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Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA., Competing Interests: Conflicts of Interest: The authors have no potential conflicts of interest to disclose., (Copyrights © 2024 The Korean Society of Radiology.)

Cardiac CT has been proven to provide diagnostic and prognostic evaluation of coronary artery disease for cardiovascular risk stratification and treatment decision-making based on rapid technological development and various research evidence. Coronary CT angiography has emerged as a gateway test for coronary artery disease that can reduce invasive angiography due to its high negative predictive value, but the diagnostic specificity is relatively low. However, coronary CT angiography is likely to overcome its limitations through functional evaluation to identify the hemodynamic significance of coronary artery disease by analyzing myocardial perfusion and fractional flow reserve through cardiac CT. Recently, studies have been actively conducted to incorporate artificial intelligence to make this more objective and reproducible. In this review, functional imaging techniques of cardiac computerized tomography are explored., Competing Interests: Conflicts of Interest: The authors have no potential conflicts of interest to disclose., (Copyrights © 2022 The Korean Society of Radiology.)

Background: Therapeutic drug monitoring (TDM) of tacrolimus is essential because of narrow therapeutic range and poor correlation of dose to blood concentration. Affinity Column Mediated Immunometric Assay (ACMIA) does not require a pretreatment steps in measurement of tacrolimus. In this study, we evaluated the performance of tacrolimus assay using ACMIA (Dimension RxL Max, Dade Behring)., Methods: The imprecision, the linearity and the detection limits and the interferences by bilirubin and chyle, and correlation with hematocrit for tacrolimus by ACMIA were evaluated according to Clinical and Laboratory Standards Institute guidelines EP5-A2, EP6-A, EP17-A, EP9-A2, and EP7-A2. Method comparison studies with microparticle enzyme immunoassay (MEIA) (IMx Tacrolimus II, Abbott Laboratories) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) (Waters 2795 Quattromicro API, Micromass) were also performed., Results: The total imprecision for low, middle and high level was 12.8%, 9.0% and 6.7%, respectively. The range of tacrolimus from 3.1 ng/mL to 35.4 ng/mL showed a clinically relevant linearity. The limit of detection and the functional sensitivity were 0.24 ng/mL and 0.72 ng/mL, respectively. Tacrolimus concentration measurement (Tac-CM) with ACMIA did not show significant interferences with bile and chyle and also did not show significant correlation with hematocrit. In comparison study for Tac-CM with MEIA and LC-MS/MS, Tac-CM with ACMIA showed a good correlation with MEIA (r=0.950) and LC-MS/MS (r=0.946)., Conclusions: The imprecision, linearity, detection limits, interference and correlation of Tac-CM with ACMIA were suitable for clinical use. Tac-CM with ACMIA could reduce turn around time and help clinicians to manage transplant patients on immunosuppressant therapy.

Background: We have evaluated the analytical performance of SureStep Flexx (Johnson and Johnson, USA) which can report the plasma equivalent glucose test results and be connected to the hospital information networks, following ISO15197 analytic procedure for glucometer for the first time., Methods: Adopting the guidelines of ISO15197, we measured the precision of ten glucometers from their repeatability and intermediate precision, and determined the accuracies of the glucometer, comparing to those of GEM Premier 4000 (Instrumentation Laboratory, USA). In addition, the guidelines of CLSI EP9-A2 and EP6-A were applied to correlate between data of glucometer and those of laboratory reference method by TBA-200FR (Toshiba Medical Systems, Japan) and to examine its linearity of glucose concentrations measured by SureStep Flexx. We used the clinical specimens and commercial control materials., Results: Repeatabilities and intermediate precisions of those glucometers were 4.0-7.3%, and 4.3-6.2%, respectively. When glucose levels are under 75 mg/dL, the difference between results of those meters and the reference values were within +/-6 mg/dL. However when glucose levels are over 75 mg/dL, those differences were within +/-12.7%. These results were acceptable for the ISO15197 criteria in all glucose concentrations. The glucose concentrations showed the clinically relevant linearity in the range from 36 mg/dL to 491 mg/dL. Moreover, Error Grid Analysis showed that all glucose results were in "zone A", which means that these values were clinically accurate., Conclusions: This study showed that SureStep Flexx can provide reliable results for patients and clinicians to manage the diabetes mellitus, satisfying the ISO15197 criteria.

Background: Additional tests ordered by doctors after checking abnormal routine test results for inpatients are usually delayed for one day or more, which in turn delays diagnostic and therapeutic procedures and prolongs length of stay (LOS) for the patients. We at Department of Laboratory Medicine, Asan Medical Center (AMC), established a "secondary order system for laboratory tests without additional blood sampling" to improve the conventional reflexive tests., Methods: Oracle 8.0 (Oracle Co., Belmont, CA, USA) was used for data base software and Powerbuilder (Powersoft, Burlington, UK) for client development tool. Specimens subjected to "reflexive tests by doctors without additional blood sampling" were SST tubes for routine chemistry and EDTA for routine hematology requested in the morning of additional requests of the laboratory tests., Results: Programs of registration and request for "reflexive tests by doctors without additional blood sampling" and bar code printing were developed for clinicians to check the routine test results and to order additional tests, if necessary, and for laboratory to perform the requested tests using the same samples used for routine chemistry and hematology tests in the morning. Additionally requested tests were done by finding the SST and EDTA samples, putting newly printed bar code, and processing them as usual. In February 2004, right after introducing reflexive tests by doctors without additional blood sampling, 75 additional requests were made for 50 patients, but they increased gradually up to 1,020 tests for 698 patients in December 2004. In 2005, the monthly average number of tests was 1,035 for 742 patients., Conclusions: The reflexive tests by doctors without additional blood sampling developed at AMC helped establish a rapid reporting of test results, which in turn reduced LOS related to laboratory. It also increased patient satisfactory indices by reducing repeated blood sampling and would also contribute to the financial health of the hospital.