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Objective:To compare the values of medical image technologies in evaluating the tansperineal laser ablation (TPLA) in canine prostate.Methods:TPLA (3 W/600 J and 3 W/1 200 J) were operated in the prostate of six adult male beagles guided by transrectal ultrasound (TRUS). TRUS, transrectal contrast-enhanced ultrasound (TR-CEUS) and multiparameter magnetic resonance imaging (mpMRI) were used to evaluate the ablation on the day of TPLA, one week and one month after TPLA. The animals were sacrificed for pathology to calculate the volume of the ablation. SPSS 22.0 software was used for statistical analysis.Results:TRUS could be used to guide and observe the puncture and ablation process during TPLA. TR-CEUS and contrast enhanced MRI showed good consistency in the volume of ablation ( P>0.05). One month after TPLA, the ablation volume were (1.69±0.51)ml vs (1.73±0.36)ml vs (1.52±0.41)ml (3 W/600 J) and (2.23±0.54)ml vs (2.34±0.29)ml vs (2.19±0.34)ml (3 W/1 200 J) measured by the two medical image technologies and pathology, with good consistency ( P>0.05). Conclusions:TRUS can be used to guide and observe the puncture and ablation process during TPLA. TR-CEUS and mpMRI can be used for postoperative evaluation and follow-up of TPLA. The former has advantages of real-time and low price, which can be promoted and applied in clinical practice.
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Objective:To prepare ultrasound-responsive nanodroplets with block polymer PEG-PCL as shell and perfluoropentane (PFP) as core, and study the effects of mechanical index (MI) on contrast-enhanced imaging properties of nanodroplet.Methods:PEG-PCL micelles were first prepared by dialysis, and then the micelles were mixed with PFP for emulsification to obtain nanodroplets. The particle size and zeta potential of nanodroplets were measured, and the morphology of nanodroplets were observed using transmission electron microscope (TEM). The stability of nanodroplets after storage at 25 ℃ and 37 ℃ was investigated. The phase transition and contrast-enhanced imaging of nanodroplets in vitro under a series of mechanical index (MI) were studied using an ultrasound diagnostic instrument.Results:The particle size of the nanodroplets was (356.6±5.6)nm, and the zeta potential was -(7.30±0.14)mV. The nanodroplets were close to spherical under TEM and had a clear core-shell structure. The particle size and dispersion of the nanodroplets increased after storage at 37 ℃ and 25 ℃. For imaging in vitro, no acoustic signal were observed at 25 ℃ when the MI varied from 0.08 to 1.0. At 37 ℃, acoustic signals were observed when MI≥0.4, and the intensity was stronger for higher MIs.Conclusions:The contrast-enhanced imaging of nanodroplets are closely related to the MI, and a higher MI could induce the phase transition of more nanodroplets and produce stronger contrast enhancement. This study could provide basis for the application of polymeric nanodroplets in ultrasound diagnosis and targeted therapy.
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Objective:To compare the efficacy and safety of ultrasound-guided percutaneous translumial septal myocardial ablation in dogs using laser and radiofrequency.Methods:Twelve healthy adult Beagle dogs (males or females) were randomly divided into two groups, namely, group laser and group radiofrequency (6 dogs each group). Under ultrasound guidance, laser fiber or radiofrequency ablation needle was respectively inserted into the basal and middle segments of the interventricular septa via the percutaneous transapical approach to perform ablation. The Beagle dogs received radiologic examination, laboratory tests and pathological detection before ablation, immediately after ablation, at 1 week after ablation, and at 1 month after ablation, respectively. The efficacy and safety of the two ablation procedures were compared.Results:All dogs survived after ablation. The peak gradient of LVOT decreased immediately after ablation using either laser or radiofrequency ( P<0.05), but it increased at 1 week after ablation than before ( P<0.05). At 1 month after ablation, no significant differences were found in the peak gradient of LVOT compared with that before surgery ( P<0.05). The interventricular septum thickness was increased immediately after ablation using either laser or radiofrequency than before ( P<0.05), but it decreased at 1 week and at 1 month after surgery than before ( P<0.05). The ablation zone using radiofrequency was slightly larger than that of using laser[(372.50±69.06)mm 3 vs (116.65±20.15)mm 3, P<0.001], and the surgical time of the former was significantly shorter than that of using laser [(56.00±3.22)s vs (260.00±65.39)s, P<0.05)]. Conclusions:Ultrasound-guided percutaneous translumial septal myocardial ablation is feasible, safe and effective using either laser or radiofrequency. Comparatively speaking, radiofrequency ablation is more simple and convenient.
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Objective To investigate the clinical application value of longitudinal peak strain( LPS ) and peak strain dispersion ( PSD ) in evaluating left ventricular systolic function and synchrony in patients with essential hypertension . Methods Fifty‐five patients with essential hypertension were enrolled , including 30 patients with non‐left ventricular hypertrophy ( NLV H ) , 25 patients with left ventricular hypertrophy ( LV H ) , at the same time , 30 healthy volunteers were selected as the control group . Echocardiography was performed in all three groups ,and two‐dimensional dynamic images of the left ventricular apical four‐chamber ,three‐chamber ,and two‐chamber′s long‐axis view s were collected for three consecutive cardiac cycles . T he myocardial layer‐specific strain was used to measure the LPS of the left ventricular myocardium of subendocardium ,the middle layer ,the subepicardium ,and the myocardial strain and the PSD of the w hole myocardial layers . Correlation analysis and ROC curve analysis were performed . Results T he LPS in the control group ,NLV H group and LV H group were decreased in turn from inner to out myocardial layers . Compared with the control group , the LPS in the subendocardial , middle , subepicardial ,and w hole myocardial layer of NLV H group were decreased ( P ＜ 0 .05 ) , and the subepicardial myocardial LPS was slightly lower than that in the control group ,the difference was not statistically significant ( P ＞ 0 .05 ) . T he LPS in the subendocardial , middle , subepicardial ,and whole myocardial layer of LV H group were all reduced ( P＜0 .05) . Between the NLV H group and LV H group , the declines of the LPS in the subendocardial and middle layer in the LV H group were statistically significant ( P ＜0 .05) ,the LPS in the subepicardial layer and the w hole myocardial layer had no significant difference ( P ＞0 .05) . Compared with the control group ,the PSD of the NLVH group and the LVH group increased ( P ＜ 0 .05 ) . Compared with the NLV H group ,the PSD of the LV H group increased ( P ＜0 .05) . Inter‐ventricular septum thickness ( IVSd) and the LPS in the subendocardial ,middle ,subepicardial , and w hole myocardial layer were negatively correlated ( r ＝ －0 .537 ,－0 .518 ,－0 .266 ,－0 .471 ; all P ＜0 .05) , left ventricle posterior wall thickness ( LVPWd ) and the LPS in the subendocardial , middle , subepicardial ,and whole myocardial layer were negatively correlated ( r ＝ －0 .539 , －0 .524 , －0 .283 ,－0 .478 ;all P ＜0 .05) . T he area under the ROC curve ( AUC) of the LPS in the subendocardial ,middle , subepicardial ,and w hole myocardial layer and PSD for the diagnosis of hypertension were 0 .685 ,0 .652 , 0 .510 ,0 .623 ,0 .995 ,respectively . T he cut‐off values were －21 .70% ,－18 .90% ,－16 .95% ,－19 .45% , 46 .50 ms , and the sensitivities were 94 .4% , 83 .3% , 77 .8% , 94 .4% , 100% , respectively , and the specificities were 47 .8% ,52 .2% ,39 .1% ,39 .1% ,95 .7% ,respectively . Conclusions T he layer‐specific strain can quantitatively evaluate myocardial longitudinal strain in patients with essential hypertension , provide a non‐invasive test for early diagnosis of hypertensive heart disease ,and the evaluation of left ventricular myocardial stratification . PSD for evaluating primary synchronous changes in left ventricular myocardial contraction in patients with hypertension has certain advantages .