Faculty Bibliography

Introduction: Coronary CTA is a reliable non-invasive imaging test for evaluating coronary artery disease (CAD). Obtaining diagnostic image quality (IQ) with low radiation exposure in patients with irregular heart rates such as atrial fibrillation, however, remains challenging. This study evaluated IQ and inter-reader variability using prospective ECGtriggered sequential dual-source data acquisition at end-systole (PROS-CT) for evaluation of CAD in patients with atrial fibrillation. Methods: 30 consecutive patients (22 men, mean age 64 years, mean BMI 29) with persistent atrial fibrillation who underwent PROS-CT for evaluation of pulmonary vein anatomy were identified from our cardiac CT patient registry. Images were reconstructed using standard protocols every 50ms from 250 to 400ms after the R wave trigger. Two independent, blinded readers evaluated the coronary arteries using an 18-segment model and all available reconstructions. IQ was graded on a 5-point Likert scale (worst to best) and coronary stenosis on 5-point semi-quantitative (none to severe) and binary scales (greater or less than 50%). In addition, overall IQ and diagnostic quality were graded for each reconstruction. Results: 11 patients (37%) had significant (>50% stenosis) CAD. The average heart rate was 82+/-20 bpm and the average heart rate variability (range) was 71+/-22 bpm. The mean effective radiation dose was 6.5+/-2.4 mSv and mean CTDIvol was 23.8+/-8.0 mGy. There were 304 coronary segments available for interpretation with mean IQ of 2.9+/-0.8. Diagnostic IQ was noted in 97.9% of segments, with 2 patients demonstrating at least 1 segment with non-diagnostic IQ. The 300ms reconstruction phase provided the highest IQ with 70% of patients demonstrating diagnostic IQ, but the combination of all phases (250-400ms) performed significantly better than single or other double and triple reconstruction phase combinations (p<0.0005 for all comparisons). Inter-reader variability for detection of stenosis was excellent, with 98.4% concordance using the binary scale with 50% stenosis cutoff, and 75.3% concordance using 5-point stenosis grade. Conclusions: PROS-CT with acquisition at end-systole provides good diagnostic image quality for evaluation of significant CAD in patients with atrial fibrillation. The use of multiple end-systolic phases over a 150ms window for each study improves diagnostic IQ

OBJECTIVE: Total renal volume and changes in kidney volume are markers of disease progression in autosomal-dominant polycystic kidney disease (ADPKD) but are not used in clinical practice in part because of the complexity of manual measurements. This study aims to assess the intra- and interobserver reproducibility of a semiautomated renal volumetric algorithm using fluid-sensitive MRI pulse sequences. SUBJECTS AND METHODS: Renal volumes of 17 patients with ADPKD were segmented from high-resolution coronal HASTE and true fast imaging with steady-state precession (FISP) MR acquisitions. Measurements performed independently by four readers were repeated, typically after 7 days. Intraobserver agreement indexes were calculated for total kidney volume for each patient. Interobserver agreement indexes were obtained for the six paired combinations of readers as well as for two readers after rigorous formalized training. Pearson and concordance correlation coefficients, coefficients of variation (CVs), and 95% limits of agreement were determined. RESULTS: The HASTE and true FISP sequences performed similarly with a median intraobserver agreement of greater than 98.1% and a CV of less than 2.4% across all readers. The median interobserver agreement was greater than 95.2% and the CV was less than 7.1%, across all reader pairs. Reader training further lowered interobserver CV. The mean total kidney volume was 1420 mL (range, 331-3782 mL) for HASTE imaging and 1445 mL (range, 301-3714 mL) for true FISP imaging, with mean image processing times per patient of 43 and 28 minutes, respectively. CONCLUSION: This semiautomated MR volumetric algorithm provided excellent intraobserver and very good interobserver reproducibility using fluid-sensitive pulse sequences that emphasize cyst conspicuity.

OBJECTIVE: The purpose of this study is to retrospectively compare 1D, 2D, and 3D measurements on CT for detection of growth of solid renal masses on active surveillance. MATERIALS AND METHODS: Forty solid renal masses measuring at least 1 cm in patients who underwent two CT studies at least 3 months apart were included. Two radiologists independently assessed the studies for interval growth using gestalt visual assessment and 1D, 2D, and 3D measurements. Prospective reports were also evaluated for indications of growth. The summation-of-areas technique was used to calculate volumes of lesions, which served as reference standard in determination of growth. Logistic regression analysis for correlated data was used to compare accuracy of methodologies for detection of lesion growth. Interreader agreement was assessed using kappa coefficients and intraclass correlation coefficients. RESULTS: The accuracy of gestalt visual, 1D, 2D, and 3D assessments for detection of interval growth was 72.5%, 70.0%, 82.5%, and 85% for reader 1 and 77.5%, 70.0%, 90.0%, and 95.0% for reader 2. These differences were significant or nearly significant (p = 0.003-0.054) for the greater accuracy of 2D or 3D measurements than for 1D measurements for reader 1 as well as the greater accuracy of 2D measurements than 1D measurements and 3D measurements than gestalt visual assessment or 1D measurements for reader 2. The accuracy of prospective reports for detection of growth was 65.0%. Reader agreement was fair for gestalt visual assessment (kappa = 0.31) and nearly perfect for 1D, 2D, and 3D measurements (intraclass correlation coefficient = 0.97-0.99). CONCLUSION: Our results show that 2D or 3D measurements may be preferable to 1D measurements on CT in assessment for growth of solid renal masses on active surveillance.

AIM: To evaluate safety and utility of coronary computed tomography angiography (CCTA) compared to invasive coronary angiography (ICA) in new cardiomyopathy. METHODS: Eighteen patients (mean age 56.5 years, 10 males) who presented for evaluation of new onset heart failure with evidence of systolic dysfunction (ejection fraction < 40%) on echocardiography and recent ICA were prospectively enrolled. Patients with known coronary artery disease, atrial fibrillation, creatinine > 1.5 g/dL, and contraindication to intravenous contrast administration were excluded. CCTA was performed using a dual source 64-slice scanner. Mean heart rate was 75 beats per minute. Stenosis was graded for each coronary segment as: none, mild (< 50%), moderate (50%-70%), severe (> 70%), or non-evaluable. Ischemic cardiomyopathy (ICM) was diagnosed if severe stenosis was present in the left main, proximal left anterior descending artery, or two or more major arteries. RESULTS: Two patients were diagnosed with ICM by ICA. CCTA correctly identified 2 patients with ICM and 16 patients as non-ICM. CCTA successfully evaluated 240/246 coronary segments with an accuracy of 97.5%, sensitivity 70%, specificity 98.7%, positive predictive value of 70%, and negative predictive value of 98.7% for identifying severe stenosis on a per-segment level. CONCLUSION: Dual source 64-slice multi-detector CCTA is a safe, accurate, and non-invasive technique for diagnosing ICM in patients presenting during the acute phase of newly diagnosed cardiomyopathy.

OBJECTIVE: The purpose of this study is to qualitatively and quantitatively assess MDCT urography performed with a high volume of low-concentration (240 mg I/mL) IV contrast agent supplemented with peroral hydration, IV furosemide, and IV saline. MATERIALS AND METHODS: This retrospective evaluation of 100 consecutive normal MDCT urograms was performed for clinical indication of hematuria; patients (76 men and 24 women) were 27-90 years old (mean [+/- SD] age, 60 +/- 15 years). Three radiologists evaluated the degree of opacification across six urinary tract segments (for a total of 1200 measurements per radiologist) on a 4-point scale (0-3). One radiologist measured the maximum short-axis diameter of the proximal, mid, and distal ureters in each patient. Mean opacification scores were calculated for each segment. Radiologist agreement was assessed by kappa coefficient and Spearman rank correlation. Ureteral diameter was correlated to degree of opacification using the Jonckheere-Terpstra trend test. A comparison with published studies using similar scoring methods was undertaken. RESULTS: Of 1200 measured ureteral segments, a total of 24 among the three radiologists were reported as nonopacified. The mean opacification scores ranged from 2.63 +/- 0.8 to 3.00 +/- 0.8. Calculated kappa coefficients are indicative of substantial agreement (> 0.61). The mean maximal ureteral diameters were 5.44 +/- 1.10, 6.32 +/- 1.54, and 5.32 +/- 1.55 mm for the proximal, mid, and distal ureters, respectively. For all three radiologists, the mean opacification scores increased as distention increased. The Spearman correlation and corresponding p value (p < 0.001) for the association between the distention with the opacification scores show significant correlation. The opacification scores and ureteral distention exceeded published results. CONCLUSION: An MDCT urography technique using high-volume low-concentration IV contrast, oral and IV hydration, and IV diuretic reliably optimizes urinary tract opacification and distention. A positive correlation was found between ureteral distention and opacification.

OBJECTIVE: The purpose of this study was to assess the performance of a near-isotropic 3D turbo spin-echo sequence in comparison with a standard 2D protocol and with arthroscopy in direct 1.5-T MR arthrography of the shoulder. SUBJECTS AND METHODS: Dilute gadolinium was injected into three cadaver shoulders, and 3D turbo spin-echo and 2D sequences were evaluated with respect to the signal-to-noise and contrast-to-noise ratios of key tissues. In a prospective study, the 3D intermediate-weighted fat-suppressed sequence (reformatted in three planes) was added to shoulder MR arthrography of 43 consecutively registered patients, 13 of whom later underwent arthroscopy. Two radiologists independently graded the 3D and 2D images in separate sessions to visualize normal anatomic features and to detect pathologic changes in the labrum, cartilage, cuff, and glenohumeral ligaments, assigning confidence levels to their readings. One reader repeated the readings of images of 10 patients. Reports of subsequent arthroscopy were available for 13 patients. RESULTS: The sequences performed comparably with respect to signal-to-noise and contrast-to-noise ratios in the cadavers. The 3D images suffered from mildly increased blurring, but the readers were significantly more confident in assessing the proximal biceps tendon and curved portions of the labrum and in their findings of partial tears of the articular side of the supraspinatus tendon and posterior labral tears on the 3D images. A larger number of partial-thickness cartilage defects were found on 2D images. CONCLUSION: The 3D turbo spin-echo sequence is a promising technique that can be used in shoulder arthrography with image quality and results comparable to those of traditional 2D techniques. Use of the 3D technique may result in greater anatomic detail in evaluating small obliquely oriented structures, including the curved portions of the labrum and the intraarticular portion of the biceps tendon.

OBJECTIVE: Sarcoidosis lesions revealed on MRI in the axial skeleton and long bones resemble osseous metastases, which can lead to a potentially significant misdiagnosis. We hypothesized that osseous sarcoidosis lesions could be differentiated from osseous metastases on MRI and sought to propose and evaluate features distinguishing these entities. MATERIALS AND METHODS: MR images obtained at 1.5 T of 34 subjects (22 with osseous metastatic disease, 12 with osseous sarcoidosis) with 79 single or multiple bone lesions (40 metastatic, 39 sarcoidal) were reviewed independently by two blinded, experienced musculoskeletal radiologists. Fluid-sensitive and T1-weighted images were viewed separately. Proposed discriminating features were peri- or intralesional fat, specified border characteristics, and the presence of an extraosseous soft-tissue mass. An additional feature for spinal lesions was posterior element involvement. On the basis of these criteria, the readers provided a binary diagnosis and confidence score. RESULTS: The overall sensitivity for both readers was 46.3% and specificity, 97.4%. T1-weighted images were associated with higher sensitivity than T2-weighted images (59.0% vs 34.1%, respectively; p = 0.025) and with comparable specificity (97.6% vs 97.2%, p = 0.91). Diagnostic accuracy was higher using the discriminators of a mass or posterior element involvement for metastasis (83.3%) than border characteristics (68.0%) or lesion fat (65.0%) for sarcoidosis; the latter two features provided near 100% specificity but poor sensitivity (14.3% and 0%, respectively). Readers reported higher confidence diagnosing osseous sarcoidosis lesions than metastatic lesions, with a trend for higher confidence with T1-weighted images (p = 0.088). CONCLUSION: Osseous sarcoidosis lesions cannot be reliably distinguished from metastatic lesions on routine MRI studies by readers experienced in evaluating these lesions.

OBJECTIVE:Clinical observations have suggested therapeutic effects for omega-3 fatty acids (O3FA) in Tourette's disorder (TD), but no randomized, controlled trials have been reported. In a placebo-controlled trial, we examined the efficacy of O3FA in children and adolescents with TD.METHODS:Thirty-three children and adolescents (ages 6-18) with TD were randomly assigned, double-blind, to O3FA or placebo for 20 weeks. O3FA consisted of combined eicosapentaenoic acid and docosahexaenoic acid. Placebo was olive oil. Groups were compared by using (1) intent-to-treat design, with the last-observation-carried-forward controlling for baseline measures and attention-deficit/hyperactivity disorder via (a) logistic regression, comparing percentage of responders on the primary Yale Global Tic Severity Scale (YGTSS)-Tic and secondary (YGTSS-Global and YGTSS-Impairment) outcome measures and (b) analysis of covariance; and (2) longitudinal mixed-effects models.RESULTS:At end point, subjects treated with O3FA did not have significantly higher response rates or lower mean scores on the YGTSS-Tic (53% vs 38%; 15.6 +/- 1.6 vs 17.1 +/- 1.6, P > .1). However, significantly more subjects on O3FA were considered responders on the YGTSS-Global measure (53% vs 31%, P = .05) and YGTSS-Impairment measure (59% vs 25%, P < .05), and mean YGTSS-Global scores were significantly lower in the O3FA-treated group than in the placebo group (31.7 +/- 2.9 vs 40.9 +/- 3.0, P = .04). Obsessive-compulsive, anxiety, and depressive symptoms were not significantly affected by O3FA. Longitudinal analysis did not yield group differences on any of the measures.CONCLUSIONS:O3FA did not reduce tic scores, but it may be beneficial in reduction of tic-related impairment for some children and adolescents with TD. Limitations include the small sample and the possible therapeutic effects of olive oil.

Abstract Background: Early identification of coronary artery disease (CAD) among symptomatic women is critical given their worse outcomes as compared to men. We evaluated the value of the Morise score, a simple clinical risk score, for the assessment for CAD as determined by computed tomography coronary angiography (CTCA) and compared it to the Diamond-Forrester risk assessment. Methods: One hundred forty women (mean age, 64+/-11 years) with chest pain syndromes and no known CAD referred for CTCA were analyzed. Patients were risk stratified for likelihood of CAD by Morise and Diamond-Forrester scores. The presence and degree of CAD were determined by CTCA and classified as normal, nonobstructive (<50% stenosis), or obstructive (>50% stenosis). Total coronary calcium was calculated based on Agatston scores. Results: When risk was assessed by Morise vs. Diamond-Forrester, 5% vs. 7% of women were stratified as low, 41% vs. 82% as intermediate, and 54% vs. 11% as high risk for CAD, respectively. CAD was present in 95 (68%) patients; 22 (16%) had obstructive CAD, and 73 (52%) had nonobstructive CAD. Morise scores significantly correlated with calcium scores (p<0.001) as well as the presence and degree of CAD (p<0.0001). Morise scores also demonstrated significantly higher accuracy (66% vs. 48%, p<0.005) and higher sensitivity (56% vs. 16%, p<0.001) but lower specificity (82% vs. 97%, p<0.05) when compared to Diamond-Forrester risk assessment. Conclusions: The Morise score performed better than Diamond-Forrester for CAD risk assessment, which highlights the importance and power of a simple history and physical examination in determining women at risk for CAD.

Purpose: To assess the feasibility of diffusional kurtosis (DK) imaging for distinguishing benign from malignant regions, as well as low- from high-grade malignant regions, within the peripheral zone (PZ) of the prostate in comparison with standard diffusion-weighted (DW) imaging. Materials and Methods: The institutional review board approved this retrospective HIPAA-compliant study and waived informed consent. Forty-seven patients with prostate cancer underwent 3-T magnetic resonance imaging by using a pelvic phased-array coil and DW imaging (maximum b value, 2000 sec/mm(2)). Parametric maps were obtained for apparent diffusion coefficient (ADC); the metric DK (K), which represents non-Gaussian diffusion behavior; and corrected diffusion (D) that accounts for this non-Gaussianity. Two radiologists reviewed these maps and measured ADC, D, and K in sextants positive for cancer at biopsy. Data were analyzed by using mixed-model analysis of variance and receiver operating characteristic curves. Results: Seventy sextants exhibited a Gleason score of 6; 51 exhibited a Gleason score of 7 or 8. K was significantly greater in cancerous sextants than in benign PZ (0.96 ± 0.24 vs 0.57 ± 0.07, P < .001), as well as in cancerous sextants with higher rather than lower Gleason score (1.05 ± 0.26 vs 0.89 ± 0.20, P < .001). K showed significantly greater sensitivity for differentiating cancerous sextants from benign PZ than ADC or D (93.3% vs 78.5% and 83.5%, respectively; P < .001), with equal specificity (95.7%, P > .99). K exhibited significantly greater sensitivity for differentiating sextants with low- and high-grade cancer than ADC or D (68.6% vs 51.0% and 49.0%, respectively; P ≤ .004) but with decreased specificity (70.0% vs 81.4% and 82.9%, respectively; P ≤ .023). K had significantly greater area under the curve for differentiating sextants with low- and high-grade cancer than ADC (0.70 vs 0.62, P = .010). Relative contrast between cancerous sextants and benign PZ was significantly greater for D or K than ADC (0.25 ± 0.14 and 0.24 ± 0.13, respectively, vs 0.18 ± 0.10; P < .001). Conclusion: Preliminary findings suggest increased value for DK imaging compared with standard DW imaging in prostate cancer assessment. Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112290/-/DC1