Faculty Bibliography

Collectively, cardiac and large artery sources are responsible for the largest proportion of acute ischemic stroke. Technological advancements in computed tomography (CT) continue to improve evaluation of these patients. The literature was reviewed for the potential role and impact of these innovations in evaluation and management of these patients. In conclusion, incorporation of early cardiac and extracranial vascular CT angiography (CTA) in evaluation of patients with acute ischemic stroke may potentially improve patient management and outcome, while decreasing cost.

A fundamental consideration in the workup of a jaundiced patient is the pretest probability of mechanical obstruction. Ultrasound is the first-line modality to exclude biliary tract obstruction. When mechanical obstruction is present, additional imaging with CT or MRI can clarify etiology, define level of obstruction, stage disease, and guide intervention. When mechanical obstruction is absent, additional imaging can evaluate liver parenchyma for fat and iron deposition and help direct biopsy in cases where underlying parenchymal disease or mass is found. Imaging techniques are reviewed for the following clinical scenarios: (1) the patient with painful jaundice, (2) the patient with painless jaundice, and (3) the patient with a nonmechanical cause for jaundice. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

There are a variety of advanced gastrointestinal endoscopic procedures, many of which are guided by endosonography, which are performed by interventional gastroenterologists or minimally-invasive surgeons. The purpose of this pictorial review is to briefly describe several advanced gastrointestinal endoscopically guided procedures, to review the implications for radiologists interpreting the associated imaging examinations, and to demonstrate the expected preprocedural imaging findings, as well as the expected and the unexpected postprocedural findings, in patients undergoing these procedures.

Sonography is the primary imaging modality for the evaluation of pelvic pain in female patients, especially if gynaecological pathology is suspected. However, computed tomography (CT) is frequently used in patients who present to emergency departments (and elsewhere) with otherwise nonspecific abdominal and pelvic pain and may be the first imaging modality to demonstrate an acute gynaecological abnormality. Computed tomography can also be used prospectively in selected patients to further evaluate findings initially identified on sonography, although to reduce radiation exposure, magnetic resonance imaging is being used more frequently in this situation. The purpose of this article is to discuss the spectrum of gynaecological findings of the acute female pelvis that may be identified on CT by the emergency radiologist and by the general radiologist, with a brief review of the imaging literature of each specific diagnosis.

The purpose of this article is to illustrate and discuss the various etiologies of perforation of the mesenteric small bowel and associated findings on abdominal CT. Perforation of the mesenteric small bowel is an uncommon cause of an acute abdomen and can be due to various etiologies. In underdeveloped countries, infection is probably the most common cause, while in industrialized nations, perforation may be due to Crohn disease, diverticulitis, foreign body, trauma, tumor, mechanical obstruction, primary ischemic event, or iatrogenic causes. CT is usually the initial imaging examination in patients with an acute abdomen and is sensitive in diagnosing small bowel perforation. CT findings in the setting of small bowel perforation are often subtle, but when present, may help the radiologist determine a specific cause of perforation. The aims of this pictorial essay are to review the various causes of mesenteric small bowel perforation and to discuss and illustrate the CT findings that can help arrive at the diagnosis.

This article reviews the computed tomography (CT) findings of miscellaneous regional and diffuse small bowel disorders. CT technique and potential pitfalls are discussed. Several categories of regional and diffuse small bowel conditions are reviewed, with representative CT images. These disorders often have relatively nonspecific CT appearances, and correlation with the history, clinical, and laboratory findings in each specific case is critical. In selected conditions, the CT findings are highly specific. The imaging literature of some of the common as well as some of the less common entities is reviewed, and clues to narrowing the differential diagnosis are provided.

A broad spectrum of skin and subcutaneous (SQ) findings may be discovered in the emergency setting on CT examinations. There are some findings that are directly relevant to the reason or reasons why the patient has undergone the CT examination. However, other findings may be incidental. The skin and SQ tissues are by definition on the periphery of CT images and may be overlooked by the radiologist, although findings related to them can be of clinical importance. The purpose of this pictorial essay is to present a broad spectrum of skin and subcutaneous findings which may be identified on CT examinations in the emergency setting (and in some cases nonemergently), and to briefly review the relevant imaging literature, which surprisingly is relatively limited on this topic. Categories of cutaneous and subcutaneous abnormalities that will be covered include trauma and hemorrhage, iatrogenic findings, infection, neoplasms, calcification, and other miscellaneous entities, all of which may initially present on emergency CT examinations of the body.

Cesarean scar pregnancies (CSPs) are a relatively rare form of ectopic pregnancy in which the embryo is implanted within the fibrous scar of a previous cesarean section. A greater number of cases of CSPs are currently being reported as the rates of cesarean section are increasing globally and as detection of scar pregnancy has improved with use of transvaginal ultrasound (TVUS) with color Doppler imaging. Delayed diagnosis and management of this potentially life-threatening condition may result in complications, predominantly uterine rupture and hemorrhage with significant potential maternal morbidity. Diagnosis of a cesarean scar pregnancy (CSP) requires a high index of clinical suspicion, as up to 40% of patients may be asymptomatic. TVUS has a reported sensitivity of 84.6% and has become the imaging examination of choice for diagnosis of a CSP. Magnetic resonance imaging (MRI) has been used in a small number of patients as an adjunct to TVUS. In the present report, MRI is highlighted as a problem-solving tool capable of more precisely identifying the relationship of a CSP to adjacent structures, thereby providing additional information critical to directing appropriate patient management and therapy.

Because virtually all patients with colonic cancer will undergo some form of surgical therapy, the role of preoperative imaging is directed at determining the presence or absence of synchronous carcinomas or adenomas and local or distant metastases. In contrast, preoperative staging for rectal carcinoma has significant therapeutic implications and will direct the use of radiation therapy, surgical excision, or chemotherapy. CT of the chest, abdomen, and pelvis is recommended for the initial evaluation for the preoperative assessment of patients with colorectal carcinoma. Although the overall accuracy of CT varies directly with the stage of colorectal carcinoma, CT can accurately assess the presence of metastatic disease. MRI using endorectal coils can accurately assess the depth of bowel wall penetration of rectal carcinomas. Phased-array coils provide additional information about lymph node involvement. Adding diffusion-weighted imaging to conventional MRI yields better diagnostic accuracy than conventional MRI alone. Transrectal ultrasound can distinguish layers within the rectal wall and provides accurate assessment of the depth of tumor penetration and perirectal spread, and PET and PET/CT have been shown to alter therapy in almost one-third of patients with advanced primary rectal cancer. The ACR Appropriateness Criteria((R)) are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.