Contrast-enhanced Quantitative Analysis Research Articles

Quantitative Gd-DOTA-based aerosol deposition mapping in the lungs of asthmatic rats using 3D UTE-MRI.

Asthma is a chronic respiratory disease, commonly treated with inhaled therapy. Better understanding of the mechanisms of aerosol deposition is required to improve inhaled drug delivery. Three-dimensional ultrashort echo time (UTE) MRI acquisitions at 1.5T were combined with spontaneous nose-only inhalation of aerosolized gadolinium (Gd) to map the aerosol deposition and to characterize signal enhancement in asthmatic rat lungs. The rats were sensitized to ovalbumin (OVA) to develop asthmatic models and challenged before imaging by nebulization of OVA to trigger asthmatic symptoms. The negative controls were not sensitized or challenged by nebulization of saline. The animal lungs were imaged before and after administration of Gd-based aerosol in freely breathing rats, by using a T1 -weighted 3D UTE sequence. A contrast-enhanced quantitative analysis was performed to assess regional concentration. OVA-sensitized rats had lower signal enhancement and lower deposited aerosol concentration. Their enhancement dynamics showed large inter-subject variability. The signal intensity was homogeneously enhanced for controls while OVA-sensitized rats showed heterogeneous enhancement. Contrast-enhanced 3D UTE was applied with aerosolized Gd to efficiently measure spatially resolved deposition in asthmatic lungs. The small administered dose (around 1μmol/kg body weight) and the use of standard clinical MRI suggest a potential application for the exploration of asthma.

The role of quantitative analysis of contrast-enhanced ultrasound combined with tumor marker in the diagnosis of peripheral pulmonary lesions

Objective To explore the value of contrast-enhanced ultrasound (CEUS) in the diagnosis of peripheral pulmonary lesions, and to evaluate the diagnostic efficiency of CEUS combined with tumor markers peripheral lung cancer. Methods According to the pathological results, 105 patients with 105 peripheral pulmonary lesions were divided into benign (50 cases) and malignant group (55 cases). Before CEUS examination, lesions′ location, size, shape and internal echogenicities were recorded by two-dimensional (2D) ultrasound. After contrast agent injection, arrive time (AT) in the lesion, difference of AT between the lesion and lung (tAT), and lesions′ enhanced morphology were observed. The time intensity curve (TIC) was used to obtain the rise time (RT), mean transit time (MTT), time from peak to one half of peak(TPH), time to peak (TTP), peak intensity (PI) and wash-in slope (WIS). The parameters of TIC between the two groups were compared. Serum carcino-embryonic antigen (CEA), neuron specific enolase (NSE) and cyrokeratin fragment antigen 21-1 (CYFRA21-1) level were detected and analyzed between the two groups. Results Lesions′ shape and intralesional bronchial syndrome had significant difference in the diagnosis of peripheral pulmonary benign and malignant lesions (P<0.01). In benign group, 27 lesions (54.00%, 27/50) were enhanced in late pulmonary arterial phase and 32 lesions(64.00%, 32/50)showed homogeneous enhancement. At the meantime, in malignant group, most of lesions (76.36%, 42/55) were enhanced in bronchial arterial phase and 36.00% (18/50) of lesions indicated inhomogeneous enhancement. The difference of enhanced phase and morphology between benign and malignant lesions were significant (all P<0.05). While the statistical differences of such quantitative parameters AT, tAT, RT, TTP, PI and WIS, except to MTT and TPH were found between benign and malignant lesions (all P<0.05) in experiment group. In the diagnosis of peripheral lung cancer, the accuracy and specificity of tAT combined with joint detection of 3 kinds of tumor markers were 76.37% and 75.00%, respectively, and higher than any single detection, but the sensitivity was a little lower(76.47%). Conclusions CEUS quantitative analysis has certain value in the diagnosis of benign and malignant peripheral lung lesions, and combined with tumor markers can improve the diagnostic efficiency of peripheral lung cancer. Key words: Contrast-enhanced ultrasound; Pulmonary neoplasms; Tumor markers

Study of quantitative analysis of contrast-enhanced ultrasonic technique in acute radiation-induced liver injury

Objective To evaluate early diagnostic value of quantitative analysis of contrast-enhanced ultrasound (CEUS) in acute radiation-induced liver injury. Methods Sixty female rats were divided into two groups: 50 rats in an experimental group (model group) and 10 rats in a negative control group. The rats in model group were radiated with stereotactic single dose of 20Gy on their liver to establish acute radiation-induced liver injury models. Each 10 rats from model groups and 2 rats from control group were randomly selected and underwent CEUS and histopathological examination on the 3, 7, 14, 21, 28 days after radiation. The degree of injury was classified into four groups according to pathological grading: non-injured group, mild injured group, moderated injured group and severe injured group. The dynamic images of CEUS were off-line analysis and the parameters of arrival time of contrast agent to hepatic artery (HAAT), the arrival time of contrast agent to hepatic vein (HVAT), and the transit time of hepatic artery-hepatic vein (HA-HVTT) were recorded. Time intensity curve (TIC) of liver parenchyma drawn by the software of quantitative analysis was used to obtain quantitative parameters including time to peak (TTP) and peak intensity (PI). Results Along with the severity degree of radiation-induced liver injury, the quantitative parameters, PI decreased while TTP extended. PI of mild injured group, moderated injured group and severe injured group were lower than that of non-injured group (P<0.05). TTP of the three liver injuried groups was higher than non-injured group ( P<0.05). The quantitative parameters HA-HVTT of moderated injured group and severe injured group were decreased than the non-injured group (P<0.05), whereas the difference between mild injured group and non-injured group was not significant. Conclusions Quantitative analysis of CEUS can provide a certain value for early diagnosis in acute radiation-induced liver injury. Key words: Ultrasonography; Microbubbles; Radiation-induced liver injury

Aerosol deposition in the lungs of spontaneously breathing rats using Gd-DOTA-based contrast agents and ultra-short echo time MRI at 1.5 Tesla.

Aerosol toxicology and drug delivery through the lungs, which depend on various parameters, require methods to quantify particle deposition. Intrapulmonary-administered MRI contrast agent combined with lung-specific imaging sequences has been proposed as a high performance technique for aerosol research. Here, aerosol deposition is assessed using ultra-short echo (UTE) sequences. Before and after administration of Gd-DOTA-based aerosol delivered nose-only in free-breathing healthy rats, a T1 -weighted 3D UTE sequence was applied in a clinical 1.5 Tesla scanner. Administration lasted 14 min, and the experiment was performed on six rats. A contrast-enhanced quantitative analysis was done. Fifty percent signal enhancement was obtained in the lung parenchyma. Lung clearance of the contrast agent was evaluated to be 14% per h (corresponding to a characteristic clearance time of 3.6 h) and aerosol deposition was shown to be homogeneous throughout the lung in healthy rats. The total deposited dose was estimated to be 1.05 µmol/kg body weight, and the concentration precision was 0.02 mM. The UTE protocol with nebulized Gd-DOTA is replicable to significantly enhance the lung parenchyma and to map aerosol deposition. This functional strategy, applied in a clinical system with a clinical nebulization setup and a low inhaled dose, suggests a feasible translation to human.

Quantitative analysis of contrast-enhanced ultrasound in acute rejection of kidney graft

Objective To study the value of quantitative analysis of contrast-enhanced ultrasound in diagnosing acute rejection of kidney graft.Methods Sixty-seven patients with normal kidney grafts and thirty-five patients with acute rejection were recruited.In conventional ultrasound,the peak systolic velocity (PSV) and resistance index (RI) of segmental artery and interlobar artery were measured.In quantitative analysis of contrast-enhanced ultrasound,four regions of interest including renal cortex,medulla,segmental artery and interlobar artery were drew and three parameters including rising time(RT),time to peak(TTP) and mean transit time(mTT) were obtained.In addition,the difference in RT,TTP and mTT between the renal cortex and interlobar artery,as well as medulla and interlobar artery were calculated.Results The differences of PSV in interlobar artery between the two groups were statistically significant (P ＜0.05).The time-intensity curves of the whole kidney grafts,and the difference in RT and TTP between the renal cortex and interlobar artery were statistically different between two groups (P ＜0.05).Conclasions Quantitative analysis of contrast-enhanced ultrasound proved a quantitative method for diagnosing kidney allograft acute rejection. Key words: Ultrasonography; Microbubbles; Kidney transplantation; Graft rejection

Quantitative analysis of contrast-enhanced ultrasound in renal lesions: a preliminary study

Objective To investigate the value of quantitative analysis in the diagnosis of renal lesions with contrast-enhanced ultrasound.Methods Sixty cases with renal lesions confirmed by surgery and pathology underwent contrast-enhanced ultrasound preoperatively and quantitative analysis retrospectively.The Sonoliver software was applied in the analysis of CEUS imaging and in the recoustruction of quantitative parameter,s.Five parameters were calculated,including the maximum intensity (IMAX),rise time (RT),time to peak (TTP),mean transit time (mTT) and area under the curve (AUC).Results There were statistically differences in parameters RT,mTT and AUC ( P ＜ 0.05) and significant differences in parameter IMAX ( P ＜0.01).In malignant tumors,the RT and mTT were less than that of the benign while IMAX and AUC were more than that of the benign.Conclusions Contrast-enhanced ultrasound using a quantitative parametric analysis offers more information and is a promising tool in the diagnosis and differentiation of renal masses. Key words: Ultrasonography; Microbubbles; Kidney neoplasms

Quantitative analysis of contrast-enhanced ultrasound in the evaluation of YC-1 effect

Objective To explore the value of contrast-enhanced ultrasound quantitative analysis in the evaluation of YC-1 effect on transplanted tumor of human gastric carcinoma in nude mice.Methods The transplanted tumor model of human gastric carcinoma in nude mice was established by injecting SGC7901/displatin (DDP) cells into the subcutaneous space of 24 nude mice.The mice were randomized into four groups as control group ( DMSO given),DDP group ( DDP given),YC-1 group (YC-1 given) and YC-1 + DDP group ( both YC-1 and DDP given).Contrast-enhanced ultrasound was performed one week after withdrawl and the dynamic image was analyzed quantitatively using SonoLiver software.For each tumor,two ROIs as ROItotal (including the total tumor) and ROIsmall (including the highest enhanced part of the tumor)were drawn and parameters including time-to-peak (TTP),rise time (RT),mean transit time (mTT),maximun intensity ( Imax),R10,R20 and R30 ( descending velocity-the rate of intensity at TTP + 10/20/30 s to Imax) and ascending velocity (Vasc) were recorded for the statistical analysis.Results No parameter had significant difference between control group and DDP group or between YC-1 group and YC-1 + DDP group in both ROIsamll and ROItotal (P ＞ 0.05 ).The mice were regrouped into YC-1-treated-group and non-YC-1-treated-group.For ROItotal,no parameter had significant difference between the two groups (P ＞ 0.05 ).For ROIsmall,microbubbles in YC-1-treated-group reached the peak earlier (TTP:5.47 ±0.93 vs 8.05 ±2.00; RT:4.99 ±0.96 vs 7.67 ± 1.78,P＜0.05) and regressed faster (mTT:37.49 ± 19.51 vs 98.94 ±60.97; R10:0.39 ±0.15 vs 0.55 ±0.08; R20:0.30 ±0.10 vs 0.43 ±0.10; R30:0.25 ±0.08 vs0.33±0.08) than in non-YC-1-treated-group (P＜0.05).Conclusion Contrast-enhanced ultrasound quantitative analysis could reflect the change of tumor blood supply after antiangiogenesis treatment.ROIsmall was more suitable and sensitive than ROItotal to evaluate antiangiogenesis effect. Key words: Ultrasonography ; Contrast media; Neovascularization