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Case report: MRI appearance of isolated fallopian tube torsion in an adolescent with a congenital Mullerian duct anomaly and ispilateral renal agenesis [Case Report]

Kopec, M; Rosenkrantz, A B; Rivera, R; Wells, J L; Berg, R E; Milla, S S
PMID: 20103428
ISSN: 1365-229x
CID: 106378

The efficacy of digital fluoroscopic image capture in the evaluation of vesicoureteral reflux in children

Fefferman, Nancy R; Sabach, Amy S; Rivera, Rafael; Milla, Sarah; Pinkney, Lynne P; Strubel, Naomi A; Babb, James
BACKGROUND: In accordance with ALARA, minimizing radiation exposure associated with voiding cystourethrograms (VCUG) is of critical importance. Advances in fluoroscopic technology might help achieve this goal. OBJECTIVE: To determine the efficacy of fluoroscopic image capture compared to conventional digital radiographic spot (DRS) images in voiding cystourethrograms (VCUG) for the evaluation of vesicoureteral reflux (VUR) in children. MATERIALS AND METHODS: The study was a retrospective review of 65 VCUG examinations (130 kidney/ureter units). Each examination consisted of fluoroscopically captured spot (FCS) images and the corresponding DRS images. Each set of images was evaluated by three pediatric radiologists for the diagnosis of VUR for a total of 390 kidney/ureter units reviewed. Using the DRS image set as the reference standard, the efficacy of the FCS images for diagnosing reflux was determined. RESULTS: The diagnostic accuracy of the FCS images in terms of the binary characterization of reflux as negative or positive was 97.2% (379/390). The sensitivity of the FCS images was 92.6% (88/95); the specificity of the FCS images was 98.6% (291/295). CONCLUSION: Fluoroscopically captured images are adequate in documenting absence of VUR on VCUG examinations, obviating the need for radiographic spot images and resulting in reduction in radiation exposure
PMID: 19727697
ISSN: 0301-0449
CID: 106491

Time-resolved dynamic contrast-enhanced MR urography for the evaluation of ureteral peristalsis: initial experience

Kim, Sooah; Jacob, Jason S; Kim, Danny C; Rivera, Rafael; Lim, Ruth P; Lee, Vivian S
PURPOSE: To determine the feasibility of time-resolved dynamic contrast-enhanced magnetic resonance urography (MRU) for the evaluation of ureteral peristalsis using a data-sharing 3D gradient echo sequence with spiral k-space filling. MATERIALS AND METHODS: Eight patients (M=3, F=5, mean 48.1 years) were referred for MRU for the evaluation for renal mass (n=3), hematuria (n=2), urinary tract tuberculosis (n=1), postoperative bladder cancer (n=1), and postoperative ureteric reimplantation (n=1). Dynamic MRU was performed for 120 seconds at 1.5T after intravenous furosemide and gadolinium administration using an oblique sagittal, time-resolved T1 3D gradient echo sequence with 1 second effective temporal resolution. Study quality was assessed based on artifacts and extent of ureteric visualization. Frequency of peristalsis from the renal pelvis to urinary bladder was evaluated for each subject. RESULTS: A total of 16 ureters were examined. Image quality was good in four ureters, satisfactory in 11 ureters, and poor in one ureter. Mean peristaltic frequency was 3.5 waves per minute (range, 2.5-6.5 waves/minute) in normal ureters (n=11). Five ureters were considered abnormal (one urinary tract tuberculosis and four postsurgical ureters), and all had decreased or no peristalsis (0-1.5 waves per minute). CONCLUSION: MRU using a time-resolved, data-sharing 3D contrast-enhanced technique is able to demonstrate ureteral peristalsis and permits quantification of ureteral peristaltic frequency
PMID: 18972340
ISSN: 1053-1807
CID: 91480

Dynamic MR angiography of upper extremity vascular disease: pictorial review

Stepansky, Flora; Hecht, Elizabeth M; Rivera, Rafael; Hirsh, Laurie E; Taouli, Bachir; Kaur, Manmeen; Lee, Vivian S
Unlike peripheral lower extremity vascular disease, upper extremity vascular disease is relatively uncommon. While atherosclerosis and embolic disease are the most common causes of upper extremity ischemia, a wide variety of systemic diseases and anatomic abnormalities can affect the upper extremity. Upper extremity ischemia poses a significant diagnostic and therapeutic challenge for both clinicians and radiologists. Although history and physical examination remain the mainstays of diagnosis, imaging can be vital in confirming suspected disease and guiding treatment planning. Digital subtraction angiography is often the preferred method for detection of upper extremity vascular disease, particularly for characterization of complex arteriovenous anatomy such as in vascular malformations and for evaluation of dialysis fistulas and grafts. However, this modality is invasive, requires iodinated contrast agents and radiation, and may fail to demonstrate significant extraluminal disease. More recently, magnetic resonance (MR) angiography techniques have made important advances, permitting higher temporal and spatial resolution that is preferable for diagnosing upper extremity vascular disorders. In this review, the authors present an overview of upper extremity MR angiography techniques and protocols, revisit the often variable vascular anatomy of the arm and hand, and offer examples of various pathologic entities diagnosed with MR angiography. Finally, several imaging pitfalls that one must be aware of for accurate diagnosis are illustrated and reviewed
PMID: 17967936
ISSN: 1527-1323
CID: 75846

Calcified catheter "cast" masquerading as a retained catheter fragment after removal of an implanted venous access device [Case Report]

Sabbaghian, M Shirin; Rivera, Rafael; Ginsburg, Howard B; Nadler, Evan P
Calcified catheter 'cast' found on radiologic studies after central venous catheter removal is a rare complication that has been reported twice. Both cases were associated with thrombus. In this case report, we present a 15-year-old boy with acute lymphoblastic leukemia who demonstrated on CT scan a radiopacity in his left brachiocephalic vein after removal of an implanted venous access device. This was initially thought to be a retained catheter fragment. Diagnostic studies, including venogram, excluded the presence of a retained catheter fragment. Additional procedures to retrieve a nonexistent catheter fragment were thus avoided. Therefore, a catheter 'cast' should be considered as part of the differential diagnosis when calcification is found on an imaging study after removal of an implantable venous access device to prevent an unwarranted surgical exploration
PMID: 17394003
ISSN: 0179-0358
CID: 75649

Laparoscopic neo-os creation in an adolescent with uterus didelphys and obstructed hemivagina [Case Report]

Patterson, Danielle; Mueller, Claudia; Strubel, Naomi; Rivera, Rafael; Ginsburg, Howard B; Nadler, Evan P
Uterus didelphys is a rare congenital anomaly with a well-documented association with obstructed hemivagina and ipsilateral renal agenesis. Treatment of this anomaly includes drainage of hematocolopos and excision of the vaginal septum, which has traditionally used a scalpel or scissors, often with hymenotomy. Recently, a less invasive approach using hysteroscopic resection has been reported, allowing improved visualization with preservation of the hymenal ring. In this article, we present an alternative minimally invasive approach using a combination of laparoscopy and vaginoscopy in the case of a 10-year-old girl. This approach allows for treatment in cases wherein vaginoscopy provides inadequate visualization with the advantage of enabling full evaluation for associated complications affecting future fertility including endometriosis, pelvic infection, and pelvic adhesions
PMID: 17011253
ISSN: 1531-5037
CID: 69029

An appendiceal leiomyoma in a child with acquired immunodeficiency syndrome [Case Report]

Sambol, Elliot; Patterson, Danielle; Rivera, Rafael; Borys, Dariusz; Greco, M Alba; Kaul, Aditya; Nadler, Evan P
Children with acquired immunodeficiency syndrome (AIDS) are at an increased risk for lymphoproliferative and neoplastic disorders. Included among these are smooth muscle neoplasms such as leiomyomas and leiomyosarcomas. There have been at least 15 reported cases of smooth muscle tumors in the approximately 8,000 children with AIDS, however the incidence in immunocompetent children is only two per ten million. The lesions in children with human immunodeficiency virus infection are usually found in the lung, liver, and gastrointestinal tract. Here, we present an unusual case of a 12-year-old African American girl with vertically acquired AIDS who presented to the pediatric emergency department with severe diffuse abdominal pain. She was ultimately found to have an appendiceal leiomyoma on abdominal exploration, the first reported case. Our report suggests that smooth muscle tumors of the appendix be included in the differential diagnosis of abdominal masses in children with AIDS
PMID: 16944181
ISSN: 0179-0358
CID: 69689

The relationship between alpha angle and resistive index of the femoral epiphysis in the normal and abnormal infant hip

Amodio, John; Rivera, Rafael; Pinkney, Lynne; Strubel, Naomi; Fefferman, Nancy
BACKGROUND: The arterial vascularity of the hip has been investigated in normal infants using duplex Doppler sonography. This study addressed the differences in hip vascularity in infants with respect to gender and acetabular morphology. OBJECTIVE: To determine whether there is a relationship between the resistive index of the vessels of the femoral chondroepiphysis and the alpha angle in normal infant hips and in those with developmental dysplasia of the hip. MATERIALS AND METHODS: We studied 76 hips (38 patients) with gray-scale and power Doppler US. The patients were referred because of a possible abnormal clinical hip examination or had risk factors for developmental dysplasia of the hip. The infants ranged in age from 1 day to 6 weeks. There were 13 boys and 25 girls. Gray-scale images were initially performed in the coronal and transverse planes to evaluate acetabular morphology, alpha angle and position of the femoral chondroepiphysis relative to the acetabulum. The hips were then examined with power Doppler US, in both sagittal and transverse planes, to identify arterial vessels within the femoral epiphysis. Resistive indices were then recorded from the spectral analysis in each vessel identified. Each examination was performed by one of five pediatric radiologists. Mixed model regression was used to assess the relationship between resistive index and alpha angle, age and gender. RESULTS: Of the 76 hips, 34 had an alpha angle of 60 degrees or greater and were classified as normal, 26 had an alpha angle between 50 degrees and 59 degrees and were classified as immature, and 13 had an alpha angle of less than 50 degrees and were either subluxed or dislocated at the time of examination. At least two vessels were documented in each femoral epiphysis except in three hips, in which no vessels could be documented because of technical factors. There was a statistically significant linear relationship between the alpha angle and resistive index, such that the resistive index tended to rise with increasing alpha angle (P=0.0022). In addition, female infants had a significantly higher average resistive index than the average resistive index in male infants with the same alpha angle (P=0.0005). CONCLUSION: There is a direct linear relationship between alpha angle and resistive index in the infant hip. Female infants have a higher average resistive index than male infants. We believe that these results might serve as a model for predicting an infant hip at risk of ischemia. In addition, the fact that lower resistive indices of the femoral epiphysis are associated with acetabular dysplasia might help explain the documented low incidence of avascular necrosis in untreated hip dysplasia
PMID: 16688445
ISSN: 0301-0449
CID: 71139

Influence of selenium on heat shock protein 70 expression in heat stressed turkey embryos (Meleagris gallopavo)

Rivera, Rafael E; Christensen, V L; Edens, F W; Wineland, M J
Heat shock protein 70 (hsp70) family of proteins, which functions as molecular chaperones, has been associated with tolerance to stressors in avian species. Selenium (Se) is an essential trace mineral incorporated into the seleno-enzymes such as glutathione peroxidase (GSHpx). GSHpx reduces oxidized glutathione (GSSG) to reduced glutathione (GSH) in the GSH/GSSG antioxidant system and protects cells from oxidative damage. This study was conducted to examine if the relationship between dietary supplementation of selenium to turkey (Meleagris gallopavo) hens and the embryonic expression of hsp70 and GSHpx activity in heat stressed embryos. Livers of embryos developing in eggs from turkey hens fed diets with or without supplemental Se were analyzed for hsp70 concentration and GSHpx activity before and after recovery from a heating episode. Before heat stress, hsp70 concentrations were equivalent in each treatment, but GSHpx activity was maximized in the SE treatment group. After recovery from the heating episode, hsp70 concentrations were significantly higher (P<0.05) in the non-Se-supplemented groups, but in the Se-supplemented groups the hsp70 concentrations were not different from pre-stress concentrations. In the pre-stress Se-supplemented group, liver GSHpx activity was significantly higher than GSHpx activity in the non-Se-supplemented embryo livers, and in the livers from embryos recovering from heat stress, GSHpx activity in the non-Se-supplemented group was lower than the pre-stress activity and significantly lower than the GSHpx activity in liver from Se-supplemented embryos recovering from heat distress. Se supplementation to the dams resulted in a significant increase in their embryos and that condition would facilitate a decreased incidence of oxidative damage to cells. A more reduced redox status in embryos from Se-supplemented dams decreased the need for cellular protection attributed to stress induced hsp70 and presumably allows heat distressed embryos to resume normal growth and development than embryos from dams with inadequate selenium nutrition
PMID: 16230039
ISSN: 1095-6433
CID: 94460

Appendicitis in children: low-dose CT with a phantom-based simulation technique--initial observations

Fefferman, Nancy R; Bomsztyk, Elan; Yim, Angela M; Rivera, Rafael; Amodio, John B; Pinkney, Lynne P; Strubel, Naomi A; Noz, Marilyn E; Rusinek, Henry
PURPOSE: To retrospectively determine the accuracy of low-dose (20-mAs) computed tomography (CT) in the diagnosis of acute appendicitis in children by using a technique that enables the simulation of human CT scans acquired at a lower tube current given the image acquired at a standard dose. MATERIALS AND METHODS: Institutional review board approval was obtained, informed consent was not required, and the study was HIPAA compliant. The authors reviewed 100 standard-dose pediatric abdominal-pelvic CT scans (50 positive and 50 negative scans) obtained in 100 patients and corresponding simulated low-dose (20-mAs) scans. The standard-dose scans were obtained for evaluation in patients suspected of having appendicitis. Scans were reviewed in randomized order by four experienced pediatric radiologists. The patients with positive findings included 21 girls (mean age, 9.2 years) and 29 boys (mean age, 8.4 years). The patients with negative findings included 28 girls (mean age, 9.2 years) and 22 boys (mean age, 8.4 years). Simulation was achieved by adding noise patterns from repeated 20-mAs scans of a pediatric pelvis phantom to the original scans obtained with a standard tube current. Observers recorded their confidence in the diagnosis of appendicitis by using a six-point scale. Dose-related changes were analyzed with generalized estimating equations and the nonparametric sign test. RESULTS: There was a statistically significant (P < .001, sign test) decrease in both sensitivity and accuracy with a lower tube current, from 91.5% with the original tube current to 77% with the lower tube current. A low dose was the only statistically significant (P < .001) risk factor for a false-negative result. The specificity was unchanged at 94% for both the images obtained with the original tube current and the simulated low-dose images. The overall accuracy decreased from 92% with the original dose to 86% with the low dose. CONCLUSION: Preliminary findings indicate that it is feasible to optimize the CT dose used to evaluate appendicitis in children by using phantom-based computer simulations
PMID: 16170015
ISSN: 0033-8419
CID: 62345