Weechang Kang

Low-dose and standard-dose unenhanced helical computed tomography for the assessment of acute renal colic: prospective comparative study.

Purpose: To compare the efficacy of low-dose and standard-dose computed tomography (CT) for the diagnosis of ureteral stones. Material and Methods: Unenhanced helical CT was performed with both a standard dose (260 mAs, pitch 1.5) and a low dose (50 mAs, pitch 1.5) in 121 patients suspected of having acute renal colic. The two studies were prospectively and independently interpreted for the presence and location of ureteral stones, abnormalities unrelated to stone disease, identification of secondary signs, i.e. hydronephrosis and perinephric stranding, and tissue rim sign. The standard-dose CT images were interpreted by one reviewer and the low-dose CT images independently by two reviewers unaware of the standard-dose CT findings. The findings of the standard and low-dose CT scans were compared with the exact McNemar test. Interobserver agreements were assessed with kappa analysis. The effective radiation doses resulting from two different protocols were calculated by means of commercially available software to which the Monte-Carlo phantom model was given. Results: The sensitivity, specificity, and accuracy of standard-dose CT for detecting ureteral stones were 99%, 93%, and 98%, respectively, whereas for the two reviewers the sensitivity of low-dose CT was 93% and 95%, specificity 86%, and accuracy 92% and 94%. We found no significant differences between standard-dose and low-dose CT in the sensitivity and specificity for diagnosing ureter stones (P>0.05 for both). However, the sensitivity of low-dose CT for detection of 19 stones less than or equal to 2 mm in diameter was 79% and 68%, respectively, for the two reviewers. Low-dose CT was comparable to standard-dose CT in visualizing hydronephrosis and the tissue rim sign. Perinephric stranding was far less clear on low-dose CT. Low-dose CT had the same diagnostic performance as standard-dose CT in diagnosing alternative diseases. Interobserver agreement between the two low-dose CT reviewers in the diagnosis of ureter stones and alternative diseases, the identification of secondary signs, and tissue rim sign were high, with kappa values ranging from 0.769 to 0.968. On standard-dose CT scans, the calculated mean effective radiation dose was 7.30 mSv for males and 10.00 mSv for females. On low-dose CT scans, the calculated mean effective radiation dose was 1.40 mSv for males and 1.97 mSv for females. Conclusion: Compared with standard scans using 260 mAs, low-dose unenhanced helical CT using a reduced tube current of 50 mAs results in a concomitant decrease in the radiation dose of 81%. Although low-dose CT was limited in its ability to depict small-sized calculi less than or equal to 2 mm, it is still comparable to standard-dose CT for the diagnosis of ureter stones and alternative disease.

Manual Acupuncture Improved Quality of Life in Cancer Patients with Radiation-Induced Xerostomia

PURPOSE Radiotherapy-induced xerostomia seriously reduces the quality of life (QOL) for patients with head and neck cancer. This study aimed to investigate the effects of manual acupuncture on objective and subjective assessment of symptom changes in patients with cancer who have with radiation-induced xerostomia. MATERIALS AND METHODS Twelve (12) patients with radiation-induced xerostomia were randomized into 2 groups (real or sham acupuncture). Acupuncture was conducted twice weekly for 6 weeks in a single-blind setting. The effect was evaluated by measuring whole salivary flow rates (stimulated and unstimulated) and questionnaire-based assessment of subjective symptoms pre- and post-treatment (3 and 6 weeks after acupuncture treatment). RESULTS Both groups showed a slight increase in whole salivary flow rates, with no significant difference between them. However, real acupuncture markedly increased unstimulated salivary flow rates, and improved the score for dry mouth according to the xerostomia questionnaire, by 2.33 points versus 0.33 in the controls. CONCLUSIONS Our results showed the significantly meaningful amelioration of the subjective sensation of xerostomia closely associated with QOL in patients with head and neck cancer treated with irradiation.

Plasminogen activator inhibitor‐1 is an independent diagnostic marker as well as severity predictor of hepatic veno‐occlusive disease after allogeneic bone marrow transplantation in adults conditioned with busulphan and cyclophosphamide

Summary. We attempted to identify the diagnostic markers and severity predictors of hepatic veno‐occlusive disease (VOD) in 115 adult patients who were uniformly conditioned with busulphan and cyclophosphamide and who underwent allogeneic bone marrow transplantation (BMT). A diagnosis of VOD was made according to clinical criteria. Severity of VOD was classified as mild, moderate or severe. Various haemostatic parameters were determined at five time points (d −7, 0, 7, 14 and 21). Using clinical and haemostatic parameters, we developed multivariate models to identify diagnostic markers as well as severity predictors of VOD. Of the 115 patients included in the study, 50 (43·5%) developed VOD. Twenty‐nine had mild VOD, 13 moderate and 8 severe. Multiple logistic regression models showed that plasminogen activator inhibitor‐1 (PAI‐1) antigen (P = 0·029), percentage change of body weight (P = 0·001) and bilirubin (P < 0·001) were independent marker variables for the occurrence of VOD, and PAI‐1 antigen (P = 0·030) and bilirubin (P = 0·049) were independent marker variables for the occurrence of severe VOD. Our study suggests that PAI‐1 antigen can be used as a diagnostic marker as well as a severity predictor of VOD after allogeneic BMT.

Study of retinal nerve fibre layer thickness in eyes with high tension glaucoma and hemifield defect

AIM To quantitatively evaluate retinal nerve fibre layer (RNFL) difference in areas of apparently normal appearing visual field in eyes with high tension glaucoma (HTG) and hemifield defects using scanning laser polarimetry. METHODS 40 eyes from 40 patients with HTG with superior or inferior hemifield defects based on the Humphrey field analyser (HFA) underwent RNFL thickness measurements. 20 normal eyes from 20 subjects matched in age and refractive error were selected as a control group. The RNFL thickness was measured with a scanning laser polarimeter. Mean RNFL thickness was evaluated in four quadrants (superior, inferior, nasal, and temporal). A superior or inferior quadrant in the defined ring of scanning laser polarimetry corresponds to inferior or superior hemifield in HFA. RESULTS The mean RNFL thickness in the unaffected quadrant (the quadrant corresponding to the hemifield with apparently normal visual field based on HFA) of the HTG group was significantly thinner than the average RNFL thickness of the corresponding quadrant of the control eyes. The RNFL thickness of the unaffected quadrant in the eyes with HTG was reduced and statistically similar to that of the affected quadrant. Symmetry, calculated as the ratio of superior to inferior RNFL thickness, showed no statistical difference between the study and control group. CONCLUSION Changes in RNFL are present in the apparently normal hemifield in the eyes with HTG. The thickness of the RNFL is reduced symmetrically in both superior and inferior quadrants based on the GDx parameters.

Cohort study for the effect of chronic noise exposure on blood pressure among male workers in Busan, Korea

OBJECTIVE It has not yet been established whether exposure to chronic noise induces an increase in blood pressure or an increase in the development of hypertension. Therefore, a cohort study was performed to identify the effects of chronic noise exposure on blood pressure. METHODS Five hundred thirty male workers at a metal manufacturing factory in Busan, Korea, were enrolled in the study. They were monitored with an annual health check-ups for nine consecutive years from 1991 to 1999. The subjects were divided into four groups which were determined by noise level categories (NLCs) according to the exposure of noise intensity; NLC-I: office workers who were exposed to <60 dBA at work; NLC-II: worksite technical supporters or inspectors who were intermittently exposed to noise and were not using hearing protection devices; NLC-III: worksite workers exposed to a noise below 85 dBA (TWA) and used one type of hearing protection device, earplug or earmuff; NLC-IV: worksite workers who were exposed to a noise level of 85 dBA or higher in average and used both earplug and earmuff. RESULTS After controlling the possible confounders, such as baseline age, smoking, alcohol intake, exercise, family history of hypertension, systolic blood pressure (SBP), or diastolic blood pressure (DBP), and changes in body mass index (BMI), we determined that the mean values for the SBP over the duration of this study were 3.8, 2.0, and 1.7 mmHg higher in groups NLC-IV, NLC-III, and NLC-II, respectively, in comparison to that of the NLC-I group. There was no significant difference in DBP among the groups. CONCLUSION This study suggests that chronic noise exposure increases SBP independently, among male workers.

Ethnic differences in the age-related distribution of serum prostate-specific antigen values: a study in a healthy Korean male population.

OBJECTIVES To further improve the use of prostate-specific antigen (PSA) as a screening test for prostate cancer in Asian countries, we sought to establish the normal distribution of serum PSA values in Korean men, because, until recently, studies conducted to establish normal serum PSA values have involved few Asian populations. METHODS Between May 1995 and June 1997, 5805 healthy Korean men 30 to 79 years old who visited our hospital for a routine health checkup were entered into a prospective study of early screening for prostate cancer. All men underwent detailed clinical examinations, including a digital rectal examination and serum PSA determination. All men who were more than 50 years old with abnormal digital rectal examination findings and/or an elevated serum PSA level (greater than 4.0 ng/mL) also underwent transrectal ultrasound-guided sextant biopsy. Four were found to have cancer and were excluded from the analysis. RESULTS The median serum PSA concentration (5th to 95th percentile range) was 0.8 ng/mL (0.2 to 1.8) for patients 30 to 39 years old (n = 1382); 0.8 ng/mL (0.2 to 2.0) for patients 40 to 49 years old (n = 1776); 0.9 ng/mL (0.2 to 2.4) for those 50 to 59 years old (n = 1775); 1.0 ng/mL (0.2 to 3.9) for men 60 to 69 years old (n = 746); and 1.3 ng/mL (0.5 to 6.3) for patients 70 to 79 years old (n = 122). The serum PSA concentration correlated with age (P <0.001), with an increase by approximately 1.2% annually, although the statistical correlation was weak (r = 0.16). Almost no change occurred in the median serum PSA value in patients 50 years old or younger; a gradual increase was observed in patients older than 50. In those 50 years old or older, the median and 95th percentile serum PSA values for Korean men were lower than those for white men. CONCLUSIONS Contrary to earlier observations that the serum PSA level strongly correlates with age, the influence of age on serum PSA was found to be weaker in this study. Moreover, the results also demonstrated that the distribution of the serum PSA level differs along ethnic lines. The cutoff value for serum PSA in mass screening for prostate cancer should be adjusted in nonwhite races.

Reproducibility of scanning laser polarimetry (GDx) of peripapillary retinal nerve fiber layer thickness in normal subjects.

Abstract.Purpose: To assess the reproducibility of measurement of retinal nerve fiber layer (RNFL) thickness among subjects using the GDx Nerve Fiber Analyzer (NFA). Methods: One eye of each of five young and healthy volunteers was imaged by three newly trained technicians (R.-H.P, K.-R.K., and S.-T.K.). Each volunteer was scanned six consecutive times for five independent times within a 1-month period. One composite image was selected out of three best images per session. Intra- and interoperator reproducibilities were calculated and the influence of placement of measurement ellipse by a single operator on interobserver reproducibility was also investigated. Results: Mean coefficients of variation for total integral value of RNFL were 3.67±1.47%, 3.86±2.13%, and 4.16±1.97%, respectively for the three technicians. Interoperator variability was not statistically significant (P=0.075), and the difference was even less if a single ellipse drawn by one operator was used in all measurements (P=0.1528) by repeated-measures analysis of variance (ANOVA). Conclusions: The results suggest that GDx NFA may provide acceptable intraoperator as well as interoperator reproducibility among Asian eyes.

Myelophil, an extract mix of Astragali Radix and Salviae Radix, ameliorates chronic fatigue: A randomised, double-blind, controlled pilot study

OBJECTIVES To investigate the anti-fatigue effects of Myelophil, an extract of a mix of Astragali Radix and Salviae Radix, which has been used to treat patients with chronic fatigue. SUBJECTS AND DESIGN A randomised, double-blind, controlled clinical trial was performed with 36 adults who complained of chronic fatigue. The subjects were divided among a control group and low- and high-dose groups (3 or 6g of oral Myelophil per day, respectively) and were monitored for 4 weeks. Fatigue severity was subjectively characterised, and the expression of 42 cytokines was evaluated using an antibody array. RESULTS Myelophil administration (3g per day) significantly decreased the fatigue severity score compared with the control (p<0.05). No changes were noted in cytokine expression. CONCLUSIONS Myelophil appears to have a pharmacological effect against fatigue, suggesting the clinical relevance of the traditional medicinal plants, Astragalus membranaceus and Salvia miltiorrhiza.

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.

Diagnostic Performance of Virtual Gastroscopy Using MDCT in Early Gastric Cancer Compared with 2D Axial CT: Focusing on Interobserver Variation

OBJECTIVE The objective of our study was to assess the diagnostic performance of virtual gastroscopy using MDCT for the detection of early gastric cancer (EGC) compared with 2D axial CT, focusing on interobserver reliability. MATERIALS AND METHODS During an 11-month period, we performed CT examinations of 94 consecutive patients with EGC and a control group composed of 68 patients without EGC. Three radiologists retrospectively interpreted the 2D axial CT and virtual gastroscopy images. Diagnostic performances were compared within each observer using the area under the receiver operating characteristic curve (A(z)). Sensitivity and specificity were also calculated for each individual observer. The simple kappa statistic was used to evaluate interobserver reliability in the detection of EGC. RESULTS The diagnostic performance for overall lesion detection in patients with EGC was significantly higher with virtual gastroscopy (A(z) = 0.829-0.885) than with 2D axial CT (A(z) = 0.734-0.793) (p < 0.001). The sensitivity and specificity of virtual gastroscopy for EGC were 78.7-84.0% and 83.8-91.2%, respectively. The sensitivity and specificity of 2D axial CT for EGC were 62.8-69.2% and 83.8-92.7%, respectively. Virtual gastroscopy showed a higher sensitivity for EGC than 2D axial CT (p < 0.001). The interobserver reliabilities showed moderate to substantial agreement (kappa = 0.40-0.74 for 2D axial CT, kappa = 0.57-0.71 for virtual gastroscopy). CONCLUSION Virtual gastroscopy showed excellent results with a good interobserver reliability for the detection of EGC compared with 2D axial CT.