Marc D. Kohli

Response Criteria in Oncologic Imaging: Review of Traditional and New Criteria

There has been a proliferation and divergence of imaging-based tumor-specific response criteria over the past 3 decades whose purpose is to achieve objective assessment of treatment response in oncologic clinical trials. The World Health Organization (WHO) criteria, published in 1981, were the first response criteria and made use of bidimensional measurements of tumors. The Response Evaluation Criteria in Solid Tumors (RECIST) were created in 2000 and revised in 2009. The RECIST criteria made use of unidimensional measurements and addressed several pitfalls and limitations of the original WHO criteria. Both the WHO and RECIST criteria were developed during the era of cytotoxic chemotherapeutic agents and are still widely used. However, treatment strategies changed over the past decade, and the limitations of using tumor size alone in patients undergoing targeted therapy (including arbitrarily determined cutoff values to categorize tumor response and progression, lack of information about changes in tumor attenuation, inability to help distinguish viable tumor from nonviable components, and inconsistency of size measurements) necessitated revision of these criteria. More recent criteria that are used for targeted therapies include the Choi response criteria for gastrointestinal stromal tumor, modified RECIST criteria for hepatocellular carcinoma, and Immune-related Response Criteria for melanoma. The Cheson criteria and Positron Emission Tomography Response Criteria in Solid Tumors make use of positron emission tomography to provide functional information and thereby help determine tumor viability. As newer therapeutic agents and approaches become available, it may be necessary to further modify existing anatomy-based response-assessment methodologies, verify promising functional imaging methods in large prospective trials, and investigate new quantitative imaging technologies.

Functional imaging of the pelvic floor.

The clinical treatment of patients with anorectal and pelvic floor dysfunction is often difficult. Dynamic cystocolpoproctography (DCP) has evolved from a method of evaluating the anorectum for functional disorders to its current status as a functional method of evaluating the global pelvic floor for defecatory disorders and pelvic organ prolapse. It has both high observer accuracy and a high yield of positive diagnoses. Clinicians find it a useful diagnostic tool that can alter management decisions from surgical to medical and vice versa in many cases. Functional radiography provides the maximum stress to the pelvic floor, resulting in levator ani relaxation accompanied by rectal emptying-which is needed to diagnose defecatory disorders. It also provides organ-specific quantificative information about female pelvic organ prolapse-information that usually can only be inferred by means of physical examination. The application of functional radiography to the assessment of defecatory disorders and pelvic organ prolapse has highlighted the limitations of physical examination. It has become clear that pelvic floor disorders rarely occur in isolation and that global pelvic floor assessment is necessary. Despite the advances in other imaging methods, DCP has remained a practical, cost-effective procedure for the evaluation of anorectal and pelvic floor dysfunction. In this article, the authors describe the technique they use when performing DCP, define the radiographic criteria used for diagnosis, and discuss the limitations and clinical utility of DCP.

CT enteroclysis in small bowel Crohn's disease.

The diagnostic evaluation of small bowel Crohns disease has changed dramatically over the last decade. The introduction of wireless capsule endoscopy, double balloon endoscopy and the introduction of newer therapeutic agents have changed the role of imaging in the small bowel. Additionally, advances in multidetector CT technology have further changed how radiologic investigations are utilized in the diagnosis and management of small bowel Crohns disease. This article describes how we perform CT enteroclysis in the investigation of small bowel Crohns disease and discusses the role of CT enteroclysis in the current management of small bowel Crohns disease.

What is a Wiki, and How Can it be Used in Resident Education?

Training as a radiology resident is a complex task. Residents frequently encounter multiple hospital systems, each with unique workflow patterns and heterogenous information systems. We identified an opportunity to ease some of the resulting anxiety and frustration by centralizing high-quality resources using a wiki. In this manuscript, we describe our choice of wiki software, give basic information about hardware requirements, detail steps for configuration, outline information included on the wiki, and present the results of a resident acceptance survey.

Implementing Machine Learning in Radiology Practice and Research

OBJECTIVE The purposes of this article are to describe concepts that radiologists should understand to evaluate machine learning projects, including common algorithms, supervised as opposed to unsupervised techniques, statistical pitfalls, and data considerations for training and evaluation, and to briefly describe ethical dilemmas and legal risk. CONCLUSION Machine learning includes a broad class of computer programs that improve with experience. The complexity of creating, training, and monitoring machine learning indicates that the success of the algorithms will require radiologist involvement for years to come, leading to engagement rather than replacement.

CT enteroclysis in incomplete small bowel obstruction

The timing of surgical intervention as well as the optimal method of radiologic investigation for patients with incomplete, open loop small bowel obstruction has changed over the past two decades. This review focuses on the role of computed tomographic enteroclysis in the evaluation of patients with suspected small bowel obstruction. The technique of examination is described and an overview of its clinical applications and imaging controversy are presented.

Technology Standards in Imaging: A Practical Overview

Technology standards form the basis for clinical workflow in radiology. This article reviews 3 types of standards relevant for radiology: the DICOM standard for handling images; the Health Level 7 standard for communicating with the health care enterprise; and standards in coding and terminology such as International Classification of Diseases, Current Procedural Terminology, and RadLex. This third category has an impact on radiology reporting and practice management. Familiarity with all these standards can help radiologists optimize operations and plan for the future.

Advanced Practice Quality Improvement Project: How to Influence Physician Radiologic Imaging Ordering Behavior

With growing pressure on the health care sector to improve quality and reduce costs, the stakes associated with imaging appropriateness have never been higher. Although radiologists historically functioned as imaging gatekeepers, this role has been deprioritized in the recent past. This article discusses several potential practice quality improvement projects that can help radiologists regain their role as valued consultants and integral members of the care team. By applying the PDSA framework, radiologists can incrementally optimize their practices consultation service. While it can be expected that different strategies will gain traction in different environments, it is our hope that the methodology described here will prove useful to most or all practices as a starting point. In addition, we discuss several other influencing techniques that extend beyond traditional consultation services.

Medical Image Data and Datasets in the Era of Machine Learning—Whitepaper from the 2016 C-MIMI Meeting Dataset Session

At the first annual Conference on Machine Intelligence in Medical Imaging (C-MIMI), held in September 2016, a conference session on medical image data and datasets for machine learning identified multiple issues. The common theme from attendees was that everyone participating in medical image evaluation with machine learning is data starved. There is an urgent need to find better ways to collect, annotate, and reuse medical imaging data. Unique domain issues with medical image datasets require further study, development, and dissemination of best practices and standards, and a coordinated effort among medical imaging domain experts, medical imaging informaticists, government and industry data scientists, and interested commercial, academic, and government entities. High-level attributes of reusable medical image datasets suitable to train, test, validate, verify, and regulate ML products should be better described. NIH and other government agencies should promote and, where applicable, enforce, access to medical image datasets. We should improve communication among medical imaging domain experts, medical imaging informaticists, academic clinical and basic science researchers, government and industry data scientists, and interested commercial entities.

Creation and Curation of the Society of Imaging Informatics in Medicine Hackathon Dataset

In order to support innovation, the Society of Imaging Informatics in Medicine (SIIM) elected to create a collaborative computing experience called a “hackathon.” The SIIM Hackathon has always consisted of two components, the event itself and the infrastructure and resources provided to the participants. In 2014, SIIM provided a collection of servers to participants during the annual meeting. After initial server setup, it was clear that clinical and imaging “test” data were also needed in order to create useful applications. We outline the goals, thought process, and execution behind the creation and maintenance of the clinical and imaging data used to create DICOM and FHIR Hackathon resources.