Until recently, MRI has not been considered to be suitable for the evaluation of the small intestine due to artifacts associated with bowel peristalsis or respiration. However, recent advances of MR techniques enable the acquisition of clear images of the small intestine. Therefore, the purpose of this article is to review the details for the application of MRI in patients with small intestinal diseases. This article discusses bowel preparation and oral contrast agents as well as MR techniques and pulse sequences. Thereafter, the usefulness of MRI for the lesions in the peritoneal cavity or in the gastrointestinal tract are discussed. Small intestinal lesions are categorized into inflammatory, neoplastic, ischemic, and obstructive bowel diseases. In conclusion, MRI can be used as an alternate modality of choice for imaging various diseases of the small intestine.

PurposeAdjuvant radiotherapy of breast cancer using a photon tangential field incurs a risk of late heart and lung toxicity. The use of free breathing (FB), expiration breath hold (EBH), and deep inspiration breath hold (DIBH) during tangential breast radiotherapy as a means of reducing irradiated lung and heart volume was evaluated.MethodsIn 10 women with left-sided breast cancer (mean age, 44 years) post-operative computed tomography (CT) scanning was done under different respiratory conditions using FB, EBH, and DIBH in 3 CT scans. For each scan, an optimized radiotherapy plan was designed with 6 MV photon tangential fields encompassing the clinical target volume after breast-conserving surgery.ResultsThe results of dose-volume histograms were compared using three breathing pattern techniques for the irradiated volume and dose to the heart. A significant reduction dose to the irradiated heart volume for the DIBH breathing technique was compared to FB and EBH breathing techniques (p<0.05).ConclusionThis study demonstrated that the irradiated heart volume can be significantly reduced in patients with left-sided breast cancer using the DIBH breathing technique for tangential radiotherapy.

Background: Although there are studies on the growth of thoracic aorta in the general population, research based on serial computed tomography scan is rare. We investigated the influence of patient age and anthropometric variables on the size and growth rate of the thoracic aorta in the general hospital population. Methods: Data on 2,353 adults [2003][2004][2005][2006][2007][2008][2009][2010][2011][2012][2013][2014] who underwent ≥2 serial computed tomography examinations with at least a 6-year interval were analyzed. There were 1,444 men (61%), and the mean age was 58±12 years (range, 17-92 years). Thoracic aortic diameters were measured at 5 levels (the sinus of Valsalva, ascending aorta, aortic arch, and proximal and distal descending thoracic aorta) in the first and last computed tomography scans taken at a median interval of 7.0 years (interquartile range: 6.4-8.0). Results: The mean aorta diameters were 34.9±4.7, 34.1±4.6, 28.0±3.8, 24.8±3.4, and 23.8±3.3 mm in the sinus of Valsalva, ascending aorta, arch, and proximal and distal descending thoracic aorta, respectively. The initial aorta diameter was larger in older subjects and in those with a larger body surface area (BSA). Female subjects had a significantly larger indexed diameter (diameter/BSA) than male subjects (P<0.001 at all five levels). In all thoracic aorta levels, the growth rate was the highest in subjects in their 40s, and the growth rate negatively correlated with the initial indexed diameter (P<0.001 at all five levels). In 40-50% of the subjects, thoracic aorta size remained stable during the interval. Conclusions: The thoracic aorta dilated with aging and was larger in subjects with a larger body size.Sex differences in the gross aortic diameter might be related to differences in body size. The growth of the thoracic aorta was faster in younger subjects with a smaller indexed diameter.