PubMed Health⌕ Search

Biomedical subjects

Raymond B Dyer

Publications and source records attributed to Raymond B Dyer.

7 recordsLinked to original sources
PubMed2004

The trend of using computed tomography in the detection of acute thoracic aortic and branch vessel injury after blunt thoracic trauma: single-center experience over 13 years.

BACKGROUND: The purpose of this study was to review the trend of using chest computed tomography (CT) and aortography in evaluating patients with blunt thoracic trauma. METHODS: A total of 85 patients who had blunt aortic injury diagnosed by chest CT, aortography, or both were included in this study. RESULTS: Aortography was the dominant modality before 1998, and the use of chest CT has increased to 50% of patients with aortic injuries as of 2001. Isolated aortic, branch vessel, or combined injuries were found in 71 (84%), 11 (13%), and 3 (4%) patients, respectively. All 14 patients with branch vessel injuries were diagnosed by aortography. Ninety-eight percent of patients with aortography were true-positives, and 20% of patients with chest CT had indirect signs of aortic injury. CONCLUSION: Our institution has increased the use of chest CT to evaluate blunt thoracic trauma. Patients with indirect signs of aortic injuries shown on chest CT require further evaluation. In our experience, angiography remains the optimal diagnostic modality for evaluating aortic branch vessel injuries.

Adolescent↗
PubMed2004

Classic signs in uroradiology.

The language of radiology is rich with descriptions of imaging findings, often metaphorical, which have found common usage in the day-to-day practice of genitourinary radiology. These "classic signs" give us confidence in our diagnosis. Some of the signs have become so familiar to us that they are referred to as an "Aunt Minnie." When the sign is invoked, or an Aunt Minnie is recognized, it often brings an impression of the image to mind, and it may have specific diagnostic and pathologic implications. The article uses classic signs accumulated from the literature to review a variety of pathologic conditions in the urinary tract.

Humans↗
PubMed2004

Percutaneous CT-guided radiofrequency ablation of renal neoplasms: factors influencing success.

OBJECTIVE: The objective of our study was to evaluate the success rate for radiofrequency ablation of renal tumors and to determine the risk of serious complications. CONCLUSION: No serious complications occurred after 27 CT-guided radiofrequency ablation sessions in 22 patients. In total, no residual tumor was detected on follow-up contrast-enhanced CT or MRI 1-35 months (mean, 7 months) after final tumor ablation in 20 (91%) of 22 patients. Two patients with residual viable tumor deferred further treatment. Complete tumor ablation was achieved after a single treatment session in 83% of patients, and in 8% of patients after subsequent ablation sessions. Size was the major determinant for achieving tumor eradication with a single session of ablation, with all 11 tumors 3 cm or smaller being completely ablated after one session. Tumor location, histology, and the presence of renal disease did not correlate with treatment success. Contrast-enhanced CT performed immediately after ablation is reliable to exclude residual viable tumor. CT-guided radiofrequency ablation of renal tumors is safe and has a high rate of success in the treatment of small renal tumors, with no evidence of recurrence at midterm follow-up of treated patients.

Aged↗
PubMed2003

Computerized tomography guided access for percutaneous nephrostolithotomy.

PURPOSE: Access for percutaneous nephrostolithotomy (PNL) using conventional fluoroscopic guidance may carry an increased risk of damage to surrounding organs in patients with renal calculi and aberrant anatomy. In these situations cross-sectional anatomical imaging may facilitate safe percutaneous access. We describe our experience with computerized tomography (CT) guided percutaneous access for such patients undergoing PNL. MATERIALS AND METHODS: Between June 2000 and December 2001, 154 patients underwent PNL at our institution. Five of these patients (3%) required a total of 6 percutaneous access tracks under CT guidance. All patients in this group had anatomical abnormalities precluding standard access to the collecting system without risk to adjacent organs. These abnormalities included a retrorenal colon in 2 and a severely distorted body habitus due to spinal dysraphism in 3. RESULTS: Percutaneous access was achieved without complication in all cases. At subsequent PNL 5 of the 6 renal units (83%) were rendered completely stone-free. CONCLUSION: CT guided percutaneous access is infrequently required for PNL. However, there is a select group of patients with anatomical anomalies that may predictably require this procedure to facilitate safe and efficacious PNL.

Adult↗
PubMedDate not supplied

Percutaneous nephrostomy with extensions of the technique: step by step.

Minimally invasive therapy in the urinary tract begins with renal access by means of percutaneous nephrostomy. Indications for percutaneous nephrostomy include urinary diversion, treatment of nephrolithiasis and complex urinary tract infections, ureteral intervention, and nephroscopy and ureteroscopy. Bleeding complications can be minimized by entering the kidney in a relatively avascular zone created by branching of the renal artery. The specific site of renal entry is dictated by the indication for access with consideration of the anatomic constraints. Successful percutaneous nephrostomy requires visualization of the collecting system for selection of an appropriate entry site. The definitive entry site is then selected; ideally, the entry site should be subcostal and lateral to the paraspinous musculature. Small-bore nephrostomy tracks can be created over a guide wire coiled in the renal pelvis. A large-diameter track may be necessary for percutaneous stone therapy, nephroscopy, or antegrade ureteroscopy. The most common extension of percutaneous nephrostomy is placement of a ureteral stent for treatment of obstruction. Transient hematuria occurs in virtually every patient after percutaneous nephrostomy, but severe bleeding that requires transfusion or intervention is uncommon. In patients with an obstructed urinary tract complicated by infection, extensive manipulations pose a risk of septic complications.

Humans↗
PubMedDate not supplied

Complications of ureteral stent placement.

The recent increase in usage of ureteral stents in the management of a variety of urinary tract disease processes mandates familiarity with these devices, their consequences, and their potential complications, which at times can be devastating. Radiology plays an important role in the routine monitoring of stents and in the evaluation of these consequences and complications. It may also offer solutions for their correction. Stents should be monitored while in place, promptly removed when no longer needed, and changed periodically if chronically indwelling. Risk factors for complications should be minimized with high fluid intake, timely evaluation of clinical complaints, and aggressive treatment of documented infection. Certain patients may not be best served by indwelling stent placement, and urinary diversion by means of other mechanisms may be indicated. The implanting physician is responsible for informing the patient of the requirements, consequences, and complications associated with stent placement. Failure to do so has obvious management and potential medicolegal implications.

Catheterization↗