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Biomedical subjects

D B Downey

Publications and source records attributed to D B Downey.

46 records · Page 3Linked to original sources

Cecal diverticulitis mimicking appendicitis on ultrasonography.

The authors describe a case of acute cecal diverticulitis in which the ultrasonographic features, as well as the clinical features, mimicked those of acute appendicitis. Though rare, acute cecal diverticulitis is an important differential diagnosis when ultrasonographic features suggest acute appendicitis, because the condition can be managed initially without surgery.

Adult↗

Number of siblings and intellectual development. The resource dilution explanation.

The resource dilution model posits that parental resources are finite and that as the number of children in the family increases, the resources accrued by any one child necessarily decline. Siblings are competitors for parents' time, energy, and financial resources and so the fewer the better. Even one sibling is too many. The author describes the general elements of the dilution position and assesses its merits for explaining the effect of siblings on one component of the educational process--tests of intellectual development. The author identifies critical flaws in recent critiques of the dilution position and concludes that dilution continues to provide the most promising explanation for why children with few siblings score higher on tests of cognitive skills than children with many siblings.

Achievement↗

Three-dimensional ultrasound and magnetic resonance imaging of pelvic anatomy: potential for complications from minimally invasive procedures.

OBJECTIVE: Several new minimally invasive therapies have recently been popularized for both malignant and benign prostate disorders, including interstitial implantation of radioactive seeds and high-radiofrequency wires, cryoablation, transurethral thermotherapy, and laser prostatectomy. Complications can be incurred during the various procedures, often as a result of injury to adjacent anatomic structures. Some of the complications are inadvertent, whereas others are inherent in the particular treatment process. We hope to increase awareness and understanding of some of the potential complications. METHODS AND MATERIALS: Magnetic resonance (MR) and three-dimensional transrectal ultrasonography (TRUS) imaging were utilized to illustrate the relevant pelvic anatomy in, respectively, a healthy volunteer and four patients undergoing evaluation for prostate symptoms. In addition, data from the Visible Human dataset (the Visible Human Project is part of the National Library of Medicine 1986 Long-Range Plan) were used. RESULTS: The potential complications relating to urinary sphincter and anal sphincter control, sexual function, pelvic musculature, and pelvic nerve physiology could be explained on the basis of the MR and TRUS findings using cryoablation for illustrative purposes. CONCLUSION: A clear understanding of the relevant anatomy and physiology is essential for the physician to provide patient counseling preoperatively regarding anticipated sequelae and to avoid preventable intraoperative complications related to minimally invasive therapeutic procedures for the prostate.

Adult↗

Clinical utility of three-dimensional US.

Three-dimensional (3D) ultrasonography (US) is rapidly gaining popularity as it moves out of the research environment and into the clinical setting. This modality offers several distinct advantages over conventional US, including 3D image reconstruction with a single pass of the US beam, virtually unlimited viewing perspectives; accurate assessment of long-term effects of treatment; and more accurate, repeatable evaluation of anatomic structures and disease entities. In obstetric imaging, 3D US provides a novel perspective on the fetal anatomy, makes anomalies easier to recognize, facilitates maternal-fetal bonding, and helps families better understand fetal abnormalities. Three-dimensional pelvic US allows volume data sets to be acquired with both transvaginal and transabdominal probes. Viewing multiple 3D power Doppler US images in a fast cine loop has proved useful in angiographic applications. Three-dimensional prostate US can help make accurate volume assessments for dosimetry planning or for estimating prostate-specific antigen levels. In breast imaging, 3D US has the capacity to demonstrate lesion margins and topography, thereby helping differentiate benign from malignant masses. Three-dimensional US can also help determine the need for biopsy and help facilitate needle localization and guidance during biopsy. With recent advances in computer technology and display techniques, 3D US will likely play an increasingly important role in medicine.

Biopsy↗