Preliminary study of virtual touch tissue quantification in the diagnosis of chronic renal failure with secondary hyperparathyroidism

Objective To study the application value of virtual touch tissue quantification (VTQ) in parathyroid examination and parathyroidectomy of chronic renal failure patients with secondary hyperparathyroidism (SHPT). Methods Ninety-five patients of renal failure with maintenance hemodialysis from October 2013 to June 2014 in Beijing Chaoyang Hospital of Capital Medical University were analyzed. Any diameter over 5 mm of one single gland was defined as hyperplasia gland. First, hyperplasia gland was examined, the size of gland was also calculated. Then VTQ was applied to measure the shear wave velocity (SMV)of hyperplasia gland. Parathyroid was grouped according to iPTH, calcium-phosphorus product and size of hyperplasia gland. A comparison of SMV among groups was conducted through Independent-Samplesttest. ROC curve was performed by SMV results. Results Thirty-three cases with fifty-nine enlarged parathyroid were detected by conventional ultrasound examination. The detection rate was 34%. The average SMV of hyperplasia gland was (1.29±0.43) m/s, the SMV [(1.75±0.59) m/s] of hyperplasia gland was higher in the group which the volum of single gland was larger than 500 mm3. The best threshold of SMV to distinguish the size of hyperplasia parathyroid was 1.555 m/s, of which the area under the curve was 0.794, sensitivity was 79% and specificity was 76%. The SMV [(1.36±0.47) m/s] of hyperplasia gland was higher in the group which the calcium-phosphorus product was more than 4.52 mmol2/L2. The difference of the impact of iPTH to SMV was not statistically significant. Conclusions VTQ shows that both chronic renal failure patients with calcium-phosphorus product beyond the normal and patients with bigger parathyroid glands usually get the higher SMV results, which could provide help for the indications of parathyroidectomy of SHPT patients. Key words: Ultrasonography; Renal insufficiency; Hyperparathyroidism, secondary; Elasticity imaging techniques