Doppler ultrasonography of the lower extremity arteries: anatomy and scanning guidelines

Doppler ultrasonography of the lower extremity arteries is a valuable technique, although it is less frequently indicated for peripheral arterial disease than for deep vein thrombosis or varicose veins. Ultrasonography can diagnose stenosis through the direct visualization of plaques and through the analysis of the Doppler waveforms in stenotic and poststenotic arteries. To perform Doppler ultrasonography of the lower extremity arteries, the operator should be familiar with the arterial anatomy of the lower extremities, basic scanning techniques, and the parameters used in color and pulsed-wave Doppler ultrasonography.

Novel technique of virtual touch tissue imaging quantification shear wave elastography in differential diagnosis of thyroid nodules:initial experience / 中华医学超声杂志（电子版）

Objective To evaluate diagnostic value of the novel virtual touch tissue imaging quantification (VTIQ) technique of acoustic radiation force impulse (ARFI) shear wave elastography in the differential diagnosis between benign and malignant thyroid lesions. Methods From June to July 2014, the imaging data of 82 thyroid lesions in 75 patients proven by fine needle aspiration cytology (FNAC) biopsy on conventional ultrasound and VTIQ were retrospectively analyzed. The thyroid nodules were examined by conventional ultrasound firstly and then the lesions were classified by thyroid imaging report and data system (TI-RADS). The maximum, minimum, median and average of shear wave velocity (SWV) values were obtained from multiple SWV measurement under the VTIQ speed mode. The region of interest (ROI) was determined according to the VTIQ quality mode after the patients holding the breath. According to the FNAC cytology results, ROC curve were plotted to determine the most accurate SWV value and the cut-off value for differential diagnosis. Results According to the FNAC results, grading≥5 level was set as the positive results and FNAC<5 level as the negative results. There were 28 positive nodules and 54 negative nodules in 82 thyroid nodules. The positive rates of TI-RADS classification were consistent with the theoretical results. The SWVmax, SWVmin, SWVmedian, and SWVmean on VTIQ of negative and positive thyroid nodules were (3.2±0.6), (2.2±0.4), (2.7±0.4), (2.6±0.4) m/s, and (4.6±1.7), (3.1±0.8), (3.5±1.0), (3.6±1.1) m/s. There were significant differences between positive and negative thyroid nodules in SWVmax, SWVmin, SWVmedian, and SWVmean on VTIQ (t=3.53, 3.68, 3.32, 3.81, all P<0.01). Based on the area under curve of ROC, the SWVmean value in the nodule was the best value in comparison with other SWV values. The cut-off value of VTIQ mean was 2.9 m/s. According to ROC curve analysis, the sensitivity, specificity and Youden index for VTIQ were 70.6%, 88.5%, 0.59, respectively. Conclusion The study proved that VTIQ elastography technique plays an important role in differential diagnosis of thyroid nodules and the VTIQ SWVmean is the best parameter for differential diagnosis.

Usefulness of resistive index on spectral Doppler ultrasonography in the detection of renal cell carcinoma in patients with end-stage renal disease

PURPOSE: The aim of this study was to explore the usefulness of the resistive index (RI) on spectral Doppler ultrasonography (US) in the detection of renal cell carcinoma (RCC) in patients with end-stage renal disease (ESRD). METHODS: Seventeen ESRD patients with kidneys in which renal masses were suspected in routine US were subjected. They underwent computed tomography scans and additional Doppler US for the characterization of the detected lesions. All underwent radical nephrectomy with the suspicion of RCC. Fourteen patients finally were included. RI measurements were conducted in the region of the suspected renal mass and the background renal parenchyma. The intraclass correlation coefficient was used to assess the reproducibility of the RI measurement. A paired t-test was used to compare the RI values between the renal mass and the background renal parenchyma (P<0.05). RESULTS: The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma (0.41-0.65 vs. 0.75-0.89; P<0.001). The intrareader reproducibility proved to be excellent and good for the renal masses and the parenchyma, respectively (P<0.001). CONCLUSION: RI on spectral Doppler US is useful in detecting RCC in patients with ESRD. The RI values measured at the RCCs were significantly lower than those measured at the background renal parenchyma.

Assessment of left ventricular hypertrophy and impaired diastolic function in elderly hypertensive patients by brain natriuretic peptide level in combination with tissue doppler imaging / 中华老年医学杂志

Objective To investigate the clinical values of brain natriuretic peptide (BNP) in combination with TDI in diagnosing left ventricular hypertrophy (LVH) and impaired diastolic function in elderly hypertensive patients. Methods The 140 elderly hypertensive patients were divided into LVH group (n=69) and NLVH group (n=71). Control group consisted of 50 normal subjects. Plasma BNP level and index of echocardiography, including mitral peak flow velocity during early and late diastole (E, A), ratio of E/A, average peak velocities of six LV wall sites at mitral annuluses during early and late diastole (MEm, MAm), ratios of MEm/MAm and E/MEm were measured in all patients. The correlation of plasma BNP level with cardiac ultrasonographic findings was also examined. Results The level of BNP [(61.64±37.18)ng/L, (138. 65±30. 23)ng/L] and the ratio of E/MEm (11.3±1.83, 15.7±1.45) were significantly higher in NLVH group and LVH group than in normal group (P＜0. 05 or P＜0. 01). MEm [(6.32±0. 94)cm/s, (4.29±0. 91)cm/s]and MEm/MAm (0.76±0.19, 0.51±0. 11) were significantly lower in NLVH and LVH group than in normal group (P＜0.05 or P＜0. 01). The BNP level was negatively correlated with E/A, MEm and MEm/MAm (r=- 0. 294, r= 0. 387 and r= 0. 422, all P＜0. 01), and was positively correlated with LVMI and E/MEm (r=0.342, r=0.501, all P＜0.01). Conclusions Left ventricular diastolic function is impaired in elderly hypertension patients regardless of LVH or NLVH.Plasma BNP level in combination with echocardiography parameter is accurate to evaluate the LVHand impaired diastolic function in elderly hypertensive patients.

Pulsed wave Doppler ultrasonic manifestations of acute experimental incomplete testicular torsion / 中国医学影像技术

Objective To explore the pulsed wave Doppler (PWD) manifestations of acute experimental incomplete testicular torsion. Methods Eight healthy dogs were surgically modeled to obtain unilateral acute testis torsion from 180° to 630°, respectively. The peak systole velocity (PSV) and resistance index (RI) of intratesticular artery, capsular artery and arteria spermatica interna were measured with PWD before torsion, 2 h, 4 h and 6 h after torsion. Testes were examined pathologically after the experiment. Results PSV and RI of capsular artery and intratesticular artery decreased gradually with the extension of torsional time (P<0.05). PSV and RI of superior, torsional and inferior segments of arteria spermatica interna varied greatly and showed no strong regularity (P＞0.05) . The pathological results of testes showed no distinct changes or just mild interstitial hyperemia and edema. Conclusion The decrease of PSV and RI of capsular artery and intratesticular artery, especially RI have referential value in the judgement of acute experimental incomplete testicular torsion, whereas changes of PSV and RI of superior, torsional and inferior segments of arteria spermatica interna are not reliable.