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Biomedical subjects

D C Levin

Publications and source records attributed to D C Levin.

At least 55 records · Page 3Linked to original sources
PubMed1993

Self-referral in private offices for imaging studies performed in Pennsylvania Blue Shield subscribers during 1991.

PURPOSE: To define the frequency of physician self-referral for diagnostic imaging studies. MATERIALS AND METHODS: High-volume radiographic (n = 65) and ultrasound (US) (n = 29) procedural codes in claims filed by Pennsylvania Blue Shield subscribers were analyzed to determine private-office (nonhospital) utilization of these examinations by radiologists and nonradiologists during 1991. A total of 787,703 radiographic and 159,281 US claims were filed. RESULTS: Nonradiologists self-referred 550,878 radiographic examinations (69.9%) and 99,931 US examinations (62.7%). Patterns of utilization varied considerably by anatomic category: The imaging studies with the highest rates of utilization by nonradiologists were skeletal radiography, vascular US, and obstetric and pelvic US. Aggregate reimbursement allowance by Pennsylvania Blue Shield for all examinations in these 94 codes was approximately $68 million, of which $44 million (65%) went to non-radiologists.

Blue Cross Blue Shield Insurance Plans↗
PubMed1993

Cost containment in the use of low-osmolar contrast agents: effect of guidelines, monitoring, and feedback mechanisms.

PURPOSE: To describe a program for controlling intravenous use of low-osmolar contrast agents (LOCAs). MATERIALS AND METHODS: The department of radiology at the authors' institution adopted a policy of selective use of intravenously administered LOCAs. Clinical indications for LOCA use were specified after consultation with the administration, risk managers, legal department, and ethics committee of the hospital. The guidelines were then publicized throughout the department and hospital, and a contrast agent data form was developed to collect data on all cases. Monitoring mechanisms were instituted. RESULTS: Over the next 23 months, 11,373 patients received intravenous iodinated contrast agents, of whom 28.1% were deemed to be at high risk and were given LOCAs. Monthly tracking showed no evidence of a trend toward increasing use of LOCAs. CONCLUSION: Clear definition of use guidelines, close monitoring, and feedback can stabilize LOCA use at acceptably low levels.

Adult↗
PubMed1992

Disparities in reimbursement to radiologists and nonradiologists for 65 common outpatient imaging studies.

The authors examined global charges (incorporating both technical and professional components) and global reimbursement allowances for all radiographic and ultrasound (US) examinations performed on Pennsylvania Blue Shield subscribers in the Lehigh Valley area of Pennsylvania during 1990. Data for radiologists and nonradiologists were compared with respect to all procedure codes for which at least 25 claims were submitted, yielding a sample of 40,619 radiographic examinations (54 procedure codes) and 9,761 US examinations (11 procedure codes). Radiologists' mean charges were higher than those of nonradiologists for 38 of the 54 radiographic codes. However, nonradiologists received higher mean reimbursement allowances for 39 of the 54 codes. Among the 11 US codes, nonradiologists' mean charges were higher for 10 and they received higher mean reimbursement allowances for seven. The averages of the mean reimbursement allowances for individual codes were higher for nonradiologists in both the radiographic and US categories. Pennsylvania Blue Shield has begun steps to eliminate disparities in reimbursements to providers who submit claims for imaging examinations.

Ambulatory Care↗
PubMed1991

Successful percutaneous closure of a complex coronary-to-pulmonary artery fistula using a detachable balloon: benefits of intra-procedural physiologic and angiographic assessment.

A 48-yr-old woman presented with a loud continuous precordial murmur and symptoms of fatigue. Color-flow doppler imaging and nuclear magnetic resonance imaging failed to show the cause of the murmur. Diagnostic catheterization showed a large left anterior descending coronary artery to pulmonary artery fistula with impaired left ventricular wall motion. Two detachable balloons were deployed in the fistula with complete abolition of flow in the main fistula channel. A small parallel channel of the fistula, previously not appreciated due to vessel overlap, remained patent but had trivial flow as assessed by green-dye and oximetric techniques. The patient had immediate resolution of her symptoms and return of normal ventricular wall motion.

Angiography↗
PubMed1991

Radiation exposure to angiographers under different fluoroscopic imaging conditions.

Radiation levels near an imaging chain commonly used in angiography were measured with both a 100- and a 200-mm-thick scatter phantom. The scatter was measured in lines parallel in space to the central ray of the x-ray beam, at lateral distances of 300, 500, and 800 mm. The effects of fluoroscopic kilovoltage and image intensifier magnification mode were also measured. The results indicate that the highest scattered radiation levels occur near the surface of the patient where the x-ray beam enters. Exposure rates were measured in both anteroposterior (AP) and posteroanterior (PA) geometries on a U-arm system. In PA geometry, the highest radiation levels occur below the angiographer's waist, an area well protected by the lead apron. The AP geometry increases the exposure rate to the neck, head, and upper extremities, areas where apron shielding is less effective.

Angiography↗
PubMed1991

Evidence for reduced fibrinolytic activity in unstable angina at rest. Clinical, biochemical, and angiographic correlates.

BACKGROUND: The goal of this study was to evaluate the role of the fibrinolytic system in patients with unstable angina at rest associated with transient electrocardiographic changes. METHODS AND RESULTS: Tissue plasminogen activator activity in plasma was comparable among patients with unstable angina (n = 17), patients with stable exertional angina (n = 10), and control patients with normal coronary arteriograms (n = 8). In contrast, plasminogen activator inhibitor-1 (PAI-1) activity in plasma was elevated in the unstable angina group (21.67 +/- 9.52 AU/ml) as compared with either the stable angina group (12.01 +/- 7.06 AU/ml, p less than 0.02) or the controls (12.49 +/- 8.54 AU/ml, p less than 0.02). Coronary angiography performed within 24 hours after the last anginal episode showed a similar extent of coronary artery disease in the unstable and stable angina groups. However, intracoronary thrombi were observed in eight patients in the unstable angina group while no thrombus was noted in the stable angina group (chi 2 = 7.22, p less than 0.01). CONCLUSIONS: We conclude that patients with unstable angina at rest have a reduced fibrinolytic activity and an increased incidence of intracoronary thrombi. It is postulated that elevated PAI-1 activity in the presence of coronary arterial wall injury may be an important factor leading to the development of acute coronary syndromes.

Angina Pectoris↗
PubMed1991

Home care for respiratory problems.

This article reviews current recommendations for the home care of geriatric patients with chronic pulmonary disease. Special attention is given to new bronchodilators, indications for home oxygen and ventilator use, as well as the use of nasal CPAP in elderly sleep apnea patients. The necessity of do not resuscitate (DNR) orders is also discussed.

Aged↗
PubMed1991

Efficacy of thrombolysis in infrainguinal bypass grafts.

The initial outcome of a consecutive series of 43 intra-arterial urokinase infusions for thrombosed infrainguinal grafts in 37 patients was analyzed. There was an 88% (38/43) technical success rate (complete clot lysis) and a 74% (32/43) clinical success rate. Complications occurred in 10 patients (23%) and were related to bleeding in four patients (9%). Patient age, graft age, location, material, and the duration of occlusion did not significantly influence the initial outcome, although there was a trend toward a higher bleeding complication rate among grafts less than or equal to 1 month of age at the time of thrombolysis. A second group of 43 infrainguinal grafts successfully recanalized using regional infusions of thrombolytic agents were followed for long-term patency. This group included 32 grafts successfully treated with urokinase and 11 grafts recanalized with streptokinase. By life-table analysis there was a 55.6% 1-year patency, which fell to 42.4% at 4 years. Vein grafts had significantly (p = 0.01) better long-term patency than prosthetic grafts (69.3% versus 28.6% at 30 months). Grafts with flow-limiting lesions identified and corrected by angioplasty or surgery also had significantly (p = 0.01) better long-term patency than those without such lesions (79.0% versus 9.8% at 2 years). Based on the results of our study compared with a survey of long-term results following secondary surgical procedures for thrombosed infrainguinal grafts, thrombolysis can be recommended in several circumstances. Thrombolysis is indicated for thrombosed vein grafts or when thrombus is present in distal runoff vessels. Thrombosed prosthetic grafts should be replaced by autogenous vein grafts whenever possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Palmaz vascular stent: initial clinical experience.

The safety and efficacy of the Palmaz balloon-expandable vascular stent and its effect on the results of percutaneous transluminal angioplasty (PTA) were assessed in a prospective study. Technical success was achieved in the placement of 34 of 35 stents (97%) in 27 common and external iliac artery lesions in 19 patients (23 limbs) who presented with disabling claudication, rest pain, or gangrene. Stent placement improved the angiographic results achieved by PTA alone in all 19 patients. Seventeen of 23 limbs (74%) had significant (greater than 20%) elevation of the ankle-arm index after combined angioplasty and stent placement, including nine limbs with occlusive outflow lesions. All 10 patients with continuous runoff distal to the stent and one patient with discontinuous runoff had resolution of their symptoms, remaining unchanged at a mean follow-up time of 6 months. There were three complications: One significantly altered the patient's hospital course, but none detracted from the achieved stent result. Stent placement is effective and does not significantly increase the complication rate of conventional iliac PTA. The current delivery system, however, may limit its utility.

Angioplasty, Balloon↗
PubMed1990

"Turf battles" over imaging and interventional procedures in community hospitals: survey results.

A survey of nonacademic community hospitals was conducted to ascertain the degree of control radiologists have of 38 selected imaging or imaging-related interventional procedures. Responses from 187 hospitals showed that community hospital radiologists totally controlled or strongly dominated almost half of these procedures, including all computed tomographic and magnetic resonance imaging studies, bone radiography, breast needle localization, emergency department radiography, arthrography, obstetric ultrasound (US), renal and peripheral angioplasty, percutaneous abscess and biliary drainage, percutaneous nephrostomy, cerebral angiography, and interventional neuroangiography. Radiologists dominated in prostate and vascular US, myelography, urethrography, cardiac nuclear medicine, percutaneous lung biopsy, ureteral stent placement, and pulmonary angiography, but there was also significant participation in these studies by nonradiologists. Radiologists and nonradiologists had roughly equivalent roles in hysterosalpingography, peripheral atherectomy and laser angioplasty, and percutaneous inferior vena cava filter placement. Nonradiologists dominated in echocardiography, endoscopic retrograde cholangiopancreatography, biliary and kidney stone lithotripsy, percutaneous gastrostomy, coronary angiography and angioplasty, and pediatric angiocardiography.

Data Collection↗
PubMed1989

Salvage of occluded arterial bypass grafts by means of thrombolysis.

Seventy-two thrombosed peripheral arterial bypass grafts in 62 patients were treated by local intraarterial thrombolytic infusion. The initial success rate was 69% (50 of 72 grafts). Graft material and location had no significant effect on the initial results. Urokinase was used in 43 cases with a 84% success rate, and streptokinase was used in 29 cases with a 48% success rate. After a follow-up period that ranged from 2 to 58 months, 27 grafts remained patent, with an average patency duration of 15 months (median 8 months). Overall graft patency at the end of 1 year was 60% applying life-table analysis. Factors that were evaluated to determine their effect on long-term patency included graft age and material, graft location, and the presence or absence of an underlying correctable lesion. The most significant factor in long-term patency was the presence of a lesion that was correctable by surgical revision or balloon angioplasty. In 25 grafts with underlying stenotic lesions, the 1-year patency was 86% after successful treatment. Twenty-five grafts without detectable lesions had 37% 1-year patency.

Adult↗
PubMed1989

Do radiologists control imaging studies? Survey results from 198 academic institutions.

Survey data were collected in 1987 from 198 academic radiology departments in North America to determine the degree to which radiologists are responsible for 32 imaging or imaging-related interventional procedures. The 32 were chosen because they were thought to be potential sources of conflict with nonradiology clinicians. The data reveal that academic radiologists either totally control or strongly dominate bone and breast radiography, percutaneous lung biopsy, percutaneous genitourinary and biliary tract interventional procedures, abscess drainages guided with computed tomography (CT) or ultrasound (US), both peripheral and renal angioplasty, pulmonary angiography, all of neuroradiology, all of CT, and all of magnetic resonance imaging. Radiologists have a dominant role in obstetric US, percutaneous inferior vena cava filter placement, and urethrography, although there is significant participation by nonradiologists in these studies. Radiologists and nonradiologists have roughly equivalent roles in vascular US and hysterosalpingography. Nonradiologists have the dominant roles in percutaneous gastrostomy, endoscopic retrograde cholangiopancreatography, kidney stone lithotripsy, coronary angiography and angioplasty, pediatric angiocardiography, and echocardiography.

Academic Medical Centers↗