Multimodality imaging systems such as positron emission tomography-computed tomography (PET-CT) and MRI-PET are widely available, but a simultaneous CT-MRI instrument has not been developed. Synergies between independent modalities, e.g., CT, MRI, and PET/SPECT can be realized with image registration, but such postprocessing suffers from registration errors that can be avoided with synchronized data acquisition. The clinical potential of simultaneous CT-MRI is significant, especially in cardiovascular and oncologic applications where studies of the vulnerable plaque, response to cancer therapy, and kinetic and dynamic mechanisms of targeted agents are limited by current imaging technologies. The rationale, feasibility, and realization of simultaneous CT-MRI are described in this perspective paper. The enabling technologies include interior tomography, unique gantry designs, open magnet and RF sequences, and source and detector adaptation. Based on the experience with PET-CT, PET-MRI, and MRI-LINAC instrumentation where hardware innovation and performance optimization were instrumental to construct commercial systems, the authors provide top-level concepts for simultaneous CT-MRI to meet clinical requirements and new challenges. Simultaneous CT-MRI fills a major gap of modality coupling and represents a key step toward the so-called "omnitomography" defined as the integration of all relevant imaging modalities for systems biology and precision medicine.

Cardiothoracic diseases result in substantial morbidity and mortality. Chest computed tomography (CT) has been an imaging modality of choice for assessing a host of chest diseases, and technologic advances have enabled the emergence of coronary CT angiography as a robust noninvasive test for cardiac imaging. Technologic developments in CT have also enabled the application of dual-energy CT scanning for assessing pulmonary vascular and neoplastic processes. Concerns over increasing radiation dose from CT scanning are being addressed with introduction of more dose-efficient wide-area detector arrays and iterative reconstruction techniques. This review article discusses the technologic innovations in CT and their effect on cardiothoracic applications.

In patients presenting for an evaluation of pregnancy in the first trimester, transvaginal ultrasound is the modality of choice for establishing the presence of an intrauterine pregnancy; evaluating pregnancy viability, gestational age, and multiplicity; detecting pregnancy-related complications; and diagnosing ectopic pregnancy. In this pictorial review article, the sonographic appearance of a normal intrauterine gestation and the most common complications of pregnancy in the first trimester in the acute setting are discussed.

Recent studies have supported the use of low-dose computed tomography (LDCT) of the chest as a screening tool for lung cancer. Several professional organizations have now included LDCT screening in high-risk populations in their guidelines. The United States Preventive Services Task Force has added LDCT to its lung cancer-screening guidelines as of December 2013. Recently, the Centers for Medicare and Medicaid Services acknowledged that the evidence for LDCT lung cancer screening is adequate, provided that eligibility criteria are met. As widespread use of LDCT is anticipated, the radiation dose associated with LDCT needs to be optimized. The American College of Radiology-Society of Thoracic Radiology collaboration and the National Comprehensive Cancer Care Network recently provided some guidelines for LDCT utilization for lung cancer screening. There are several scanning and image reconstruction techniques that can be used for reducing radiation dose in LDCT lung cancer screening. This review article presents protocols and guidelines for use of LDCT in lung cancer screening and describes our early experience in implementing LDCT at our institution.