Acute abdominal and pelvic processes account for more than half of all surgical procedures performed in the emergency setting. Rapid and accurate diagnosis in the emergency department is essential for the appropriate management of these acute conditions. Magnetic resonance (MR) imaging is an attractive modality for diagnostic imaging in patients for whom the risks of radiation or the potential nephrotoxicity of iodinated contrast agents is a major concern, such as pregnant and pediatric patients. MR imaging is most useful for evaluating pregnant patients with acute lower abdominal pain believed to have an extra-uterine cause, such as appendicitis or ovarian torsion. Other patients with other conditions commonly seen in the emergency setting may be better evaluated with another cross-sectional imaging modality. Imaging protocols should be adapted to the constraints of acute illness, with emphasis placed on minimizing the duration of image acquisition, and should include strategies to decrease motion-related artifacts. A prudent approach is to select the imaging modalities that can best depict a particular subset of clinical conditions to help narrow the differential diagnosis. Disadvantages of MR imaging include its high cost, the limited availability of MR imaging systems and trained radiologists, and the incompatibility of MR imaging systems and the equipment used for intensive care and monitoring of patient status.

The Association of University Radiologists Radiology Research Alliance Task Force on three-dimensional (3D) printing presents a review of the logistic considerations for establishing a clinical service using this new technology, specifically focused on implications for radiology. Specific topics include printer selection for 3D printing, software selection, creating a 3D model for printing, providing a 3D printing service, research directions, and opportunities for radiologists to be involved in 3D printing. A thorough understanding of the technology and its capabilities is necessary as the field of 3D printing continues to grow. Radiologists are in the unique position to guide this emerging technology and its use in the clinical arena.

This study shows that the use of 3D printers for fabrication of models to prebend maxillofacial reconstruction plates is associated with decreased operating room time and costs. Using an on-site 3D printer requires minor start-up and use costs and results in a significant reduction in operating room time, which remains one of the most expensive aspects of facial trauma care.

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Comprehensive bowel examination results from the combined use of T2-weighted single-shot and breath hold T1-weighted gradient echo, minus/plus fat suppression, and gadolinium-enhanced 3D gradient echo (3D VIBE, T1 FAME, 3D THRIVE). Gadolinium-enhanced imaging should be performed dynamically, but the venous 60- to 90-second delayed phase images with fat suppression are generally the most valuable. Removal of fat signal for detection of enhancing normal and abnormal structures is critical. Newly available True-FISP (FIESTA, BFFE) sequences obtained in the 2D form can be very helpful in delineation of bowel wall pathology and overall bowel anatomy, particularly when combined with a water-based intraluminal distending agent. Advantages include rapid acquisition, high signal-to-noise, and motion insensitivity. Generalized protocol for comprehensive evaluation of the entire abdomen and pelvis can be used for the following bowel indications: type and severity of inflammatory bowel disease (IBD); identifying enteric abscesses and fistulae; preoperative staging of malignant neoplasms, including rectal carcinoma; differentiating postoperative and radiation therapy changes from recurrent carcinoma; follow-up evaluation of metastases response to localized ablative or systemic chemotherapy. For improved visualization of bowel wall in dedicated examinations, bowel distension should be achieved using either orally or rectally delivered contrast agents to produce either bright or dark lumen. We have found 2D True-FISP without fat suppression superior to 3D True-FISP and to single-shot echo-train sequences to provide a T2-weighted image of bowel morphology. Strengths include: performed without fat suppression results in the very dark bowel wall being sandwiched between intermediate high signal fat adjacent to bowel serosa, and very high lumen signal from water-distending agent; 2D True-FISP provides motion insensitivity that is lost if 3D is used; True-FISP produces better edge sharpness than single-shot echo-train, higher contrast, and resists flow void artifacts commonly seen with single-shot echo-train imaging combined with a water distending agent. Drawbacks of this technique include: artifacts related to extreme sensitivity to field inhomogeneity, including air-soft tissue interfaces at the patient skin surface, and from retained bowel gas; retained bowel gas is dark against dark bowel wall, impairing bowel wall assessment; and True-FISP does not provide sensitivity for edema, which is superior on single-shot echo-train imaging. Small/large bowel indications for MRI include: inflammatory bowel disease, infectious disease including abscess evaluation or for appendicitis, inflammatory conditions including ischemia, and partial obstruction, malnutrition, and neoplasm search.

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