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Biomedical subjects

Ronald O Bude

Publications and source records attributed to Ronald O Bude.

7 recordsLinked to original sources

Imaging of joints with laser-based photoacoustic tomography: an animal study.

Photoacoustic tomography (PAT), a nonionizing, noninvasive, laser-based technology was adapted to joint imaging for the first time. Pulsed laser light in the near-infrared region was directed toward a joint with resultant ultrasonic signals recorded and used to reconstruct images that present the optical properties in subsurface joint tissues. The feasibility of this joint imaging system was validated on a Sprague Dawley rat tail model and verified through comparison with histology. With sufficient penetration depth, PAT realized tomographic imaging of a joint as a whole organ noninvasively. Based on the optical contrast, various intra- and extra-articular tissues, including skin, fat, muscle, blood vessels, synovium and bone, were presented successfully in images with satisfactory spatial resolution that was primarily limited by the bandwidth of detected photoacoustic signals rather than optical diffusion as occurs in traditional optical imaging. PAT, with its intrinsic advantages, may provide a unique opportunity to enable the early diagnosis of inflammatory joint disorders, e.g., rheumatoid arthritis, and to monitor therapeutic outcomes with high sensitivity and accuracy.

Acoustics↗

The use of additionally trained sonographers as ultrasound practitioners: our first-year experience.

OBJECTIVE: Two sonographers were trained to help manage an abrupt, permanent increase in the number of ultrasound examinations in our department. Called "ultrasound practitioners," they functioned as physician assistants and triaged 20 to 30 cases per day, allowing the cases to be batch read at a formal reading at day's end. We report our first-year experience with this program. METHODS: Two sonographers with 10 and 30 years of experience, respectively, were trained to triage and dictate cases. Once trained, they triaged the cases of 20 to 30 patients per day. Reports were predictated with voice recognition technology. A radiologist was always readily available to provide support, and consultation with a radiologist was always obtained for the infrequent verbal reports that were requested. Reports from the practitioner were graded subjectively on a 4-point scale for the first year, according to the modification required at formal readout (A, no change; B, minor change not affecting patient care; C, moderate change not affecting care in a dramatic way; and D, major change markedly affecting care). RESULTS: Practitioner 1 monitored the examinations of 2858 patients. The graded report results were as follows: A, 96.2%; B, 3.5%; C, 0.3%; and D, 0.00%. Practitioner 2 monitored the examinations of 2825 patients. The graded report results were as follows: A, 96.1%; B, 3.6%; C, 0.2%; and D, 0.00%. There were no category D reports. CONCLUSIONS: The results far exceeded expectations, with a very low rate of category B and C reports and an absence of category D reports. The practitioners allowed the cases of 20 to 30 patients to be batch read by the existing radiologist staff at the end of the day.

Clinical Competence↗

Is it necessary to study accessory arteries when screening the renal arteries for renovascular hypertension?

PURPOSE: To determine the prevalence of isolated hemodynamically significant stenoses of accessory renal arteries when the main renal arteries are patent. MATERIALS AND METHODS: In 68 adults (24 men, mean age, 67 years +/- 10; 44 women, mean age, 67 years +/- 12), angiograms that fulfilled the following criteria were studied: (a) technically adequate renal angiograms obtained to evaluate suspected renovascular hypertension and (b) angiographically documented hemodynamically significant stenosis of any renal artery. The percentage of kidneys and the percentage of patients with hemodynamically significant isolated stenoses of accessory renal arteries were calculated. RESULTS: Eighty-seven kidneys in 68 patients had hemodynamically significant renal artery stenoses. Fifteen kidneys had 16 accessory renal arteries. Four accessory arteries in three patients had hemodynamically significant stenoses. Only one of 68 patients (1.5%) had an accessory artery stenosis unaccompanied by a main renal artery stenosis in either kidney; this patient had bilateral hemodynamically significant accessory artery stenoses. Two patients had coexistent hemodynamically significant stenoses of accessory and main renal arteries. CONCLUSION: The prevalence of a hemodynamically significant stenosis isolated to an accessory renal artery was 1.5% in our study. Thus, failure to detect accessory renal arteries should not unduly affect the utility of a noninvasive test for detecting renovascular hypertension.

Adult↗

Sonographic appearance of extensive hepatic arterial calcification mimicking pneumobilia.

Pneumobilia appears sonographically as intrahepatic linear echogenic regions that often produce distal acoustic shadowing. We present a case in which extensive hepatic arterial calcification mimicked the sonographic appearance of pneumobilia. In the appropriate clinical setting, extensive hepatic arterial calcification should be considered when intrahepatic linear echogenic regions are found sonographically.

Air↗

Evaluation of sonographically guided percutaneous core biopsy of renal masses.

OBJECTIVE: Our objective was to determine the utility of sonographically guided percutaneous core biopsy to evaluate renal masses. MATERIALS AND METHODS: We conducted a retrospective analysis of our imaging-guided procedures from January 1999 to June 2001. We performed 26 sonographically guided percutaneous core biopsies of renal masses in 26 patients. From two to five specimens were obtained from a single mass in each patient using an 18-gauge automated biopsy system. We examined the patients' medical records, pathology results, and imaging studies. Core biopsy results were compared with surgical pathology (n = 6) or clinical follow-up (n = 20). RESULTS: All biopsies provided sufficient material for analysis. Biopsy findings were positive for malignancy in 19 (73%) of 26 masses. Histologic diagnoses included renal cell carcinoma were (n = 11), metastasis (n = 3), lymphoma (n = 2), and transitional cell carcinoma (n = 2). Specific cell type characterization could not be made on one biopsy, but the specimens were highly suspicious for malignancy. Biopsy revealed seven (27%) of 26 benign diagnoses: oncocytoma (n = 3), angiomyolipoma (n = 2), and fibrosis (n = 2). The average follow-up period for patients with benign diagnoses was 10 months. One case of surgically proven necrotic pyelonephritis was mischaracterized as fibrosis at core biopsy. Sonographically guided percutaneous core biopsy of renal masses showed a sensitivity of 100% and a specificity of 100% for the diagnosis of malignancy. The core specimens yielded a specific diagnosis in 92% (24/26) of masses. No immediate complications occurred after the procedure. One patient developed a pseudoaneurysm that presented 3 months after the biopsy. CONCLUSION. Sonographically guided percutaneous core biopsy is a reliable and accurate method for evaluating renal masses.

Adult↗