) correctly classifies 26 of the 31 intrauterine pregnancies and all of the nine pseudosacs. The sensitivity of the Doppler technique for the detection of intrauterine pregnancies was 84%, and the specificity was 100%.

Abortion, Incomplete↗

PubMed1990

Renal masses: characterization with Doppler US.

The vascularity of indeterminate renal masses in 70 patients was investigated prospectively with duplex ultrasound. The peak-systolic Doppler shift frequency obtained from the renal mass was utilized to attempt distinction between benign and malignant lesions. With use of the criterion of a peak-systolic Doppler shift frequency of 2.5 kHz or greater as evidence of neovascularity, 26 of 37 malignant lesions demonstrated tumor signals (70% sensitivity). Thirty-one of 33 benign lesions lacked tumor signals (94% specificity). Both of the false-positive lesions were infections with inflammatory masses, with peak frequencies of 3.0 and 3.7 kHz. Tumor vascularity in most malignant renal mass lesions gives rise to abnormal, high-frequency, Doppler-shifted signals that can aid the differential diagnosis of renal masses.

Carcinoma, Renal Cell↗

PubMed1989

Ectopic pregnancy: duplex Doppler evaluation.

Of 398 patients in whom there was a clinical suspicion of ectopic pregnancy, 96 (24%) were found to have the condition. Of the 96, 70 underwent duplex Doppler imaging. A viable ectopic fetus was seen in 10 of 70 (14%), and an extrauterine sac without an identifiable fetus was seen in an additional 27, giving a sensitivity for imaging alone of 53%. Fetal heart activity was detected with Doppler in 13 (19%). High-velocity flow, which suggested the presence of an ectopic pregnancy, was detected in 38 of 70 (54%) patients (total preoperative sensitivity, 73%). In the 91 patients who did not have an ectopic pregnancy, duplex Doppler imaging of the intrauterine contents alone allowed an ectopic pregnancy to be excluded in 29 (32%) on the first examination and in a further 21 on the second scan (specificity, 55%). Nine vascular adnexal masses were falsely considered to be ectopic pregnancies (specificity, 90%). The positive predictive values were 47% for imaging alone and 85% for Doppler. The negative predictive values were 60% for imaging alone and 81% for Doppler.

Adult↗