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]]>Materials and Methods: This retrospective study was approved by the institutional review board and was HIPAA compliant; informed consent was waived. From 1995 to 2002, gadolinium-enhanced MR imaging data were acquired with a three time point high-resolution method in women undergoing neoadjuvant therapy for invasive breast cancers. Forty-eight women (mean age, 49.1 years; range, 29.7–72.4 years) were divided into recurrence-free or recurrence groups. Volume measurements were tabulated for SER values between set ranges; cutoff criteria were defined to predict disease recurrence after surgery. Wilcoxon rank sum tests and the multivariate Cox proportional hazards regression model were used for evaluation.
Results: Breast tumor volume calculated from the number of voxels with SER values above a threshold corresponding to the upper limit of mean redistribution rate constant in benign tumors (0.88 minutes–1) and the volume of cancerous breast tissue infiltrating into the parenchyma were important predictors of disease recurrence. Seventy-five percent of patients with recurrence and 100% of deceased patients were identified as being at high risk for recurrence. Thirty percent of patients with recurrence and 67% of deceased patients were identified as having high risk before chemotherapy. No patients in the recurrence-free group were misidentified as likely to have recurrence. All three prechemotherapy parameters (total tumor volume, tumor volumes with high and low SER) and the postchemotherapy tumor volume with high SER were significantly different between the two groups. The multivariate Cox proportional hazards regression showed that, of the three prechemotherapy covariates, only the low SER and high SER tumor volumes (P = .017 and .049, respectively) were significant and independent predictors of tumor recurrence. Tumor volume with high SER was the only significant postchemotherapy covariate predictor (P = .038).
Conclusion: High-spatial-resolution SER imaging may improve prediction for patients at high risk for disease recurrence and death.
Supplemental material:
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]]>Materials and Methods: Delayed contrast material–enhanced 1.5-T hydrogen 1 (1H) magnetic resonance (MR) imaging was used to measure the size and location of nonacute MIs in 20 patients (18 men, two women; mean age, 63 years ± 9 [standard deviation]; age range, 48–82 years) examined at least 90 days after MI. End-systolic and end-diastolic volumes, ejection fraction, and left ventricle (LV) mass were measured with cine MR imaging. The TSC in normal, infarcted, and adjacent myocardial tissue was measured on sodium 23 (23Na) MR images coregistered with delayed contrast-enhanced 1H MR images. Programmed electric stimulation to induce monomorphic ventricular tachycardia (MVT) was used to assess arrhythmic potential, and myocardial TSC was compared between the inducible MVT and noninducible MVT patient groups.
Results: The mean TSC for MIs (59 µmol/g wet weight ± 10) was 30% higher than that for noninfarcted (remote) LV regions (45 µmol/g wet weight ± 5, P < .001) and that for healthy control subjects, and TSC did not correlate with infarct age or functional and morphologic indices. The mean TSC for tissue adjacent to the MI (50 µmol/g wet weight ± 6) was intermediate between that for the MI and that for remote regions. The elevated TSC measured in the MI at 23Na MR imaging lacked sufficient contrast and spatial resolution for routine visualization of MI. Cardiac TSC did not enable differentiation between patients in whom MVT was inducible and those in whom it was not.
Conclusion: Absolute TSC is measurable with 23Na MR imaging and is significantly elevated in human MI; however, TSC increase is not related to infarct age, infarct size, or global ventricular function. In regions adjacent to the MI, TSC is slightly increased but not to levels in the MI.
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]]>Materials and Methods: This HIPAA-compliant study was IRB-approved; formal consent was obtained. One hundred seventeen patients (83 men, 34 women; mean age, 64.3 years; range, 18–86 years) with decreased renal function underwent contrast-enhanced CT with either iso-osmolality iodixanol (n = 61) or low-osmolality iopromide (n = 56). Outcome measures were of SCr increase or GFR decrease for 3 days after CT, a SCr increase (of ≥0.5 mg/dL [44.2 µmol/L, 25%] or ≥1.0 mg/dL [88.4 µmol/L, 50%]), a GFR reduction (of ≥5 mL/min), and patient outcome at 30- and 90-day follow-up.
Results: Iodixanol decreased SCr (mean ± standard deviation) from 1.77 mg/dL ± 0.24 (156.47 µmol/L ± 21.22) at baseline to 1.65 mg/dL ± 0.35 (145.86 µmol/L ± 30.94, P = .046) at day 1, 1.73 mg/dL ± 0.53 (152.93 µmol/L ± 46.85, not significant) at day 2, and 1.73 mg/dL ± 0.55 (152.93 µmol/L ± 48.62, not significant) at day 3 (not significant). Iopromide increased SCr from 1.75 mg/dL ± 0.32 (154.7 µmol/L ± 28.29) at baseline to 1.8 mg/dL ± 0.42 (159.12 µmol/L ± 15.59) at day 1, 1.77 mg/dL ± 0.49 (156.47 µmol/L ± 43.32) at day 2, and 1.77 mg/dL ± 0.62 (156.47 µmol/L ± 54.81) at day 3 (not significant). Iodixanol increased and iopromide decreased GFR on all 3 days after CT (not significant). Fewer patients in the iodixanol group (8.5%) than in the iopromide group (27.8%) had SCr increase 0.5 mg/dL or higher (≥25%, P = .012). Two patients in each group had SCr increase of 1.0 mg/dL or more (not significant). More patients in the iopromide group (42.3%) than in the iodoxanol group (24.1%) had a GFR reduction of 5 mL/min or higher (P = .0426). No patient had a contrast material–related adverse event at 30- or 90-day follow-up.
Conclusion: Intravenous contrast material application in high-risk patients is unlikely to be associated with permanent adverse outcomes. SCr levels after contrast material administration are lower in iodixanol than iopromide groups.
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]]>Materials and Methods: The study was HIPAA compliant and institutional review board approved for medical chart review; the requirement for informed patient consent was waived. Patients (n = 5138; 2569 women, 2569 men, 753 African Americans, 4385 non–African Americans) examined during a 2-year period formed the final study group after exclusion of patients undergoing dialysis (n = 49), for whom no age data were recorded (n = 9), and younger than 18 years (n = 113). Patient age, sex, and race and the blood urea nitrogen, albumin, and serum creatinine levels most recently measured within 6 months before CT were obtained from the electronic medical records. The number of patients with creatinine levels higher than 1.4 mg/dL was directly compared with the number of patients with eGFR values (calculated with four- and six-variable Modification of Diet in Renal Disease [MDRD] equations) lower than 60 mL/min/1.73 m2 by using the two-tailed McNemar test. For 2689 patients, data to calculate the eGFR by using the four-variable equation were available, and for 2005 patients, data to calculate the eGFR by using the six-variable equation were available.
Results: Among the outpatients scheduled to undergo CT, the percentage of patients with an eGFR lower than 60 mL/min/1.73 m2 was significantly greater than the percentage of patients with a creatinine level higher than 1.4 mg/dL for both the four-variable (412 [15.3%] vs 166 [6.2%] of 2689 patients) and the six-variable (346 [17.3%] vs 117 [5.8%] of 2005 patients) MDRD equation groups (P < .001).
Conclusion: A significantly higher number of outpatients scheduled for contrast medium–enhanced CT met the National Kidney Foundation criteria for renal insufficiency when the MDRD equations were used to estimate the glomerular filtration rate compared with the number of outpatients who met the criteria on the basis of elevated creatinine levels.
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]]>Materials and Methods: Lumbar vertebral osteomyelitis was induced in 10 rabbits with intradiscal injection of bacteria in a vertebral disk (test level) versus saline injection in another disk (control level). After a mean interval of 12 days, rabbits were imaged prior to and 24 hours after administration of USPIO. The MR imaging protocol included T1-weighted spin-echo, T2-weighted fast spin-echo, and T2*-weighted gradient-echo sequences. MR findings were compared with histologic findings (macrophage immunostaining and Perls Prussian blue staining). A Wilcoxon signed rank test was used to compare signal-to-noise ratio (SNR) results before and after USPIO administration.
Results: T1-weighted MR images of infected vertebral test levels obtained 24 hours after USPIO administration showed a significant increase in SNR (P = .005), whereas T2- and T2*-weighted images showed no significant changes in SNR (P = .14 and P = .87, respectively). Histologic examination results of infected areas demonstrated complete replacement of hematopoietic bone marrow by macrophage infiltration. Perls Prussian blue staining showed that some macrophages were iron loaded. T1- (P = .02), T2- (P = .04), and T2*-weighted (P = .04) images of control vertebrae showed a significant decrease in SNR. Histologic examination results confirmed the persistence of normal hematopoietic bone marrow without macrophage infiltration, which was reflected by more intensive Perls Prussian blue staining compared with that in infected areas.
Conclusion: MR imaging can depict USPIO-loaded macrophage infiltration present in infected areas in an experimental rabbit model of vertebral osteomyelitis.
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]]>Materials and Methods: Institutional review board approval was obtained, with waiver of informed consent. A total of 245 consecutive patients (133 men, 112 women), including 48 patients who subsequently underwent cholecystectomy, were examined. Two independent observers evaluated the CT data set on the basis of axial sections, coronal and sagittal multiplanar reformations, and three-dimensional volume rendering. The relationship between the cystic arteries and the Calot triangle—which is bordered by the undersurface of the liver, common hepatic duct, and cystic duct—was also evaluated, and each patient was classified on the basis of the origin of the cystic arteries and the course to the Calot triangle. Statistical analysis was performed, and percentages and confidence intervals were calculated.
Results: The cystic arteries were delineated in 234 of the 245 patients. Both the Calot triangle and the cystic arteries were delineated in 223 patients. One cystic artery was seen in the Calot triangle in 173 patients, and two cystic arteries were seen in the Calot triangle in 12. One artery in the Calot triangle with accessory arteries from different origins outside the Calot triangle was seen in 18 patients, and no cystic artery was identified in 20. Cystic arteries were seen in 42 (92%; 95% confidence interval: 87%, 98%) of the 48 patients who subsequently underwent cholecystectomy. The relationship between the cystic arteries and the Calot triangle was in agreement with the surgical records for all patients.
Conclusion: The configuration of the cystic duct and cystic arteries can be depicted preoperatively with 64–detector row CT in patients scheduled to undergo cholecystectomy.
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]]>Materials and Methods: The study had institutional review board approval; all participants gave informed consent. Data in a total of 383 prospectively enrolled patients who underwent duplex Doppler US and screening endoscopy were divided into training (n = 240) and validation (n = 143) sets. Duplex Doppler US indexes, including mean portal vein velocity (PVV), hepatic impedance indexes, splenic impedance indexes, and the splenic index were evaluated with univariate and multivariate logistic regression analyses to find the independent factors predictive of the presence of esophageal varices. Receiver operating characteristic (ROC) curves were constructed for these factors to evaluate diagnostic accuracy in the training set and reproducibility in the validation set.
Results: Multivariate logistic regression analysis showed that splenic index and mean PVV were predictive of the presence of esophageal varices in the training set. A splenoportal index (SPI) was calculated as the splenic index divided by mean PVV to amplify the opposite effects on esophageal varices. Areas under ROC curves for SPI were significantly higher than those for the splenic index (0.93 vs 0.90, P = .02) and mean PVV (0.93 vs 0.67, P < .001) in the training set and in the validation set (0.96 vs 0.91 for splenic index, P = .01; 0.93 vs 0.80 for mean PVV, P < .001). An SPI threshold of 3.0 had 92% sensitivity, 93% specificity, 91% positive predictive value, and 94% negative predictive value for esophageal varices. Applying this cutoff value correctly predicted the presence or absence of esophageal varices in 92% of the patients without screening endoscopy.
Conclusion: SPI can serve as a useful noninvasive index to predict the presence or absence of esophageal varices.
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]]>Materials and Methods: A fat-saline phantom was used to perform IP and OP 3.0-T MR imaging for various fat fractions. The institutional review board approved this HIPAA-compliant study, with waiver of informed consent. Single-breath-hold IP and OP 3.0-T MR images in 21 patients (14 women, seven men; mean age, 63 years) with 23 adrenal tumors (16 adenomas, six metastases, one adrenocortical carcinoma) were reviewed. The MR protocol involved two acquisition schemes: In scheme A, the first OP echo (approximately 1.5-msec TE) and the second IP echo (approximately 4.9-msec TE) were acquired. In scheme B, the first IP echo (approximately 2.4-msec TE) and the third OP echo (approximately 5.8-msec TE) were acquired. Quantitative analysis was performed, and analysis of variance was used to test for differences between adenomas and nonadenomas.
Results: In the phantom study, scheme B did not enable discrimination among voxels that had small amounts of fat. In the clinical study, no overlap in signal intensity (SI) index values between adenomas and nonadenomas was seen (P < .05) with scheme A. However, with scheme B, no overlap in the adrenal gland SI–to–liver SI ratio between adenomas and nonadenomas was seen (P < .05). With scheme B, no overlap in adrenal gland SI index–to–liver SI index ratio between adenomas and nonadenomas was seen (P < .05).
Conclusion: This initial experience indicates SI index is the most reliable parameter for characterization of adrenal tumors with 3.0-T MR imaging when obtaining OP echo before IP echo. When acquiring IP echo before OP echo, however, nonadenomas can be mistaken as adenomas with use of the SI index value.
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]]>Materials and Methods: Ethics committee approval was obtained, with waiver of informed consent. Patients consented to having their data used for future retrospective research. Forty-one women (age range, 22–73 years) with 48 epithelial ovarian tumors underwent dynamic contrast-enhanced MR imaging before surgical excision. In case of bilateral tumors (n = 7), only the most complex tumor was analyzed. Thus, 41 tumors (12 benign, 13 borderline, and 16 invasive) were examined with dynamic contrast-enhanced MR imaging and immunohistochemical methods. Dynamic contrast-enhanced MR imaging parameters (enhancement amplitude [EA], time of half rising [Tmax], and maximal slope [MS]) were analyzed according to histopathologic findings, microvessel density, pericyte coverage index (PCI), and vascular endothelial growth factor receptor 2 (VEGFR-2) expression. Statistical analyses were performed by using Kruskal-Wallis, Fisher exact, and Spearman tests and receiver operating curve analysis.
Results: EA was higher for invasive tumors than for benign (P < .001) and borderline (P < .05) tumors. Tmax was longer for benign tumors than for borderline (P < .05) and invasive (P < .01) tumors. MS was steeper for invasive tumors than for benign (P < .001) and borderline (P < .001) tumors. PCI was lower in invasive tumors than in borderline (P < .05) and benign (P < .05) tumors. Microvessels showed stronger immunohistochemical VEGFR-2 expression in invasive tumors than in benign or borderline tumors (P < .05). MS correlated with a lower PCI (r = –0.34, P = .04) and stronger VEGFR-2 expression by using both epithelial (r = 0.41, P < .01) and endothelial (r = 0.66, P < .001) cells.
Conclusion: The early enhancement patterns of ovarian epithelial tumors on dynamic contrast-enhanced MR images can help distinguish among benign, borderline, and invasive tumors and were found to correlate with tumoral angiogenic status.
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]]>Materials and Methods: All study activities were approved by the institutional review board. A self-administered, mailed survey was used to collect data on the practices and attitudes of U.S. radiologists regarding three CT screening tests—coronary artery calcium scoring (CACS), lung cancer screening CT, and whole-body screening CT. The survey was sent to 1000 diagnostic radiologists who were randomly sampled from the American Medical Association Physician Masterfile.
Results: A total of 398 (41.4%) of 961 eligible radiologists completed the survey. Among respondents, 33.6% reported reading CT screening studies, the most common being CACS (26.7%), followed by lung screening (19.2%) and whole-body screening (9.5%). Among respondents, 34.1% supported CACS and 29.9% supported lung CT screening for particular patients, while 1.9% supported whole-body CT screening. The most common reasons reported for reading CT screening studies were responses to requests from physicians (83.3%) or patients (75.0%), while fewer (40.8%) cited patient benefit from screening as a reason.
Conclusion: A substantial proportion of a nationally representative sample of radiologists in the United States reads CT screening studies of the heart, lungs, and whole body and holds favorable attitudes toward CACS and lung CT screening. These attitudes may allow for the premature diffusion of new screening tests into practice before higher-level evidence demonstrates their benefits for population mortality.
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]]>Materials and Methods: A decision-analytic Markov model was developed to estimate life expectancy and lifetime costs for 65-year-old patients with a small RCC treated with RF ablation or NSS. The model incorporated RCC presence, treatment effectiveness and costs, and short- and long-term outcomes. An incremental cost-effectiveness analysis was performed to identify treatment preference under an assumed $75 000 per quality-adjusted life-year (QALY) societal willingness-to-pay threshold level, within proposed ranges for guiding implementation of new health care interventions. The effect of changes in key parameters on strategy preference was addressed in sensitivity analysis.
Results: By using base-case assumptions, NSS yielded a minimally greater average quality-adjusted life expectancy than did RF ablation (2.5 days) but was more expensive. NSS had an incremental cost-effectiveness ratio of $1 152 529 per QALY relative to RF ablation, greatly exceeding $75 000 per QALY. Therefore, RF ablation was considered preferred and remained so if the annual probability of post–RF ablation local recurrence was up to 48% higher relative to that post-NSS. NSS preference required an estimated NSS cost reduction of $7500 or RF ablation cost increase of $6229. Results were robust to changes in most model parameters, but treatment preference was dependent on the relative probabilities of local recurrence after RF ablation and NSS, the short-term costs of both, and quality of life after NSS.
Conclusion: RF ablation was preferred over NSS for small RCC treatment at a societal willingness-to-pay threshold level of $75 000 per QALY. This result was robust to changes in most model parameters, but somewhat dependent on the relative probabilities of post–RF ablation and post-NSS local recurrence, NSS and RF ablation short-term costs, and post-NSS quality of life, factors which merit further primary investigation.
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]]>Materials and Methods: The study was approved by the Swiss Ethics Committee. A prediction rule was computed by using data from a 3-year prospective multicenter study to assess the predictive value of heel-bone quantitative US in 6174 Swiss women aged 70–85 years. A quantitative US device to calculate the stiffness index at the heel was used. Baseline characteristics, known risk factors for osteoporosis and fall, and the quantitative US stiffness index were used to elaborate a predictive rule for osteoporotic fracture. Predictive values were determined by using a univariate Cox model and were adjusted with multivariate analysis.
Results: There were five risk factors for the incidence of osteoporotic fracture: older age (>75 years) (P < .001), low heel quantitative US stiffness index (<78%) (P < .001), history of fracture (P = .001), recent fall (P = .001), and a failed chair test (P = .029). The score points assigned to these risk factors were as follows: age, 2 (3 if age > 80 years); low quantitative US stiffness index, 5 (7.5 if stiffness index < 60%); history of fracture, 1; recent fall, 1.5; and failed chair test, 1. The cutoff value to obtain a high sensitivity (90%) was 4.5. With this cutoff, 1464 women were at lower risk (score, <4.5) and 4710 were at higher risk (score, ≥4.5) for fracture. Among the higher-risk women, 6.1% had an osteoporotic fracture, versus 1.8% of women at lower risk. Among the women who had a hip fracture, 90% were in the higher-risk group.
Conclusion: A prediction rule obtained by using quantitative US stiffness index and four clinical risk factors helped discriminate, with high sensitivity, women at higher versus those at lower risk for osteoporotic fracture.
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]]>Materials and Methods: The study was institutional review board approved and HIPAA compliant, as appropriate, for the four institutions at which the involved patients were treated. Informed patient consent was obtained, were applicable. Thirty-six male patients (age range, 15–80 years; mean age, 40.2 years) with clinically documented first-time traumatic posterior shoulder dislocation were examined with MR arthrography (18 patients) or conventional shoulder MR imaging (18 patients). Causes of posterior shoulder dislocation were electric shock in one patient, seizure in one patient, and trauma in 34 patients. Hill-Sachs lesions, rotator cuff tears, biceps tendon abnormalities, posterior labrocapsular complex lesions, humeral head translation, and osseous glenoid version angle were evaluated. Spearman rank correlation and Student t test analyses were performed.
Results: In 31 (86%) of the 36 patients, a reverse Hill-Sachs lesion was found. Eleven (31%) patients had a reverse osseous Bankart lesion. Twelve full-thickness rotator cuff tears were seen in seven (19%) patients: four supraspinatus tendon, three infraspinatus tendon, and five subscapularis tendon tears. Six (17%) patients had biceps tendon abnormalities. Posterior labrocapsular complex tears were identified in 21 (58%) patients: 10 (48%) with posterior labral sleeve avulsions and 11 (52%) with reverse Bankart lesions. Twenty-seven (75%) patients had a retroverted scaphoglenoid angle (mean, 4.5°). The mean humeral translation distance relative to the osseous glenoid fossa was –4.8 mm; in 33 (92%) patients, this distance was translated posteriorly.
Conclusion: The MR appearance of traumatic posterior shoulder dislocation was characterized by reverse Hill-Sachs lesions in 86% of patients and posterocaudal labrocapsular lesions in nearly 60% of patients. Full-thickness rotator cuff tears were seen in approximately 20% of patients.
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]]>Materials and Methods: The regional ethics committee approved the study and written informed consent was obtained from all participants. The study included 25 patients with AD (11 men, 14 women; mean age ± standard deviation [SD], 73 years ± 6; Mini-Mental State Examination (MMSE) score, 24.4 ± 2.7), 24 patients with amnestic MCI (10 men, 14 women; mean age ± SD, 74 years ± 8; MMSE score, 27.2 ± 1.4) and 25 elderly healthy controls (13 men, 12 women; mean age ± SD, 64 years ± 8). For each participant, the hippocampi were automatically segmented on three-dimensional T1-weighted magnetic resonance (MR) images with high spatial resolution. Segmentation was performed by using recently developed software that allows fast segmentation with minimal user input. Group differences in hippocampal volume were assessed by using Student t tests. To obtain robust estimates of P values, the correct classification rate, sensitivity, and specificity, bootstrap methods were used.
Results: Significant hippocampal volume reductions were detected in all groups of patients (–32% in AD patients vs controls, P < .001; –19% in MCI patients vs controls, P < .001; and –15% in AD patients vs MCI patients, P < .01). Individual classification on the basis of hippocampal volume resulted in 84% correct classification (sensitivity, 84%; specificity, 84%) between AD patients and controls and 73% correct classification (sensitivity, 75%; specificity, 70%) between MCI patients and controls.
Conclusion: This automated method can serve as an alternative to manual tracing and may thus prove useful in assisting with the diagnosis of AD.
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]]>Materials and Methods: All patients gave written informed consent for the initial magnetic resonance (MR) studies, and the institutional review board and local research ethics committee waived initial informed consent for the pooled analysis. A total of 190 patients with symptomatic carotid artery disease underwent fluid-attenuated inversion-recovery imaging of the brain and fat-suppressed black-blood T1-weighted MR imaging of the carotid arteries. The volumes of periventricular lesions, subcortical lesions, and total WMHLs were calculated and compared between hemispheres in relation to symptoms and IPH, and their interaction was calculated and compared by using repeated measures three-factorial multivariate analysis.
Results: After exclusion of 12 patients, 178 patients (116 men, 62 women; mean age, 70.2 years ± 8.6 [standard deviation]) remained. There was no significant difference in WMHL volume between the symptomatic and asymptomatic hemispheres, and WMHL volume was not related to the degree of carotid stenosis. The presence of carotid IPH significantly interacted with the interhemispheric WMHL difference (Wilks test, F = 9.95; df = 3; P < .001). Univariate analysis showed larger total and periventricular WMHL volumes (P < .05) in patients with ipsilateral IPH.
Conclusion: Carotid artery disease and leukoaraiosis were associated with features that indicated plaque instability, namely IPH, whereas the degree of stenosis had no effect.
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]]>Materials and Methods: This study was approved by the institutional review board and was compliant with HIPAA regulations. Informed consent was obtained from each subject. The authors identified 54 subjects who underwent antemortem 1H MR spectroscopy and were clinically healthy or had AD-type pathology with low to high likelihood of AD according to National Institute on Aging–Reagan neuropathologic criteria at autopsy. They investigated the associations between 1H MR spectroscopy metabolite measurements and Braak neurofibrillary tangle stage (Braak stage), neuritic plaque score, and AD likelihood, with adjustments for subject age, subject sex, and time between 1H MR spectroscopy and death.
Results: Decreases in N-acetylaspartate–to-creatine ratio, an index of neuronal integrity, and increases in myo-inositol–to-creatine ratio were associated with higher Braak stage, higher neuritic plaque score, and greater likelihood of AD. The N-acetylaspartate–to–myo-inositol ratio proved to be the strongest predictor of the pathologic likelihood of AD. The strongest association observed was that between N-acetylaspartate–to–myo-inositol ratio and Braak stage (RN2 = 0.47, P < .001).
Conclusion: Antemortem 1H MR spectroscopy metabolite changes correlated with AD-type pathology seen at autopsy. The study findings validated 1H MR spectroscopy metabolite measurements against the neuropathologic criteria for AD, and when combined with prior longitudinal 1H MR spectroscopy findings, indicate that these measurements could be used as biomarkers for disease progression in clinical trials.
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]]>Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant study. Records of 462 patients with primary hyperparathyroidism who underwent preoperative imaging with a technetium 99m (99mTc) sestamibi and 99mTcO4– protocol that consisted of early and late pinhole 99mTc sestamibi, pinhole thyroid imaging, image subtraction, and single photon emission computed tomography (SPECT) were retrospectively reviewed. An experienced nuclear medicine physician without knowledge of other test results or of the final diagnoses graded images on a scale from 0 (definitely normal) to 4 (definitely abnormal). Early pinhole 99mTc sestamibi images, late pinhole 99mTc sestamibi images, subtraction images, SPECT images, early and late pinhole 99mTc sestamibi images, all planar images, and all images—including SPECT images—were read in seven sessions. Receiver operating characteristic curves were generated for each session and were used to calculate sensitivity, specificity, and accuracy.
Results: A total of 534 parathyroid lesions were excised. Of the 462 patients, 409 had one lesion, whereas 53 had multiple lesions. Reading all images together was more accurate (89%, P = .001) than was reading early (79%), late (85%), subtraction (86%), and SPECT (83%) images seperately; however, it was not significantly more accurate than reading planar images (88%) or early and late images together (87%). Reading all images was significantly less sensitive in the detection of lesions with a median weight of 600 mg or less than in the detection of lesions with a median weight of more than 600 mg (86% vs 94%, P = .004). Per-lesion sensitivity for reading all images was significantly higher for SGD than for MGD (90% vs 66%, P < .001). Sensitivity of reading all images together in the identification of patients with MGD was 62%.
Conclusion: Reviewing early, late, and subtraction pinhole images together with SPECT images maximizes parathyroid lesion detection accuracy. Test sensitivity is adversely affected by decreasing lesion weight and MGD.
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]]>Materials and Methods: Written informed consent was obtained and the study was approved by the local research ethics committee. FLV was measured on MR images in 95 fetuses (52 female neonates, 43 male neonates) with CDH between 22 and 39 weeks gestation by using multiplanar T2-weighted half-Fourier acquired single-shot turbo spin-echo MR imaging. On the basis of logistic regression analysis results, mortality and the need for ECMO therapy were calculated for fetuses before and after 30 weeks gestation.
Results: Overall, higher FLV was associated with improved survival (P < .001) and decreasing probability of need for ECMO therapy (P = .008). Survival at discharge was 29.2% in neonates with an FLV of 5 mL, compared with 99.7% in neonates with an FLV of 25 mL. The corresponding need for ECMO therapy was 56.1% in fetuses with an FLV of 5 mL and 8.7% in fetuses with an FLV of 40 mL. Prognostic power was considerably lower before 30 weeks gestation.
Conclusion: Beyond 30 weeks gestation, logistic regression analysis that is based on MR FLV measurements is useful to estimate neonatal survival rates and ECMO requirements. Prior to 30 weeks gestation, the method is not reliable and the FLV measurement should be repeated, particularly in fetuses with small lung volumes, before a decision is made about therapeutic options.
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]]>Materials and Methods: This retrospective study was approved by the research ethics committee, and informed consent was received from all mothers for previous prospective studies. In total, 68 fetuses with CDH were assessed by using MR image FLV measurement within 23–39 weeks gestation. The relative FLV was expressed as a percentage of the predicted lung volume calculated with biometric parameters according to seven formulas previously described in the literature. Applying the area under the curve (AUC), the various relative FLVs and the absolute FLV were investigated for their prognostic accuracy to predict neonatal survival and the need for ECMO therapy.
Results: All relative FLVs and the absolute FLV revealed a significant difference in mean lung volume between neonates who survived and neonates who did not survive (P = .001 to P < .001) and measurement accuracy was excellent for each method (AUC, 0.800–0.900). For predicting neonatal ECMO requirement, differences in FLVs were smaller but still significant (P = .05 to <.009) and measurement accuracy was acceptable throughout (AUC, 0.653–0.739).
Conclusion: The various relative FLVs and the absolute FLV measured at MR planimetry are each highly valuable in predicting survival in fetuses with CDH. For predicting whether neonatal ECMO therapy is required, the accuracy of the absolute FLV (AUC, 0.68) and that of the relative FLVs (AUC, 0.653–0.739) was acceptable.
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]]>Materials and Methods: Research ethics board approval, with waived informed patient consent, was obtained for review of the data of 37 children (17 male, 20 female; age range, 1–20 months; mean age, 4.3 months) in whom gastrostomy or gastrojejunostomy tubes were inserted between 1995 and 2004. Twenty-two patients had CDH, eight had gastroschisis, five had omphalocele, and two had both CDH and omphalocele. The technical success and complications of the procedures were recorded. Tube maintenance problems were analyzed separately from postprocedural complications. Initial and final patient growth percentiles were compared by using a one-sided paired Student t test.
Results: Thirty-six of the 38 procedures performed in the 37 patients were successful. There were three intraprocedural complications (two cases of access difficulty, one case of bleeding) and three major complications (one skin and prosthetic material infection, one track loss during tube replacement, one delayed gastrostomy track closure necessitating surgery). Sixteen patients had at least one minor complication (cellulitis, feeding intolerance, skin-site bleeding, intussusception). Twenty-two patients had at least one tube maintenance problem. All patients gained weight (mean weight gain, 4.7 kg) after the procedure, with a significant increase in growth percentile (average increase, 6.5%; P = .029).
Conclusion: Radiologically guided percutaneous gastrostomy and gastrojejunostomy tube placements in children with gastroschisis, omphalocele, and/or CDH are associated with high success rates and low major complication rates. Although tube maintenance problems and minor complications are common, use of gastrostomy and gastrojejunostomy tubes effectively improves nutritional support.
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]]>Materials and Methods: The study was approved by institutional review boards and was HIPAA compliant. Deidentified individual-level data from participants (1520 current or former smokers aged 50–85 years) in the Mayo Clinic helical CT screening study were used to populate the Lung Cancer Policy Model, a comprehensive microsimulation model of lung cancer development, screening findings, treatment results, and long-term outcomes. The model predicted diagnosed cases of lung cancer and deaths per simulated study arm (five annual screening examinations vs no screening). Main outcome measures were predicted changes in lung cancer–specific and all-cause mortality as functions of follow-up time after simulated enrollment and randomization.
Results: At 6-year follow-up, the screening arm had an estimated 37% relative increase in lung cancer detection, compared with the control arm. At 15-year follow-up, five annual screening examinations yielded a 9% relative increase in lung cancer detection. The relative reduction in cumulative lung cancer–specific mortality from five annual screening examinations was 28% at 6-year follow-up (15% at 15 years). The relative reduction in cumulative all-cause mortality from five annual screening examinations was 4% at 6-year follow-up (2% at 15 years).
Conclusion: Screening may reduce lung cancer–specific mortality but may offer a smaller reduction in overall mortality because of increased competing mortality risks associated with smoking.
© RSNA, 2008
]]>Materials and Methods: Twenty-six patients (four women, 22 men; median age, 72 years) with cirrhosis (Child-Pugh class A disease, 22 patients; Child-Pugh class B disease, four patients) and at least one 5.0–9.0-cm-diameter HCC without invasion of the portal trunk or main portal branches were treated with multipolar RF ablation performed by a single operator. The procedure was performed with three separate bipolar linear internally cooled electrodes with ultrasonographic guidance. Twenty-seven of the 33 tumors treated had a diameter of 5.0 cm or greater (median diameter, 5.7 cm; range, 5.0–8.5 cm); 12 of these 27 tumors were infiltrative, and four invaded segmental portal vein branches. Ten patients had a serum -fetoprotein level higher than 400 µg/L. Results were assessed by using computed tomography. Primary effectiveness, complications, tumor progression, and survival rates were recorded. Probabilities of survival were calculated by using the Kaplan-Meier method.
Results: One to two RF ablation procedures per patient (mean, 1.15 ± 0.43 [standard deviation]) led to the complete ablation of 22 (81%) of the 27 tumors (18 tumors after one and four tumors after two procedures), including three tumors that showed segmental portal vein invasion. All patients experienced postablation syndrome, and one experienced subcapsular hematoma and a segmental liver infarct, but no major complication occurred. After a mean follow-up of 14 months (range, 3–34 months), local and distant tumor progression and actual survival rates were 14% (three of 22), 24% (five of 21), and 65% (17 of 26), respectively. The probabilities of 1- and 2-year survival, respectively, were 68% (95% confidence interval: 49%, 86%) and 56% (95% confidence interval: 51%, 81%).
Conclusion: HCCs larger than 5.0 cm (but smaller than 9.0 cm)—even those that are infiltrative and those that involve a segmental portal vein—can be completely and safely ablated with multipolar RF ablation.
© RSNA, 2008
]]>Materials and Methods: Patients with symptomatic femoropopliteal in-stent restenosis were randomly assigned to undergo CBA or peripheral cutting balloon angioplasty (PCBA) for treatment of lesions up to 20 cm in length. Patients were followed up clinically and with duplex ultrasonography (US) at 1, 3, and 6 months for occurrence of a restenosis of 50% or higher. The Fisher exact test and Mann Whitney U test were used for statistical analyses.
Results: Forty patients were enrolled; one patient was lost to follow-up. In the remaining patients, CBA was performed in 22 patients; PCBA was used in 17 patients. Average lesion length was 80 mm ± 68 (standard deviation). Restenosis rates at 6 months were 65% (11 of 17; 95% confidence interval: 42%, 88%) after PCBA versus 73% (16 of 22; 95% confidence interval: 54%, 92%) after CBA (P = .73). Ankle brachial index (0.83 vs 0.75, P = .26) and maximum walking capacity on the treadmill (117 m vs 103 m, P = .97) at 6 months were also not significantly different between the two groups.
Conclusion: PCBA failed to prove superiority compared with CBA for treatment of femoropopliteal in-stent restenosis in this pilot study. In restenotic lesions with an average length of approximately 8 cm, both treatment modalities yielded disappointing 6-month patency rates.
© RSNA, 2008
]]>Materials and Methods: This HIPAA-compliant study had institutional review board approval. Informed consent was waived. Biochemical and hematologic laboratory values from 48 procedures in 39 patients (18 men and 21 women; age range, 29–86 years) who underwent magnetic resonance (MR) imaging–guided percutaneous cryoablation of 65 liver tumors (62 metastases, three hepatocellular carcinomas) were retrospectively reviewed. Changes in laboratory values at baseline and 0–6 hours and 1–2 weeks after the procedure were analyzed with respect to tumor and ablative margin volumes by using generalized estimating equations. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were correlated with percent maximal decrease in platelet count.
Results: Mean ablation zone volume was 67.3 cm3 ± 41.2 (standard deviation) (range, 7.3–191.4 cm3). AST and ALT values increased after all procedures and peaked at 6 hours (median change in AST value, +835 U/L; median change in ALT value, +614.5 U/L). Platelet count decreased after 47 procedures (mean maximal decrease, 92.3 x 109/L [38%]), reaching a nadir at 12–24 hours after 24 procedures (50%) and returning to normal in 31 (84%) of 37 procedures at 1–2 weeks. One procedure was complicated by disseminated intravascular coagulation that necessitated transfusion and arterial embolization. Myoglobin values increased after 21 (44%) of 48 procedures and peaked at 6 hours (trimmed-mean value, 183.4 µg/L). Ablative margin volumes were predictive of changes at 0–6 hours in AST (P = .02), ALT (P = .003), and myoglobin (P < .001) values. Percent maximal decrease in platelet count correlated with peak change in AST (r = 0.72) (P < .001).
Conclusion: Following percutaneous cryoablation of liver tumors, alterations in liver enzymes, myoglobin, and platelet count are common, are usually self-limited, and correlate with ablative margin volume—except for changes in platelet count, which correlate with changes in AST and ALT.
© RSNA, 2008
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