Use of a bedside blood gas analyzer is associated with clinically important reductions in RBC transfusions in the ELBW infant during the first two weeks of life.

Purpose To evaluate the Blood oxygen-level dependent (BOLD) MR imaging findings in kidneys of patients with diabetic nephropathy. Materials and Methods BOLD MR imaging of the kidneys (1.5 Tesla, multi-gradient-recalled-echo sequence with 12 echoes) was performed in 20 patients with diabetic nephropathy (moderate to severe chronic kidney disease: n=14; mild chronic kidney disease: n=6), and 7 healthy volunteers. The medullary and cortical R2* values were compared between patients with diabetic nephropathy and healthy volunteers using student t-tests. Results The mean medullary R2* values were lower in patients with diabetic nephropathy compared to healthy volunteers (13.8 ± 2.4 sec-1 versus 19.3±1.2 sec-1, p=0.0002). The cortical R2* values were not significantly different between the two groups (11.1±0.9 sec-1 versus 11.5±0.7 sec-1, p=0.7). A multiple logistic regression model using patient age, gender, and degree of chronic kidney disease (none, mild, or moderate to severe) as variables showed that the degree of kidney disease was independently associated with a decrease in medullary R2* values (p=0.005). Conclusions The medullary R2* values were lower in patients with diabetic nephropathy compared to healthy volunteers.

Purpose To compare the CT imaging performance of a carboxybetaine zwitterionic-coated tantalum oxide (TaCZ) nanoparticle CT contrast agent with that of a conventional iodinated contrast agent in a swine model meant to simulate overweight and obese patients. Materials and Methods Four swine were evaluated inside three different-sized adipose-equivalent encasements emulating abdominal girths of 102, 119, and 137 cm. Imaging was performed with a 64-detector row CT scanner at six scan delays after intravenous injection of 240 mg element (Ta or I) per kilogram of body weight of TaCZ or iopromide. For each time point, contrast enhancement of the aorta and liver were measured by using regions of interest. Two readers independently recorded the clarity of vasculature using a five-point Likert scale. Findings were compared by using paired t tests and Wilcoxon signed-rank tests. Results Mean peak enhancement was higher for TaCZ than for iopromide in the aorta (270 HU [σ = 24.5] vs 199 HU [σ = 10.2], P < .001) and liver (61.3 HU [σ = 11.7] vs 45.2 HU [σ = 8], P < .001). Vascular clarity was higher for TaCZ than for iopromide in 63% (132 of 208), 82% (170 of 208), and 86% (178 of 208) of the individual vessels at the 102-, 119-, and 137-cm girths, respectively (P < .01). Arterial clarity scores were higher for TaCZ than for iopromide in 62% (208 of 336) of vessels. Venous clarity scores were higher for TaCZ than for iopromide in 89% (128 of 144) of the veins in the venous phase and in 100% (144 of 144) of veins in the delayed phase (P < .01). No vessel showed higher clarity score with iopromide than with TaCZ. Conclusion An experimental tantalum nanoparticle-based contrast agent showed greater contrast enhancement compared with iopromide in swine models meant to simulate overweight and obese patients. © RSNA, 2018.

Purpose To retrospectively investigate the effects of furosemide on the visualization of renal medullary hyperattenuation at unenhanced CT. Materials and Methods This retrospective single-institution study was approved by our Institutional Review Board, the requirement for informed consent was waived. We identified 289 consecutive patients (152 men, 137 women; mean age 59 years) without ureteral obstruction who underwent unenhanced CT as part of CT urography, of whom 178 patients did not receive and 111 received intravenous furosemide prior to imaging. The presence of renal medullary hyperattenuation, renal stones, and bladder urine CT attenuation were recorded and compared between patients who did not receive and those who received furosemide prior to imaging using chi-squared test and unpaired t-test. A multiple logistic regression model was used to evaluate independent predictors of visualization of renal medullary hyperattenuation. Results Renal medullary hyperattenuation was seen less commonly in patients who received furosemide (27 of 111, 24%) than in those who did not receive furosemide prior to imaging (79 of 178, 44%, P =0.001). Bladder urine CT attenuation was lower in patients who received furosemide (−0.1 HU) compared to those who did not (6.4 HU, P <0.001). A multiple logistic regression model revealed independent associations between the visualization of renal medullary hyperattenuation and absence of furosemide administration (P =0.002), younger age (P <0.001), and presence of renal stones (P =0.047). Conclusion Furosemide administration prior to unenhanced CT is associated with decreased visualization of renal medullary hyperattenuation.

Focal FDG avid lesions without CT correlate were malignant in 41% of cases in our series of oncology patients. Lesions in lymph node location and in bones had the highest rates of malignancy. Knowledge of the patterns and risk of malignancy of focal FDG-avid lesions without CT correlate in oncology patients may facilitate the management of oncology patients with such lesions on PET-CT, and could lead to an improved interpretation of PET-CT scans by imaging specialists.

Objective To evaluate the feasibility of dual-energy CT (DECT) for monitoring dynamic changes in the renal corticomedullary sodium gradient in swine. Material and Methods This study was approved by our Institutional Animal Care and Use Committee. Four water-restricted pigs were CT-scanned at 80 and 140 kVp at baseline and at 5 minute intervals for 30 minutes during saline or furosemide diuresis. The renal cortical and medullary CT numbers were recorded. A DECT basis material decomposition method was used to quantify renal cortical and medullary sodium concentrations and medulla-to-cortex sodium ratios at each time point based on the measured CT numbers. The sodium concentrations and medulla-to-cortex sodium ratios were compared between baseline and at 30 minutes diuresis using paired student t-tests. The medulla-to-cortex sodium ratios were considered to reflect the corticomedullary sodium gradient. Results At baseline prior to saline diuresis, the mean medullary and cortical sodium concentrations were 103.8 ± 8.7 and 65.3 ± 1.7 mmol/l, respectively, corresponding to a medulla-to-cortex sodium ratio of 1.59. At 30 minutes of saline diuresis, the medullary and cortical sodium concentrations decreased to 72.3 ± 1.0 and 56.0 ± 1.4 mmol/l, respectively, corresponding to a significantly reduced medulla-to-cortex sodium ratio of 1.29 (P = 0.045). At baseline prior to furosemide diuresis, the mean medullary and cortical sodium concentrations were 110.5 ± 3.6 and 66.7 ± 4.1 mmol/l, respectively, corresponding to a medulla-to-cortex sodium ratio of 1.66. At 30 minutes of furosemide diuresis, the medullary and cortical sodium concentrations decreased to 68.5 ± 0.3 and 58.9 ± 4.0 mmol/l, respectively, corresponding to a significantly reduced medulla-to-cortex sodium ratio of 1.16 (P = 0.026). One of the 4 pigs developed acute tubular necrosis likely related to prolonged hypoxia during intubation prior to the furosemide diuresis experiment. The medulla-to-cortex sodium ratio for this pig, which was excluded from the mean medulla-to-cortex ratio above, was 1.07 at baseline and 1.15 at 30 minutes following the administration of furosemide. Conclusion DECT monitoring of dynamic changes in the renal corticomedullary sodium gradient after physiologic challenges is feasible in swine.

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