Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension:A review

Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH,however these are limited by radiation exposure,subjective qualitative bias,and lack of cardiac functional assessment.This review aims to assess the methodology,diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages,limitations and future research scope.

Determination of the degree of pulmonary arteryhypertension by plasma atrial nateiuretic peptide levelsand pulmonary perfusion imaging

To evaluate the degree of pulmonary artery hypertension (PAH) and its significance, pulmonary perfusion tomographic imaging (PPTI) and radioimmunoassay of plasma atrial nateiuretic peptide (ANP) levels were examined in different stages of rabbit PAH models, controlled with cardiac catheterization. When the PAH was mild, ANP levels were not significantly changed (t= 1, p >0.05). The mean pulmonary artery pressures (mPAP) measured by catheterization had no significant change, but there was a significant increase of the ratio of dorsal/abdominal counts using pulmonary perfusion tomographic imaging (PPTI) (t=2.5, p <0.05). The ANP levels rose when PAH was moderate or severe, and the difference was significant compared with the control group (t=4 and 6.5, p <0.05). The other two methods also showed significant changes (p <0.01). There was positive correlation between the results of ANP/PPTI, ANP/catheterization, and PPTI/catheterizations (p <0.01). These results suggest that ANP levels can assess the degree of the PAH as a simple method, but it is not as sensitive as that of the PPTI in mild PAH.

Correlation analysis of dual-energy CT iodine maps with quantitative pulmonary perfusion MRI

AIM:To correlate dual-energy computed tomography(DECT) pulmonary angiography derived iodine maps with parameter maps of quantitative pulmonary perfusion magnetic resonance imaging(MRI).METHODS:Eighteen patients with pulmonary perfusion defects detected on DECT derived iodine maps were included in this prospective study and additionally underwent time-resolved contrast-enhanced pulmonary MRI [dynamic contrast enhanced(DCE)-MRI].DCE-MRI data were quantitatively analyzed using a pixel-by-pixel deconvolution analysis calculating regional pulmonary blood flow(PBF),pulmonary blood volume(PBV) and mean transit time(MTT) in visually normal lung parenchyma and perfusion defects.Perfusion parameterswere correlated to mean attenuation values of normal lung and perfusion defects on DECT iodine maps.Two readers rated the concordance of perfusion defects in a visual analysis using a 5-point Likert-scale(1 = no correlation,5 = excellent correlation).RESULTS:In visually normal pulmonary tissue mean DECT and MRI values were:22.6 ± 8.3 Hounsfield units(HU);PBF:58.8 ± 36.0 mL/100 mL per minute;PBV:16.6 ± 8.5 mL;MTT:17.1 ± 10.3 s.In areas with restricted perfusion mean DECT and MRI values were:4.0 ± 3.9 HU;PBF:10.3 ± 5.5 mL/100 mL per minute,PBV:5 ± 4 mL,MTT:21.6 ± 14.0 s.The differences between visually normal parenchyma and areas of restricted perfusion were statistically significant for PBF,PBV and DECT(P < 0.0001).No linear correlation was found between MRI perfusion parameters and attenuation values of DECT iodine maps(PBF:r = 0.35,P = 0.15;PBV:r = 0.34,P = 0.16;MTT:r = 0.41,P = 0.08).Visual analysis revealed a moderate correlation between perfusion defects on DECT iodine maps and the parameter maps of DCE-MRI(mean score 3.6,k 0.45).CONCLUSION:There is a moderate visual but not statistically significant correlation between DECT iodine maps and perfusion parameter maps of DCE-MRI.

The application study of dual-energy CT nonlinearblending technique in pulmonary angiography

Objective This study aimed to explore the feasibility of enhancing image quality in computed tomography(CT) pulmonary angiography (CTPA) and reducing radiation dose using the nonlinear blending (NLB)technique of dual-energy CT.Methods A total of 61 patients scheduled for CTPA were enrolled, and 30 patients underwent dual-energyscanning. Nonlinear blending images (NLB group) and three groups of linear blending images (LB group,80 kV group, and 140 kV group) were reconstructed after scanning;31 patients underwent single-energyscanning (120 kV group). The CT values and standard deviations of the pulmonary trunk, left and rightpulmonary arteries, and ipsilateral back muscle at the bifurcation level of the left and right pulmonaryarteries were measured. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the fivegroups were calculated. The subjective image quality of the five groups was assessed. The radiation dosesof the dual- and single-energy groups were recorded and calculated.Results The CNR and SNR values of blood vessels in the NLB group were significantly higher than thosein the LB, 140 kV, and 80 kV groups (CNR of pulmonary artery trunk: t = 3.50, 4.06, 7.17, all P < 0.05;SNRof pulmonary trunk: t = 3.76, 4.71, 6.92, all P < 0.05). There were no statistical differences in the CNR andSNR values between the NLB group and 120 kV group (P > 0.05). The effective radiation dose of the dualenergygroup was lower than that of the single-energy group (t = –4.52, P < 0.05). The subjective scores ofimages in the NLB group were the highest (4.28 ± 0.74).Conclusion The NLB technique of dual-energy CT can improve the image quality of CTPA and reducethe radiation dose, providing more reliable imaging data for the clinical diagnosis of pulmonary embolism.

Correlation between Automated Quantification of Lung Perfusion Blood Volume (PBV) and Pulmonary Artery Pressure

Purpose: Dual-energy CT (DECT) can be used for quantification of lung perfusion blood volume (PBV), allowing objective evaluation. However, no reports have investigated pulmonary perfusion correlating with pulmonary artery pressure (PAP) in patients with chronic pulmonary diseases. The purpose was to evaluate automated quantification of the lung PBV using dual-energy CT, and its correlation with PAP. Methods: 274 patients who underwent echocardiography within two weeks also underwent CT. The population was divided into high (&ge;40 mmHg) and low (<40 mmHg) estimated systolic PAP (sPAP) groups (n = 63 and n = 211, respectively). We retrospectively eva-luated the lung PBV using Syngo software, and correlations between the lung PBV and estimated sPAP. Results: Lung PBV values were 25.0 ± 9.6 and 29.0 ± 9.3 Hounsfield units (HU) in high and low sPAP groups, respectively, with a significant difference between them (p = 0.003). In the high sPAP group with underlying lung diseases (n = 15), chronic thromboembolism (n = 25), pulmonary artery stenosis (n = 12), and left heart failure (n = 11), using the Dana Point classification system, lung PBV values were 18.6 ± 1.6, 25.1 ± 4.5, 25.8 ± 4.5, and 32.7 ± 9.4 HU, respectively. There were significant differences in quantification of the lung PBV among them. The mean sPAP of subjects with left heart failure was significantly higher than in the others. In subjects with left heart failure, a positive correlation between the lung PBV value and sPAP was noted (R = 0.721, p < 0.0001). Conclusions: Automated quantification of the lung PBV may estimate the high sPAP. The lung PBV may contribute to clarifying the etiology of a high PAP due to left heart failure.

Gadolinium Enhances Dual-energy Computed Tomography Scan of Pulmonary Artery

Objective To evaluate the feasibility of using gadopentetate dimeglumine(Gd-DTPA)for dual-energy computed tomography pulmonary angiography(CTPA).Methods Sixty-six patients were randomly divided into three groups and underwent CTPA.Group A had a turbo flash scan using an iohexol injection,Group B had a turbo flash scan using Gd-DTPA,and Group C had a dual-energy scan using Gd-DTPA.The original images of Group C were linearly blended with a blending factor of 0.5 or reconstructed at 40,50,60,70,80,90,100,and 110 keV,respectively.The groups were compared in terms of pulmonary artery CT value,image quality,and radiation dose.Results The pulmonary artery CT values were significantly higher in Group C40keV than in Groups B and C,but lower than in Group A.There was no significant difference in the image noise of Groups C40keV,B,and C.Moreover,Group A had the largest beam hardening artifacts of the superior vena cava(SVC),followed by Groups B and C.Group C40keV showed better vascular branching than the other three groups,among which Group B was superior to Group A.The subjective score of the image quality of Groups A,B,and C showed no significant difference,but the score was significantly higher in Group C40keV than in Groups A and B.The radiation dose was significantly lower in Group B than in Groups A and C.Conclusion Gd-CTPA is recommended to patients who are unsuitable for receiving an iodine-based CTPA.Furthermore,a turbo flash scan could surpass a dual-energy scan without consideration for virtual monoenergetic imaging.

Preliminary study on CT perfusion imaging in guiding biopsy of pulmonary lumps

Background CT perfusion imaging （CTP） has been proved to be a powerful functional imaging technique. This study aimed to evaluate the value of CTP in guiding biopsy of pulmonary lumps. Methods A total of 147 patients with pulmonary lumps who had CT guided biopsies were enrolled in this study from February 2005 to June 2007. The patients were assigned to 3 groups： 33 cases guided by CTP as group 1, 45 cases guided by contrast-enhanced scan of CT as group Ⅱ, and 69 cases guided by plain scan of CT as group Ⅲ. Each group was subdivided into central and peripheral types according to the location of the lumps. The achievement ratio of biopsy, the accuracy in grouping, and grading of lung cancer, and the incidence of complication were compared. Results The total achievement ratios of biopsy from group Ⅰ to Ⅲ were 100% （33/33）, 91% （41/45）, and 80% （55/69） respectively, and the difference was statistically significant between group Ⅰ and Ⅲ （P 〈0.05）. For the central type, they were 100% （18/18）, 88% （15/17）, and 79% （11/14） respectively, and the difference was also statistically significant between group Ⅰand Ⅲ （P 〈0.05）. For the peripheral type, they were 100% （15/15）, 93% （26/28）, and 80% （44/55） respectivelies, and the difference was not statistically significant among the three groups. The total accuracies in grouping and grading of lung cancer from group Ⅰ to Ⅲ were 100% （27/27）, 91% （31/34）, and 72% （33/46） respectively, and the difference was statistically significant between group Ⅰ and Ⅲ and between group Ⅱ and Ⅲ （P 〈0.05）. For the central type, they were 100% （16/16）, 94% （16/17）, and 70% （8/12） respectively, and the difference was statistically significant between group Ⅰ and Ⅲ （P〈0.05）. For the peripheral type, they were 100% （11/11）, 88% （15/17）, and 72% （26/36） respectively, and the difference was statistically significant between group Ⅰ and Ⅲ （P 〈0.05）. The total incidence of complication from group Ⅰ to Ⅲ were 15% （5/33）, 27% （12/45）, and 43% （30/69） respectively, and the difference was statistically significant between group Ⅰ and Ⅲ （P 〈0.01）. For the central type, they were 11% （2/18）, 24% （4/17）, and 57% （8/14） respectively, and the difference was statistically significant between group Ⅰ and Ⅲ （P 〈0.01）. For the peripheral type, they were 20% （3/15）, 29% （8/28）, and 40% （22/55） respectively, and no statistically significant difference was found among the three groups. Conclusions CTP guided biopsy of pulmonary lumps using multi-detector row CT has the potential to improve the accuracy of histopathological diagnosis with a lower risk and higher achievement ratio. More research and technical improvements are needed before it is widelv used.

MSCT灌注成像参数鉴别诊断孤立性肺结节良恶性的价值

目的:探讨多层螺旋CT(multi-slice spiral CT,MSCT)灌注成像参数鉴别诊断孤立性肺结节(solitary pulmonary nodules,SPN)良恶性的价值。方法:选取2021年10月至2022年10月我院收治的80例SPN患者,所有患者入院后均行MSCT灌注成像检查、病理检查。根据组织病理学检查结果将患者分为良性结节组和恶性结节组。比较2组患者的MSCT灌注成像参数(血容量、平均通过时间、血流量、表面渗透系数),采用受试者工作特征曲线分析MSCT灌注成像参数鉴别诊断SPN良恶性的价值。结果:80例SPN患者中,经组织病理学检查确诊47例为恶性结节,33例为良性结节。2组患者MSCT灌注成像参数中的平均通过时间比较,差异无统计学意义(P>0.05);恶性结节组MSCT灌注成像参数中的血容量、血流量、表面渗透系数高于良性结节组(P<0.05)。受试者工作特征曲线结果显示,MSCT灌注成像参数中的血容量、血流量、表面渗透系数单独及联合诊断SPN良恶性的曲线下面积(AUC)分别为0.823(95%CI:0.721~0.926)、0.855(95%CI:0.761~0.949)、0.850(95%CI:0.752~0.948)、0.963(95%CI:0.924~1.000),均有一定诊断价值,且当血容量、血流量、表面渗透系数分别为4.405 ml/100 g、51.325 ml/(min·100 g)、21.115 ml/(min·100 g)时,可获得最佳诊断效能,且联合诊断的价值较高。结论:MSCT灌注成像参数中血容量、血流量、表面渗透系数联合诊断SPN良恶性的价值较高,可为SPN良恶性的早期诊断与治疗提供有效依据。

双能量CT成像技术在肺血管疾病中的应用进展

双能量CT(DECT)应用两种能量、两套探测器,根据不同能量下物质衰减特性的差异进行定性及定量的数据采集。DECT具有高分辨率、易获得等优势,通过后处理技术,从形态学、功能学两方面获取疾病信息。近年来,DECT在肺血管疾病如肺栓塞、慢性血栓栓塞性肺动脉高压、动脉型肺动脉高压、肺静脉闭塞性疾病/肺毛细血管瘤等诊治中展现出优越的作用。现从DECT的技术原理及其在肺血管疾病中的应用进展做一综述。

Role of MR-DWI and MR-PWI in the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbits

Objective： To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging（MR-DWI） and magnetic resonance perfusion weighted imaging（MR-PWI）, and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages.Methods： A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine（Philips, Netherland）. MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MRDWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient（ADC） values; whereas MR-PWI was used for the measurement of wash in rate（WIR）, wash out rate（WOR）, and maximum enhancement rate（MER）. The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 c Gy to yield a total dosage of 5,000 c Gy.Results： The ADC parameters in the region of interest on DWI were as follows： on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group（P〉0.05）. During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137（P〉0.05）. During weeks 1-2, the t values were 1.731 and 1.736（P〈0.05）. During weeks 2-3, the t values were 1.742 and 1.749（P〈0.05）. During weeks 3-4, the t values were 2.050 and 2.127（P〈0.05）. During weeks 4-5, the t values were 2.764 and 2.985（P〈0.05）. The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy（5,000 c Gy）, the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group（P〉0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51（P〉0.05）. During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931（P〈0.05）; in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137（P〈0.05）. During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057（P〈0.05）. During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154（P〈0.05）. During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869（P〈0.05） and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951（P〈0.05）. During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285（P〈0.05） and the t values of the WIR, WOR, andMER at the edge of the lesions were 3.45, 3.246, and 3.614（P〈0.05）. After the radiotherapy（500 c Gy）, the tumors shrank on the T1 WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value.Conclusions： MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung.

PULMONARY BLOOD DISTRIBUTION AFTER TOTAL CAVOPULMONARY CONNECTION OF DIFFERENT TYPES

Objective.To assess the feature of pulmonary blood flow distribution after total cavopulmonary connection(TCPC)of different types,and to provide the selection of the best type.Methods. Thirty-two consecutive survival patients after TCPC underwent radionuclide lung perfusion imaging. According to the radionuclide counts in the left and right lungs,analyses of the distribution of blood flow from superior venous cava(SVC) and inferior venous cava(IVC)and the whole pulmonary blood flow in both lungs were made. All patients were divided into 4 groups by the the anastomosis between IVC and pulmonary artery.Results. GroupⅠ:The flow ratio of the IVC to left lung was greater than that to the right lung,P≤0.01;the flow ratio of the SVC to right lung was greater than that to the left lung,P≤0.01;and the whole pulmonary blood flow went dominantly to the left lung,P≤0.05,which is not in line with physiological distribution. GroupⅡ:the flows from the SVC and IVC were mixed in the middle of the junction and ran evenly into the right and left lungs,the whole pulmonary blood flow went to both lungs,P≥0.05. Group Ⅲ:the flow ratio of the SVC to both lungs were the same,P≥0.05,and major part from IVC went to the right lung,P≤0.01;the pulmonary blood flow go dominantly to the right lung,P≤0.05,which is in accord with physiological distribution. Group Ⅳ:the flows from the right SVC went to right lung by 100%,P≤0.01,and that from the left SVC went to left lung by 100% too,P≤0.01;the flows from IVC went dominantly to the left lung,with little part to the right lung ,P≤0.05.Conclusions. Different types of TCPC can result in different pulmonary blood distributions. The best flow distribution between the left and right lungs can be obtained by an offset of the IVC anastomosis toward the RPA with widening anastomosis for the patients without persist left superior venous cava(PLSVC).

双源CT肺动脉造影联合双能量肺灌注成像对肺栓塞的诊断价值

目的:分析双源CT肺动脉造影联合双能量肺灌注成像对肺栓塞的诊断价值。方法:选取2021年1月-2023年1月广元市第一人民医院收治的疑似肺栓塞患者50例,均进行双源CT肺动脉造影联合双能量肺灌注成像诊断,以临床后期综合诊断结果为依据,分析双源CT肺动脉造影联合双能量肺灌注成像诊断结果以及患者治疗前后肺组织灌注CT值差异。结果:最终诊断结果证实,50例患者中40例为肺栓塞,联合诊断的准确率为96.00%、灵敏度95.00%、特异度100.00%,Kappa=0.884,与后期综合诊断结果一致性极好。患者治疗后的不同部位肺组织灌注CT值均高于治疗前,差异有统计学意义(P<0.05)。结论:肺栓塞的临床诊断中,双源CT肺动脉造影联合双能量肺灌注成像检出率较高,为临床治疗提供准确数据支持,并可以判断和观察治疗效果。

肺栓塞肺动脉能谱CT胸部扫描影像学特征及其诊断价值

目的:探讨肺栓塞(PE)肺动脉能谱CT胸部扫描影像学特征及其诊断价值。方法:回顾性分析53例高度疑似PE患者,获取单能量能谱CT肺动脉造影(CTPA)图像和碘基肺灌注图,记录CTPA图像和碘基肺灌注图检出的肺动脉栓子数目及其分布、分型情况;分析肺动脉能谱CT胸部扫描影像学特征;比较不同栓塞程度及类型能谱CT扫描碘基值;比较栓塞区与对照区能谱CT扫描碘基值、水基值和CT值等能谱CT扫描参数。结果:以CTPA为金标准,53例高度疑似PE的患者中确诊32例。能谱CTPA检出162个栓子,完全型栓子37个,非完全型栓子125个;碘基肺灌注图检出171个栓子,完全型栓子49个,非完全型栓子122个。中心型、偏心型和完全型栓子栓塞区能谱CT扫描碘基值均明显低于对照区(P<0.05);附壁型栓子栓塞区能谱CT扫描碘基值与对照组无显著差异(P>0.05);完全型栓塞区碘基值显著低于中心型、偏心型和附壁型等非完全型栓塞区(P<0.05)。结论:PE肺动脉能谱CT胸部扫描影像学特征主要表现为肺动脉内充盈缺损、肺动脉扩张、肺动脉高压、马赛克征、轨道征等征象,肺动脉能谱CT胸部扫描碘基肺灌注图可作为PE早期诊断及栓塞程度评估的影像学依据。

双输入模型CT灌注成像在肺结节经皮穿刺活检中的临床应用

目的 分析双输入模型CT灌注成像(dual-input body CT perfusion imaging,DI-CTP)在肺结节经皮CT穿刺活检中的临床应用价值。方法 收集94例接受DI-CTP引导经皮穿刺活检肺结节患者的临床资料,分析DI-CTP引导肺结节穿刺阳性率及病理诊断准确率,比较DI-CTP引导穿刺活检与肺动脉灌注指数(PI)对肺结节的诊断效能。结果 94例患者中,良性结节30例,恶性结节(周围型肺癌)64例。DI-CTP引导穿刺活检病理诊断准确率为89.36%(84/94),穿刺活检阳性率为96.80%(91/94);DI-CTP引导穿刺活检诊断肺结节的敏感度和特异度均高于PI,差异有统计学意义(χ^(2)=5.83、4.02,均P<0.01)。结论 DI-CTP灌注伪彩图及定量参数分析为肺结节穿刺活检提供了直观影像学依据,提高了肺结节穿刺活检阳性率、病理诊断准确性及鉴别诊断效能。

320排CT双输入模型灌注成像在肺结节穿刺活检中的临床应用研究

目的分析320排CT低剂量全肺双输入模型灌注成像(DI-CTP)血供分析在肺结节经皮CT引导穿刺活检的临床应用价值。方法回顾性分析CT引导穿刺活检病例单发肺结节113例(直径1~4 cm),分为常规组(胸部增强CT)51例、DI-CTP组62例,比较两种穿刺方法的穿刺成功率、阳性率及临床符合率。结果常规组对肺结节穿刺成功率92.15%(47/51)、穿刺活检阳性率82.35%(42/51),临床符合率为76.47%(39/51),DI-CTP组穿刺成功率98.38%(61/62)、穿刺活检阳性率95.16%(59/62),临床符合率为91.93%(57/62)。DI-CTP组穿刺活检阳性率(χ^(2)=4.83,P<0.05)及临床符合率(χ^(2)=5.23、P<0.05)显著高于常规组。结论肺结节DI-CTP灌注参数结合灌注伪彩图为穿刺活检提供了直观影像学依据,显著提高了肺结节的鉴别诊断效能及穿刺活检临床符合率。

CT灌注成像在肺部肿物诊断及鉴别诊断中的应用研究

背景与目的:良、恶性肿瘤的血流供应与代谢在质、量上有着明显的差异,目前正在开发使用新的影像学技术来鉴别恶性、良性结节的血供情况,灌注成像技术是其中一种。本文采用多层螺旋CT灌注成像技术,定量评价肺内块状病灶的血流特点及其对良、恶性肿瘤进行鉴别诊断的价值。方法:52例初诊为肺部肿物的患者(37例恶性、7例良性、8例活动性炎性),行16排螺旋CT灌注扫描。利用功能软件包自动获取动、静脉、病灶的时间-密度曲线及病变的灌注参数,包括灌注量(perfusionvolume,PV)、血容量(bloodvolume,BV)、对比剂平均通过时间(meantransittimeMTT)、增强峰值(peakheight,PH)。结果:恶性、活动性炎性、良性病变PV值分为(27.63±15.06)ml·min-1·ml-1、(30.80±20.33)ml·min-1·ml-1、(11.81±3.74)ml·min-1·ml-1,PH值分别为(28.46±12.07)Hu、(32.15±15.89)Hu、(10.41±3.77)Hu,BV分别为(21.64±10.97)ml/100g、(28.38±14.55)ml/100g、(10.61±5.33)ml/100g,恶性及活动性炎性病变这3值均显著高于良性病变。恶性、活动性炎性、良性病变的MTT值分别为(28.39±21.66)s、(25.91±14.57)s、(29.86±13.57)s,三者差异没有统计学意义。恶性、活动性炎性病变间4个灌注参数均没有统计学差异。若以PV值>20ml·min-1·ml-1,且PH>15Hu作为鉴别恶性、良性病变(除外活动炎性病变)的阈值,其灵敏度、特异度、准确性分为91.9%、100%、84.1%。结论:多层螺旋CT灌注成像能定量评价肺部肿物血流模式,可用于无创性诊断和鉴别诊断肺部病变。

肺通气/血流灌注显像与螺旋CT肺动脉造影诊断肺栓塞的实验研究

目的评价肺通气/血流灌注(pulmonary perfusion/ventilation,V/Q)显像与64层螺旋CT肺动脉造影(spiral computed tomographic pulmonary angiography,SCTPA)诊断肺栓塞的灵敏度和特异性。方法12只家兔按不同时间点分成4个实验组,每组3只,另设2只作为对照组。实验组经颈静脉插管注入海绵栓子制备急性肺栓塞模型,建模后分组行V/Q显像和SCTPA检查,随后处死实验动物行病理解剖,查找并记录肺动脉栓子位置及数目。对照组颈静脉插管注入生理盐水,于24 h和第3天处死。结果实验组家兔术中死亡1只,11只建模成功。家兔处死后共解剖动脉165支,发现栓子43个,栓塞肺动脉39支。V/Q显像共检出36处节段肺动脉栓塞,与病理解剖对照,假阳性7处、假阴性10处;SCTPA共诊断栓塞肺动脉32支,假阳性6支、假阴性13支。V/Q显像、SCTPA诊断实验家兔肺栓塞的灵敏度分别为74.4%、66.7%,特异性分别为94.4%和95.2%,准确性分别为89.7%和88.5%。结论肺通气/血流灌注显像诊断肺栓塞的灵敏度和准确性高于64层螺旋CT肺动脉造影,而特异性稍低,但无统计学差异。

MSCT灌注成像鉴别诊断肺结节良恶性:Meta分析

目的应用Meta分析方法评价MSCT灌注成像鉴别诊断肺结节良恶性的价值。方法检索Cochrane图书馆、Cochrane协作网、Pubmed、Web of science、中国知网及万方数据库中于2004年1月—2015年10月发表的有关CT灌注成像诊断肺结节的中英文文献,提取符合纳入标准的诊断试验数据。采用Meta disc 1.4分别汇总MSCT以不同灌注参数[血容量(BV)、表面通透性(PS)、BV+PS]诊断恶性肺结节的敏感度、特异度及95%可信区间(CI),拟合工作特征曲线(SROC)并计算曲线下面积(AUC)。结果共纳入文献18篇,肺结节1 221个,其中恶性结节780个,良性结节441个。依次以BV、PS、BV+PS作为灌注诊断指标进行分析,其汇总敏感度分别为0.91[95%CI(0.89,0.93)]、0.88[95%CI(0.85,0.90)]、0.91[95%CI(0.88,0.93)],汇总特异度分别为0.77[95%CI(0.73,0.81)]、0.83[95%CI(0.79,0.86)]、0.91[95%CI(0.87,0.94)];相应AUC分别为0.92、0.93、0.97。结论 MSCT以BV、PS作为灌注诊断参数对鉴别肺结节良恶性具有较高的敏感度及特异度,当二者结合时诊断效能更高,可作为鉴别诊断的标准化灌注指标。

双源CT肺动脉造影及肺灌注成像对肺栓塞治疗后效果评价

目的探讨双源CT肺动脉造影(CTPA)结合双能量肺灌注成像(DEPI)对肺栓塞(PE)治疗效果的评价。方法选取我院2014年10月至2016年3月经CTPA及DEPI扫描确诊的PE患者25例,均行抗凝及溶栓治疗,治疗后复查CTPA及DEPI,对比治疗前后肺灌注图像及CTPA上肺血管内栓子分支的数目及类型。结果 25例患者经治疗后16例治愈,9例好转;与治疗前相比,治愈者在CTPA上表现为栓子消失,在DEPI上表现为肺组织灌注良好,无缺损及稀疏;好转者则在CTPA上表现为栓子数目减少或栓塞类型由完全栓塞变为部分栓塞,在DEPI上表现为原肺组织灌注缺损或稀疏区域减少;治疗前后肺组织灌注量CT值(HU)比较,差异存在统计学意义(P<0.05)。结论 CTPA结合DEPI可作为评价PE治疗效果的良好检查手段。

家兔急性肺栓塞模型双源CT双能量肺灌注成像与核素肺灌注显像

目的探讨双源CT双能量肺灌注成像(DEPI)与核素肺灌注显像诊断实验性急性肺栓塞的价值。方法24只家兔,20只采用股静脉入路注射明胶海绵制成急性肺栓塞模型,另外4只注射生理盐水作为对照组。栓塞后2h行DEPI及核素肺灌注平面显像。以病理结果为金标准,比较两种方法在肺叶基础上诊断急性肺栓塞的准确性。比较增强DEPI图像上栓塞区与正常肺实质的CT值和强化值(Overlay值)。结果对照组DEPI图像表现为大致均匀的黄红色伪彩,栓塞后栓塞区肺灌注图像表现为灌注缺损,核素肺灌注显示栓塞区放射性稀疏或缺损;DEPI和肺灌注平面显像诊断肺栓塞的敏感度、特异度、阳性预测值、阴性预测值分别为100%、97.50%、95.24%、100%;67.50%、81.25%、64.29%、83.33%。增强后栓塞区和非栓塞区CT值及强化值的差异均有统计学意义(P<0.05)。结论与核素肺灌注显像相比,DEPI诊断实验性急性肺栓塞有更高的敏感度和特异度。