Thoracolithiasis: 11 cases with a calcified intrapleural loose body.

PURPOSE: To describe clinical and imaging characteristics of thoracolithiasis. MATERIALS AND METHODS: Medical records from our center from September 2005 to March 2007 were reviewed. A definitive diagnosis was made by multidetector-row computed tomography studies of the chest, which revealed in each patient an intrapleural calcified nodular opacity, which changed in intrapleural location on serial examinations. Eleven patients fulfilled this criteria. The images were analyzed by experienced radiologists, who focused on the distribution, size, and shape of the thoracolithiasis. RESULTS: The incidence of thoracolithiasis was 0.086% (11 of 12,835 individuals). All the patients were asymptomatic and did not have any history of intrathoracic disease. The nodules ranged in size from 5 to 15 mm (median 8 mm), and were ovoid and smoothly marginated. Each nodule contained homogeneous diffuse calcification. Eight nodules occurred in the left pleural space and 3 in the right. Their locations varied, which included on the diaphragm, along the posterior chest wall of the lower lung, abutting the left cardiac margin, and near the paraspinal space of the lower thoracic spine. Each of the calcified pleural bodies changed in intrapleural location on follow-up computed tomography examination. CONCLUSIONS: The calcified intrapleural nodular opacities of thoracolithiasis tended to be located inferiorly, presumably secondary to the effects of gravity, and they seemed to migrate freely within the pleural cavity.

Lipid re-screening: what is the best measure and interval?

OBJECTIVES: To estimate the long-term true change variation ('signal') and short-term within-person variation ('noise') of the different lipid measures and evaluate the best measure and the optimal interval for lipid re-screening. DESIGN: Retrospective cohort study from 2005 to 2008. SETTING: A medical health check-up programme at a centre for preventive medicine in a teaching hospital in Tokyo, Japan. PARTICIPANTS: 15 810 apparently healthy Japanese adults not taking cholesterol-lowering drugs at baseline, with a mean body mass index of 22.5 kg/m(2) (SD 3.2). MAIN OUTCOME MEASURES: Annual measurement of the serum total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and calculation of the ratio of TC/HDL and LDL/HDL. Measurement of the ratio of long-term true change variation ('signal') to the short-term within-person variation ('noise') for each measure. RESULTS: At baseline, participants (53% male) with a mean age of 49 years (range 21-92) and a mean TC level of 5.3 mmol/l (SD 0.9 mmol/l) had annual check-ups over 4 years. Short-term within-person variations of TC, LDL, HDL, TC/HDL, and LDL/HDL were 0.12 (coefficient of variation (CV) 6.4%), 0.08 (CV 9.4%), 0.02 (CV 8.0%) mmol(2)/l(2), 0.08 (CV 7.9%) and 0.05 (CV 10.6%), respectively. The ratio of signal-to-noise at 3 years was largest for TC/HDL (1.6), followed by LDL/HDL (1.5), LDL (0.99), TC (0.8) and HDL (0.7), suggesting that cholesterol ratios are more sensitive re-screening measures. CONCLUSION: The signal-to-noise ratios of standard single lipid measures (TC, LDL and HDL) are weak over 3 years and decisions based on these measures are potentially misleading. The ratios, TC/HDL and LDL/HDL, seem to be better measures for monitoring assessments. The lipid re-screening interval should be >3 years for those not taking cholesterol-lowering drugs.

Relationship between prostate-specific antigen and hematocrit: does hemodilution lead to lower PSA concentrations in men with a higher body mass index?

OBJECTIVES: To examine whether a lower hematocrit was associated with a lower prostate-specific antigen (PSA), when stratifying by body mass index (BMI) in healthy men. PSA test is widely used in screening for prostate cancer. Many studies have found that PSA levels inversely correlate with BMI. It remains unclear whether hemodilution causes this inverse relationship. METHODS: We investigated 19,367 men who visited a hospital for a routine health checkup in 2007. We obtained information on age, BMI, PSA, hematocrit, and smoking status. BMI was categorized as < 18.5, 18.5-22.0, 22.0-25.0, 25.0-30.0, and > or = 30.0 kg/m(2). RESULTS: In all subjects, older age and lower BMI were weakly correlated with a higher PSA (r = 0.20, P <.001 and r = -0.05, P <.001, respectively). A multiple regression model for predicting PSA was constructed using age, current smoking status, and hematocrit for each BMI category. After controlling for age and smoking, PSA increased significantly with increasing hematocrit in participants with BMIs of 18.5-30 kg/m(2) (all P <.001). For example, in men with a BMI of 22-25 kg/m(2), slight increases (1.4% increase; 95% confidence interval, 1.0%-1.9%) were observed in PSA with a 1-unit increase in hematocrit. CONCLUSIONS: In healthy men with a BMI of 18.5-30 kg/m(2), a lower hematocrit was significantly associated with a lower PSA. Hemodilution may explain the lower PSA levels observed in men with a higher BMI, resulting in an inverse relationship between BMI and PSA.

Evaluated reference intervals for serum free thyroxine and thyrotropin using the conventional outliner rejection test without regard to presence of thyroid antibodies and prevalence of thyroid dysfunction in Japanese subjects.

The determination of the reference intervals for serum free thyroxine (FT4) and thyrotropin (TSH) is usually based on central 95 percentile intervals using subjects without detectable antibodies against thyroid peroxidase (TPO) or thyroglobulin (Tg). However, some subjects with extreme data over reference intervals are generally included. The study objective was to evaluate the reference intervals for FT4 and TSH using different outlier tests. 1,007 Japanese subjects screened based on the National Academy of Clinical Biochemistry criteria in the United States participated in this study. Serum FT4, TSH, and TPOand Tg antibodies were measured in all subjects. To make appropriate reference intervals, the Smirnov-Grubbus' outlier test was taken for antibody-free subjects (Ab[-] S-G), and the conventional outlier rejection method rejecting the value out of +/-3 standard deviation was taken for antibody-free subjects (Ab[-] STD) and all subjects (ALSTD), respectively. 12.8% of all subjects had either TPOor Tg antibodies in their serum. The 2.5(th) and 97.5(th) percentiles of reference intervals of serum FT4 (ng/dL) and TSH (mU/L) were 1.03~1.66 and 0.51 approximately 5.14 in (Ab[-] S-G), 1.03 approximately 1.65 and 0.51 approximately 4.57 in (Ab[-] STD) and 1.03 approximately 1.66 and 0.51 approximately 4.67 in (ALSTD), respectively. FT4 in males were significantly and negatively correlated with age, and TSH was significantly and positively correlated with age (P<0.000001 and P<0.00001, respectively). There was a significant difference between the sexes in FT4 (P<0.00001) but not in TSH. The prevalence of hypothyroidism, subclinical hypothyroidism, sublinical hyperthyroidism and hyperthyroidism were 0.2, 3.1, 2.3 and 0.3% (Ab[-] S-G), 0.3, 4.7, 2.3 and 0.3%(Ab[-] STD), and 0.3, 4.3, 2.3 and 0.3% (AL STD), respectively. This finding indicates that the conventional outlier rejection method is both convenient and appropriate to provide reference intervals for serum FT4 and TSH levels without regard to thyroid antibodies using large samples.

Comparison of reading time between screen-film mammography and soft-copied, full-field digital mammography.

PURPOSE: To compare the reading time for full-field digital mammography (FFDM) and screen-film mammography (SFM) using a recommended reading method and to provide data regarding the reading time required to establish the optimal conditions for digital mammography. METHODS: Reading time was measured during image interpretation by two expert radiologists. FFDM images were taken for screening, and readers A and B read images obtained for 79 and 82 patients, respectively. The mammograms read by both readers were similar with regard to patients' backgrounds. Further, 100 SFM mammograms were read to perform comparative analyses. The reading times were compared. RESULT: Reader A recorded mean reading times of 31 and 56 s, respectively, for the SFM and FFDM images with no comparative mammograms, and means of 45 and 62 s for those with comparative mammograms. Reader B recorded mean reading times of 43 and 74 s, respectively, for SFM and FFDM images with no comparative mammograms, and 53 and 66 s for those with comparative mammograms. CONCLUSION: The reading time is prolonged in FFDM performed according to a recommended method. Post-processing is thought to affect the reading time.

Evaluation of a new rapid and fully automated electrochemiluminescence immunoassay for thyrotropin receptor autoantibodies.

BACKGROUND: Hyperthyroidism in Graves' disease is caused by autoantibodies to the TSH receptor (TSHR), and measurement of the TSHR autoantibody (TRAb) yields important information to diagnose and decide on the course of treatment of Graves' disease. We evaluated basic and clinical performance of a new, rapid, and fully automated electrochemiluminescence immunoassay Elecsys Anti-TSHR (Elecsys TRAb) for measuring serum TRAb. METHODS: For evaluation of basic performance of the assay, we carried out intra- and interassay precision studies using five serum pools and three serum pools, respectively, and the assay was compared with four commercial TRAb assays. Clinical performance of the assay was evaluated with sera from 298 patients with untreated Graves' disease, 220 patients with destructive (painless and subacute) thyroiditis, and 332 healthy volunteers. The optimal cutoff point, which was calculated by receiver operating characteristic (ROC) analysis with the above subjects, was then used to classify an independent sample set of 80 patients with untreated Graves' disease, and 152 patients with destructive thyroiditis. RESULTS: Intraassay coefficient of variation (CV) was 4.24% at 1.85 IU/L and interassay CV was 10.1% at 1.46 IU/L. All the correlation coefficient values calculated against four commercial assays were larger than 0.85. ROC analysis resulted in a specificity of 99.1% with a sensitivity of 97.0% at a decision limit of 1.86 IU/L from comparison with untreated Graves' disease and destructive thyroiditis. The cutoff point yielded a sensitivity of 87.5% and specificity of 96.7% with the independent sample set. CONCLUSION: In spite of the short measuring time of only 27 minutes, the assay showed the same or better results with the existing commercial products. The short measuring time would contribute to speedy, preconsultation diagnosis of thyroid disease, especially of Graves' disease.