Background: An international reference measurement laboratory network for creatinine (Cr) is lacking; therefore, Korea developed an independent evaluation and certification system. The in vitro diagnostics (IVD) certification program, launched in 2017, formed part of a broader Cr standardization initiative intended to enhance accuracy at the manufacturing stage. Methods: The program was designed to evaluate analytical systems, including all reagent lots, calibrators, and instrument models, twice annually. Bias, imprecision, total error (TE), and linearity were evaluated based on established acceptance criteria. A post-certification process allows submission for a second challenge and validation of corrective actions. Results: Between 2017 and 2023, 489 analytical systems were evaluated. Average acceptance rates for bias, imprecision, TE, and linearity were 70.8%, 95.9%, 87.7%, and 87.8%, respectively. The lowest acceptance rate for bias evaluation was 8.7% for the kinetic Jaffe method without compensation in 2018. Over the 7-year period, the mean absolute percentage bias (absBias%), coefficient of variation (CV), and TE were 4.62%, 1.37%,and 7.29%, respectively. The highest absBias% (7.94%) was observed in the 0.0 ≤ Cr < 1.0target value range. Since 2019, a consistent reduction in absBias% has been observed. Conclusions This program is a pioneering response to the absence of a global certification program for Cr assays. It offers significant advantages, including comprehensive evaluations, fee-free participation, and a robust post-certification process. Continuous participation and improvement efforts by manufacturers have contributed to enhanced accuracy in Cr assays.

Hyponatremia is primarily a water balance disorder associated with high morbidity and mortality. The pathophysiological mechanisms behind hyponatremia are multifactorial, and diagnosing and treating this disorder remains challenging. In this review, the classification, pathogenesis, and step-by-step management approaches for hyponatremia in patients with liver disease are described based on recent evidence. We summarize the five sequential steps of the traditional diagnostic approach: 1) confirm true hypotonic hyponatremia, 2) assess the severity of hyponatremia symptoms, 3) measure urine osmolality, 4) classify hyponatremia based on the urine sodium concentration and extracellular fluid status, and 5) rule out any coexisting endocrine disorder and renal failure. Distinct treatment strategies for hyponatremia in liver disease should be applied according to the symptoms, duration, and etiology of disease. Symptomatic hyponatremia requires immediate correction with 3% saline. Asymptomatic chronic hyponatremia in liver disease is prevalent and treatment plans should be individualized based on diagnosis. Treatment options for correcting hyponatremia in advanced liver disease may include water restriction; hypokalemia correction; and administration of vasopressin antagonists, albumin, and 3% saline. Safety concerns for patients with liver disease include a higher risk of osmotic demyelination syndrome.

Purpose: This study aimed to apply doxorubicin-loaded nanoparticle microbubble (Dox-NP-MB) therapy in an orthotopic rat model of hepatocellular carcinoma (HCC) and investigate the utility of contrast-enhanced ultrasound (CEUS) and intravoxel incoherent motion diffusion-weighted magnetic resonance imaging (IVIM-DWI) for response evaluation. Methods: Twenty-eight N1S1 HCC model rats were treated with either Dox-NP-MB (group [G] 1, n=8), doxorubicin (Dox) alone (G2, n=7), nanoparticle microbubbles alone (G3, n=7), or saline (G4, control, n=6) on days 0 and 7, and were sacrificed on day 11. IVIM-DWI and CEUS were performed before each treatment and before euthanasia. Efficacy was estimated by the percentage of tumor volume growth inhibition compared with control. Toxicity was assessed by body weight changes and blood tests. Post-treatment changes in IVIM-DWI and CEUS parameters were analyzed. Results: Tumor volume growth was inhibited by 48.4% and 90.2% in G1 and G2 compared to G4, respectively. Compared to G2, G1 had a significantly lower degree of body weight change (median, 91.0% [interquartile range, 88.5%-97.0%] vs. 88.0% [82.5%-88.8%], P<0.05) and leukopenia (1.75×103 cells/μL [1.53-2.77] vs. 1.20×103 cells/μL [0.89-1.51], P<0.05). After the first treatment, an increase in peak enhancement, wash-in rate, and wash-in perfusion index on CEUS was observed in G3 and G4 but suppressed in G1 and G2; the apparent diffusion coefficients, true diffusion coefficients, and perfusion fractions significantly increased in G1 and G2 compared to baseline (P<0.05). Conclusion Dox-NP-MB showed reduced Dox toxicity. Early changes in some CEUS and IVIM-DWI parameters correlated with the therapeutic response.

Objective: We aimed to develop and test a deep learning algorithm (DLA) for fully automated measurement of the volume and signal intensity (SI) of the liver and spleen using gadoxetic acid-enhanced hepatobiliary phase (HBP)-magnetic resonance imaging (MRI) and to evaluate the clinical utility of DLA-assisted assessment of functional liver capacity. Materials and Methods: The DLA was developed using HBP-MRI data from 1014 patients. Using an independent test dataset (110 internal and 90 external MRI data), the segmentation performance of the DLA was measured using the Dice similarity score (DSS), and the agreement between the DLA and the ground truth for the volume and SI measurements was assessed with a Bland-Altman 95% limit of agreement (LOA). In 276 separate patients (male:female, 191:85; mean age ± standard deviation, 40 ± 15 years) who underwent hepatic resection, we evaluated the correlations between various DLA-based MRI indices, including liver volume normalized by body surface area (LV BSA), liver-to-spleen SI ratio (LSSR), MRI parameter-adjusted LSSR (aLSSR), LSSR x LV BSA, and aLSSR x LV BSA, and the indocyanine green retention rate at 15 minutes (ICG-R15), and determined the diagnostic performance of the DLA-based MRI indices to detect ICG-R15 ≥ 20%. Results: In the test dataset, the mean DSS was 0.977 for liver segmentation and 0.946 for spleen segmentation. The BlandAltman 95% LOAs were 0.08% ± 3.70% for the liver volume, 0.20% ± 7.89% for the spleen volume, -0.02% ± 1.28% for the liver SI, and -0.01% ± 1.70% for the spleen SI. Among DLA-based MRI indices, aLSSR x LV BSA showed the strongest correlation with ICG-R15 (r = -0.54, p < 0.001), with area under receiver operating characteristic curve of 0.932 (95% confidence interval, 0.895–0.959) to diagnose ICG-R15 ≥ 20%. Conclusion Our DLA can accurately measure the volume and SI of the liver and spleen and may be useful for assessing functional liver capacity using gadoxetic acid-enhanced HBP-MRI.

Purpose: To investigate the MRI features associated with neural foraminal stenosis (NFS) in patients older than 60 years with lumbar (L) radiculopathy. Materials and Methods: This study included 133 retrospectively selected patients older than 60 years with lumbar radiculopathy who had undergone a lumbar spine MRI (from January 2018 to April 2018). For L4/L5 and L5/sacral (S)1 levels, NFS was reviewed blindly by two radiologists. Spondylolisthesis, retrolisthesis, disc height loss, disc bulging/herniation/central canal stenosis, ligamentum flavum thickening, and facet hypertrophy were evaluated separately for the NFS and non-NFS groups, and they were compared using univariate and multivariate analyses. Results: The univariate analysis revealed that disc height loss (p = 0.006) was associated with NFS for L4/L5. For L5/S1, both spondylolisthesis (p = 0.005) and facet hypertrophy (p = 0.006) were associated with NFS. The multivariate logistic analysis revealed that disc height loss was associated with NFS for L4/L5 [odds ratio (OR) = 4.272; 95% confidence interval (CI) 1.736– 10.514]. For L5/S1, spondylolisthesis (OR = 3.696; 95% CI 1.297–10.530) and facet hypertrophy (OR = 6.468; 95% CI 1.283–32.617) were associated with NFS. Conclusion Disc height loss was associated with NFS for L4/L5 and spondylolisthesis and facet hypertrophy were associated with NFS for L5/S1.

Objectives: The aim of this study was to examine the clinical presentation, treatment delivery, and cisplatin eligibility of Korean patients with urothelial carcinoma (UC) in a real-world setting. Methods: We performed a retrospective cohort study of patients initially diagnosed with UC from March 2013 to June 2018. Creatinine clearance >60 mL/min and Eastern Cooperative Oncology Group performance status (0–1) were adopted as cisplatin eligibility criteria. Results: This study included 557 eligible patients. Median age was 71.0 years (range, 33–94 years), and males were dominant (80%). Primary tumor sites were: upper genitourinary tract, 18%; bladder, 81%; and urethra, 0.4%. Initial disease status was non-muscle invasive bladder cancer (313, 56%), diffuse infiltrating non-muscle invasive bladder cancer (19, 3%), cTanyN0 upper tract UC (75, 13%), cT2-4N0 bladder UC (82, 15%), TanyN1-3 UC (36, 7%), or initially metastatic UC (32, 6%). At the time of analysis (June 2019), following treatments were delivered to 134 patients with localized UC: radical operation with or without perioperative treatment (89, 67%), definitive chemoradiation (7, 5%), and palliative surgery or supportive care only (36, 28%). In total, 89 patients had metastatic UC, including those with recurrent disease (n=57), and 34 (38%) of the 89 were eligible for cisplatin. Conclusion Clinical presentations in East Asian UC patients were consistent with those of previous studies in other countries, except for a relatively high incidence of upper genitourinary tract. Our results can serve as a benchmark for further advances and future research for treatments of UC in East Asian patients.

Purpose: To investigate the MRI features associated with neural foraminal stenosis (NFS) in patients older than 60 years with lumbar (L) radiculopathy. Materials and Methods: This study included 133 retrospectively selected patients older than 60 years with lumbar radiculopathy who had undergone a lumbar spine MRI (from January 2018 to April 2018). For L4/L5 and L5/sacral (S)1 levels, NFS was reviewed blindly by two radiologists. Spondylolisthesis, retrolisthesis, disc height loss, disc bulging/herniation/central canal stenosis, ligamentum flavum thickening, and facet hypertrophy were evaluated separately for the NFS and non-NFS groups, and they were compared using univariate and multivariate analyses. Results: The univariate analysis revealed that disc height loss (p = 0.006) was associated with NFS for L4/L5. For L5/S1, both spondylolisthesis (p = 0.005) and facet hypertrophy (p = 0.006) were associated with NFS. The multivariate logistic analysis revealed that disc height loss was associated with NFS for L4/L5 [odds ratio (OR) = 4.272; 95% confidence interval (CI) 1.736– 10.514]. For L5/S1, spondylolisthesis (OR = 3.696; 95% CI 1.297–10.530) and facet hypertrophy (OR = 6.468; 95% CI 1.283–32.617) were associated with NFS. Conclusion Disc height loss was associated with NFS for L4/L5 and spondylolisthesis and facet hypertrophy were associated with NFS for L5/S1.