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Aim To determine the absorbed radiation dose to the female breast during chest computed tomography (CT), and whether a custom-designed breast shield can reduce that dose. Materials and methods Bilateral breast phantoms were combined with an anthropomorphic torso phantom. Each breast phantom contained 20 thermoluminescent dosimeter (TLD) cavities. Eight cavities were used per phantom. Absorbed radiation was measured using TLD 100s. Three-stacked TLDs comprised a set. Three sets of three TLDs were positioned at eight designated locations and three depths (surface; 1 cm; 4 cm). One set of three TLDs was positioned at eight additional designations, 1 cm deep. Each breast was divided anatomically into quadrants. In total, 32 TLD sets/96 TLDs were deployed. The breast–torso phantom was consecutively imaged using a 16-detector array CT machine. Subsequently, 32 new TLD sets were similarly placed, the phantom re-imaged in a likewise manner, but with the application of a tungsten–antimony composite breast shield. TLD readings were averaged and calculated. Results Average absorbed radiation doses for unshielded right and left breast phantoms ranged from 13.83–19.36 mGy, and 14–20.47 mGy, respectively. The absorbed dose in the shielded right and left breast was reduced to 6.64–8.12 mGy, and 6.7–8.03 mGy, respectively. Average absorbed radiation doses based on the depth for the unshielded breasts ranged from 15.4–18.3 mGy. Shielding reduced this dose to 7–7.9 mGy. Unshielded absorbed radiation doses based on anatomic quadrants ranged from 17.5–18.9 mGy. Shielding reduced this dose to 7–7.5 mGy. Conclusions The average absorbed radiation dose to the unshielded female breast phantom is approximately 14–20 mGy. An externally applied shield can reduce this absorbed dose by 56–61%.

Enhanced ferrite nanoparticles are a new class of contrast agents for magnetic resonance imaging (MRI). The enhanced ferrites are synthesized by reverse micelles technique to form iron core and oxide or ferrite shell preventing further oxidation of the nanoparticles. The nanoparticles are further functionalized using dopamine and PEG-600 to increase the solubility of the high magnetic moment nanoparticles. 1 H relaxation measurements of aqueous solutions of the nanoparticles were conducted at 2.4 T. The relaxivities r 1 and r 2 , representing the slopes of these curves, are 7.19 and 9.96 s −1 mM −1 , respectively. These values should be compared with relaxivities of 4–5 s −1 mM −1 corresponding to commonly used commercial contrast agents in human MR examinations.

Even after the precipitant of a hepatic encephalopathy (HE) episode is treated,lactulose is often continued indefinitely. Clinical tools to predict relapse off of lactulose and guide the safe withdrawal of Rx have not been studied. Aim: Evaluate change in psychometric & MR spectroscopic(MRS)after lactulose withdrawal. Methods: Cirrhotics with prior HE underwent number connection (NCT-A/B),Block design(BDT),Digit symbol(DST)& Inhibitory control tests(ICT;lures are the outcomes) & MRS while on lactulose. Lactulose was then withdrawn. Psychometric tests were repeated 2,14& 30 days post-withdrawal. MRS was repeated 14 days post-withdrawal. Occipital gray(GM) & right parietal white matter(WM) regions were studied for glutamine(Gln), myoinositol & choline. Worsening HE leads to increase in Gln. Repeated measures analyses were used to model tests over time & determine relapse predictors. Results: 7 cirrhotics (age 53±7yrs,5 HCV,2 alcohol) on lactulose for 6±5 mths for precipitated HE(5 GI bleed, 2 infections) were included.3 patients clinically relapsed 38±6 days post-withdrawal; all 3 had >15 ICT lures while on lactulose. None of those who scored 15 ICT lures on lactulose relapsed. Gln levels in gray/white matter increased after lactulose withdrawal. Psychometric performance on therapy can predict the risk of relapse off of lactulose treatment.

A projection MR technique for imaging the velocity profiles of moving fluids has been applied to various steady flow models designed to simulate a variety of flow conditions. From such profiles can be readily deduced peak velocities, volume flow rates, information concerning the degree of flow development, features such as flow separation, and estimates of shear stresses at the vessel wall.