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Biomedical subjects

I M Ramos

Publications and source records attributed to I M Ramos.

12 recordsLinked to original sources
PubMed1993

Endovaginal pulsed and color Doppler in first-trimester pregnancy.

Endovaginal pulsed and color Doppler techniques were used to evaluate 23 unselected first-trimester pregnancies prior to elective abortion. Mean estimated gestational age was 8.9 +/- 1.6 weeks (range = 6.6-13.0). Low impedance, high velocity peritrophoblastic flow was seen in all cases. Mean peak systolic and end-diastolic velocities were 41.0 +/- 19.7 and 22.9 +/- 6.5 cm/s; mean resistance index (RI) was 0.41 +/- 0.10. Forty-five uterine arteries were evaluated with mean peak systolic and end-diastolic velocities of 44.1 +/- 14.7 and 7.6 +/- 4.3 cm/s; mean RI was 0.81 +/- 0.10. The peritrophoblastic and uterine artery velocities did not correlate with gestational age. Both ovaries were evaluated in 14 patients. One had no detectable flow in either ovary. For the active ovary in the other 13 patients, mean peak systolic and end-diastolic velocities were 27.4 +/- 9.9 and 15.2 +/- 5.9 cm/s; mean RI was 0.44 +/- 0.09. The corresponding values for the inactive ovary were 8.9 +/- 3.8 cm/s, 2.0 +/- 2.0 cm/s, and 0.76 +/- 0.22. These results can be used as a baseline for future studies of abnormal pregnancies.

Adult↗
PubMed1993

Endovaginal US and Doppler findings after first-trimester abortion.

Endovaginal ultrasound (US) imaging and color Doppler flow imaging techniques were used to evaluate the uterus and its contents and to establish characteristics of a normal post-abortion appearance in 19 women who underwent elective first-trimester abortions. Twenty-two examinations were performed between 2 and 17 days after the procedure. Thirteen of the 22 examinations (59%) showed different amounts of intrauterine material of varying echogenicity. Seven of the 22 examinations (32%) showed a thick endometrial stripe, and only two showed a normal stripe. Color Doppler flow imaging demonstrated typical peritrophoblastic flow in four of eight patients on the second and third days after the abortions were performed. After the third day, flow was observed in only two of 11 patients, and intrauterine material was also seen. These results indicate that intrauterine material and low-impedance flow are frequently observed after an abortion and do not necessarily indicate clinically important retained products of conception.

Abortion, Induced↗
PubMed1992

Ectopic pregnancy: evaluation with endovaginal color flow imaging.

Endovaginal sonography and endovaginal color flow imaging were compared in 155 patients with clinical suspicion of ectopic pregnancy. Sixty-five patients (42%) had surgically confirmed ectopic pregnancies. Thirty-six of the pregnancies were diagnosed with endovaginal sonography alone, the criteria being an extrauterine sac or ectopic fetus (sensitivity, 54%). Sixty-two ectopic pregnancies were diagnosed with endovaginal color flow imaging (sensitivity, 95%) when an ectopic fetus or sac was seen or placental flow was identified in an adnexal mass separate from the ovary and uterus. The diagnosis of ectopic pregnancy was excluded with endovaginal sonography (specificity, 98%) and endovaginal color flow imaging (specificity, 98%) by finding an intrauterine gestation, nonvisualization of an adnexal mass, and absence of placental flow. Three false-positive and three false-negative diagnoses were made with endovaginal color flow imaging (positive predictive value, 97%). The addition of color Doppler flow imaging to endovaginal sonography allows increased sensitivity in the detection of ectopic pregnancy.

Adult↗
PubMed1991

Ultrasound imaging of pancreatico-duodenal transplants.

A preliminary investigation of the role of ultrasound, including color and duplex Doppler, was performed in recipients of cadaveric pancreatico-duodenal transplants. Twenty such examinations were done on three patients. Three different complications were noted: rejection, pancreatitis, and peripancreatic abscess. The mean normal resistive index (RI) was 0.71 +/- 0.12. The normal allograft anteroposterior (AP) dimension ranged from 1.5 to 2.0 cm. Intraparenchymal and main feeding vessels were demonstrated easily. RI calculations alone were not helpful in diagnosing graft rejection. However, this diagnosis can be made using a new biochemical marker, serum anodal trypsinogen. We conclude that when used in conjunction with a reliable biochemical marker for rejection (serum anodal trypsinogen), ultrasound, including color and duplex Doppler, provides an important adjunct for the rapid, inexpensive, and complete evaluation of patients with pancreatico-duodenal transplants.

Cadaver↗
PubMed1990

Hepatoblastoma: detection of tumor vascularity with duplex Doppler US.

The evaluation of pediatric abdominal masses commonly includes computed tomography, ultrasound (US), and, more recently, magnetic resonance imaging. A previous study suggested that duplex US is of use in further tissue characterization of hepatic lesions in adults. The authors describe the Doppler signals arising from hepatoblastomas in three infants. Peak systolic Doppler frequency shifts in the neoplasms of these three patients were all equal to or greater than 4 kHz, well above the normal range for hepatic arteries. Each neoplasm also exhibited antegrade diastolic flow. The detection of high Doppler frequency shifts associated with neovascularity may prove useful in future evaluation of pediatric hepatic masses.

Carcinoma, Hepatocellular↗
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↗
PubMed1988

Tumor vascular signals in renal masses: detection with Doppler US.

The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.

Adolescent↗