Contributions of global and local processing on medical image perception.

Purpose: The influential holistic processing hypothesis attributes expertise in medical image perception to cognitive processing of global gist information. However, it has remained unclear whether or how experts use rapid global impression of images for their subsequent diagnostic decisions based on the focal sign of cancer. We hypothesized that continuous-global and discrete-local processes jointly attribute to radiological experts' detection of mammogram, with different weights and temporal dynamics. Approach: We examined experienced versus inexperienced observers' performance at first (500 ms) versus second (2500 ms) mammogram image presentation in an abnormality detection task. We applied a dual-trace signal detection (DTSD) model of receiver operating characteristic (ROC) to assess the time-varying contributions of global and focal cancer signals on mammogram reading and medical expertise. Results: The hierarchical Bayesian DTSD modeling of empirical ROCs revealed that mammogram expertise (experienced versus inexperienced observers) manifests largely in a continuous-global component for the detection of the gist of abnormality at the early phase of mammogram reading. For the second presentation of the same mammogram images, the experienced participants showed increased task performance that was largely driven by better processing of discrete-local information, whereas the global processing of abnormality remained saturated from the first exposure. Modeling of the mouse trajectory of the confidence rating responses further revealed the temporal dynamics of global and focal processing. Conclusions: These results suggest a joint contribution of continuous-global and discrete-local processes on medical expertise, and these processes could be analytically dissociated.

Kratom-Induced Liver Injury: A Case Series and Clinical Implications.

Drug-induced liver injury (DILI) is among the most common causes of acute liver injury and acute liver failure in the United States. Kratom is an herbal supplement made from the leaves of a tropical evergreen tree (Mitragyna speciosa) that is native to Southeast Asia. Due to its psychotropic and opioid-like activity, there has been an increase in its use as a recreational drug. Despite this increase, little is known regarding the toxicities and adverse effects though it is known to cause DILI. We present two cases of DILI associated with Kratom use.

Primary Duodenal Periampullary Adenocarcinoma: An Uncommon Presentation.

Periampullary carcinoma is a broad term used to define the group of carcinomas arising from the head of the pancreas, the distal common bile duct, and the duodenum. It is clinically important to differentiate ampullary from periampullary carcinoma as this can affect resectability and prognosis. Atypical left-sided chest pain is an atypical presentation of periampullary duodenal adenocarcinoma. A 58-year-old man presented with a two-month duration of worsening intermittent, atypical, migratory left-sided chest pain. Imaging studies were unremarkable; however, endoscopic evaluation demonstrated a duodenal mass. While most periampullary carcinomas are generally curable with pancreaticoduodenectomy, if left untreated, these tumors are uniformly fatal.

Active Surveillance as Initial Management of Newly Diagnosed Prostate Cancer: Data from the PURC.

PURPOSE: We describe contemporary active surveillance utilization and variation in a regional prostate cancer collaborative. We identified demographic and disease specific factors associated with active surveillance in men with newly diagnosed prostate cancer. MATERIALS AND METHODS: We analyzed data from the PURC (Pennsylvania Urologic Regional Collaborative), a cooperative effort of urology practices in southeastern Pennsylvania and New Jersey. We determined the rates of active surveillance among men with newly diagnosed NCCN® (National Comprehensive Cancer Network®) very low, low or intermediate prostate cancer and compared the rates among participating practices and providers. Univariate and multivariable analyses were used to identify factors associated with active surveillance utilization. RESULTS: A total of 1,880 men met inclusion criteria. Of the men with NCCN very low or low risk prostate cancer 57.4% underwent active surveillance as the initial management strategy. Increasing age was significantly associated with active surveillance (p <0.001) while adverse clinicopathological variables were associated with decreased active surveillance use. Substantial variation in active surveillance utilization was observed among practices and providers. CONCLUSIONS: More than 50% of men with low risk disease in the PURC collaborative were treated with active surveillance. However, substantial variation in active surveillance rates were observed among practices and providers in academic and community settings. Advanced age and favorable clinicopathological factors were strongly associated with active surveillance. Analysis of regional collaboratives such as the PURC may allow for the development of strategies to better standardize treatment in men with prostate cancer and offer active surveillance in a more uniform and systematic fashion.

Functional Parenchymal Volume-based Spectrum Score Is Able to Quantify Ischemic Injury After Partial Nephrectomy.

OBJECTIVE: To externally validate the Spectrum Score (SS) using a modified calculation based on functional parenchymal volumes (FPVs) instead of renal scans. The SS quantifies acute ischemic injury in the ipsilateral kidney after partial nephrectomy. However, this metric requires renal split function assessment via renal scans, which may be unavailable in routine practice. METHODS: We retrospectively reviewed patients with a solitary renal mass and contralateral kidney who underwent partial nephrectomy at our institution between 2015 and 2017. FPVs were calculated using cylindrical volume approximation and used to quantitate relative renal function. Based on renal split function and parenchyma preserved, we determined creatinineideal, assuming no ipsilateral kidney ischemic injury, and creatinineworst-case, assuming temporary ipsilateral kidney nonfunction. FPV-based SS was defined as follows: (observed peak creatinine-creatinineideal)/(creatinineworst-case-creatinineideal). Functional recovery was defined as follows: (% function saved)/(% parenchyma preserved). Factors associated with FPV-based SS and functional recovery were assessed using linear regression. RESULTS: We assessed 174 patients with a median renal mass size of 2.7 cm (IQR 2.0-3.6), warm ischemia time of 26.0 minutes (IQR 19.0-34.3), and parenchyma preservation of 92.6% (IQR 80.8-100). Preoperative ipsilateral kidney % split function (P = .003), preoperative ipsilateral kidney glomerular filtration rate (P = .045), and warm ischemia time (P = .005) were independently associated with FPV-based SS. Only FPV-based SS (P<.001) was independently associated with functional recovery. CONCLUSION: The FPV-based SS, which does not require renal scans, quantifies acute ipsilateral renal dysfunction and predicts functional recovery after partial nephrectomy.