Guk Myung Choi

Comparison of Three Free-Breathing T2-Weighted MRI Sequences in the Evaluation of Focal Liver Lesions

OBJECTIVE The purpose of this study was to compare three free-breathing T2-weighted MRI sequences in the evaluation of focal liver lesions. MATERIALS AND METHODS Forty-nine patients with 86 focal liver lesions (56 malignant, 30 benign) underwent liver MRI with free-breathing sequences: turbo spin-echo (TSE) with navigator-triggered prospective acquisition correction (PACE), respiration-triggered TSE, and HASTE with navigator-triggered PACE. The images were retrospectively reviewed by two independent observers. Diagnostic performance was evaluated with receiver operating characteristics and sensitivity. The images were assessed quantitatively by measurement of the liver signal-to-noise ratio (SNR) and the lesion-to-liver contrast-to-noise ratio (CNR). RESULTS The PACE TSE sequence had better receiver operating characteristic curves for lesion detection and characterization than did the respiration-triggered TSE sequence, but the difference was not statistically significant (p > 0.05). The PACE TSE sequence had a significantly greater area under the curve for lesion detection (p < 0.01) and lesion characterization (p < 0.001) than did the PACE HASTE sequence. The composite sensitivity of the PACE TSE sequence for lesion detection was significantly higher than that of respiration-triggered TSE (p < 0.05) and PACE HASTE (p < 0.01). The mean signal-to-noise ratio for liver and the contrast-to-noise ratio for hepatic lesions were higher with the PACE HASTE than with the other sequences. CONCLUSION The navigator-triggered PACE technique is a valid method for T2-weighted MRI of the liver and may replace conventional respiration-triggered techniques.

The Efficacy of Primary Interventional Urethral Realignment for the Treatment of Traumatic Urethral Injuries

PURPOSE To evaluate the efficacy of primary interventional urethral realignment (PIUR) in patients with traumatic urethral injuries. MATERIALS AND METHODS This retrospective study included 13 patients with traumatic urethral injuries who were treated with PIUR between September 2008 and February 2014. All 13 patients were men with the mean age of 56.3 years. Technical success rate of PIUR, time to PIUR, required procedure time, length of hospital stay, duration of urethral catheterization, and complications after PIUR were investigated. RESULTS PIUR was technically successful in 12 of 13 patients (92.3%). The mean time from trauma to PIUR was 44 hours (range, 1-240 h). The mean procedure time was 20.2 minutes (range, 3-90 min). The median length of hospital stay was 15 days (range, 1-60 d). The mean duration of urethral catheterization after PIUR was 25 days (range, 9-65 d). There were no immediate complications related to PIUR, although 6 of 12 patients developed symptomatic urethral stricture after PIUR. The mean time to stricture development after PIUR was 4.3 months (range, 2-12 mo). Of the 6 patients, 2 were treated with endoscopic internal urethrotomy, and 4 were treated with interventional radiologic urethral balloon dilation. CONCLUSIONS PIUR can be safe and effective for patients with traumatic urethral injuries. However, symptomatic stricture formation occurred in one-half of the successful realignment procedures.

Sonographic Growth Charts for Kidney Length in Normal Korean Children: A Prospective Observational Study

Kidney length is the most useful parameter for clinical measurement of kidney size, and is useful to distinguish acute kidney injury from chronic kidney disease. In this prospective observational study of 437 normal children aged between 0 and < 13 years, kidney length was measured using sonography. There were good correlations between kidney length and somatic values, including age, weight, height, and body surface area. The rapid growth of height during the first 2 years of life was intimately associated with a similar increase in kidney length, suggesting that height should be considered an important factor correlating with kidney length. Based on our findings, the following regression equation for the reference values of bilateral kidney length for Korean children was obtained: kidney length of the right kidney (cm) = 0.051 × height (cm) + 2.102; kidney length of the left kidney (cm) = 0.051 × height (cm) + 2.280. This equation may aid in the diagnosis of various kidney disorders.

Ultrasonographic Quantitative Analysis of Fatty Pancreas in Obese Children: Its Correlation with Metabolic Syndrome and Homeostasis Model Assessment of Insulin Resistance

Objectives To evaluate pancreatic echogenicity on transabdominal ultrasonography and the correlation of fatty pancreas with metabolic syndrome (MetS), as well as insulin resistance (homeostasis model assessment of insulin resistance [HOMA‐IR]). Study design This retrospective study included 135 obese children and adolescents who underwent transabdominal ultrasonography from January 2015 to December 2015. Fatty pancreas was quantitatively analyzed using the pancreato‐perihepatic fat index (PPHFI). The correlation between the PPHFI and HOMA‐IR was analyzed, and multivariate logistic regression analysis was used to determine factors that were independently correlated with MetS. Receiver operating characteristic curve analysis was performed to determine the best cut‐off value of the PPHFI for diagnosing MetS. Results The PPHFI and the HOMA‐IR value were significantly higher in subjects with MetS than in those without MetS (P < .0001). The PPHFI also showed an association with the HOMA‐IR value (r = 0.70; P < .0001). The PPHFI was an independent factor for diagnosing MetS (OR 4.36; P = .032). The best cut‐off value for the PPHFI for a diagnosis of MetS was 2.34 with a sensitivity of 0.96 and specificity 0.70. Conclusions These results suggest that an increased PPHFI is significantly correlated with MetS and insulin resistance, and that the PPHFI may be a useful indicator for diagnosing MetS in obese children and adolescents. The impact of the presence of fatty pancreas in obese children and adolescents must be evaluated