应用全模型迭代重建技术的低剂量冠脉CTA在疑似冠心病患者中诊断价值的初步研究

目的:评估应用全模型迭代重建(IMR)技术的低剂量冠脉CTA显示冠状动脉的图像质量及其对疑似冠心病患者冠脉狭窄的诊断价值。方法:回顾分析我院疑似冠心病并接受冠脉CTA及冠状动脉造影(CAG)检查的患者80例。采用4分法对冠脉各主支进行主观质量评分。以CAG显示冠脉管腔直径缩小超过50%为阳性标准,分别在冠脉节段、主支水平分析冠脉CTA诊断冠脉狭窄的灵敏度、特异度、阳性预测值(PPV)、阴性预测值(NPV)及准确度,将患者按Agaston积分分成两组(A组<400,B组≥400),比较两组间诊断效能的差异。结果:在节段水平上,98.1%的冠脉图像质量合格,冠脉CTA诊断冠脉狭窄的灵敏度、特异度、PPV、NPV及准确度分别为93.2%、98.0%、91.3%、98.4%、97.1%;在主支水平上,96.6%的冠脉图像质量合格,冠脉CTA诊断冠脉狭窄的灵敏度、特异度、PPV、NPV及准确度分别为84.6%、93.0%、88.9%、90.1%、89.6%;A、B两组之间在特异度、PPV和准确度上存在显著差异(99.2%&91.8%,95.7%&84.2%,97.9%&93.7%,P<0.05)。结论:应用IMR技术的低剂量冠脉CTA检查可获得满意的图像质量,对冠脉狭窄具有较高的诊断准确性,但对严重钙化的血管节段的诊断尚有局限性。     

3.0TMR自动呼吸导航对比增强全心冠状动脉磁共振血管成像的临床应用

目的 评价3.0T MR自动呼吸导航全心冠状动脉磁共振血管成像(CMRA)诊断冠状动脉狭窄的临床应用价值.方法 对50例临床疑诊或确诊冠心病或心肌病的患者行自动呼吸导航对比增强CMRA,其中33例经冠状动脉造影(CAG)证实.评价CMRA图像质量,并与CAG相对照,评价CMRA诊断冠状动脉狭窄的效能.结果 1例CMRA图像质量较差,为1级;余49例CMRA图像质量均满足诊断要求,为2~4级.33例经CAG证实的患者共286段血管中,CRMA可显示238段(238/286,83.22%),未显示48段(48/286,16.78%).以患者数、血管支和血管段为单位,CMRA诊断冠状动脉狭窄的敏感度分别为80.95%(17/21)、79.31%(23/29)、84.62%(33/39),特异度分别为75.00%(9/12)、91.09%(92/101)、75.00%(33/44),阳性预测值(PPV)分别为85.00%(17/20)、71.88%(23/32)、75.00%(33/44),阴性预测值(NPV)分别为69.23%(9/13)、93.88%(92/98)、96.91%(188/194),准确率分别为78.79%(26/33)、88.46%(115/130)、92.86%(221/238).结论 3.0T MR自动呼吸导航对比增强全心CMRA有助于诊断冠状动脉狭窄.     

时间-空间标记反转脉冲非对比增强血管成像技术对肾动脉的诊断价值

目的 探讨使用时间-空间标记反转脉冲(time-spatial labeling inversion pulse,Time-SLIP)非对比增强血管成像技术评价肾动脉的价值。材料与方法 使用1.5 T MR扫描仪对36例临床怀疑肾动脉狭窄的患者行Time-SLIP磁共振血管造影术(magnetic resonance angiography,MRA)检查。以320排CT血管造影(computed tomography angiography,CTA)和数字减影血管造影(digital subtraction angiography,DSA)为参考标准,评价Time-SLIP肾动脉MRA的图像质量和诊断肾动脉狭窄的能力。结果 共71支肾动脉纳入研究,图像质量优秀的有51支(72%),良好的有17支(24%),差的有3支(4%)。Time-SLIP MRA诊断肾动脉狭窄的敏感度、特异度分别为100%、98.2%,诊断明显狭窄(狭窄程度50%)的敏感度、特异度分别为90%、98.4%。Time-SLIP MRA定量评估肾动脉狭窄程度与CTA和DSA呈高度相关(r=0.959,P0.01),但Time-SLIP MRA轻度高估肾动脉的狭窄程度[平均偏倚为(3.31±10.04)%]。结论 Time-SLIP非对比增强血管成像技术能够准确评价肾动脉。     

256层螺旋CT血管造影诊断冠状动脉狭窄——与经导管冠状动脉造影术对比

目的 初步探讨256层螺旋CT动脉造影术(CTA)在诊断冠状动脉狭窄中的价值.方法 回顾性分析32例临床初诊疑为冠心病患者的256层CTA检查结果,并与经导管冠状动脉造影术(CCA)结果进行对照.所有患者CTA检查前均未服用β受体阻滞剂.结果 32例患者中,冠状动脉直径≥2 mm的419个节段中,CT图像能满足诊断要求的为393个节段(93.79%).393个节段中,256层CTA显示中度以上狭窄(≥50%)的准确率、敏感度、特异度和阳性预测值、阴性预测值分别为95.67%、80.70%、98.21%、88.46%、96.77%;显示重度狭窄(≥75%)的准确率、敏感度、特异度、阳性预测值、阴性预测值分别为96.69%、75.00%、98.88%、87.10%、97.51%.对于中度以上以及重度狭窄的诊断,256层CTA与CCA的差异均无统计学意义.结论 在未服用β受体阻滞剂的前提下,256层CTA对冠状动脉中、重度狭窄的初步筛选和诊断方面,与CCA无明显差别.     

内膜钙化对64层CT血管造影诊断颈动脉狭窄的影响

目的评判内膜钙化对64层CT血管造影(CTA)诊断颈内动脉狭窄的影响。方法选取前循环脑缺血性症状患者106例,CT值≥130Hu定为钙化斑块,同时也将颈内动脉(ICA)的检测结果分为钙化组和非钙化组。以DSA狭窄率的平均值为"金标准",以50%为界,测量CTA的敏感度、特异度、阳性预测值、阴性预测值。结果 ICA狭窄率超过50%时,非钙化斑块组CTA诊断敏感度97.5%、特异度100%、阳性预测值100%、阴性预测值97.9%和Kappa值0.977(P<0.01);钙化斑块组CTA诊断敏感度96.4%、特异度87.5%、阳性预测值84.4%、阴性预测值97.2%和Kappa值0.822(P<0.01)。两组间的特异度和阳性预测值比较,差异有统计学意义(P<0.05)。结论 64层CTA诊断颈内动脉狭窄是可靠的,但它诊断颈内动脉狭窄精确度受到钙化斑块的影响,尚不能代替DSA。     

零钙化积分冠状动脉CTA表现分析

目的 分析零冠状动脉钙化积分(CACS)患者64层冠状动脉CTA(CTCA)表现,并评估诊断准确率。 方法 对328例零CACS的疑似冠心病患者,分析CTCA表现,包括有无狭窄、斑块形态、位置和狭窄程度。其中69例有传统冠状动脉造影结果,计算零CACS患者CTCA诊断狭窄≥70%的敏感度、特异度、准确度、阳性预测值和阴性预测值。 结果 328例零CACS患者,CTCA示37例(37/328,11.28%)存在不同程度的狭窄和斑块,无或轻度狭窄26例(26/37,70.27%),中度狭窄8例(8/37,21.62%),重度狭窄3例(3/37,8.11%)。54个狭窄斑块包括软斑块39个(39/54,72.22%)、混合斑块8个(8/54,14.81%)及7个钙化斑块(7/54,12.96%)。基于病例(69例)和基于冠状动脉节段(997个节段)CTCA诊断狭窄≥70%的敏感度、特异度、准确率、阳性预测值和阴性预测值分别为97.14%(34/35)、94.12%(32/34)、95.65%(66/69)、94.44%(34/36)、96.97%(32/33)和94.23%(49/52)、99.58%(941/945)、99.30%(990/997)、92.45%(49/53)、99.68%(941/944)。 结论 CTCA可显示零CACS患者冠状动脉的不同程度狭窄和斑块,且诊断准确度较高。     

双源64层CT在椎动脉狭窄诊断中的价值

目的 评价双源64层CT血管造影(CTA)在椎动脉狭窄诊断中的价值.方法 后循环脑缺血症状患者61例,均同时接受数字减影血管造影术(DSA)与CTA检查;使用双源64层CT进行扫描,运用最大密度投影(MIP)、多平面重组(MPR)、曲面重组(CPR)、和容积再现(VR)技术进行重组和轴位像放大以精确测量狭窄血管和正常血管的直径;采用北美症状性颈动脉内膜切除实验(North American Symptomatic Carotid Endarterectomy Trial,NASCET)方法进行血管狭窄程度分级,CTA和DSA检查结果分别由2名高年资放射科医生进行测量.结果经CTA和DSA检查的122支血管中,共有100支具有一致性;狭窄率≥70%时,CTA的敏感度96.4%,特异度96.8%,阳性预测值90.0%,阴性预测值98.9%;≥50%时,CTA的敏感度97.9%,特异度89.2%,阳性预测值85.5%,阴性预测值98.5%,CTA与DSA的狭窄率有很高的相关性(r=0.98,P<0.01).结论 CTA在诊断椎动脉狭窄程度上与DSA有很高的相关性,可作为椎动脉狭窄筛选的常规检查手段.     

双源CT冠状动脉成像评价冠状动脉狭窄

目的 评价双源CT冠状动脉成像(DSCTA)诊断冠状动脉狭窄的价值。方法 回顾性分析41例临床疑似冠心病或已经确诊的冠心病患者的DSCTA和CAG检查资料。以CAG结果为金标准,计算DSCTA诊断轻度(管腔狭窄＜50%)、中度(管腔狭窄50%~75%)、重度(管腔狭窄≥75%)冠状动脉狭窄及DSCTA诊断冠状动脉狭窄的总体敏感度、特异度、阳性预测值、阴性预测值及准确率。结果 41例患者共546个直径≥1.5 mm的冠状动脉节段中535个满足诊断要求,其余11个因钙化斑块遮蔽管腔而无法诊断。DSCTA诊断轻度、中度、重度冠状动脉狭窄敏感度、特异度、阳性预测值、阴性预测值及准确率分别为69.23%(36/52)、96.60%(341/353)、75.00%(36/48)、95.52%(341/357)、93.09%(377/405),68.42%(26/38)、99.42%(341/343)、92.86%(26/28)、96.60%(341/353)、96.33%(367/381),70.67%(53/75)、99.71%(341/342)、98.15%(53/54)、93.94%(341/363)、94.48%(394/417),诊断冠状动脉狭窄的总体敏感度、特异度、阳性预测值、阴性预测值及准确率分别为64.61%(115/178)、95.52%(341/357)、87.79%(115/131)、84.41%(341/404)、85.23%(456/535)。结论 作为一种无创性检查手段,DSCTA对评价冠状动脉狭窄程度具有较高的准确性。     

256层iCT血管造影诊断下肢动脉闭塞症

目的 探讨256层iCT血管造影诊断下肢动脉闭塞症(ASO)的诊断价值。方法 回顾性分析50例经DSA确诊的ASO患者50例,均行256层iCT血管造影,其后于两周内行DSA造影或治疗。以DSA为金标准,计算CTA诊断ASO的效能,计算与DSA评估血管狭窄分级的符合率。结果 共检测730段血管,CTA诊断ASO的敏感度、特异度、阳性预测值、阴性预测值和准确率分别为99.34%(453/456)、96.35%(264/274)、97.84%(453/463)、98.88%(264/267)和98.22%(717/730);CTA评估血管狭窄分级共686段与DSA相符,符合率为93.97%(686/730)。结论 256层iCT血管造影检查无创、方便,诊断ASO和评价血管狭窄程度准确率高,对制定治疗方案具有重要指导意义。     

三维动态增强MR血管造影诊断肾动脉狭窄:与DSA对照研究

目的评价三维动态增强磁共振血管造影(CEMRA)诊断肾动脉狭窄的价值.方法对28例可疑肾动脉狭窄的病人行CEMRA和DSA检查,由两位医师独立对图像进行分析均并最终达成一致,分5级记录肾动脉的情况,统计CEMRA诊断肾动脉狭窄(＞50%)的敏感度、特异性、阳性预测值和阴性预测值,并用ROC法分析其诊断价值.用CohenKappa法评价CEMRA与DSA在诊断肾动脉狭窄和对狭窄分级方面的一致性.观察副肾动脉显示情况.结果CEMRA诊断肾动脉狭窄(＞50%)的敏感度为95.0%、特异性为94.4%、阳性预测值为90.4%、阴性预测值为97.1%,其ROC曲线下面积为0.955,两种方法诊断肾动脉狭窄和对狭窄分级的κ值分别为0.924和0.899.CEMRA副肾动脉显示率为87.5%(7/8).结论CEMRA可以准确诊断有意义的肾动脉狭窄(＞50%),做出肾动脉狭窄的除外诊断,避免不必要的DSA检查,可作为诊断肾动脉病变的首选影像检查方法.     

The diagnostic accuracy of coronary computed tomography angiography in patients with and without previous coronary interventions

BackgroundInvasive coronary angiography (ICA) is the gold standard for imaging coronary arteries and the severity of coronary artery disease (CAD). Coronary computed tomography angiography (CCTA) has undergone remarkable progress in the diagnosis of CAD.ObjectivesTo evaluate the effect of prior vs no previous coronary interventions on the diagnostic accuracy of CCTA as an alternative to ICA to improve health outcomes for patients with suspected CAD.MethodsA prospective cohort study was carried out among patients suspected of CAD and for evaluation of grafts and stents to investigate recurrent ischemic symptoms. 120 patients imaged by CCTA were then referred to ICA, which is considered the gold standard. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CCTA were assessed relative to ICA.ResultsBased on a per-patient analysis, the comparison with ICA reveals variations in sensitivity, specificity, PPV, NPV and accuracy of CCTA. In patients without any previous coronary interventions, the sensitivity was 97.8%, and specificity was 95.6%. The PPV and NPV were 97.8% and 95.5%, respectively. Regarding patients with coronary artery bypass grafts (CABG), the sensitivity was 95% and specificity 100%. The PPV and NPV were 100% and 90.9%, respectively. Regarding patients with prior percutaneous coronary intervention (PCI), the results were a sensitivity of 84.6%, specificity of 77.8%, PPV of 84.6% and NPV of 77.8%.ConclusionCCTA is a powerful diagnostic tool, especially for the evaluation of the major coronary arteries and evaluation of patients with prior CABG. ICA is recommended for evaluation of patients with an intracoronary stent.     

Setting minimum clinical performance specifications for tests based on disease prevalence and minimum acceptable positive and negative predictive values: Practical considerations applied to COVID-19 testing

ObjectivesSeveral guidelines for the evaluation of laboratory tests for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection have recommended establishing an a priori definition of minimum clinical performance specifications before test selection and method evaluation.MethodsUsing positive (PPV) and negative predictive values (NPV), we constructed a spreadsheet tool for determining the minimum clinical specificity (conditional on NPV or PPV, sensitivity and prevalence) and minimum clinical sensitivity (conditional on NPV or PPV, specificity and prevalence) of tests.ResultsAt a prevalence of 1%, there are no minimum sensitivity requirements to achieve a desired NPV of 60%-95% for a given clinical specificity above 20%. It is not possible to achieve 60–95% PPV even with 100% clinical sensitivity, except when the clinical specificity is near 100%. The opposite trend is seen in high prevalence settings (60%), where a relatively low minimum clinical sensitivity is required to achieve a desired PPV for a given clinical specificity, and a higher minimum clinical specificity is required to achieve a desired NPV for a given clinical sensitivity.DiscussionThe selection of laboratory tests and the testing strategy for SARS-CoV-2 involves delicate trade-offs between NPV and PPV based on prevalence and clinical sensitivity and clinical specificity. Practitioners and health authorities should carefully consider the clinical scenarios under which the test result will be used and select the most appropriate testing strategy that fulfils the a priori defined clinical performance specification.     

Diagnostic performance of mammography and magnetic resonance imaging for evaluating mammographically visible breast masses

ObjectiveWe compared the diagnostic values of mammography and magnetic resonance imaging (MRI) for evaluating breast masses.MethodsWe retrospectively analyzed mammography, MRI, and histopathological data for 377 patients with breast masses on mammography, including 73 benign and 304 malignant masses.ResultsThe sensitivities and negative predictive values (NPVs) were significantly higher for MRI compared with mammography for detecting breast cancer (98.4% vs. 89.8% and 87.8% vs. 46.6%, respectively). The specificity and positive predictive values (PPV) were similar for both techniques. Compared with mammography alone, mammography plus MRI improved the specificity (67.1% vs. 37.0%) and PPV (91.8% vs. 85.6%), but there was no significant difference in sensitivity or NPV. Compared with MRI alone, the combination significantly improved the specificity (67.1% vs. 49.3%), but the sensitivity (88.5% vs. 98.4%) and NPV (58.3% vs. 87.8%) were reduced, and the PPV was similar in both groups. There was no significant difference between mammography and MRI in terms of sensitivity or specificity among 81 patients with breast masses with calcification.ConclusionBreast MRI improved the sensitivity and NPV for breast cancer detection. Combining MRI and mammography improved the specificity and PPV, but MRI offered no advantage in patients with breast masses with calcification.     

Real-time elastography in the diagnosis of prostate tumor

AimTo assess the diagnostic gain of transrectal real-time elastography (RTE) compared to transrectal B-mode ultrasonography (US) in the detection of tumors in patients suspected of having prostate cancer.Materials and methodsEighty-four patients suspected of having prostate cancer on the basis of clinical and biochemical evaluation underwent transrectal US, RTE and transperineal prostate biopsy.ResultsBiopsy was considered the gold standard. Analysis related to the total number of patients showed a B-mode US sensitivity of 56%, specificity 80%, positive predictive value (PPV) 70% and negative predictive value (NPV) 67%. Analysis related to the total number of biopsy cores showed sensitivity 33%, specificity 92%, PPV 69% and NPV 73%. In the patient-related analysis, RTE sensitivity was 51%, specificity 75%, PPV 64% and NPV 64%, while the core-related analysis showed sensitivity 36%, specificity 93%, PPV 72% and NPV 74%. Comparison of B-mode US and RTE diagnostic accuracy in the detection of tumors located in the peripheral zone of the prostate gland showed a significant difference. Analysis related to the total number of biopsy cores harvested in the peripheral zone of the prostate gland showed a B-mode US sensitivity of 48%, specificity 81%, PPV 75% and NPV 58%, whereas RTE achieved the following values: sensitivity 66%, specificity 78%, PPV 77%, and NPV 67%.ConclusionsRTE is a valid addition to B-mode US, and RTE reached a higher accuracy than B-mode US in the evaluation of the peripheral zone of the prostate gland and in the selection of appropriate biopsy sites.     

Computer-Aided CT coronary artery stenosis detection: comparison with human reading and quantitative coronary angiography

To evaluate computer-aided stenosis detection for computed tomography coronary angiography (CTA) in comparison with human reading and conventional coronary angiography (CCA) as the reference standard. 50 patients underwent CTA and CCA and out of these 44 were evaluable for computer-aided stenosis detection. The diagnostic performance of the software and of human reading were compared and quantitative coronary angiography (QCA) served as the reference standard for the detection of significant stenosis (>50 %). Overall, three readers with high (reader 1), intermediate (reader 2) and low (reader 3) experience in cardiac CT imaging performed the manual CTA evaluation on a commercially available workstation, whereas the automated software processed the datasets without any human interaction. The prevalence of coronary artery disease was 41 % (18/44) and QCA indicated significant stenosis (>50 %) in 33 coronary vessels. The automated software accurately diagnosed 18 individuals with significant coronary artery disease (CAD), and correctly ruled out CAD in 10 patients. In summary the sensitivity of computer-aided detection was 100 %/94 % (per-patient/per-vessel) and the specificity was 38 %/70 %, the positive predictive value (PPV) was 53 %/42 % and the negative predictive value (NPV) was 100 %/98 %. In comparison, reader 1–3 showed per-patient sensitivities of 100/94/89 %, specificities of 73/69/50 %, PPVs of 72/68/55 % and NPVs of 100/95/87 %. Computer-aided detection yields a high NPV that is comparable to more experienced human readers. However, PPV is rather low and in the range of an unexperienced reader.     

CEUS鉴别诊断肾脏高回声局灶性病变

目的 探讨CEUS鉴别诊断肾脏局灶性高回声良恶性病变的价值。方法 回顾性分析56例肾脏单发高回声局灶性病变患者的常规超声（US）及CEUS声像图资料,对其进行定性诊断;以病理诊断为金标准,计算并比较两者的诊断效能。结果 US及CEUS诊断肾恶性高回声病变的敏感度、特异度、阳性预测值、阴性预测值、准确率为70.00%（14/20）、75.00%（27/36）、60.87%（14/23）、81.82%（27/33）、73.21%（41/56）和80.00%（16/20）、94.44%（34/36）、88.89%（16/18）、89.47%（34/38）、89.29%（50/56）,CEUS的诊断准确率、特异度和阳性预测值均高于US（P均<0.05）。CEUS结果与病理诊断一致性好（Kappa值=0.761）,US与病理诊断一致性一般（Kappa值=0.435）。结论 CEUS可提高对于肾脏局灶性高回声良、恶性肿物的诊断及鉴别诊断效能。     

甲状腺影像报告和数据系统在甲状腺结节分级中的应用

目的 评价甲状腺超声影像和数据报告系统（TI-RADS）在甲状腺结节分级中的应用。方法 对1665个甲状腺结节进行TI-RADS分级,在超声引导下对结节行穿刺活检,根据病理结果,分析其诊断效能（敏感度、特异度、阳性预测值、阴性预测值、准确率）。结果 以TI-RADS 2、3级为良性病变,TI-RADS 4、5级为恶性病变,TI-RADS分级提示甲状腺结节良恶性的敏感度、特异度、阳性预测值、阴性预测值、准确率分别为95.35%（862/904）、16.16%（123/761）、57.47%（862/1500）、74.55%（123/165）、59.16%（985/1665）。结论 TI-RADS分级有助于规范甲状腺结节的超声描述及诊断,但仍需不断的补充、修改和完善。     

经胸肺超声彗尾征诊断心源性呼吸困难

目的 探讨床旁经胸肺超声彗尾征诊断急性心源性呼吸困难的准确性。 方法 选择因急性呼吸困难入院的患者58例,于药物治疗前行床旁经胸肺超声检查。将患者分为心源性呼吸困难与肺源性呼吸困难,比较经胸肺超声检查结果,判断经胸肺超声彗尾征诊断心源性呼吸困难的敏感度、特异度及准确率。 结果 经胸肺超声彗尾征诊断急性心源性呼吸困难的敏感度为93.75%(30/32, 95%CI 77.78%~98.91%),特异度为88.46%(23/26, 95%CI 68.72%~96.97%),阳性预测值为90.90%(30/33, 95%CI 74.53%~97.62%),阴性预测值为92.00%(23/25,95%CI 72.50%~98.60%),诊断准确率为91.38%(53/58)。 结论 根据经胸肺超声彗尾征可以较准确地诊断急性心源性呼吸困难。