Biomedical subjects

Elkan F Halpern

Publications and source records attributed to Elkan F Halpern.

72 records · Page 4Linked to original sources

PubMed2002

Characterization of human atherosclerosis by optical coherence tomography.

BACKGROUND: High-resolution visualization of atherosclerotic plaque morphology may be essential for identifying coronary plaques that cause acute coronary events. Optical coherence tomography (OCT) is an intravascular imaging modality capable of providing cross-sectional images of tissue with a resolution of 10 micro m. To date, OCT imaging has not been investigated in sufficient detail to assess its accuracy for characterizing atherosclerotic plaques. The aim of this study was to establish objective OCT image criteria for atherosclerotic plaque characterization in vitro. METHODS AND RESULTS: OCT images of 357 (diseased) atherosclerotic arterial segments obtained at autopsy were correlated with histology. OCT image criteria for 3 types of plaque were formulated by analysis of a subset (n=50) of arterial segments. OCT images of fibrous plaques were characterized by homogeneous, signal-rich regions; fibrocalcific plaques by well-delineated, signal-poor regions with sharp borders; and lipid-rich plaques by signal-poor regions with diffuse borders. Independent validation of these criteria by 2 OCT readers for the remaining segments (n=307) demonstrated a sensitivity and specificity ranging from 71% to 79% and 97% to 98% for fibrous plaques, 95% to 96% and 97% for fibrocalcific plaques, and 90% to 94% and 90% to 92% for lipid-rich plaques, respectively (overall agreement, kappa=0.83 to 0.84). The interobserver and intraobserver reliabilities of OCT assessment were high (kappa values of 0.88 and 0.91, respectively). CONCLUSIONS: Objective OCT criteria are highly sensitive and specific for characterizing different types of atherosclerotic plaques. These results represent an important step in validating this new intravascular imaging modality and will provide a basis for the interpretation of intracoronary OCT images obtained from patients.

Aged↗

PubMed2002

Schizophrenic subjects show deficient inhibition but intact task switching on saccadic tasks.

BACKGROUND: Schizophrenic patients have executive function deficits, presumably on the basis of prefrontal cortex dysfunction. Although they consistently show impaired inhibition, the evidence of a task switching deficit is less consistent and is often based on performance of neuropsychological tests that require several cognitive processes (e.g., the Wisconsin Card Sort Test [WCST]). We investigated inhibition and task switching using saccadic tasks to determine whether schizophrenic patients have selective impairments of these executive functions. METHODS: Sixteen normal and 21 schizophrenic subjects performed blocks of randomly mixed prosaccade and antisaccade trials. This gave rise to four trial types: prosaccades and antisaccades that were either repeated or switched. Response accuracy and latency were measured. Schizophrenic subjects also performed the WCST. RESULTS: Schizophrenic subjects showed abnormal antisaccade and WCST performance. In contrast, task switching was normal and unrelated to either antisaccade or WCST performance. CONCLUSIONS: The finding of intact task switching performance that is unrelated to other measures of executive function demonstrates selective rather than general impairments of executive functions in schizophrenia. The findings also suggest that abnormal WCST performance is unlikely to be a consequence of deficient task switching. We hypothesize that inhibition and task switching are mediated by distinct neural networks, only one of which is dysfunctional in schizophrenia.

Adult↗

PubMed2002

Improved coagulation with saline solution pretreatment during radiofrequency tumor ablation in a canine model.

PURPOSE: To determine whether pretreatment with local NaCl injection can increase radiofrequency (RF)-induced coagulation in a large animal model. MATERIAL AND METHODS: Multiple canine venereal sarcomas (n = 25) were implanted subcutaneously in eight mildly immunosuppressed dogs (25 mg/kg cyclosporin A twice daily). Tumors were incubated for 8-12 weeks to a diameter of 4.2-6.3 cm (5.1 cm +/- 0.7). Internally cooled RF ablation (1-cm tip; 12 min; pulsed technique; 2,000-mA maximum) was performed. Tumors were pretreated with 6 mL of 18%, 24%, or 36% NaCl injected intratumorally under direct ultrasound guidance after RF electrode insertion, and this treatment was compared to RF treatment without NaCl injection and to 36% NaCl injection without RF ablation. Impedance measurements and remote thermometry were performed. These measurements and resultant coagulation were compared. RESULTS: Significantly greater RF heating (73 degrees C +/- 11 degrees C at 20 mm) was observed when the tumors were treated with 24% or 36% NaCl pretreatment, compared to the 47 degrees C +/- 5 degrees C observed when 18% or no NaCl was injected (P <.02). In the 36% NaCl group, the entire tumor (5.2 cm +/- 0.8 diameter) was completely ablated in every case, with coagulation extending several centimeters into the surrounding tissues. By comparison, control tumors (without NaCl injection) contained coagulation measuring 3.1 cm +/- 0.2, surrounded by viable, well-perfused tumor (P <.01), and 36% NaCl alone produced 2.7 cm +/- 0.6 of patchy necrosis. CONCLUSIONS: Pretreatment with intratumoral injection of small volumes of highly concentrated NaCl markedly increases RF heating and coagulation in a large animal tumor model. The complete destruction of tumors 5 cm in diameter or larger suggests that this substantial increase may be achieved for tumor ablation in clinical practice.

Animals↗

PubMed2002

Percutaneous tumor ablation: increased necrosis with combined radio-frequency ablation and intravenous liposomal doxorubicin in a rat breast tumor model.

PURPOSE: To determine whether a combination of intravenous liposomal doxorubicin and radio-frequency (RF) ablation increases tumor destruction compared with RF alone in an animal tumor model. MATERIALS AND METHODS: R3230 mammary adenocarcinoma 1.4-1.8-cm- diameter nodules were implanted subcutaneously in 132 female Fischer rats. Initially, tumors were treated with (a) conventional, monopolar RF (mean, 250 mA +/- 25 [SD] at 70 degrees C +/- 1 for 5 minutes) ablation alone, (b) RF ablation followed by intravenous administration of 1 mg of liposomal doxorubicin, (c) RF ablation followed by intravenous administration of 1 mg of empty liposomes, (d) RF ablation and direct intratumoral administration of liposomal doxorubicin, or (e) no treatment. Subsequently, the dose (0.06-2.00 mg) of liposomal doxorubicin, the timing of administration (3 days before to 3 days after RF ablation), and the time of pathologic examination (0-72 hours after treatment) were varied. RESULTS: Mean coagulation diameter for treated tumors follows: 6.7 mm +/- 0.6, RF ablation alone; 11.1 mm +/- 1.5, RF ablation and intravenous administration of empty liposomes (P <.05, compared with RF ablation alone); and 8.4 mm +/- 1.1, RF ablation with intratumoral administration of liposomal doxorubicin (P <.05, compared with RF ablation alone). Maximal increased mean coagulation diameter (13.1 mm +/- 1.5) was observed with a combination of liposomal doxorubicin and RF ablation (P <.001, for all comparisons). The increased coagulation for combination therapy developed over 48 hours after therapy. Coagulation diameter did not vary with the doxorubicin concentration range and was not dependent on the timing of administration of liposomal doxorubicin from 3 days before to 24 hours after RF ablation. CONCLUSION: Intravenous administration of liposomal doxorubicin can improve RF ablation, since it increases coagulation diameter in solid tumors compared with RF ablation alone or a combination of RF ablation with administration of empty liposomes.

Animals↗

PubMed2002

CT and conventional and diffusion-weighted MR imaging in acute stroke: study in 691 patients at presentation to the emergency department.

PURPOSE: To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance (MR) imaging in a consecutive series of patients at presentation to the emergency department with symptoms of acute stroke. MATERIALS AND METHODS: Clinical data and images obtained in 691 consecutive patients with suspected acute stroke were examined. Results of first and second head CT and brain diffusion-weighted (DW) and conventional MR imaging were compared with each other and with the final neurologic discharge diagnosis. RESULTS: Five hundred seventy-three patients underwent CT at presentation, with 42% sensitivity (95% CI: 37%, 46%) and 91% specificity (95% CI: 82%, 96%). A total of 173 patients underwent a second CT examination, with 77% sensitivity (95% CI: 70%, 84%) and 79% specificity (95% CI: 49%, 95%). Of 498 MR images, 411 were DW, with 94% sensitivity (95% CI: 1%, 96%) and 97% specificity (95% CI: 88%, 100%), and 87 were conventional, with 70% sensitivity (95% CI: 58%, 81%) and 94% specificity (95% CI: 70%, 100%). By using DW MR imaging in the early period (<6 hours after presentation to emergency department), a 97% sensitivity (95% CI: 92%, 100%) and a 100% specificity (95% CI: 69%, 100%) were achieved, compared with 58% (29%-84%) and 100% (16%-100%), respectively, with conventional MR imaging, and 40% (35%-45%) and 92% (84%-97%), respectively, with CT. Negative predictive value was higher with DW MR imaging (73%) than with conventional (42%) MR imaging or CT (24%). In studies conducted within 12 hours, DW MR imaging achieved substantially superior accuracy than did CT. After 12 hours, accuracy was equivalent. CONCLUSION: In the diagnosis of stroke in the early period (<12 hours after presentation), DW MR imaging is superior to conventional MR imaging and CT.

Acute Disease↗

PubMed2002

Elective endovascular versus open surgical repair of abdominal aortic aneurysms: systematic review of short-term results.

PURPOSE: To summarize and compare published short-term results of elective endovascular and open surgical repair of abdominal aortic aneurysms. MATERIALS AND METHODS: A MEDLINE search of the English literature was performed. Studies with at least 10 patients in each treatment group were included if they reported patient characteristics, complications, and mortality. Two reviewers independently extracted the data. A random-effects model was used to pool the data and calculate pooled odds ratios (endovascular vs open surgical repair). RESULTS: Nine studies were included, reporting results of 1,318 procedures (687 endovascular repair and 631 open surgical repair). Mean blood loss was 456 mL for endovascular repair and 1,202 mL for open surgical repair (P =.003). On average, patients undergoing endovascular repair spent 0.5 days in the intensive care unit and 3.9 days in the hospital, and patients undergoing open surgical repair spent 2.2 days (P =.04) in the intensive care unit and 10.3 days (P =.02) in the hospital. The pooled 30-day-mortality was 0.03 for endovascular repair (95% CI: 0.02, 0.04) and 0.04 for open surgical repair (95% CI: 0.00, 0.07) (P =.03), and the odds ratio was 0.55 (95% CI: 0.33, 0.92). The pooled local and/or vascular complication rate was 0.16 for endovascular repair (95% CI: 0.06, 0.25) and 0.12 for open surgical repair (95% CI: 0.06, 0.18) (P =.46), and the odds ratio was 0.97 (95% CI: 0.62, 1.54). The pooled systemic and/or remote complication rate was 0.17 for endovascular repair (95% CI: 0.09, 0.25) and 0.44 for open surgical repair (95% CI: 0.21, 0.66) (P <.001), and the odds ratio was 0.22 (95% CI: 0.11, 0.45). CONCLUSION: On the basis of this systematic review, endovascular repair results in less blood loss, shorter intensive care unit and hospital stays, lower 30-day mortality, and lower systemic and/or remote complication rates than those of open surgical repair.

Aortic Aneurysm, Abdominal↗

PubMed2002

CT tumor measurement for therapeutic response assessment: comparison of unidimensional, bidimensional, and volumetric techniques initial observations.

PURPOSE: To compare unidimensional, bidimensional, and volumetric techniques for evaluation of treatment response in patients with liver metastases from breast cancer in a phase III clinical trial. MATERIALS AND METHODS: Helical computed tomographic (CT) studies in 38 patients with liver metastases from breast cancer who were enrolled in a phase III clinical trial were evaluated before treatment and at 6 months after treatment. Two subspecialty radiologists measured all lesions on transverse CT scans with use of electronic calipers according to both unidimensional and bidimensional criteria. Volumetric measurements were made by tracing individual lesions. Measurements of individual lesions were summed to obtain patient response, which was categorized as complete response, disappearance of lesions; partial response, greater than 30% decrease in tumor diameter (unidimensional), greater than 50% reduction in tumor area (bidimensional), or greater than 65% reduction in tumor volume (volumetric); disease progression, greater than 20% increase in tumor diameter, greater than 25% increase in tumor area, or greater than 73% increase in tumor volume: or stable disease (size response other than that of complete response, partial response, or disease progression). RESULTS: In 37 patients, there was concordant treatment response with use of unidimensional and bidimensional techniques. Volumetric measurement produced results different from those of the unidimensional and bidimensional techniques in 12 and 13 patients, respectively. In six patients with partial response per unidimensional and bidimensional criteria, the response based on the volumetric technique was stable disease. In two patients with stable disease per bidimensional and unidimensional criteria, the response was partial response by volumetric measurement. In four patients with disease progression per bidimensional and unidimensional criteria, the response was stable disease per volumetric criteria. CONCLUSION: Volumetric measurement of tumor burden gives different results for treatment response compared with that of the unidimensional or bidimensional technique in a considerable proportion of patients.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

Using multidetector CT for preoperative vascular evaluation of liver neoplasms: technique and results.

OBJECTIVE: The purpose of our study was to evaluate the performance of CT angiography using multidetector CT (MDCT) for preoperative vascular evaluation in candidates who were scheduled for liver neoplasm resection. SUBJECTS AND METHODS: Forty-two consecutive subjects with malignant liver tumors scheduled for resection were studied with multiphase MDCT. The first 22 subjects underwent both multiphase MDCT angiography and catheter angiography before surgery. The subsequent 20 subjects underwent only preoperative CT angiography. Postprocessing was performed, and the images were analyzed for the depiction of arterial, portal vein, and hepatic vein anatomy and for the identification of important vascular variants. The postprocessing findings were compared and correlated with the findings from catheter angiography (22/42) or intraoperative sonography (42/42) and surgery (42/42). RESULTS: Arterial anomalies were detected on the images of 17 of 42 patients, including a replaced right hepatic artery in five, replaced left hepatic artery in six, accessory right and left hepatic arteries in two, common trunk for the celiac and superior mesenteric arteries in one, and early bifurcation of the celiac artery in one. In 22 patients in whom catheter angiography confirmation was available, the number of arteries and almost all the significant anomalies were correctly identified on CT angiography (accuracy, 97%; sensitivity, 94%; specificity, 100%). In the subset of 20 patients who underwent MDCT angiography without catheter angiography confirmation, all clinically relevant information was provided by CT angiography. The portal and hepatic vein anatomy and the relationships of the liver tumors to the neighboring venous structures were shown on CT. CONCLUSION: Multidetector CT provides valuable preoperative information about hepatic vascular architecture and can be used as a noninvasive alternative to catheter angiography before oncologic liver surgery.

Adult↗

PubMed2002

Clinical comparison of standard-dose and 50% reduced-dose abdominal CT: effect on image quality.

OBJECTIVE: We hypothesized that radiation doses for abdominal CT could be reduced by adjusting the dose for a patient's weight and cross-sectional abdominal dimensions, with the resultant scans still being of diagnostic quality. SUBJECTS AND METHODS: Using a multidetector CT scanner, we prospectively studied 39 patients who were 65 years and older who had a known history of cancer. After performing a diagnostic contrast-enhanced CT examination, we obtained four slices each (centered at the top of the right kidney) at a standard radiation dose (240-300 mA) and at a 50% reduced dose (120-150 mA) at a constant kilovoltage of 140. Scans were obtained during a single breath-hold, with a 2.5-mm detector configuration and a slice pitch of 6:1. Reconstructed slice thickness was 5 mm. In a blinded review, two radiologists rated the randomized CT scans for overall image quality and anatomic details of liver, spleen, adrenal glands, kidneys, pancreas, and abdominal wall, using a 5-point scale (1 = unacceptable, 2 = substandard, 3 = acceptable, 4 = above average, and 5 = superior). Patients' weight and abdominal circumference, area, and anteroposterior and transverse diameters were correlated with image quality of scans obtained at standard-dose and 50% reduced-dose CT. Statistical analysis of the data was performed using Wilcoxon's signed rank test. RESULTS: Overall, the image quality score was significantly higher (p < 0.005) on the scans obtained with standard-dose CT. No statistically significant difference in image quality was noted in the 50% reduced- and standard-dose CT scans in patients who weighed less than 180 lb, or 81 kg, (p > 0.05) and who had a transverse abdominal diameter of less than 34.5 cm (p > 0.05), an anteroposterior diameter of less than 28 cm (p > 0.05), a cross-sectional circumference of less than 105 cm (p > 0.05), and a cross-sectional area of less than 800 cm(2) (p > 0.05). Good interobserver agreement (p > 0.5) was found between the two reviewing radiologists. CONCLUSION: Abdominal CT scan quality appears to be acceptable even with a 50% reduction in radiation dose except in patients with large anthropometric measurements. A reduction in CT radiation dose is possible if the tube current is optimized for the patient's weight and abdominal dimensions.

Abdomen↗

PubMedDate not supplied

Treatment outcome and outcome associations in children with pervasive developmental disorders treated with selective serotonin reuptake inhibitors: a chart review.

PURPOSE: The aim of this study was to determine the outcome and predictors of outcome with selective serotonin reuptake inhibitors (SSRIs) in outpatient children and adolescents with pervasive developmental disorders (PDDs). METHOD: Clinic charts were reviewed for 89 outpatient youths with a Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) diagnosis of a PDD who were treated with SSRIs. Response was determined using the Clinical Global Impressions (CGI) scale. Side-effect and demographic data, including family history, were recorded. RESULTS: Forty-four point nine percent (44.9%) were determined to be much improved and considered responders. Fifty-four percent (54%) of the subjects demonstrated activation side effects. In 35.4% of these subjects, the activation side effects led to drug discontinuation. Pearson chi-squared and regression analysis demonstrated an association between SSRI response and a family history of PDD. There were no significant associations between clinical variables and activation side effects. CONCLUSIONS: SSRI treatment led to modest response rate in this group of youths with PDDs. Activation side effects were frequent, often leading to treatment dropouts. Potential outcome associations include a family history of PDDs.

Adolescent↗

PubMedDate not supplied

CT characterization of "indeterminate" renal masses: targeted or comprehensive scanning?

PURPOSE: A comprehensive renal mass evaluation CT protocol is usually performed for simultaneous characterization and staging of incidentally discovered renal masses considered indeterminate on ultrasound (US). The purpose of the study was to determine if a comprehensive examination is appropriate in these patients. MATERIALS AND METHODS: The authors performed a retrospective review of 100 patients (mean age, 61 years) with 102 sonographically indeterminate renal masses and who were referred to undergo CT for lesion characterization. Lesions were classified according to surgical histology or imaging follow-up evaluation. Statistical analysis was performed. RESULTS: Thirteen lesions (12.7%) in 11 (11%) patients (mean age, 59 years) were malignant. Eighty-seven lesions (85.3%) in 87 patients (87%; mean age, 62 years) were benign. Two lesions (1.96%) in two patients (2%) remained indeterminate. CONCLUSION: Although comprehensive renal mass evaluation protocol provides a more thorough patient evaluation, only a small fraction of indeterminate renal masses seen on US are malignant. The authors' results suggest a targeted renal CT imaging protocol for evaluation of indeterminate renal masses incidentally discovered on US.

Adult↗

PubMedDate not supplied

Comparison between low (3:1) and high (6:1) pitch for routine abdominal/pelvic imaging with multislice computed tomography.

PURPOSE: The purpose of this study was to compare the performance of low helical pitch acquisition (3:1) and high helical pitch acquisition (6:1) for routine abdominal/pelvic imaging with multislice computed tomography (CT). METHOD: Three hundred eighty-four patients referred for abdominal/pelvic CT were examined in a breath-hold on a multislice CT scanner (LightSpeed QX/I; General Electric Medical Systems, Milwaukee, WI). Patients were randomized and scanned with pitch of 3:1 or 6:1 using a constant 140 peak kV and 280-300 mA. Images were reconstructed at a 3.75-mm slice thickness. Direct comparison between the two pitches was possible in a subset of 40 patients who had a follow-up scan performed with the second pitch used in each patient. A comparison was also performed between standard dose CT using a pitch of 6:1 and 20% reduced radiation dose CT using a pitch of 3:1. Two readers performed a blind evaluation using a three-point scale for image quality, anatomic details, and motion artifacts. Statistical analysis was performed using a rank sum test and the Wilcoxon signed rank test. RESULTS: Overall image quality mean scores were 2.5 and 2.3 for a pitch of 3:1 and a pitch of 6:1, respectively (P = 0.134). Likewise, mean anatomic detail and motion artifact scores were 2.5 and 2.6 for a 3:1 pitch and 2.3 and 2.5 for a 6:1 pitch, respectively (P > 0.05). In patients with a direct comparison of the two pitches (with the standard radiation dose as well as with a 20% reduction in milliamperes), no statistically significant difference in the performance of the two pitches was observed (P > 0.05). CONCLUSION: Image quality with a high pitch (6:1) is acceptable for routine abdominal/pelvic CT.

Adult↗

PubMedDate not supplied

Improved radiologic staging of lung cancer with 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography and computed tomography registration.

PURPOSE: To determine if volumetric nonlinear registration or registration of thoracic computed tomography (CT) and 2-[18F]-fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET) datasets changes the detection of mediastinal and hilar nodal disease in patients undergoing staging for lung cancer and if it has any impact on radiologic lung cancer staging. METHOD: Computer-based image registration was performed on 45 clinical thoracic helical CT and FDG-PET scans of patients with lung cancer who were staged by mediastinoscopy and/or thoracotomy. Thoracic CT, FDG-PET, and registration datasets were each interpreted by 2 readers for the presence of metastatic nodal disease and were staged independently of each other. Results were compared with surgical pathologic findings. RESULTS: One hundred and thirty lymph node stations in the mediastinum and hila were evaluated each on CT, PET, and registration datasets. Sensitivity, specificity, positive predictive value, and negative predictive value, respectively, for detecting metastatic nodal disease for CT were 74%, 78%, 55%, 88%; for PET with CT side by side, 59% to 76%, 77% to 89%, 48% to 68%, and 84% to 91%; and for CT-PET registration, 71% to 76%, 89% to 96%, 70% to 86%, and 90% to 91%. Registration images were significantly more sensitive in detecting nodal disease over PET for 1 reader (P = 0.0156) and were more specific than PET (P = 0.0107 and 0.0017) in identifying the absence of mediastinal disease for both readers. Registration was significantly more accurate for staging when compared with PET for both readers (P = 0.002 and 0.035). CONCLUSION: Registration of CT and FDG-PET datasets significantly improved the specificity of detecting metastatic disease. In addition, registration improved the radiologic staging of lung cancer patients when compared with CT or FDG-PET alone.

Adult↗

PubMedDate not supplied

Characterization of small liver lesions: Added role of MR after MDCT.

OBJECTIVE: The purpose of this study is to evaluate the added role of magnetic resonance imaging (MR) in characterizing subcentimeter focal liver lesion(s) detected on multidetector row helical computed tomography (MDCT). MATERIALS AND METHODS: A retrospective analysis was performed in 59 noncirrhotic patients with focal subcentimeter liver lesion(s) detected on a 4- or 16-slice MDCT. All patients had a gadolinium enhanced liver MR on 1.5-T systems within 6 weeks after MDCT. Imaging diagnosis was graded on an ordinal scale of 0-5 (0, normal; 1, definitely benign; and 5, definitely malignant). The final diagnosis was established either by histopathology or follow-up imaging for a period of at least 6 months. Receiver operating characteristic analysis was performed to compare the performances of MDCT and MR in characterization of subcentimeter liver lesions. RESULTS: A total of 178 lesions were detected on MDCT in 59 patients. Of these lesions, 129 (72.5%) lesions were benign and the remaining 49 were malignant. The sensitivity, specificity, positive predictive value, and negative predictive value in differentiation of benign from malignant lesions on MDCT were 81.2%, 77.3%, 60.5%, 90.6 % and on MR were 83.3%, 97.5%, 92.1%, and 94.4 %, respectively. Comparative receiver operating characteristic analysis showed an area under curve for MDCT = 0.76 and MR = 0.95 (P < 0.001). CONCLUSIONS: Liver MR has significantly higher accuracy for characterization of subcentimeter focal liver lesions discovered on MDCT.

Adult↗

PubMedDate not supplied

Comparison of preference-based utilities of the Short-Form 36 Health Survey and Health Utilities Index before and after treatment of patients with intermittent claudication.

The authors compared SF-36 utilities with Health Utilities Index (HUI) utilities (HUI2 and HUI3) assessed in patients with intermittent claudication. A total of 87 patients with intermittent claudication completed the SF-36 and HUI before and 1, 3, and 12 months after revascularization. Utilities were estimated using SF-36 and HUI published algorithms (i.e., both algorithms were based on standard-gamble utilities assessed in random samples of the general population). The utilities were compared using repeated-measures multivariate analysis of variance, paired t tests, and univariate linear regression analyses. Before treatment, the mean SF-36 and HUI3 utilities were the same (0.66 vs. 0.66, P = 0.92) and less than the mean HUI2 utility (0.70, P = 0.02). After treatment, all utilities showed improvement from before treatment (P < 0.05); the gain in utilities from treatment was lowest when using the SF-36 (e.g., 0.74, 0.80, 0.77 at 3 months for the SF-36, HUI2, and HUI3, respectively). The correlations of changes over time of the SF-36 with HUI2 utilities and of the SF-36 with HUI3 utilities were 0.39 and 0.49, respectively. The relationships between the SF-36 and HUI2 or HUI3 utilities were moderate to good (i.e., range-adjusted R2 = 31% to 72%). The results suggest that SF-36 data can be transformed to preference-based utilities and be used for economic evaluation in health care. The gain in utilities from treatment, however, was less for SF-36 utilities than for HUI utilities.

Algorithms↗

PubMedDate not supplied

Medicare's national coverage decisions, 1999-2003: quality of evidence and review times.

In 1998 Medicare amended its procedures for making national coverage decisions for new technologies in an attempt to make the process more transparent and evidence based. We examined the quality of evidence for sixty-nine technologies reviewed by Medicare since then. Determinations by the Centers for Medicare and Medicaid Services (CMS) have generally been consistent with the strength of evidence. Good clinical evidence from rigorous studies is usually lacking for the technologies Medicare considers, although in most cases the CMS covers with conditions if there is at least fair evidence that benefits outweigh harms. Decisions referred to the external Medicare Coverage Advisory Committee (MCAC) have averaged eight months longer than non-MCAC decisions.

Centers for Medicare and Medicaid Services, U.S.↗

PubMedDate not supplied

Correlation of patient weight and cross-sectional dimensions with subjective image quality at standard dose abdominal CT.

OBJECTIVE: We evaluated the association between patients' weight and abdominal cross-sectional dimensions and CT image quality. MATERIALS AND METHODS: We prospectively evaluated 39 cancer patients aged more than 65 years with multislice CT scan of abdomen. All patients underwent equilibrium phase contrast-enhanced abdominal CT with 4 slices (from top of the right kidney) obtained at standard tube current (240-280 mA). All other scanning parameters were held constant. Patients' weight was measured just prior to the study. Cross-sectional abdominal dimensions such as circumference, area, average anterior abdominal wall fat thickness and, anteroposterior and transverse diameters were measured in all patients. Two subspecialty radiologists reviewed randomized images for overall image quality of abdominal structures using 5- point scale. Non-parametric correlation analysis was performed to determine the association of image quality with patients' weight and cross-sectional abdominal dimensions. RESULTS: A statistically significant negative linear correlation of 0.46, 0.47, 0.47, 0.58, 0.56, 0.54, and 0.56 between patient weight, anterior abdominal fat thickness, anteroposterior and transverse diameter, circumference, cross-sectional area and image quality at standard scanning parameters was found (p<0.01). CONCLUSION: There is a significant association between image quality, patients' weight and cross-sectional abdominal dimensions. Maximum transverse diameter of the abdomen has the strongest association with subjective image quality.

Aged↗

PubMedDate not supplied

Risk factors for the development of aphakic glaucoma after congenital cataract surgery.

BACKGROUND: It is well-known that lensectomy surgery during the first year of life increases one's risk of aphakic glaucoma. However, it is controversial whether there is a specific time period during the first year of life after which performing lensectomy surgery has a lower risk of aphakic glaucoma development. PATIENTS AND METHODS: A retrospective chart review was performed of all patients seen by a pediatric glaucoma specialist from 1970 to 2003. Patients were included in the study if they underwent congenital cataract surgery. Cataracts were defined as congenital if they were identified within the first 6 months of life, were dominantly inherited, or were of the lamellar type. Aphakic glaucoma was defined as having repeated intraocular pressures > 25 mm Hg after congenital cataract surgery. Patients were excluded if they had any conditions that were independently associated with glaucoma. RESULTS: A total of 368 eyes of 258 patients were included in the study. Of these, 216 (58.7%) eyes of 150 patients developed aphakic glaucoma. Risk factors of greatest significance (P < .0001) included having lensectomy within the first year of life and the development of postoperative complications. CONCLUSIONS: No specific age for lensectomy during the first year of life was associated with a decreased risk for development of aphakic glaucoma. Surgery for congenital cataracts should not be delayed if the only reason for delay is to prevent the development of aphakic glaucoma.

Adolescent↗