Faculty Bibliography

Purpose: To retrospectively evaluate the frequency of recommendations for additional imaging (RAIs) for important extracolonic findings and polyp prevalence among a cohort of seniors (age >/= 65 years) and nonseniors (age < 65 years) undergoing low-dose computed tomographic (CT) colonography. Materials and Methods: Institutional review board approval was obtained for this HIPAA-compliant retrospective study. Four hundred fifty-four patients (204 nonseniors: mean age, 52 years; 250 seniors: mean age, 69 years) underwent CT colonography at an outpatient facility. Cases were prospectively reported by one of four abdominal radiologists with expertise in CT colonography. The dictated reports were reviewed to determine the frequency of polyps (>/=6 mm), the number of extracolonic findings, and the number of RAIs generated. The Fisher exact test was used to compare the percentage of seniors and nonseniors with at least one reported polyp, with at least one extracolonic finding, as well as the frequency of RAIs. Results: The percentage of patients with at least one reported polyp was 14.2% (29 of 204) for the nonsenior group and 13.2% (33 of 250) for seniors, which was not significantly different (P = .772). The percentage of patients with at least one extracolonic finding was 55.4% (113 of 204) for nonseniors and 74.0% (185 of 250) for seniors (P < .0001). The percentage of patients in which an RAI was suggested was 4.4% (nine of 204) for nonseniors and 6.0% (15 of 250) for seniors, which was not significantly different (P = .450). Conclusion: Extracolonic findings were more frequent in seniors than in nonseniors; however, there was no significant difference in the frequency of RAIs between the two groups. (c) RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11102144/-/DC1

OBJECTIVE: The purpose of our study was to compare the visibility of prostate cancer on trace diffusion-weighted (DW) images and the apparent diffusion coefficient (ADC) map. MATERIALS AND METHODS: In this retrospective study, 45 patients with prostate cancer underwent preoperative MRI, including DW imaging (DWI) (b values 0, 500, and 1,000 s/mm(2)). A single observer reviewed the images in conjunction with tumor maps constructed from prostatectomy. For 132 peripheral zone (PZ) tumor foci, the visibility and contrast relative to benign PZ were recorded for T2-weighted imaging, trace DWI b500 images, trace DWI b1,000 images, and ADC maps. Trace DWI b1,000 images and ADC maps were compared in terms of Gleason score, size, normalized T2 signal intensity, ADC, and normalized ADC of visible tumors. RESULTS: For each image set, the percentage of visible tumor foci and contrast relative to benign PZ were as follows: T2-weighted imaging, 80.3% and 0.411; trace DWI b500, 26.5% and 0.131; trace DWI b1,000, 46.2% and 0.119; and ADC maps, 62.1% and 0.309. Forty-seven tumor foci were visible on both trace DWI b1,000 images and ADC maps, 14 only on trace DWI b1,000 images, 35 only on ADC maps, and 36 on neither image set. There was no significant difference in Gleason score, size, normalized T2 signal intensity, ADC, or normalized ADC between tumors visible only on trace DWI b1,000 images and those visible only on ADC maps. CONCLUSION: Given a greater proportion of tumors visible on the ADC map than trace DWI and greater contrast relative to benign PZ on the ADC map, we suggest that, when performing DWI of the prostate, careful attention be given to the ADC map for tumor identification

PURPOSE: To compare single-shot echo-planar imaging (SS EPI) diffusion-weighted MRI (DWI) of abdominal organs between 1.5 Tesla (T) and 3.0T in healthy volunteers in terms of image quality, apparent diffusion coefficient (ADC) values, and ADC reproducibility. MATERIALS AND METHODS: Eight healthy volunteers were prospectively imaged in this HIPAA-compliant IRB-approved study. Each subject underwent two consecutive scans at both 1.5 and 3.0T, which included breathhold and free-breathing DWI using a wide range of b-values (0 to 800 s/mm(2) ). A blinded observer rated subjective image quality (maximum score= 8), and a separate observer placed regions of interest within the liver, renal cortices, pancreas, and spleen to measure ADC at each field strength. Paired Wilcoxon tests were used to compare abdominal DWI between 1.5T and 3.0T for specific combinations of organs, b-values, and acquisition techniques. RESULTS: Subjective image quality was significantly lower at 3.0T for all comparisons (P = 0.0078- 0.0156). ADC values were similar at 1.5T and 3.0T for all assessed organs, except for lower liver ADC at 3.0T using b0-500-600 and breathhold technique. ADC reproducibility was moderate at both 1.5T and 3.0T, with no significant difference in coefficient of variation of ADC between field strengths. CONCLUSION: Compared with 1.5T, SS EPI at 3.0T provided generally similar ADC values, however, with worse image quality. Further optimization of abdominal DWI at 3.0T is needed. J. Magn. Reson. Imaging 2011;33:128-135. (c) 2010 Wiley-Liss, Inc

BACKGROUND AND PURPOSE: Neuro-axonal damage is a well known sequelae of MS pathogeneses. Consequently, our aim was to test whether the approximately 20% of patients with MS exhibiting a clinically benign disease course also have minimal neural dysfunction as reflected by the global concentration of their MR imaging marker NAA. MATERIALS AND METHODS: Q(NAA) was obtained with nonlocalizing whole-head (1)H-MR spectroscopy in 43 patients with benign RRMS (30 women, 13 men; mean age, 44.7 +/- 7.3 years of age) with 21.0 +/- 4.4 years (range, 15-35 years) of disease duration from the first symptom and an EDSS score of 1.9 (range, 0-3). Q(NAA) was by divided by the brain volume (from MR imaging segmentation) to normalize it into WBNAA. All participants gave institutional review board-approved written informed consent, and the study was HIPAA compliant. RESULTS: The patients' lesion load was 12.2 +/- 7.7 cm(3). Their 8.3 +/- 1.8 mmol/L WBNAA was 35% lower than that in controls (P < .001). Individual average loss rates (absolute loss compared with controls divided by disease duration) clustered around 0.22 +/- 0.09 mmol/L/year (1.7%/year, assuming monotonic decline). This rate could be extrapolated from that already reported for patients with RRMS of much shorter disease duration. WBNAA did not correlate with lesion load or EDSS. CONCLUSIONS: Normal WBNAA is not characteristic of benign MS and is not an early predictor of its course. These patients, therefore, probably benefit from successful compensation and sparing of eloquent regions. Because they may ultimately have a rapid decline once their brain plasticity is exhausted, they may benefit from treatment options offered to more affected patients

PURPOSE: : To compare image quality and lesion detection in postcontrast liver magnetic resonance imaging (MRI) between volumetric interpolated breath-hold examination (VIBE) sequences that achieve fat suppression via chemically selective fat saturation (FS-VIBE) and a 2-point Dixon water-fat separation method (Dixon-VIBE). MATERIALS AND METHODS: : Thirty patients underwent contrast-enhanced liver MRI at 1.5 T in which Dixon-VIBE was performed immediately after a delayed FS-VIBE. Two radiologists in consensus reviewed the sequences for a variety of qualitative and quantitative image quality measures and for lesion detection. RESULTS: : Dixon-VIBE received nearly perfect scores for strength and homogeneity of fat suppression that were significantly better than scores for FS-VIBE, with an associated significant improvement in liver-fat contrast (P < 0.0001 for all comparisons). Dixon-VIBE also received significantly better scores for sharpness of intrahepatic vessels (P = 0.0029) and overall image quality (P < 0.0001). Despite a slightly longer acquisition time for Dixon-VIBE, there was no significant difference in motion artifact (P = 0.3877). There was no significant difference for sensitivity, positive predictive value, or contrast relative to background liver for focal lesions (P = 0.448, P = 0.347, and P = 0.2312, respectively). CONCLUSIONS: : For postcontrast liver MRI, Dixon-VIBE demonstrated significantly improved fat suppression. Various assessments of lesion detection showed no significant difference between sequences

High-resolution magnetic resonance imaging (MRI) of trabecular bone combined with quantitative image analysis represents a powerful technique to gain insight into trabecular bone micro-architectural derangements in osteoporosis and osteoarthritis. The increased signal-to-noise ratio of ultra high-field MR (>/=7 Tesla) permits images to be obtained with higher resolution and/or decreased scan time compared to scanning at 1.5/3T. In this small feasibility study, we show high measurement precision for subregional trabecular bone micro-architectural analysis performed on 7T knee MR images. The results provide further support for the use of trabecular bone measures as biomarkers in clinical studies of bone disorders

OBJECTIVES: To determine whether significant differences in cochlear implant (CI) performance exist between older and younger CI recipients. DESIGN: Retrospective comparison of audiometric data. SETTING: University hospital center. PARTICIPANTS: Sixty participants who received CIs at age 70 and older and 48 younger adults implanted between age 18 and 69. MEASUREMENTS: Speech outcome scores (Consonant-Nucleus-Consonant words and phonemes and City University of New York Sentence test in quiet and noise). RESULTS: Older participants show significant improvement in speech perception scores after implantation. Although on average they do not perform as well as younger adults, this difference correlates with duration of deafness rather than age. In contrast to younger adults, significant differences in CI performance are seen in older recipients depending on the side of implantation, with those implanted on the right performing better than those implanted on the left. CONCLUSION: Postlingually deafened older adults obtained significant speech perception benefits from CIs, although differences in speech outcomes were seen between younger recipients and those implanted after age 70. In older adults considering CIs, hearing benefits appear greater if they are implanted in the right ear

OBJECTIVE: Published cardiac CT angiography (CTA) reference measurements for the cardiac chambers, aorta, and pulmonary artery (PA) are incomplete and compromised by study population, coronary artery disease (CAD), or its risk factors. The purpose of our study was to establish sex-specific normalized ranges of cardiac chamber size, wall thickness, ejection fraction (EF), and aorta and PA diameter on cardiac CTA in a population without CAD or its risk factors. MATERIALS AND METHODS: Seventy-six patients (38 men and 38 women) without known diabetes; hypertension; smoking history; or evidence of structural heart, vascular, or coronary artery diseases underwent 64-MDCTA. Obtained left atrial (LA) size, left ventricular (LV) volumes, LV wall thickness, thoracic aorta, and PA diameter measurements were normalized to body surface area (BSA). RESULTS: There were statistically significant differences noted between men and women for all measured left-sided heart and great vessel measurements. After normalization to BSA, only chamber dimensions and ascending aorta and left PA sizes remained significantly different. Selected normalized measurements for men versus women, respectively, include LA area, 10.6 +/- 2.1 versus 12.3 +/- 2.1 cm(2)/m(2); LV end-diastolic size, 72.4 +/- 15.1 versus 60.9 +/- 13.3 mL/m(2); EF, 67% +/- 7% versus 72% +/- 8%; aortic sinus, 1.6 +/- 0.2 versus 1.7 +/- 0.2 cm/m(2); ascending aorta, 1.4 +/- 0.2 versus 1.6 +/- 0.2 cm/m(2); descending aorta, 1.1 +/- 0.1 versus 1.2 +/- 0.1 cm/m2; main PA, 1.3 +/- 0.1 versus 1.4 +/- 0.1 cm/m(2); right PA, 1.1 +/- 0.1 versus 1.1 +/- 0.2 cm/m(2); and left PA, 1.0 +/- 0.1 versus 1.1 +/- 0.1 cm/m(2). CONCLUSION: Cardiac CTA measurements of the left cardiac chambers, thoracic aorta, and pulmonary arteries were established for a population without CAD or its risk factors

OBJECTIVE: The purpose of this article is to correlate clinicopathologic and MRI parameters with the presence of microvascular invasion at histopathologic examination in patients with hepatocellular carcinoma (HCC) who are undergoing liver transplantation. MATERIALS AND METHODS: In this retrospective single-center study, we assessed 60 patients (47 men and 13 women; mean age, 58 years) with HCC who underwent liver transplantation and pretransplant MRI (performed within 90 days before liver transplantation). Two observers analyzed the following tumor parameters in consensus: number, size, T1 and T2 signal intensity, margins, presence of capsule or pseudocapsule, distance to closest vessel, distance to liver capsule, and quantitative tumor enhancement. The size and number of HCCs, tumor differentiation, and the presence or absence of microvascular invasion were determined at histopathologic examination. Odds ratios (ORs) were calculated and logistic regression analysis was performed to assess the utility of these clinicopathologic and imaging parameters for predicting microvascular invasion. RESULTS: None of the clinical parameters or morphologic and enhancement MRI features of HCC was predictive of microvascular invasion. Tumor multifocality, on both MRI and pathologic examination, was the only variable that predicted microvascular invasion (OR = 2.43 and p = 0.013 for MRI; OR = 1.94 and p = 0.013 for pathologic examination). The presence of three or more tumors on MRI and four or more tumors at pathologic examination had high specificity (88.2% and 91.2%, respectively) for the prediction of microvascular invasion. CONCLUSION: Tumor multifocality on MRI was the only parameter that correlated significantly with microvascular invasion. All other MRI tumor characteristics failed to predict microvascular invasion

OBJECTIVE: The purpose of this study was to assess the possible clinical significance of bladder urine T1 hyperintensity based upon comparison with urinalysis findings, using a cohort of patients who underwent prostate MRI and urinalysis at a similar point in time during preoperative work-up. METHODS: We identified 56 patients who underwent prostatectomy at our institution who obtained prostate MRI and urinalysis within 1 day of each other preoperatively. A control group of 160 consecutive adult men who underwent pelvic MRI during the same time period for other indications was also identified. Two radiologists independently and in consensus reviewed the T1-weighted images to assess the frequency of bladder urine T1 hyperintensity in both groups. The urinalyses in the 56 men undergoing prostatectomy were reviewed, with the results compared between patients with and without bladder urine T1 hyperintensity. RESULTS: Four (7.1%) of 56 men with prostate cancer exhibited T1 hyperintense bladder urine, compared with six (3.8%) of 160 patients exhibiting this finding in the control group (P=.288). Of the four prostate cancer patients with this finding, all exhibited a normal urinalysis. An abnormal urinalysis was identified for four of the prostate cancer patients, all of whom exhibited normal urine T1 signal intensity. CONCLUSION: Bladder urine T1 hyperintensity may be seen occasionally in patients with prostate cancer but is not associated with abnormal urinalysis and therefore should not be regarded as a sign of acute urinary pathology