Tejas S. Mehta

Central nervous system abnormalities assessed with prenatal magnetic resonance imaging.

OBJECTIVE To determine the frequency at which magnetic resonance imaging (MRI) provides additional information in fetuses with suspected central nervous system (CNS) abnormalities on ultrasound. METHODS Between May 1, 1996, and March 26, 1999, 83 women with 90 fetuses (including seven sets of live twins) had 91 ultrasonographic and MRI examinations of the fetal CNS. Eight women were studied twice, one for two different indications. If referrals came from outside our institution, a confirmatory sonogram was obtained. Indications for examination were ventriculomegaly (n = 25), suspected neural tube defect (n = 16), arachnoid cyst (n = 12), large cisterna magna (n = 11), and miscellaneous indications (n = 20). RESULTS Magnetic resonance imaging findings led to changed diagnoses in 26 (40%) of 66 fetuses with abnormal confirmatory sonograms. Magnetic resonance imaging findings not found by ultrasound included partial or complete agenesis of the corpus callosum (n = 11), porencephaly (n = 6), hemorrhage (n = 5), tethered cord (n = 3), cortical gyral abnormality (n = 2), cortical cleft (n = 2), midbrain abnormality (n = 2), and partial or complete agenesis of the septi pellucidi (n = 3), as well as holoprosencephaly, cerebellar hypoplasia, subependymal and cortical tubers, vascular malformation, and vermian cysts (one case each). Abnormalities better delineated by MRI than ultrasound included three cephaloceles, a dural arteriovenous malformation, one distal sacral neural tube defect, and the mass effect of three arachnoid cysts. That information was used to alter patient counseling and at times management. CONCLUSION When a CNS anomaly is detected by sonography or suspected on ultrasound, MRI findings might lead to altered diagnosis and patient counseling.

Rheolytic Thrombectomy in the Management of Limb Ischemia: 30-Day Results from a Multicenter Registry

Purpose: To evaluate the use of rheolytic thrombectomy (RT) with the AngioJet catheter for treatment of lower extremity ischemia due to arterial/graft thrombotic occlusion. Methods: A retrospective multicenter review was performed of 99 consecutive patients (52 men; mean age 67 ± 13 years, range 30–90) who underwent RT for thrombotic occlusions in native arteries (n=80) or bypass grafts (n=19). Pre- and postprocedural limb ischemia and in-hospital events were evaluated. Amputation and mortality rates at 30 days were determined. Results: The majority of patients (78.8%) presented within 14 days of symptom onset. RT resulted in substantial to complete thrombus removal in 70 (70.7%) patients and partial in 22 (22.2%); there was no angiographic change in 7 (7.1%). Adjunctive post RT thrombolysis was used in 37 patients. Underlying stenoses found in 81 limbs were treated with one or more of the following procedures: balloon angioplasty (n=62), stenting (n=35), or non-emergent surgical revision (n=5). In-hospital complications included 2 major amputations, 5 cases of minor tissue loss, 7 rethromboses, and 3 cases of transient renal insufficiency. Four (4.0% patients died in-hospital; the 95 surviving patients all had viable limbs at discharge. Mortality and amputation rates at 30 days were 7.1% and 4.0%, respectively. Conclusions: Percutaneous treatment of thrombotic occlusions with RT, followed by definitive treatment of the underlying stenosis, is a promising therapeutic option for patients with limb-threatening ischemia.

Increased Cancer Detection Rate and Variations in the Recall Rate Resulting from Implementation of 3D Digital Breast Tomosynthesis into a Population-based Screening Program

PURPOSE To compare the recall and cancer detection rates (CDRs) at screening with digital breast tomosynthesis (DBT) with those at screening with two-dimensional (2D) mammography and to evaluate variations in the recall rate (RR) according to patient age, risk factors, and breast density and among individual radiologists at a single U.S. academic medical center. MATERIALS AND METHODS This institutional review board-approved, HIPAA-compliant prospective study with a retrospective cohort included 85 852 asymptomatic women who presented for breast cancer screening over a 3-year period beginning in 2011. A DBT unit was introduced into the existing 2D mammography screening program, and patients were assigned to the first available machine. Ten breast-subspecialized radiologists interpreted approximately 90% of the examinations. RRs were calculated overall and according to patient age, breast density, and individual radiologist. CDRs were calculated. Single and multiple mixed-effect logistic regression analyses, χ(2) tests, and Bonferroni correction were utilized, as appropriate. RESULTS The study included 5703 (6.6%) DBT examinations and 80 149 (93.4%) 2D mammography examinations. The DBT subgroup contained a higher proportion of patients with risk factors for breast cancer and baseline examinations. DBT was used to detect 54.3% more carcinomas (+1.9 per 1000, P < .0018) than 2D mammography. The RR was 7.51% for 2D mammography and 6.10% for DBT (absolute change, 1.41%; relative change, -18.8%; P < .0001). The DBT subgroup demonstrated a significantly lower RR for patients with extremely or heterogeneously dense breasts and for patients in their 5th and 7th decades. CONCLUSION Implementing DBT into a U.S. breast cancer screening program significantly decreased the screening RR overall and for certain patient subgroups, while significantly increasing the CDR. These findings may encourage more widespread adoption and reimbursement of DBT and facilitate improved patient selection.

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.

Frequency and Cause of Disagreements in Diagnoses for Fetuses Referred for Ventriculomegaly

PURPOSE To prospectively assess the frequency and cause of disagreements in diagnoses at ultrasonography (US) and magnetic resonance (MR) imaging for fetuses referred for ventriculomegaly (VM). MATERIALS AND METHODS One hundred ninety-five women, aged 18-44 years, with 200 fetal referrals for VM, were recruited in a prospective IRB-approved, HIPAA-compliant study. Written informed consent was obtained. US scans were prospectively interpreted by three obstetric radiologists and MR examinations were read by one obstetric radiologist and three pediatric neuroradiologists. Final diagnosis was reached by consensus (198 US, 198 MR, and 196 US-MR comparisons). Gestational age, ventricular size, types of disagreements, and reasons for disagreements were recorded. Interreader agreement was assessed with kappa statistics. Ventricular diameter, gestational age, and confidence scores were analyzed by using mixed-model analysis of variance, accounting for correlation within reader and fetus. RESULTS There was prospective agreement on 118 (60%) of 198 US and 104 (53%) of 198 MR readings. Consensus was more likely when the final diagnosis was isolated VM (83 of 104, 80% at US; 82 of 109, 75% at MR) than when the final diagnosis included other anomalies as well (14 of 63, 22% at US; seven of 68, 10% at MR; P < .001). There was disagreement on 19 (10%) of 196 and 31 (16%) of 196 fetuses about the presence of VM at US and MR, respectively, and on 29 (15%) of 198 and 39 (20%) of 198 fetuses regarding the presence of major findings at US and MR, respectively. Reasons for discrepancies in reporting major findings included errors of observation, lack of real-time US scanning, lack of neuroradiology experience, as well as modality differences in helping depict abnormalities. CONCLUSION Of radiologists who read high-risk obstetric US and fetal MR images for VM, there is considerable variability in central nervous system diagnosis.

Current uses of ultrasound in the evaluation of the breast

Ultrasound is an important imaging modality in evaluating the breast. One of the most common uses of ultrasound is to help distinguish benign from malignant breast disease, primarily with gray-scale ultrasound but also with Doppler ultrasound. Another common use is to provide guidance for interventional procedures. Less common uses include assisting in staging of breast cancer and evaluating patients with implants. Recently there has been an interest in using ultrasound to screen asymptomatic women for breast cancer, as is done with mammography. Further studies must be performed to assess if this reduces mortality from breast cancer. Although primarily used to image the female breast, ultrasound also can be used to evaluate breast-related concerns in men. Uses of contrast-enhanced ultrasound are still experimental and would add an invasive component to an otherwise noninvasive study.

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.

Imaging Approaches to Diagnosis and Management of Common Ductal Abnormalities

Ductal disease is an important, often overlooked, and poorly understood issue in breast imaging that results in delays in diagnosis and patient care. The differential diagnosis for an intraductal mass is broad and includes inspissated secretions, infection, hemorrhage, solitary or multiple papillomas, and malignancy. Each breast is composed of eight or more ductal systems, with most disease arising in the terminal ductal-lobular unit. Imaging evaluation of the ductal system usually entails a combination of mammography, galactography, ultrasonography (US), and in some cases magnetic resonance (MR) imaging. The most common finding with all modalities is ductal dilatation with a focal or diffuse abnormality. Benign diseases of the ducts include duct ectasia, blocked ducts, inflammatory infiltrates, periductal mastitis, apocrine metaplasia, intraductal papillomas, and papillomatosis. Malignant diseases of the ducts include ductal carcinoma in situ, invasive ductal carcinoma, and Paget disease. Most commonly performed with US or MR imaging guidance, percutaneous biopsy methods are helpful in diagnosis and management of ductal findings. Because most findings are smaller than 1 cm, located within a duct, and thus sometimes not visible after a single pass, vacuum-assisted devices help improve the accuracy of sampling.

Body mass index and mortality rate among Hispanic adults: a pooled analysis of multiple epidemiologic data sets.

OBJECTIVE:To evaluate the association between body mass index (BMI, kg m−2) and mortality rate among Hispanic adults.METHODS AND PROCEDURES:Analysis of five data sets (total N=16 798) identified after searching for publicly available, prospective cohort data sets containing relevant information for at least 500 Hispanic respondents (⩾18 years at baseline), at least 5 years of mortality follow-up, and measured height and weight. Data sets included the third National Health and Nutrition Examination Survey, the Puerto Rico Heart Health Program (PRHHP), the Hispanic Established Population for Epidemiologic Studies of the Elderly (HEPESE), the San Antonio Heart Study (SAHS) and the Sacramento Area Latino Study on Aging.RESULTS:Cox proportional hazards regression models, adjusting for sex and smoking, were fit within three attained-age strata (18 to younger than 60 years, 60 to younger than 70 years, and 70 years and older). We found that underweight was associated with elevated mortality rate for all age groups in the PRHHP (hazard ratios [HRs]=1.38–1.60) and the SAHS (HRs=1.88–2.51). Overweight (HRs=0.38 and 0.84) and obesity grade 2–3 (HRs=0.75 and 0.60) associated with reduced mortality rate in the HEPESE dataset for those in the 60 to younger than 70 years, and 70 years and older attained-age strata. Weighted estimates combining the HRs across the data sets revealed a similar pattern.CONCLUSION:Among Hispanic adults, there was no clear evidence that overweight and obesity associate with elevated mortality rate.

Frequency and cause of disagreements in imaging diagnosis in children with ventriculomegaly diagnosed prenatally

To assess the frequency and cause of variability in diagnosis on cranial sonography and magnetic resonance imaging (MRI) in children referred following prenatal diagnosis of ventriculomegaly.