ABSTRACT
Purpose Papillary thyroid microcarcinoma (PTMC) is difficult to diagnose its nature before surgery, thus results in misdiagnosis. This paper aims to determine the best diagnostic cutoff value using anteroposterior and transverse diameter ratio (A/L) and longitudinal and transverse diameter ration (L/T) in PTMC. Materials and Methods The CT data of 154 pathology proven benign and malignant thyroid nodules ≤ 1.0 cm in diameter in 78 cases were reviewed, including 75 PTMC in 47 patients and 79 benign nodule in 31 patients. The anteroposterior and transverse diameter ratio (A/T) on axial view, A/L on sagittal view, and L/T on coronal view were measured and calculated. A non-parametric method was used to draw the receiver operating curve of A/T, A/L and L/T. The mean and standard deviation of CT diameters in benign and malignant nodules were calculated. The area under the curve, sensitivity, specificity and diagnostic accuracy, positive predictive value and negative predictive value were determined. CT manifestations of small benign and malignant thyroid nodules were also analyzed. Results The A/T and A/L ratio were significantly larger for PTMC than benign nodules (P<0.01), while L/T diameters were significantly smaller than the benign nodules (P<0.01). The area under ROC was 0.8841, 0.7676 and 0.4052 for A/T, A/L and L/T respectively. The best diagnostic cutoff value of A/T and A/L were 1.05 and 1.0. With A/T ≥ 1.05, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value were 88.00%, 84.81%, 86.36%, 84.62% and 88.12%, respectively. With A/L ≥ 1.0, the sensitivity, specificity, accuracy, positive predictive value and negative predictive values were 66.67%, 82.28%, 74.68%, 78.13% and 72.22%, respectively. CT characteristics of PTMC included superficial location, oval low density, blurry boundary, microcalcification and progressive enhancement with accuracy of 71.43%, 50.00%, 79.22%, 68.83% and 90.91%, respectively. Conclusion The cutoff values of A/T ≥ 1.05 and A/L ≥ 1.0 can be used to diagnose PTMC with high accuracy.
ABSTRACT
<p><b>OBJECTIVE</b>To study lumbar vertebral degenerations of coal miners with low back pain.</p><p><b>METHODS</b>40 underground miners with low back pain, aged from 30 to 50 years and employed for a length from 10 to 30 years, were taken as observation group. 30 ground workers without low back pain but with almost the same age, employment length and height etc. were selected as control group. Intervertebral discs at L3/L4, L4/L5, L5/S1 were scanned with computerized tomography, comparing herniated discs, sagittal diameter of vertebral canal, height of lateral recess, vertebral hypertostosis, ligament hypertrophy and calcification between two groups.</p><p><b>RESULTS</b>L3/L4, L4/L5, L5/S1 herniated discs and narrow lateral recess in observation group(0.33 +/- 0.15, 0.53 +/- 0.25, 0.45 +/- 0.18 and 0.40 +/- 0.08, 0.31 +/- 0.05, 0.37 +/- 0.07) were more serious than that in control group(0.28 +/- 0.11, 0.32 +/- 0.21, 0.37 +/- 0.19 and 0.42 +/- 0.10, 0.43 +/- 0.07, 0.40 +/- 0.06), but only with significant difference at L4/L5 (P < 0.01). Sagittal diameter of vertebral canal in observation group is narrower than that in control group but of little significance(P > 0.05). Cases of vertebral hyperostosis, ligament hypertrophy and calcification were found more frequent in observation group(45.00%, 42.50%, 22.50%) than in control group(23.33%, 16.67%, 16.67%), but only ligament hypertrophy was remarkable(P < 0.05).</p><p><b>CONCLUSIONS</b>As compared with control group lumbar vertebral degenerations are more serious in underground miners with manifestations like herniated disc and narrow lateral recess mainly at L4/L5.</p>