New method for ultrasound-guided inferior vena cava filter placement.

OBJECTIVE: Transabdominal ultrasound (TAUS)-guided inferior vena cava filter (IVCF) placement currently uses an inferior vena cava (IVC) longitudinal plane with cross-section of the right renal artery or the transverse plane of the right renal vein (RRV)-IVC intersection. The goal of this study was to introduce a new method for TAUS-guided IVCF placement. METHODS: The study enrolled patients who were at high risk for or had pulmonary embolism from October 22, 2010, to June 30, 2016. The probe was positioned on the right flank to centralize the RRV-IVC junction during imaging and to permit a straight line through the midpoint of the probe on the surface and a parallel line 1.0 cm below the straight line as a marker. The probe was subsequently placed on the abdominal wall with the upper edge at the marker line to show the long axis of the IVC during the process of filter placement. The upper edge of the probe was considered the filter tip position. RESULTS: A total of 1029 patients were evaluated, and 98 patients (9.5%) were excluded because of poor IVC visualization (n = 14 [1.4%]), IVC or bilateral iliac vein thrombosis (n = 79 [7.7%]), and unsuitable anatomy (n = 5 [0.5%]). The remaining 931 patients (90.5%) were selected for TAUS-guided IVCF placement, and all filters (100%) were successfully placed. There were no procedure-related complications. Suprarenal IVCF was observed in 4 patients (0.4%) by computed tomography, and the filter tip exceeded the upper edge of L2 in 15 patients (1.6%) by plain film radiography; one of them had two RRVs. Severe filter tilting (20.8 degrees) occurred in one patient. CONCLUSIONS: This new method of TAUS-guided IVCF placement was simple, safe, and effective. It may be widely applied for the bedside placement of vena cava filters.

The value of quantitative shear wave elastography in differentiating the cervical lymph nodes in patients with thyroid nodules.

PURPOSE: This study aimed at evaluating the diagnostic performance of quantitative shear wave elastography (SWE) in differentiating metastatic cervical lymph nodes from benign nodes in patients with thyroid nodules. METHODS: One hundred and forty-one cervical lymph nodes from 39 patients with thyroid nodules that were diagnosed as papillary thyroid cancer had been imaged with SWE. The shear elasticity modulus, which indicates the stiffness of the lymph nodes, was measured in terms of maximum shear elasticity modulus (maxSM), minimum shear elasticity modulus (minSM), mean shear elasticity modulus (meanSM), and standard deviation (SD) of the shear elasticity modulus. RESULTS: All the patients underwent thyroid surgery, 50 of the suspicious lymph nodes were resected, and 91 lymph nodes were followed up for 6 months. The maxSM value, minSM value, meanSM value, and SD value of the metastatic lymph nodes were significantly higher than those of the benign nodes. The area under the curve of the maxSM value, minSM value, meanSM value, and SD value were 0.918, 0.606, 0.865, and 0.915, respectively. CONCLUSIONS: SWE can differentiate metastasis from benign cervical lymph nodes in patients with thyroid nodules, and the maxSM, meanSM, and SD may be valuable quantitative indicators for characterizing cervical lymph nodes.

Laser-induced interstitial thermotherapy via a single-needle delivery system: Optimal conditions of ablation, pathological and ultrasonic changes.

This study aimed to examine the optimal conditions of laser-induced interstitial thermotherapy (LITT) via a single-needle delivery system, and the ablation-related pathological and ultrasonic changes. Ultrasound (US)-guided LITT (EchoLaser system) was performed at the output power of 2-4 Wattage (W) for 1-10 min in ex vivo bovine liver. Based on the results of the ex vivo study, the output power of 3 and 4 W with different durations was applied to in vivo rabbit livers (n=24), and VX2 tumors implanted in the hind limbs of rabbits (n=24). The ablation area was histologically determined by hematoxylin-eosin (HE) staining. Traditional US and contrast enhanced ultrasound (CEUS) were used to evaluate the treatment outcomes. The results showed: (1) In the bovine liver, ablation disruption was grossly seen, including a strip-like ablation crater, a carbonization zone anteriorly along the fiber tip, and a surrounding gray-white coagulation zone. The coagulation area, 1.2 cm in length and 1.0 cm in width, was formed in the bovine liver subjected to the ablation at 3 W for 5 min and 4 W for 4 min, and it extended slightly with the ablation time. (2) In the rabbit liver, after LITT at 3 W for 3 min and more, the coagulation area with length greater than or equal to 1.2 cm, and width greater than or equal to 1.0 cm, was found. Similar coagulation area was seen in the implanted VX2 carcinoma at 3 W for 5 min. (3) Gross examination of the liver and carcinoma showed three distinct regions: ablation crater/carbonization, coagulation and congestion distributed from the center outwards. (4) Microscopy revealed four zones after LITT, including ablation crater/carbonization, coagulation, edema and congestion from the center outwards. A large area with coagulative necrosis was observed around a vessel in the peripheral area with edema and hyperemia. (5) The size of coagulation was consistent well to the CEUS findings. It was concluded that EchoLaser system at low power can produce a coagulation area larger than 1.0 cm×1.0 cm during a short time period. The real-time US imaging can be used to effectively guide and assess the treatment.

Wave intensity analysis of carotid artery: a noninvasive technique for assessing hemodynamic changes of hyperthyroid patients.

This study examined the wave intensity (WI) of the carotid artery in patients with hyperthyroid in order to assess the hemodynamic changes of hyperthyroid patients. A total of 86 hyperthyroid patients without cardiac morphological changes and arrhythmia, and 80 healthy control subjects were enrolled in the study. Right common carotid artery (RCCA) was selected for ultrasonic imaging to obtain WI indices, including amplitude of the peak during early systole (W1), amplitude of the peak during late systole (W2), area of the negative wave during mid-systole (NA), interval between R wave of electrocardiogram and W1 (R-1st), interval between W1 and W2 (1st-2nd). The levels of serum thyroid hormones, consisting of free triiodothyronine (FT3), free thyroxin (FT4) and thyroid stimulating hormone (TSH), were measured in hyperthyroid patients. Echocardiographic indices including left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were determined in each subject. The results showed that the W1, W2, NA, and (1st-2nd×HR) in hyperthyroid patients were significantly higher than those in healthy controls. There was no significant difference in LVEF and LVFS between the two groups. FT3 was correlated with W1, W2, NA, (1st-2nd×HR), pulse pressure (PP) and heart rate (HR) in hyperthyroid patients. Several abnormal waves on WI curves were present in 19 hyperthyroid patients during mid-systole. It was concluded that WI technique may prove a real-time, noninvasive, sensitive and convenient tool for assessing the cardiac function and hemodynamic alterations in hyperthyroid patients.

Wave Intensity Analysis of Carotid Artery: A Noninvasive Technique for Assessing Hemodynamic Changes of Hyperthyroid Patients / 华中科技大学学报（医学）（英德文版）

This study examined the wave intensity (WI) of the carotid artery in patients with hyperthyroid in order to assess the hemodynamic changes of hyperthyroid patients. A total of 86 hyperthyroid patients without cardiac morphological changes and arrhythmia, and 80 healthy control subjects were enrolled in the study. Right common carotid artery (RCCA) was selected for ultrasonic imaging to obtain WI indices, including amplitude of the peak during early systole (W1), amplitude of the peak during late systole (W2), area of the negative wave during mid-systole (NA), interval between R wave of electrocardiogram and W1 (R-1 st), interval between W1 and W2 (1 st-2nd). The levels of serum thyroid hormones, consisting of free triiodothyronine (FT3), free thyroxin (FT4) and thyroid stimulating hormone (TSH), were measured in hyperthyroid patients. Echocardiographic indices including left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) were determined in each subject. The results showed that the WI, W2, NA, and (lst-2nd×HR) in hyperthyroid patients were significantly higher than those in healthy controls. There was no significant difference in LVEF and LVFS between the two groups. FT3 was correlated with WI, W2, NA,(lst-2nd×HR), pulse pressure (PP) and heart rate (HR) in hyperthyroid patients. Several abnormal waves on WI curves were present in 19 hyperthyroid patients during mid-systole. It was concluded that WI technique may prove a real-time, noninvasive, sensitive and convenient tool for assessing the cardiac function and hemodynamic alterations in hyperthyroid patients.

Early detection of lesions of dorsal artery of foot in patients with type 2 diabetes mellitus by high-frequency ultrasonography.

This study evaluated the value of high-frequency ultrasonograpy for early detection of dorsal artery of foot in patients with type 2 diabetes mellitus (MD). Eighty subjects including 40 patients with type 2 MD (T2DM group) and 40 healthy volunteers (NC group) were recruited. The intima-media thickness (IMT), the inner diameter and the perfusion of dorsal artery of foot were measured by using high-frequency ultrasonograpy. Meanwhile, the parameters of vascular elasticity, including stiffness parameter (beta), pressure-strain elastic modulus (Erho), arterial compliance (AC), augment index (AI), and pulse wave conducting velocity (PWVbeta) were detected by means of echo-tracking technique. The results showed that no significant difference was found in the IMT, systolic diameter (Ds), diastolic diameter (Dd) and peak systolic velocity (PSV) between T2DM and NC groups. Erho and PWVbeta were increased, and AC was decreased in T2DM group as compared with those in NC group with the differences being significant (P<0.05 for all). There was no significant difference in beta and AI between T2DM and NC groups. It was concluded that high-frequency ultrasonography in combination with echo-tracking technique is sensitive and non-invasive, and can be used for early detection of sclerosis of the lower extremity artery in patients with type 2 MD.

Early Detection of Lesions of Dorsal Artery of Foot in Patients with Type 2 Diabetes Mellitus by High-frequency Ultrasonography / 华中科技大学学报（医学）（英德文版）

lerosis of the lower extremity artery in patients with type 2 MD.

Effect of micronized fenofibrate on vascular endothelial function in patients with hypertriglyceridemia.

OBJECTIVE: To investigate the effect of micronized fenofibrate on vascular endothelial function in patients with hypertriglyceridemia. METHODS: Using high-resolution ultrasound, we measured flow- and nitroglycerin-induced dilatation of the brachial artery in 30 patients with hypertriglyceridemia before and after treatment with micronized fenofibrate at a dose of 200 mg once daily for 4 weeks. Simultaneously, both serum lipid and plasma endothelin (ET) levels were determined. RESULTS: After micronized fenofibrate therapy, serum triglyceride (TG) levels decreased significantly (P < 0.05). Plasma ET levels also decreased markedly [(82.66 +/- 15.46) microg/L vs. (106.22 +/- 19.16) microg/L, P < 0.001]. Flow-induced vasodilatation was much improved (11.0% +/- 9.0% vs 2.7% +/- 2.0%, P < 0.01). However, no significant changes in vasodilatation occurred in response to nitroglycerin (16.2% +/- 6.0% vs 15.0% +/- 5.0%, P > 0.05) in patients with hypertriglyceridemia. CONCLUSIONS: Micronized fenofibrate can improve impaired endothelium-dependent vasodilatation in patients with hypertriglyceridemia. Improving endothelial function may also be the mechanism responsible for the beneficial effects of micronized fenofibrate.