Toshimasa J. Clark

Hepatocellular Carcinoma: Review of Epidemiology, Screening, Imaging Diagnosis, Response Assessment, and Treatment.

Hepatocellular carcinoma is a common malignancy for which prevention, screening, diagnosis, treatment, and surveillance demand a multidisciplinary approach. Knowledge of the underlying pathophysiology as well as advances in clinical management should be employed by radiologists to effectively communicate with hepatologists, surgeons, and oncologists. In this review article, we present recent developments in the clinical management of hepatocellular carcinoma.

Increased Incidence of Pseudoaneurysm Bleeding With Lumen-Apposing Metal Stents Compared to Double-Pigtail Plastic Stents in Patients With Peripancreatic Fluid Collections

Background & Aims There have been few studies that compared the effects of lumen‐apposing metal stents (LAMS) and double‐pigtail plastic stents (DPS) in patients with peripancreatic fluid collections from pancreatitis. We aimed to compare technical and clinical success and adverse events in patients who received LAMS vs DPS for pancreatic pseudocysts and walled‐off necrosis. Methods We performed a retrospective study of endoscopic ultrasound–mediated drainage in 149 patients (65% male; mean age, 47 y) with pancreatic pseudocysts or walled‐off necrosis (97 received LAMS and 152 received DPS), from January 2011 through September 2016 at a single center. We collected data on patient characteristics, outcomes, hospitalizations, and imaging findings. Technical success was defined as LAMS insertion or a minimum of 2 DPS. Clinical success was defined as resolution of pancreatic pseudocysts or walled‐off necrosis based on imaging results. The primary outcome was resolution of peripancreatic fluid collection with reduced abdominal pain or obstructive signs or symptoms. Secondary outcomes included the identification and management of adverse events, number of additional procedures required to resolve fluid collection, and the recurrence of fluid collection. Results Patients who received LAMS had larger peripancreatic fluid collections than patients who received DPS prior to intervention (P = .001), and underwent an average 1.7 interventions vs 1.9 interventions for patients who received DPS (P = .93). Technical success was achieved for 90 patients with LAMS (92.8%) vs 137 patients with DPS (90.1%) (odds ratio [OR] for success with DPS, 0.82; 95% CI, 0.33–2.0; P = .67). Despite larger fluid collections in the LAMS group, there was no significant difference in proportions of patients with clinical success following placement of LAMS (82 of 84 patients, 97.6%) vs DPS (118 of 122 patients, 96.7%) (OR for clinical success with DPS, 0.73; 95% CI, 0.13–4.0; P = .71). Adverse events developed in 24 patients who received LAMS (24.7%) vs 27 patients who received DPS (17.8%) (OR for an adverse event in a patient receiving a DPS, 0.82; 95% CI, 0.33–2.0; P = .67). However, patients with LAMS had a higher risk of pseudoaneurysm bleeding than patients with DPS (OR, 10.0; 95% CI, 1.19–84.6; P = .009). Conclusions In a retrospective study of patients undergoing drainage of pancreatic pseudocysts or walled‐off necrosis, we found LAMS and DPS to have comparable rates of technical and clinical success and adverse events. Drainage of walled‐off necrosis or pancreatic pseudocysts using DPS was associated with fewer bleeding events overall, including pseudoaneurysm bleeding, but bleeding risk with LAMS should be weighed against the trend of higher actionable perforation and infection rates with DPS.

Radiologist-Centered Decision Support Applications

Two goals of Imaging 3.0 are the widespread adoption of algorithmic observation categorization schemes such as the Liver Imaging Data and Reporting System, and the standardization of management recommendations for incidental findings [1]. Computer applications can aid radiologists in achieving these goals, but to date they have received little systematic investigation. Prior research has evaluated radiology-related educational websites, web-based applications, and smartphone applications [2,3]. We evaluated a subset of radiology applications that are intended to aid radiologists in decision support and study interpretation by designing an objective rating system. Subsequently we utilized usage data to validate the derived ratings.

Adherence to ACR Incidental Finding Guidelines

BRIEF RATIONALE Radiologists commonly encounter incidental findings, and in response, organizations such as the ACR have developed consensus management guidelines [1-9]. The use of such guidelines may increase the value of radiologists’ work by ensuring consistent management of incidental findings. There has been a paucity of data regarding radiologists’ adherence to the ACR incidental finding guidelines and methods to increase adherence.

Clinical Validation of a Predictive Model for the Presence of Cervical Lymph Node Metastasis in Papillary Thyroid Cancer

BACKGROUND AND PURPOSE: Ultrasound is a standard technique to detect lymph node metastasis in papillary thyroid cancer. Cystic changes and microcalcifications are the most specific features of metastasis, but with low sensitivity. This prospective study compared the diagnostic accuracy of a predictive model for sonographic evaluation of lymph nodes relative to the radiologists standard assessment in detecting papillary thyroid cancer metastasis in patients after thyroidectomy. MATERIALS AND METHODS: Cervical lymph node sonographic images were reported by a radiologist (R method) per standard practice. The same images were independently evaluated by another radiologist using a sonographic predictive model (M method). A test was considered positive for metastasis if the R or M method suggested lymph node biopsy. The result of lymph node biopsy or surgical pathology was used as the reference standard. We estimated relative true-positive fraction and relative false-positive fraction using log-linear models for correlated binary data for the M method compared with the R method. RESULTS: A total of 237 lymph nodes in 103 patients were evaluated. Our analysis of relative true-positive fraction and relative false-positive fraction included 54 nodes with pathologic results in which at least 1 method (R or M) was positive. The M method had a higher relative true-positive fraction of 1.46 (95% CI, 1.12–1.91; P = .006) and a lower relative false-positive fraction of 0.58 (95% CI, 0.36–0.92; P = .02) compared with the R method. CONCLUSIONS: The sonographic predictive model outperformed the standard assessment to detect lymph node metastasis in patients with papillary thyroid cancer and may reduce unnecessary biopsies.

Effect of injection rate on contrast-enhanced MR angiography image quality: Modulation transfer function analysis

Contrast‐enhanced (CE)‐MRA optimization involves interactions of sequence duration, bolus timing, contrast recirculation, and both R1 relaxivity and R2* ‐related reduction of signal. Prior data suggest superior image quality with slower gadolinium injection rates than typically used.

Launchpad for Onboarding New Faculty Into Academic Life

We developed a faculty professional development seminar series in order to facilitate the integration of our numerous new faculty into academics. The changing nature of the healthcare system, increasing clinical and administrative responsibility, and lack of access to senior mentors can hinder junior faculty productivity and possibly increase attrition. Given that no ready-made resources existed to address these issues we established a Professional Development Committee, developed a curriculum that covers relevant topics including promotion, mentorship, conflict management and feedback, and effective presentation of scientific data, and instituted changes iteratively based upon feedback. We used surveys from successive years of this seminar series to assess effectiveness, and our data demonstrate that our Professional Development Seminar Series was valued by its participants and that individual lectures improved from year to year. While it is too early to determine whether our efforts will lead to long-term changes in promotion success or faculty retention, our initial data are promising.

What Do George Clooney and Sarah Jessica Parker Have in Common? Big-data

Data-driven methods have proved their utility in radiology workflow optimization and reporting. These capabilities of natural language processing, machine learning, content extraction, and image processing largely mirror, at a conceptual level, what we as radiologists do. Traditional image processing techniques are employed to segment images into identifiable regions much like human visual processing would. More recently, deep learning researchers have emulated neural architectures to perform automated image segmentation and textural feature-based classification following training on large datasets of medical images. Imaging appropriateness, scheduling efficiency, and image interpretation performance all represent realms in which we may be able to use big data to improve our practices, in terms of throughput, diagnostic accuracy, and patient satisfaction.

Effect of injection rate on contrast-enhanced MR angiography image quality

Contrast‐enhanced (CE)‐MRA optimization involves interactions of sequence duration, bolus timing, contrast recirculation, and both R1 relaxivity and R2* ‐related reduction of signal. Prior data suggest superior image quality with slower gadolinium injection rates than typically used.

Characterization of Adrenal Adenoma by Gaussian Model-Based Algorithm☆

We confirmed that computed tomography (CT) attenuation values of pixels in an adrenal nodule approximate a Gaussian distribution. Building on this and the previously described histogram analysis method, we created an algorithm that uses mean and standard deviation to estimate the percentage of negative attenuation pixels in an adrenal nodule, thereby allowing differentiation of adenomas and nonadenomas. The institutional review board approved both components of this study in which we developed and then validated our criteria. In the first, we retrospectively assessed CT attenuation values of adrenal nodules for normality using a 2-sample Kolmogorov-Smirnov test. In the second, we evaluated a separate cohort of patients with adrenal nodules using both the conventional 10HU unit mean attenuation method and our Gaussian model-based algorithm. We compared the sensitivities of the 2 methods using McNemars test. A total of 183 of 185 observations (98.9%) demonstrated a Gaussian distribution in adrenal nodule pixel attenuation values. The sensitivity and specificity of our Gaussian model-based algorithm for identifying adrenal adenoma were 86.1% and 83.3%, respectively. The sensitivity and specificity of the mean attenuation method were 53.2% and 94.4%, respectively. The sensitivities of the 2 methods were significantly different (P value < 0.001). In conclusion, the CT attenuation values within an adrenal nodule follow a Gaussian distribution. Our Gaussian model-based algorithm can characterize adrenal adenomas with higher sensitivity than the conventional mean attenuation method. The use of our algorithm, which does not require additional postprocessing, may increase workflow efficiency and reduce unnecessary workup of benign nodules.