Faculty Bibliography

The original version of this article, published on 04 June 2018, unfortunately contained a mistake.

PURPOSE/OBJECTIVE:To correlate the histopathologic appearances of resected long head of the biceps tendon (LHBT) specimens following biceps tenodesis, with pre-operative MRI and arthroscopic findings, with attention to the radiologically normal biceps. MATERIAL AND METHODS/METHODS:Retrospective analysis of patients who had undergone preoperative MRI, subsequent arthroscopic subpectoral tenodesis for SLAP tears and histopathologic inspection of the excised sample between 2013 and 16. Those with a normal MRI appearance or mildly increased intrasubstance signal were independently analyzed by 2 blinded radiologists. A blinded orthopedic surgeon and pathologist reviewed all operative imaging and pathologic slides, respectively. RESULTS:Twenty-three LHBT resected samples were identified on MRI as either normal (Reader 1 n = 15; Reader 2 n = 14) or demonstrating low-grade increased signal (Reader 1 n = 8; Reader 2 n = 9). Of these, 86.9% demonstrated a histopathological abnormality. 50% of samples with histopathological abnormality demonstrated normal appearance on MRI. The most common reported histopathology finding was myxoid degeneration (73.9%) and fibrosis (52.2%). The most common arthroscopic abnormality was fraying (18.2%) and erythema (13.6%). Utilizing histopathology as the gold standard, the two radiologists demonstrated a sensitivity of 35.0% v 42.9%, specificity of 66.7% v 100%, PPV of 87.5% v 100%, and NPV of 13.3% v 14.3%. Corresponding arthroscopic inspection demonstrated a sensitivity of 31.6%, specificity of 66.6%, PPV 85.7% and NPV of 13.3%. There was moderate agreement between the two radiologists, κ = 0.534 (95% CI, 0.177 to 0.891), p = 0.01. CONCLUSION/CONCLUSIONS:Histopathological features of low grade tendinosis including mainly myxoid degeneration and fibrosis are frequently occult on MR imaging.

PURPOSE/OBJECTIVE:LAARx). EXPERIMENTAL DESIGN/METHODS:The CWR22PC xenograft and isogenic cell line were tested for drug interactions on tumor cell growth and androgen receptor (AR), AR-splice variant7 and AR targets. A phase I trial had a 3x3 panobinostat dose-escalation design. The phase II randomized 55 patients to panobinostat 40mg (A-arm) or 20mg (B-arm) triweekly x2 weeks with bicalutamide 50mg/day in 3-week cycles. The primary endpoint was percent of patients radiographic progression-free (rPF) at 36 weeks versus historical high-dose bicalutamide. RESULTS:In the model, panobinostat/bicalutamide demonstrated synergistic antitumor effect while reducing AR activity. The dose-limiting toxicity was not reached. The probability of remaining rPF exceeded protocol-specified 35% in the A- and B-arms (47.5%; 38.5%). The A-arm but not the B-arm exceeded expectations for times (medians) to rP (33.9 and 10 weeks), and from PSA progression to rP (24 and 5.9 weeks). A-arm/B-arm: adverse events (AEs), 62%/19%; treatment stopped for AEs, 27.5%/11.5%; dose reduction required, 41%/4%. Principal A-arm grade≥3 AEs: thrombocytopenia (31%), fatigue (14%). CONCLUSIONS:LAARx. Panobinostat toxicity was tolerable with dose reductions. Epigenetic HDACI therapy reduces AR-mediated resistance to bicalutamide in CRPC models with clinical benefit in patients. The combination merits validation using a second-generation antiandrogen.

PURPOSE/OBJECTIVE:Characterize the clinical utility of diagnostic shoulder imaging modalities commonly used in the outpatient workup of shoulder pain. MATERIALS/METHODS/METHODS:Retrospective review of adults imaged for outpatient shoulder pain from 1/1/2013 to 9/1/2015. To be categorized as "useful", a study had to meet one of the following criteria: change the clinical diagnosis or treatment plan, provide a final diagnosis, or guide definitive treatment. A utility score was assigned to each study based on the number of utility criteria met (range 0-4). A score of 1 was considered low utility; a score of greater than or equal to 2 was considered high utility. Statistical analysis included binary logistic regression and generalized estimating equations. RESULTS:210 subjects (65% male); mean age 47 (range 18-84), underwent 302 imaging studies (159 X-ray, 137 MRI, 2 CT, 4 ultrasound) during the study period. 92.1% of all studies met minimum criteria for utility (score >1). Most commonly, diagnostic studies obtained during the outpatient workup of shoulder pain were found to guide definitive treatment (70.5%) or provide a final diagnosis (53%). Most X-rays were categorized as no or low utility (85.5%). 97.8% of the MRI studies were categorized as useful with most being high utility (73%). Overall, MRI was the most useful modality in all clinical scenarios (P = 0.002) and more likely to be high utility (P < 0.001) compared to X-rays. None of the investigated patient or injury characteristics were significant predictors of useful imaging. CONCLUSION/CONCLUSIONS:Our study suggests that both radiographs and MRI are useful in the evaluation of adult unilateral shoulder pain in the outpatient setting. MRI appears to be the most useful imaging modality in terms of helping guide diagnosis and treatment selection. This serves as a potential first step towards the development of evidence based imaging algorithms that can be used and tested in future studies.

Although there is an increasing agreement that hypertension is associated with cerebrovascular compromise, relationships between blood pressure (BP) and cerebral blood flow are not fully understood. It is not known what BP level, and consequently what therapeutic goal, is optimal for brain perfusion. Moreover, there is limited data on how BP affects hippocampal perfusion, a structure critically involved in memory. We conducted a cross-sectional (n=445) and longitudinal (n=185) study of adults and elderly without dementia or clinically apparent stroke, who underwent clinical examination and brain perfusion assessment (age 69.2±7.5 years, 62% women, 45% hypertensive). Linear models were used to test baseline BP-blood flow relationship and to examine how changes in BP influence changes in perfusion. In the entire group, systolic BP (SBP) was negatively related to cortical (β=-0.13, P=0.005) and hippocampal blood flow (β=-0.12, P=0.01). Notably, this negative relationship was apparent already in subjects without hypertension. Hypertensive subjects showed a quadratic relationship between SBP and hippocampal blood flow (β=-1.55, P=0.03): Perfusion was the highest in subjects with mid-range SBP around 125 mm Hg. Longitudinally, in hypertensive subjects perfusion increased with increased SBP at low baseline SBP but increased with decreased SBP at high baseline SBP. Cortical and hippocampal perfusion decrease with increasing SBP across the entire BP spectrum. However, in hypertension, there seems to be a window of mid-range SBP which maximizes perfusion.

PURPOSE/OBJECTIVE:To investigate how breast parenchymal uptake (BPU) of 18F-FDG on positron emission tomography/ magnetic resonance imaging (PET/MRI) in patients with breast cancer is related to background parenchymal enhancement (BPE), amount of fibroglandular tissue (FGT), and age, as well as whether BPU varies as a function of distance from the primary breast cancer. MATERIALS AND METHODS/METHODS:volume of interest 1) in the same quadrant of the ipsilateral breast, 5 mm from the index lesion; 2) in the opposite quadrant of the ipsilateral breast; and 3) in contralateral breast, quadrant matched to the opposite quadrant of the ipsilateral breast. The maximum standardized uptake value (SUVmax) of the index cancer was measured using a VOI that included the entire volume of the index lesion. Bleed from the primary tumor was corrected for (PET edge, MIM). FGT and BPE was assessed by 2 readers on a 4-point scale in accordance with BI-RADS lexicon. The Wilcoxon signed rank test and the Spearman rank correlation test were performed. RESULTS:BPU was significantly greater in the same quadrant as the breast cancer as compared with the opposite quadrant of the same breast (p < 0.001 for both readers) and was significantly greater in the opposite quadrant of the same breast compared to the matched quadrant of the contralateral breast (p = 0.002 for reader 1 and <0.001 for reader 2). While the FGT SUVmax in the same quadrant as the cancer correlated significantly with SUVmax of the index lesion, the FGT SUVmax in the opposite quadrant of the same breast and in the matched quadrant of the contralateral breast did not. The FGT SUVmax in the contralateral breast positively correlated with the degree of BPE and negatively correlated with age, but did not show a significant correlation with the amount of FGT for either reader. CONCLUSION/CONCLUSIONS:There appears to be an inverse correlation between metabolic activity of normal breast parenchyma and distance from the index cancer. BPU significantly correlates with BPE.

Purpose: To assess the diagnostic performance of qualitative features and radiomics texture features for the prediction of histopathology and clinical outcomes of intrahepatic cholangiocarcinoma (ICC).
Material(s) and Method(s): Seventy-four patients (27 M/47 F, mean age 62.8 years) with 74 ICCs with pre-operative computed tomog-raphy (CT, n = 37) and/or magnetic resonance imaging (MRI, n = 52) within 6 months of resection were included in this retrospective study. Qualitative tumor features were assessed. Haralick texture features were computed. Clinicopathologic data and imaging features were compared with tumor grade, AJCC stage, and time to recurrence (TTR) using the log-rank test, Cox proportional hazards regression and logistic regression analysis.
Result(s): Median TTR was 21.4 months (range, 28-4177 days). ICC recurred in 45 patients (60.8%). For two readers, the presence of satellite lesions (CT: p = 0.013; HR 2.51 [1.21-5.17]; p = 0.001, HR 3.39 [1.61-7.12]; MRI: p = 0.003, HR 6.60 [1.95-22.41], p = 0.023, HR 4.73 [1.24-18.09]) and macrovascular invasion (CT: p = 0.024, HR 2.25 [1.11-4.54]; p = 0.047, HR 2.01 [1.01-4.01]; MRI: p = 0.001, HR 5.63 [1.96-16.16]; p = 0.001, HR 9.23 [2.64-32.28]) were predictive of TTR. Several CT and MRI texture features, including MRI difference variance (p = 0.038, HR > 10⁵ [1.82-> 10]) and MRI difference entropy (p = 0.015, HR 80.92 [2.36-2779.55]), were strong predictors of TTR. Serum CA 19-9 (p = 0.002, HR 2.84 [1.47-5.49]), metastatic lymph nodes (p = 0.005, HR 2.51 [1.32-4.77]), and AJCC stage (p = 0.004, HR 1.45 [1.13-1.87]) were predictive of TTR. No combination of clinical or imaging variables was predictive of tumor grade.
Conclusion(s): Imaging features including radiomics parameters are strong predictors of TTR in ICC, compared to AJCC stage and serum CA 19-9

BACKGROUND AND PURPOSE/OBJECTIVE:High-resolution T2-weighted sequences are frequently used in magnetic resonance imaging (MRI) studies to assess the cerebellopontine angle and internal auditory canal (IAC) in sensorineural hearing loss patients but have low yield and lengthened examinations. Because image content in the Wavelet domain is sparse, compressed sensing (CS) that uses incoherent undersampling of k-space and iterative reconstruction can accelerate MRI acquisitions. We hypothesized that an accelerated CS T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution (SPACE) sequence would produce acceptable diagnostic quality for IAC screening protocols. MATERIAL AND METHODS/METHODS:Seventy-six patients underwent 3 T MRI using conventional SPACE and a CS T2 SPACE prototype sequence for screening the IACs were identified retrospectively. Unilateral reconstructions for each sequence were separated, then placed into mixed folders for independent, blinded review by 3 neuroradiologists during 2 sessions 4 weeks apart. Radiologists reported if a lesion was present. Motion and visualization of specific structures were rated using ordinal scales. McNemar, Wilcoxon, Cohen κ, and Mann-Whitney U tests were performed for accuracy, equivalence, and interrater and intrarater reliability. RESULTS:T2 SPACE using CS reconstruction reduced scan time by 80% to 50 seconds and provided 98.7% accuracy for IAC mass detection by 3 raters. Radiologists preferred conventional images (0.7-1.0 reduction on 5-point scale, P < 0.001), but rated CS SPACE acceptable. The 95% confidence for reduction in any cerebellopontine angle, IAC, or fluid-filled inner ear structure assessment with CS SPACE did not exceed 0.5. CONCLUSIONS:Internal auditory canal screening MRI protocols can be performed using a 5-fold accelerated T2 SPACE sequence with compressed sensing while preserving diagnostic image quality and acceptable lesion detection rate.

OBJECTIVES/OBJECTIVE:F-FDG uptake on whole-body PET-CT with MR findings and compare the degree of FDG activity between symptomatic and asymptomatic knees. MATERIALS AND METHODS/METHODS:Retrospective database query was performed using codes for knee MRI as well as whole-body PET-CT. Patients with malignant disease involving the knee or hardware were excluded. Patients who had both studies performed within 1 year between 2012 and 2017 were included for analysis. Knee joint osteoarthrosis, meniscal and ligamentous integrity, presence of joint effusion, and synovitis were assessed and recorded. Bone marrow edema lesions (BMELs) were identified, segmented, and analyzed using volumetric analysis. SUVmax was assessed over the suprapatellar joint space, intercondylar notch and Hoffa's fat pad. Symptomatic and asymptomatic knees were compared in patients with unilateral symptoms. RESULTS:Twenty-two cases (20 patients) with mean age 63.3 years (range, 36-91 years) were included. Two patients had bilateral pain. The most FDG avid regions in both symptomatic and asymptomatic knees were the intercondylar notch (SUVmax = 1.84 vs. 1.51), followed by suprapatellar pouch (SUVmax = 1.74 vs. 1.29) and Hoffa's fat pad (SUVmax = 1.01 vs. 0.87). SUVmax was significantly associated with cartilage loss (mean modified Outerbridge score) (r = 0.60, p = 0.003) and degree of synovitis (r = 0.48, p = 0023). Overall, mean SUVmax was significantly higher in the presence of a meniscal tear (1.83 ± 0.67 vs. 1.22 ± 0.40, p = 0.030). Nine patients had BMELs (volume: range = 0.6-27.8, mean = 7.79) however there was no significant association between BMEL volume and SUVmax. CONCLUSIONS:Higher FDG activity correlates with intra-articular derangement and the intercondylar notch represents the most metabolically active region of the knee.

INTRODUCTION/BACKGROUND:Dermatomyositis (DM) is an idiopathic inflammatory myopathy involving severe debilitation in need of diagnostics. We evaluated the proximal lower extremity musculature with diffusion tensor imaging (DTI), intravoxel incoherent motion (IVIM) and dynamic DTI in DM patients and controls and compared with standard clinical workup.  METHODS: In this IRB-approved, HIPAA-compliant study with written informed consent, anatomical, Dixon fat/water and diffusion imaging were collected in bilateral thigh MRI of 22 controls and 27 DM patients in a 3T scanner. Compartments were scored on T1/T2 scales. Single voxel dynamic DTI metrics in quadriceps before and after 3-min leg exercise were measured. Spearman rank correlation and mixed model analysis of variance/covariance (ANOVA/ANCOVA) were used to correlate with T1 and T2 scores and to compare patients with controls. RESULTS:DM patients showed significantly lower pseudo-diffusion and volume in quadriceps than controls. All subjects showed significant correlation between T1 score and signal-weighted fat fraction; tissue diffusion and pseudo-diffusion varied significantly with T1 and T2 score in patients. Radial and mean diffusion exercise response in patients was significantly higher than controls. CONCLUSION/CONCLUSIONS:Static and dynamic diffusion imaging metrics show correlation with conventional imaging scores, reveal spatial heterogeneity, and provide means to differentiate dermatomyositis patients from controls. KEY POINTS/CONCLUSIONS:• Diffusion imaging shows regional differences between thigh muscles of dermatomyositis patients and controls. • Signal-weighted fat fraction and diffusion metrics correlate with T1/T2 scores of disease severity. • Dermatomyositis patients show significantly higher radial diffusion exercise response than controls.