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Biomedical subjects

T S Mehta

Publications and source records attributed to T S Mehta.

12 recordsLinked to original sources
PubMed2001

Remote sonographic interpretation using a laser printer network: system performance and diagnostic accuracy in actual clinical practice.

OBJECTIVE: The purpose of our study was to evaluate the technical and clinical performance of remote sonographic interpretation using a laser printer network connecting a community-based imaging center and an academic medical center. SUBJECTS AND METHODS: During a 3-month period, 161 consecutive sonographic examinations were performed at a community-based imaging center and all 161 patients were enrolled in the study. Seventy-one (44%) of 161 examinations were interpreted on-site at the community-based imaging center, and 90 (56%) of 161 were transmitted over a T-1 line to an academic medical center where the static images were interpreted remotely. For the purposes of this study, the examination time was defined as the interval from the time the technologist started to scan the patient to the time the patient was dismissed from the radiology department. Examination times were recorded for each patient. Follow-up was available for 92 (57%) of 161 studies. Sensitivity and specificity for studies interpreted at the community-based imaging center and at the academic medical center were calculated. RESULTS: The mean examination time for pelvic sonographic examinations interpreted at the academic medical center (43 min) was significantly longer than for scans interpreted at the community-based imaging center (31 min) (p < 0.01). However, no significant difference was noted in the examination time for abdominal sonography. For all examinations interpreted on-site at the community-based imaging center for which follow-up was available, the sensitivity and specificity were 95% and 100%, respectively. For all examinations interpreted remotely at the academic medical center for which follow-up was available, the sensitivity and specificity were 93% and 90%, respectively. No significant difference was seen in the sensitivity (p = 1.00) or specificity (p = 0.24) of studies interpreted on-site versus remotely. CONCLUSION: Static sonographic images can be interpreted remotely without loss of sensitivity, but with decreased specificity. However, more time must be allotted for performing pelvic sonography when these examinations are to be interpreted remotely.

Abdomen↗
PubMed2001

Patient expectations and costs of immediate reporting of screening mammography: talk isn't cheap.

OBJECTIVE: Our purpose was to determine whether patients prefer immediate or delayed results of screening mammography and to determine the cost of immediate reporting at our institution. MATERIALS AND METHODS: A survey was anonymously and randomly distributed to 129 women who were 35-70 years old during a visit to their primary care physician, asking the women's preference for receiving mammography results by one of two systems: by letter with a return visit for any additional tests; or by speaking at once with the radiologist, with the option of additional tests being performed during the same visit. Patients' willingness to pay for the latter service was also determined. A cost identification model was constructed using commercially available software. We considered the impact on radiologists' and technologists' time and the need for additional equipment and space, and we analyzed the effect on the cost of immediate reporting. RESULTS: One hundred twenty (93%) surveys were completed. Eighty women (67%) preferred immediate reporting, and 62 (78%) of these 80 patients would wait 30-60 min. The additional cost of immediate reporting is $28.22 per patient. Only 11% of patients were willing to pay this additional cost. When new equipment and space were not required, the cost would increase by $4.38. This cost was most influenced by the time required to give patients normal results. CONCLUSION: Most surveyed patients preferred speaking with a radiologist immediately but were unwilling to pay additional fees. Radiologists, hospital administrators, and health care planners must be aware of the costs of immediate reporting and must factor these costs into any change in hospital or national policy.

Adult↗
PubMed2000

Use of Doppler ultrasound in the evaluation of breast carcinoma.

Ultrasound is an imaging modality commonly used to evaluate breast lesions in hopes to distinguish benign from malignant solid masses. Angiogenesis, defined as the emergence of new vessels to further the growth of tumor, has stimulated interest in the potential uses of Doppler ultrasound in patients with breast cancer. This article describes different forms of Doppler ultrasound, including color Doppler (CD), power Doppler (PD), and spectral Doppler (SD), as well as 3-dimensional (3D) ultrasound and ultrasound contrast media. We review the role of Doppler ultrasound in distinguishing benign from malignant solid breast masses. We also discuss the role of ultrasound in predicting tumor grade, histology, node status, and lymphatic vascular invasion, and in monitoring breast cancer treatment.

Breast↗
PubMed2000

Quantitative tests of a dual circalunidian clock model for tidal rhythmicity in the sand beach isopod Cirolana cookii.

In constant conditions (constant darkness DD[, 20 degrees C), the sand beach isopod Cirolana cookii exhibits spontaneous rhythmic swimming activity with an average free-running period of 12.5 h. The rhythms are seen as temporal adaptations to a complex interidal environment. These results support a dual circalunidian clock model for tidal rhythms in which two components of the rhythm have characteristic periods and active phase lengths and are hypothesized to be controlled by separate circalunidian clocks. A quantitative model successfully simulates many of the properties of endogenous swimming rhythms of C. cookii, including free-running behavior, entrainment, and phase-response curves (PRCs).

Animals↗
PubMed1999

Power Doppler sonography of breast cancer: does vascularity correlate with node status or lymphatic vascular invasion?

OBJECTIVE: The purpose of our study was to determine how breast cancer vascularity, as revealed by power Doppler sonography, correlates with lymph node involvement and lymphatic vascular invasion. MATERIALS AND METHODS: Breast sonograms obtained during a 2-year period were retrospectively reviewed. Patients who underwent power Doppler sonography of solid masses and had biopsy-proven carcinoma composed our study population. Power Doppler findings were categorized according to the presence or absence of vessels. Pathologic findings were reviewed for lymph node involvement and lymphatic vascular invasion. RESULTS: Of 176 patients with breast cancer, vessels were seen on power Doppler sonography in 128 (73%) and not seen in 48 (27%). Of 126 patients who underwent lymph node dissection, vessels were seen in 97 (77%) and not seen in 29 (23%). Lymph node involvement was seen in 42 (43%) of the 97 patients in whom vessels were seen and in three (10%) of the 29 in whom vessels were not seen. Of 150 patients examined for lymphatic vascular invasion, vessels were seen in 111 (74%) and not seen in 39 (26%). Lymphatic vascular invasion was seen in 47 (42%) of the 111 patients in whom vessels were seen and in five (13%) of the 39 in whom vessels were not seen. CONCLUSION: Tumor vascularity revealed by power Doppler sonography correlated strongly with detection of lymph node involvement and lymphatic vascular invasion, with sensitivities of 93% and 90%, respectively. However, the specificities were low, at 32% and 35%, respectively. More important, patients with breast cancer in whom vessels were not revealed by power Doppler sonography also were unlikely to have lymph node involvement and lymphatic vascular invasion: Negative predictive values were 90% and 87%, respectively.

Adult↗
PubMed1999

Lack of sensitivity of endometrial thickness in predicting the presence of an ectopic pregnancy.

The purpose of this study was to evaluate whether endometrial thickness measurements can be used to differentiate between patients with ectopic pregnancy and spontaneous abortion. Of 676 patients with clinical suspicion of ectopic pregnancy, no intrauterine pregnancy was seen in 128. Of these, 42 (33%) had ectopic pregnancy, 52 (40%) had spontaneous abortion, and 34 (27%) had intrauterine pregnancy. No significant difference was found in endometrial thickness between women with ectopic pregnancy (mean, 9.0 mm; range, 2 to 20 mm) and those with spontaneous abortion (mean, 8.4 mm; range, 2 to 18 mm). A thin endometrium seen on transvaginal sonography cannot be used to exclude the diagnosis of ectopic pregnancy.

Abortion, Spontaneous↗
PubMed1997

Treatment of ectopic pregnancy: is a human chorionic gonadotropin level of 2,000 mIU/mL a reasonable threshold?

PURPOSE: To determine whether a human chorionic gonadotropin (hCG) level of 2,000 mIU/mL is a reasonable threshold for diagnosing ectopic pregnancy in the absence of ultrasound (US) findings of intrauterine pregnancy (IUP) and thus to prevent inappropriate treatment that will result in the loss of an otherwise normal pregnancy in women with early IUPs. MATERIALS AND METHODS: The authors reviewed the medical records of and US scans obtained in 676 patients in whom ectopic pregnancy was clinically suspected between January 1, 1994, and December 31, 1995. RESULTS: Five hundred forty-eight patients had evidence of a normal or abnormal IUP. Fifty-one (40%) of the 128 patients without evidence of an IUP had an hCG level of more than 2,000 mIU/mL. Of these 51 patients, 15 (29%) were treated for ectopic pregnancy; 17 (33%) were not immediately treated for ectopic pregnancy and had a normal IUP at follow-up US. CONCLUSION: An hCG level of 2,000 mIU/mL without US findings of IUP, while suggestive of an abnormal pregnancy, is not diagnostic. Per the results of recent studies, it is reasonable to closely follow up rather than treat many of these early, stable cases of ectopic pregnancy.

Adult↗
PubMed1993

The developmental potential of mouse embryos conceived in Ham's F-10 medium containing ethylenediaminetetraacetic acid.

OBJECTIVE: To measure fetal developmental potential of mouse eggs fertilized and cleaved in modified Ham's F-10 medium (Sigma Chemical Co., St. Louis, MO) containing the chelating agent, ethylenediaminetetraacetic acid (EDTA), as a model for establishing criteria for human IVF and GIFT procedures. DESIGN: Optimum concentrations of EDTA in modified Ham's F-10 were established by measuring blastocyst development of in vivo fertilized zygotes from a random bred (CD1) mouse strain. Postimplantation development of in vitro fertilized eggs from a hybrid inbred (B6D2F1) mouse strain was measured after conception in the modified Ham's F-10 medium without or with human serum or EDTA and compared with the results of in vivo fertilized eggs. Mouse embryo development potential and pregnancy rates (PRs) of recipients were compared with those calculated from theoretical probabilities. RESULTS: The addition of 10 to 100 microM EDTA to modified Ham's F-10 supported development of > 60% of the in vivo conceived zygotes to the blastocyst stage in the absence of serum; the addition of human serum significantly decreased embryo development to blastocysts (23%). Pregnancy rates (30% to 50%) of recipients of the in vitro conceived mouse embryos were similar for embryo cohorts from all culture conditions tested. The overall yield of fetuses from total embryos transferred was significantly higher for the groups developed in modified Ham's F-10 with 100 microM EDTA (37%) compared with embryos developed in modified Ham's F-10 alone (18%) or in modified Ham's F-10 with human serum (18%). CONCLUSIONS: [1] Based on fetal development in pregnant recipients, approximately two thirds of the mouse eggs fertilized in modified Ham's F-10 with 100 microM EDTA (or in vivo) had the potential to give rise to offspring. [2] Given the viability rate, the observed PRs of foster mothers receiving four to six embryos were only two thirds of the theoretically possible, suggesting the hormone and/or surgical interventions of the recipients reduced their pregnancy potential. [3] Including 100 microM EDTA during mouse conception in modified Ham's F-10 improved the fetal developmental potential to that of in vivo derived mouse embryos.

Animals↗
PubMed1990

Development potential of mouse embryos conceived in vitro and cultured in ethylenediaminetetraacetic acid with or without amino acids or serum.

Mouse ova were inseminated in vitro in modified Earle's balanced salts solution (EBSS) supplemented with 10 or 100 microM EDTA and 4 mg/ml BSA. After 4 h exposure to sperm, the ova were transferred to five different culture conditions based on albumin-free EBSS supplemented with 10 microM EDTA minus or plus amino acids, or with 100 microM EDTA minus or plus amino acids, or with human cord serum. After 44 h of culture, four-cell embryos from each culture group were transferred in cohorts of five into the left oviduct of pseudopregnant recipients (13-16 per culture condition). Two-cell embryos developed in vivo were similarly transferred to a separate group of recipients to serve as controls. The pregnancy rates following transfer of embryos cultured in 10 microM EDTA minus or plus amino acids or in 100 microM EDTA plus amino acids (38%, 43%, and 50%, respectively) were not significantly different from those of the in vivo control group (43%). The pregnancy rates following transfer of embryos cultured in 100 microM EDTA plus amino acids (21%) or plus cord serum (8%) were significantly lower (p less than 0.01) than those of the other groups. The overall yield of fetuses from total embryos transferred was significantly higher (p less than 0.01) for the groups developed in 100 microM EDTA plus amino acids (29%) and in vivo (26%) compared with embryos developed in 10 or 100 microM EDTA with no amino acids, 10 microM EDTA plus amino acids, or 100 microM EDTA plus cord serum (15%, 15%, 9%, and 3%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMedDate not supplied

Technical factors influencing sonographic visualization of fetal echogenic intracardiac foci.

PURPOSE: A fetal echogenic intracardiac focus (EIF) is most commonly a normal variant in a normal fetus, but owing to reports of an increased risk of aneuploidy with EIFs, the finding causes concern when noted on routine obstetric sonograms. This study was undertaken to determine which factors influence the sonographic visualization of fetal EIFs. METHODS: In part 1 of the study, records from 1,920 fetal sonographic examinations were reviewed for fetal age, indication for sonography, and abnormal findings. For all cases with EIFs recorded and 645 randomly selected cases with no record of EIFs, sonograms were reviewed for heart position at the time of the 4-chamber view, technologist performing the examination, fetal position, heart visibility, transducer frequency, machine type, amount of amniotic fluid, and presence/absence of an EIF. In part 2 of the study, machine settings were evaluated with respect to visualization of EIFs. RESULTS: In part 1 of the study, only the technologist performing the examination and the fetal position were associated with visualization of EIFs. In part 2 of the study, we found that the standard obstetric mode settings are better for visualization of EIFs than are the fetal echocardiographic mode settings. CONCLUSIONS: We conclude that technical factors influence visualization of EIFs.

Amniotic Fluid↗