Hepatocellular carcinoma in patients cured of chronic hepatitis C: Minimal steatosis.

BACKGROUND: Successful treatment of hepatitis C reduces liver inflammation and fibrosis; however, patients remain at risk of developing hepatocellular carcinoma (HCC). AIMS: To identify risk factors for new-onset HCC in patients cured of hepatitis C. METHODS: Imaging, histological, and clinical data on patients whose first HCC was diagnosed >12 months of post-SVR were analyzed. Histology of 20 nontumor tissues was analyzed in a blinded manner using the Knodel/Ishak/HAI system for necroinflammation and fibrosis/cirrhosis stage and the Brunt system for steatosis/steatohepatitis. Factors associated with post-SVR HCC were identified by comparison with HALT-C participants who did not develop post-SVR HCC. RESULTS: Hepatocellular carcinoma was diagnosed in 54 patients (45 M/9F), a median of 6 years of post-SVR [interquartile range (IQR) =1.4-10y] at a median age of 61 years (IQR, 59-67). Approximately one-third lacked cirrhosis, and only 11% had steatosis on imaging. The majority (60%) had no steatosis/steatohepatitis in histopathology. The median HAI score was 3 (1.25-4), indicating mild necroinflammation. In a multivariable logistic regression model, post-SVR HCC was positively associated with non-Caucasian race (p = 0.03), smoking (p = 0.03), age > 60 years at HCC diagnosis (p = 0.03), albumin<3.5 g/dL (p = 0.02), AST/ALT>1 (p = 0.05), and platelets <100 × 103 cells/µL (p < 0.001). Alpha fetoprotein ≥4.75 ng/mL had 90% specificity and 71% sensitivity for HCC occurrence. Noncirrhotic patients had larger tumors (p = 0.002) and a higher prevalence of vascular invasion (p = 0.016) than cirrhotic patients. CONCLUSIONS: One-third of patients with post-SVR HCC did not have liver cirrhosis; most had no steatosis/steatohepatitis. Hepatocellular carcinomas were more advanced in noncirrhotic patients. Results support AFP as a promising marker of post-SVR HCC risk.

Vibration Controlled Transient Elastography to Evaluate Steatosis in Candidate Living Donors for Liver Transplantation.

BACKGROUND: The ability of vibration controlled transient elastography (VCTE) to reliably exclude significant steatosis in living donor candidates could obviate the need for invasive liver biopsies, expedite the donor approval process, and reduce recipient wait time. We therefore aimed to determine whether VCTE controlled attenuation parameter (CAP) could be used to detect steatosis in potential living donors. METHODS: Living donor candidates who presented for evaluation between 2016 and 2019 underwent standard donor workup, VCTE, and liver biopsy if indicated. CAP scores were compared with MRI-Fat Fraction and, when available, histologic fat fraction from liver biopsy. Receiver operating characteristic curves were used to identify cutoffs with appropriate sensitivity and specificity for screening. Statistical analysis was conducted using R (version 3.6.0). RESULTS: Seventy-nine candidate living donors presented during the study period, of whom 71 were included in the final analysis and of whom 20 underwent liver biopsy. There was a positive correlation between MRI-Fat Fraction and CAP scores with an observed Spearman correlation coefficient of 0.424 ( P < 0.01). A CAP score of 271.5 dB/m or less was determined to have 89.8% sensitivity and 75% specificity for detecting <5% steatosis on MRI. The correlation between CAP and steatosis of available histologic samples had a Pearson correlation coefficient of 0.603 ( P = 0.005). A CAP cutoff of 276.0 dB/m demonstrated 66.7% sensitivity and 85.7% specificity for detecting <15% histopathologic steatosis and positive and negative predictive values of 71.5% and 82.7%, respectively. CONCLUSIONS: VCTE can be integrated into living donor evaluation to accurately screen for hepatic steatosis.

Impact of mandated prospectively reported apparent diffusion coefficient values on the rates of positivity for clinically significant prostate cancer by PI-RADS score.

BACKGROUND: Prior research has shown that retrospectively measured apparent diffusion coefficient (ADC) of prostate magnetic resonance imaging (MRI) lesions is associated with clinically significant prostate cancer (csPCa) on targeted biopsy suggesting that ADC should be measured and reported prospectively. PURPOSE: To assess the impact of mandatory prospective measurement of ADC on the rates of positivity across PI-RADS scores for csPCa. MATERIAL AND METHODS: Consecutive patients who underwent ultrasound (US)-MRI fusion prostate biopsy from August 2018 to July 2019 and who had prospectively reported ADC were compared to control patients who did not. Rates of positivity by PI-RADS category were computed and compared using Chi-square. Multivariable regression was performed. RESULTS: In total, 126 patients (median age 65 years) with 165 prostate lesions (19, 51, 70, and 25 PI-RADS 2, 3, 4, and 5, respectively) and prospectively reported ADC values were compared to 113 control patients (median age 66 years) with 157 prostate lesions (17, 42, 64, and 34 PI-RADS 2, 3, 4, and 5, respectively). Rates of positivity across PI-RADS scores were similar between the two cohorts; 11%, 25%, 55%, and 76% and 0%, 21%, 56%, and 62% for PI-RADS 2, 3, 4, and 5 in the test and control cohorts, respectively (Chi-square P = 0.78). Multivariate logistic regression showed no significant association between the presence of prospectively measured ADC and csPCa (odds ratio 1.1, 95% confidence interval 0.7-1.7, P = 0.82). CONCLUSION: Prospective ADC measurement may not impact PI-RADS category assignments or positivity rates for csPCa under current guidelines. Future versions of PI-RADS may need to incorporate ADC into scoring rules to realize their potential.

Radiomics of MRI for pretreatment prediction of pathologic complete response, tumor regression grade, and neoadjuvant rectal score in patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation: an international multicenter study.

OBJECTIVE: To investigate whether pretreatment MRI-based radiomics of locally advanced rectal cancer (LARC) and/or the surrounding mesorectal compartment (MC) can predict pathologic complete response (pCR), neoadjuvant rectal (NAR) score, and tumor regression grade (TRG). METHODS: One hundred thirty-two consecutive patients with LARC who underwent neoadjuvant chemoradiation and total mesorectal excision (TME) were retrospectively collected from 2 centers in the USA and Italy. The primary tumor and surrounding MC were segmented on the best available T2-weighted sequence (axial, coronal, or sagittal). Three thousand one hundred ninety radiomic features were extracted using a python package. The most salient radiomic features as well as MRI parameter and clinical-based features were selected using recursive feature elimination. A logistic regression classifier was built to distinguish between any 2 binned categories in the considered endpoints: pCR, NAR, and TRG. Repeated k-fold validation was performed and AUCs calculated. RESULTS: There were 24, 87, and 21 T4, T3, and T2 LARCs, respectively (median age 63 years, 32 to 86). For NAR and TRG, the best classification performance was obtained using both the tumor and MC segmentations. The AUCs for classifying NAR 0 versus 2, pCR, and TRG 0/1 versus 2/3 were 0.66 (95% CI, 0.60-0.71), 0.80 (95% CI, 0.74-0.85), and 0.80 (95% CI, 0.77-0.82), respectively. CONCLUSION: Radiomics of pretreatment MRIs can predict pCR, TRG, and NAR score in patients with LARC undergoing neoadjuvant treatment and TME with moderate accuracy despite extremely heterogenous image data. Both the tumor and MC contain important prognostic information. KEY POINTS: • Machine learning of rectal cancer on images from the pretreatment MRI can predict important patient outcomes with moderate accuracy. • The tumor and the tissue around it both contain important prognostic information.

Student-Authored Autopsy Reports of Anatomical Donors: Their First Patients.

The preparation of student-authored autopsy reports of anatomical donors was added to the Gross Anatomy course to integrate the basic and clinical sciences and determine whether students considered this early clinical exposure to be a valuable experience. All donors were scanned using computerized tomography (CT) and student groups received the scan of their donor and a report written by a radiologist. As students dissected, they took photographs and biopsies of pathological findings that were processed for microscopic evaluation. Following consultation with pathologists and radiologists, each group prepared an autopsy report that proposed a cause of death supported with macroscopic, microscopic, and CT images. Cardiovascular events and cancer were the most common. Autopsy reports were evaluated by the faculty and each student group received feedback with respect to content, accuracy, and completeness and whether faculty agreed with students' proposed cause of death. A majority of students answering an anonymous survey indicated that this exercise was valuable or somewhat valuable, but did not agree that preparation of the autopsy report resulted in their being more engaged during the course. Students agreed or somewhat agreed that the exercise should be repeated next year, that they gained insight into the clinical manifestations of disease, that they were able to interpret the CT scan themselves, that meeting with a pathologist was interesting, and that the time required to prepare the report was adequate. Since autopsy reports prepared by students are feasible and students found it to be a valuable experience, we suggest that medical schools add this to Gross Anatomy courses to introduce clinical material and increase clinical relevance.

A Multidisciplinary Head-to-Head Comparison of American College of Radiology Thyroid Imaging and Reporting Data System and American Thyroid Association Ultrasound Risk Stratification Systems.

BACKGROUND: Ultrasound plays a critical role in evaluating thyroid nodules. We compared the performance of the two most popular ultrasound malignancy risk stratification systems, the 2015 American Thyroid Association (ATA) guidelines and the American College of Radiology Thyroid Imaging and Reporting Data System (ACR TI-RADS). MATERIALS AND METHODS: We retrospectively identified 250 thyroid nodules that were surgically removed from 137 patients. Their ultrasound images were independently rated using both ATA and ACR TI-RADS by six raters with expertise in ultrasound interpretation. For each system, we generated a receiver operating characteristic curve and calculated the area under the curve (AUC). RESULTS: Sixty-five (26%) nodules were malignant. There was "fair agreement" among raters for both ATA and ACR TI-RADS. Our observed malignancy risks for ATA and ACR TI-RADS categories were similar to expected risk thresholds with a few notable exceptions including the intermediate ATA risk category and the three highest risk categories for ACR TI-RADS. Biopsy of 226 of the 250 nodules would be indicated by ATA guidelines based on nodule size and mean ATA rating. One hundred forty-six nodules would be biopsied based on ACR TI-RADS. The sensitivity, specificity, and negative and positive predictive values were 92%, 10%, 79%, and 27%, respectively, for ATA and 74%, 47%, 84%, and 33%, respectively, for ACR TI-RADS. The AUC for ATA was 0.734 and for ACR TI-RADS was 0.718. CONCLUSION: Although both systems demonstrated good diagnostic performance, ATA guidelines resulted in a greater number of thyroid biopsies and exhibited more consistent malignancy risk prediction for higher risk categories. IMPLICATIONS FOR PRACTICE: With the rising incidence of thyroid nodules, the need for accurate detection of malignancy is important to avoid the overtreatment of benign nodules. Ultrasonography is one of the key tools for the evaluation of thyroid nodules, although the use of many different ultrasound risk stratification systems is a hindrance to clinical collaboration in everyday practice and the comparison of data in research. The first step toward the development of a universal thyroid nodule ultrasound malignancy risk stratification system is to better understand the strengths and weaknesses of the current systems in use.

Validation of Liver Imaging Reporting and Data System 2017 (LI-RADS) Criteria for Imaging Diagnosis of Hepatocellular Carcinoma.

BACKGROUND: The Liver Imaging Reporting and Data System (LI-RADS) is being adapted by many clinical practices. To support continuation of its use, LI-RADS (LR) is in need of multicenter validation studies of recent LI-RADS iterations. Furthermore, while both gadoxetate and extracellular agents have been incorporated into LI-RADS, comparison of the diagnostic performance between the two has yet to be determined. PURPOSE/HYPOTHESIS: To evaluate the rate, diagnostic performance, and interreader reliability (IRR) of LI-RADS 2017 for hepatocellular carcinoma, including LR major and ancillary features, with both gadoxetate and extracellular agent-enhanced MRI against a reference standard of histopathology or imaging follow-up. STUDY TYPE: Retrospective. POPULATION: In all, 114 patients with 144 observations were included who met LR 2017 criteria for at risk and had at least one hepatic observation on liver MRI performed with either gadoxetate (n = 52) or an extracellular agent (n = 92) between 2010-2016, with histopathology (n = 103) or follow-up imaging (n = 41). FIELD STRENGTH/SEQUENCE: 1.5 and 3.0T/T1 -T2 WI, diffusion-weighted imaging. ASSESSMENT: Three radiologists independently assessed major/ancillary features and assigned overall LI-RADS category for every observation. STATISTICAL TESTS: Diagnostic performance of LR5/TIV+LR5 for identifying hepatocellular carcinoma (HCC) was compared between contrast agents with a generalized estimating equation. Weighted kappa was performed for interrater reliability. RESULTS: The frequency of HCCs among LR1, LR2, LR3, L4, LR5, LRTIV+LR5, and LRM observations were: 0% (all readers), 0-12.5%, 11.4-26.9%, 50-76%, 83.0-95.1%, 83.3-100.0%, and 45.0-65.0%, respectively. Sensitivity of LR5/LRTIV+LR5 for HCC was 59.7-71.4% and specificity 85.0-96.8%. LI-RADS specificity and positive predictive value for observations imaged with gadoxetate was higher than extracellular agent for the most inexperienced reader (R3) (P = 0.009-0.034). IRR for LI-RADS categorization was substantial (k = 0.661). DATA CONCLUSION: Increasing numerical LI-RADS 2017 categories demonstrate a greater percentage of HCCs. LR5/TIV+LR5 demonstrates excellent specificity and fair sensitivity for HCC. MRI with gadoxetate in liver transplant candidates may be beneficial for less experienced readers, although further large-scale prospective studies are needed. LEVEL OF EVIDENCE: 4 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2019;49:e205-e215.

Prediction of Lymph Node Maximum Standardized Uptake Value in Patients With Cancer Using a 3D Convolutional Neural Network: A Proof-of-Concept Study.

OBJECTIVE: The purpose of this study is to determine whether a convolutional neural network (CNN) can predict the maximum standardized uptake value (SUVmax) of lymph nodes in patients with cancer using the unenhanced CT images from a PET/CT examination, thus providing a proof of concept for potentially using deep learning to diagnose nodal involvement. MATERIALS AND METHODS: Consecutive initial staging PET/CT scans obtained in 2017 for patients with pathologically proven malignancy were collected. Two blinded radiologists selected one to 10 lymph nodes from the unenhanced CT portion of each PET/CT examination. The SUVmax of the lymph nodes was recorded. Lymph nodes were cropped and used with the primary tumor histology type as input for a novel 3D CNN with predicted SUVmax as the output. The CNN was trained using one cohort and tested using a separate cohort. An SUVmax of 2.5 or greater was defined as FDG avid. Two blinded radiologists separately classified lymph nodes as FDG avid or not FDG avid on the basis of unenhanced CT images and separately using a short-axis measurement cutoff of 1 cm. Logistic regression analysis was performed. RESULTS: A total of 400 lymph nodes (median SUVmax, 6.8 [interquartile range {IQR}, 2.7-11.6]; median short-axis, 1.1 cm [IQR, 0.9-1.6 cm]) in 136 patients were used for training. A total of 164 lymph nodes (median SUVmax, 3.5 [IQR, 1.9-8.6]; median short-axis, 1.0 cm [IQR, 0.7-1.4 cm]) in 49 patients were used for testing. The predicted SUVmax was associated with the real SUVmax (ß estimate = 0.83, p < 0.0001). The predicted SUVmax was associated with FDG avidity (p < 0.0001), with an ROC AUC value of 0.85, and it improved when combined with radiologist qualitative assessment and short-axis criteria. CONCLUSION: A CNN is able to predict with moderate accuracy the SUVmax of lymph nodes, as determined from the unenhanced CT images and tumor histology subtype for patients with cancer.

Improving Emergency Department Flow: Reducing Turnaround Time for Emergent CT Scans.

Emergency departments across the U.S. are more congested than ever, and there is a pressing need to create capacity by improving patient flow. The long turnaround time of imaging tests, such as computed tomography (CT) scans, are a major reason for delays in treatment and disposition. Over an eight-month pre-intervention period during which 10,063 CT scans were ordered in our emergency department, the average time from a CT order to the availability of the radiologist's final report was 5.9 hours (median=4.2 hours). We created a multi-disciplinary team of physicians, nurses, technicians, transporters, informaticians, and engineers to identify barriers and implement technical as well as human-factors solutions. In the corresponding eight-month period after the implementation of the intervention bundle, there was a 1.2 hour reduction in CT turnaround time, despite a 13.8% increase in the number of CT scans ordered (p<0.0001).

Imaging of Hepatocellular Carcinoma Response After 90Y Radioembolization.

OBJECTIVE: The purpose of this study is to discuss the imaging modalities and response criteria used for assessing hepatocellular carcinoma (HCC) response to 90Y radioembolization, as well as the imaging appearances of treated tumors. CONCLUSION: An understanding of the appearance of HCC after 90Y radioembolization is crucial for accurate evaluation of treatment response. Residual tumor necrosis and enhancement are essential for assessing response. Multiparametric MRI, including DWI and perfusion imaging, plays an emerging role in response assessment and outcome prediction.

FDG PET with contrast-enhanced CT: a critical imaging tool for laryngeal carcinoma.

Fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) has evolved to be an essential imaging modality in the evaluation of laryngeal carcinoma. Although the modality has limited utility in assessing the extent of the primary tumor, FDG PET has proved to be superior to anatomic modalities in the detection of lymph node and distant metastases. The role of FDG PET in the evaluation of patients with laryngeal tumors that are clinically classified as N0 has not shown consistent usefulness because of the innate resolution limitations of the camera. In the posttherapy setting, however, FDG PET has consistently demonstrated a high negative predictive value in the identification of recurrent disease, both during the course of therapy and during long-term follow-up. In addition, contrast material-enhanced computed tomography (CT) in conjunction with FDG PET has demonstrated a complementary role by allowing for superior anatomic coregistration and therefore more definitive diagnosis. There is sufficient evidence that with further advances in PET technology, this modality will likely become more useful in the detection of small lesions and occult nodal disease, as well as in guiding the management of laryngeal carcinoma.