Current Imaging Techniques for Noninvasive Staging of Hepatic Fibrosis.

OBJECTIVE. The purpose of this article is to discuss quantitative methods of CT, MRI, and ultrasound (US) for noninvasive staging of hepatic fibrosis. Hepatic fibrosis is the hallmark of chronic liver disease (CLD), and staging by random liver biopsy is invasive and prone to sampling errors and subjectivity. Several noninvasive quantitative imaging methods are under development or in clinical use. The accuracy, precision, technical aspects, advantages, and disadvantages of each method are discussed. CONCLUSION. The most promising methods are the liver surface nodularity score using CT and measurement of liver stiffness using MR elastography or US elastography.

Outcomes and complications related to the management of Bosniak cystic renal lesions.

OBJECTIVE: The objective of our study was to evaluate outcomes and complications related to the management of Bosniak category IIF, III, and IV renal cysts. MATERIALS AND METHODS: For this multiinstitutional retrospective study, a Web-based Research Electronic Data Capture (REDCap) data registry was used to record data of 286 adult patients with 312 prospectively classified Bosniak IIF, III, and IV renal cysts diagnosed between January 2000 and October 2011. Included patients were managed by surgery (n = 86), percutaneous ablation (n = 19), or imaging surveillance of 1 year or more (n = 181). The median number of years of clinical surveillance was 2.4 years (range, 0-11.7 years), 2.6 years (range, 0.4-11.4 years), and 3.2 years (range, 1.1-11.6 years) for patients managed by surgery, ablation, and imaging surveillance, respectively. Pathologic and survival outcomes and complications related to management were evaluated. RESULTS: The malignancy rate at surgical pathology was 38% (3/8) for Bosniak IIF, 40% (29/72) for Bosniak III, and 90% (18/20) for Bosniak IV renal cysts. There were no metastases or deaths (0/144) directly related to Bosniak IIF renal cysts. There were no deaths (0/113) directly related to Bosniak III renal cysts, although one patient (1/113) developed local progression and lung metastases after thermal ablation. One patient with a Bosniak IV renal cyst (1/29) presented with and died of metastatic disease. Moderate to severe complications occurred in 19% (16/86), 5% (1/19), and 0% (0/181) of patients managed by surgery, ablation, and imaging surveillance, respectively (p < 0.0001). Severe complications occurred in 7% (6/86) of surgical patients and included multiorgan failure (n = 2), acute myocardial infarction (n = 1), acute ischemic stroke (n = 1), conversion to hemodialysis-dependent chronic kidney disease (n = 1), and postoperative severe hemorrhage (n = 1). CONCLUSION: There were no deaths from Bosniak IIF or III renal cysts regardless of management approach. Moderate to severe complications are frequent in patients managed by surgery.

Locally advanced squamous cell carcinoma of the head and neck: CT texture and histogram analysis allow independent prediction of overall survival in patients treated with induction chemotherapy.

PURPOSE: To determine if computed tomographic (CT) texture and histogram analysis measurements of the primary mass are independently associated with overall survival in patients with locally advanced squamous cell carcinoma of the head and neck who were previously treated with cisplatin, 5-fluorouracil, and docetaxel (TPF) induction chemotherapy. MATERIALS AND METHODS: This institutional review board-approved retrospective study included 72 patients with locally advanced squamous cell carcinoma of the head and neck who were treated with induction TPF chemotherapy in 2004-2010. CT texture and histogram analysis of the primary mass on the pretherapy CT images were performed by using TexRAD software before and after application of spatial filters at different anatomic scales ranging from fine detail to coarse features. Cox proportional hazards models were used to examine the association between overall survival and the baseline CT imaging measurements and clinical variables. RESULTS: Primary mass entropy and skewness measurements with multiple spatial filters were associated with overall survival. Multivariate Cox regression analysis incorporating clinical and imaging variables indicated that primary mass size (hazard ratio [HR], 1.58 for each 1-cm increase; P = .018), N stage (HR, 8.77 for N3 vs N0 or N1; P = .002; HR, 4.99 for N3 vs N2; P = .001), and primary mass entropy (HR, 2.10 for each 0.5-unit increase; P = .036) and skewness (HR, 3.67 for each 1.0-unit increase; P = .009) measurements with the 1.0 spatial filter were independently associated with overall survival. CONCLUSION: Independent of tumor size, N stage, and other clinical variables, primary mass CT texture and histogram analysis parameters are associated with overall survival in patients with locally advanced squamous cell carcinoma of the head and neck who were treated with induction TPF. Online supplemental material is available for this article.

Trainee and Faculty Perceptions of Remote PACS Workstations and Next Steps in a Large US Academic Medical Institution.

OBJECTIVE: Remote workstations were rapidly deployed in our academic radiology practice in late March 2020 in response to the COVID-19 pandemic. Although well-received by faculty, there were concerns for the impact on resident education. MATERIALS AND METHODS: Surveys of the radiology trainees and faculty were conducted online seven- and thirteen-months following workstation deployment as a part of a quality improvement project to assess the impact on radiology education and faculty wellness, as well as assess the desired trajectory of remote work in an academic setting. RESULTS: The majority of trainees (52%) reported the implementation had negatively impacted resident education, greatest among lower level residents (p < .001). This perception did not change despite interventions and perceived improvement in teleconferencing. Greater than 75% of radiologists with remote workstations reported improved wellness and lower stress levels compared to the onsite radiologists. The majority of all respondents voted to continue or expand remote work following the COVID-19 pandemic in both surveys. CONCLUSIONS: Onsite teaching is important for the education of residents, particularly for lower-level residents. However, the adoption of a hybrid model in an academic setting may prove beneficial for faculty wellness and recruitment of the next generation.

Gd-EOB-DTPA as a functional MR cholangiography contrast agent: imaging gallbladder filling in patients with and without hepatobiliary dysfunction.

OBJECTIVE: To evaluate cystic duct patency on hepatobiliary-phase magnetic resonance (MR) images after intravenous gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) administration. METHODS: A radiology information system search identified patients with gallbladders that had MR imaging after intravenous Gd-EOB-DTPA injection. No patients had acute cholecystitis. Magnetic resonance image findings were correlated with clinical notes, other imaging studies, time of contrast injection, and serum laboratory tests. RESULTS: Contrast accumulated in the gallbladder in 80% of patients (n = 100) with hepatobiliary-phase MR imaging at a median of 22 minutes (range, 15-83 minutes). Absence of contrast accumulation in the gallbladder (n = 20) was associated with hepatobiliary imaging less than 30 minutes after contrast administration, gallbladder contraction, cholelithiasis, elevated liver function tests, elevated bilirubin, and cirrhosis. CONCLUSIONS: Functional assessment of cystic duct patency by Gd-EOB-DTPA-enhanced liver MR is best conducted when hepatobiliary-phase T1-weighted imaging is delayed by more than 30 minutes after contrast injection. Hepatobiliary dysfunction is associated with nonfilling of the gallbladder.

Assessing tumor response and detecting recurrence in metastatic renal cell carcinoma on targeted therapy: importance of size and attenuation on contrast-enhanced CT.

OBJECTIVE: The aim of this study was to improve response assessment in patients with metastatic renal cell carcinoma (RCC) on antiangiogenic targeted therapy by evaluating changes in both tumor size and attenuation and by detecting unique patterns of contrast enhancement on contrast-enhanced CT (CECT). MATERIALS AND METHODS: Tumor long-axis measurements and volumetric mean tumor attenuation of target lesions on CECT images were correlated with time to progression in 53 patients with metastatic clear cell RCC treated with first-line sorafenib or sunitinib. The frequencies of specific patterns of tumor progression were assessed. The data were used to develop new imaging criteria, the size and attenuation CT (SACT) criteria. CECT findings were evaluated using the SACT criteria, Response Evaluation Criteria in Solid Tumors (RECIST), and modified Choi criteria, and the Kaplan-Meier method was used to estimate survival functions. RESULTS: One or more target metastatic lesions had decreased attenuation of >or=40 HU in 59% of patients with progression-free survival of >250 days (n=44) after initiating targeted therapy; 0% of patients with earlier disease progression (n=9) had this finding. A favorable response based on SACT criteria had a sensitivity of 75% and specificity of 100% for identifying patients with progression-free survival of >250 days, versus 16% and 100%, respectively, for RECIST and 93% and 44% for the modified Choi criteria. CONCLUSION: Objectively measuring changes in both tumor size and attenuation on the first CECT study after initiating targeted therapy for metastatic RCC markedly improves response assessment. Distinct patterns of disease recurrence are seen in patients with metastatic RCC on targeted therapy.

Morphology, Attenuation, Size, and Structure (MASS) criteria: assessing response and predicting clinical outcome in metastatic renal cell carcinoma on antiangiogenic targeted therapy.

OBJECTIVE: The objective of our study was to evaluate response assessment and predict clinical outcome in patients with metastatic renal cell carcinoma (RCC) receiving antiangiogenic targeted therapy. Target lesions were assessed on routine contrast-enhanced CT (CECT) images obtained during the portal venous phase using new response criteria. MATERIALS AND METHODS: Standard CECT examinations of patients with metastatic clear cell RCC on first-line sunitinib or sorafenib therapy (n = 84) were retrospectively evaluated using Mass, Attenuation, Size, and Structure (MASS) Criteria; Response Evaluation Criteria in Solid Tumors (RECIST); Size and Attenuation CT (SACT) Criteria; and modified Choi Criteria. The objective response to therapy was compared with clinical outcomes including time to progression (TTP) and disease-specific survival. The Kaplan-Meier method was used to estimate survival functions. RESULTS: A favorable response according to MASS Criteria had a sensitivity of 86% and specificity of 100% in identifying patients with a good clinical outcome (i.e., progression-free survival of > 250 days) versus 17% and 100%, respectively, for RECIST partial response. The objective categories of response used by MASS Criteria-favorable response, indeterminate response, and unfavorable response-differed significantly from one another with respect to TTP (p < 0.0001, log-rank test) and disease-specific survival (p < 0.0001, log-rank test). CONCLUSION: Assessment of metastatic RCC target lesions on CECT for changes in morphology, attenuation, size, and structure by MASS Criteria is more accurate than response assessment by SACT Criteria, RECIST, or modified Choi Criteria. Furthermore, the use of MASS Criteria for imaging response assessment showed high interobserver agreement and may predict disease outcome in patients with metastatic RCC on targeted therapy.