王先生最近感觉腰部疼痛加剧,医生检查后,建议MRI检查,以了解腰椎具体情况.可做完检查找到医生复诊时,又被要求再做一个CT检查.王先生很是纳闷:不是说做MRI最清楚吗,为什么还要做CT?

目的 评估基于深度学习(DL)的人工智能(AI)乳腺X线影像病灶检出系统的临床价值.方法 回顾性分析484例乳腺X线影像及诊断报告,对其中存在BI-RADS 3类及以上病灶者评估AI检出敏感度,并结合双向表x2检验,验证AI对不同类型和BI-RADS分类病灶的敏感度差异.由3名高年资医师对诊断报告显示BI-RADS 1类和2类、但AI提示阳性病例进行审核,并按照不同类型和BI-RADS分类进行统计.结果 BI-RADS 3、4a、4b、4c、5类病灶分别为103、79、23、40和11个,AI检出敏感度分别为82.52％(85/103)、97.47％(77/79)、100％(23/23)、100％(40/40)和100％(11/11),总敏感度为92.19％(236/256).AI系统对不同类型(钙化、肿块、非对称、结构扭曲)和BI-RADS分类病灶的敏感度差异均无统计学意义(P均＞0.05).254例BI-RADS 1类和2类病例中,203例AI提示阳性发现,其中75例(80个病灶)为BI-RADS 0类,需结合其他检查确认,21例(23个病灶)为BI-RADS 3类及以上,多检出BI-RADS 3类及以上病灶类型差异无统计学意义(P均＞0.05).结论 AI系统对BI-RADS 3类及其以上病灶有较高敏感度,可有效辅助影像医师减少漏诊.

目的 通过CT神经重组技术观察腰椎退行性侧凸(LDS)对神经根-硬膜囊夹角(N-E角)的影响,并初步探讨其临床意义.方法 搜集2016年11月至2017年6月本院收治的LDS的患者47例(LDS组),均行腰椎CT检查,采用改良Cobb法测量侧凸角.选取同一时期患有腰腿痛的,并经过腰椎CT检查无腰椎侧弯的患者24例为对照组(NLDS组).将腰椎容积数据进行后处理,同层显示双侧腰N-E角.采用SPSS 21.0软件进行统计学分析.结果 腰椎侧凸Cobb角7.3～28.8°,平均(15.71±6.04)°,右侧凸31例(65.96％),左侧凸16例(34.04％).在神经重组图像中,腰神经是发自硬膜囊的条索状结构,与硬膜囊呈一定的夹角.LDS组凹侧的N-E角与凸侧比较,P=0.01.NLDS组两侧N-E角比较,P=0.419.NLDS组双侧N-E角角度差为(1.14±3.81)°,LDS组N-E角角度差为(6.27±7.65)°,两组N-E角角度差比较,P=0.00.LDS组中,N-E角度差与腰椎侧凸Cobb角无相关性(P=0.200,R=0.190).结论 基于CT神经重组图像,可以清晰显示N-E角,LDS组N-E角在Cobb角＜10°时已与NLDS组N-E角存在差异,且凹侧角度大于凸侧,这与LDS患者多出现凹侧疼痛相符,为以后探讨LDS引起神经根性疼痛的原因时,提供一种新的思路及影像形态学方法.由于腰椎侧凸Cobb角与N-E角无明显相关性(R=0.190),提示单纯矫正LDS Cobb角可能对N-E角影响不大.

Objective To analyze CT morphologicl characteristics of tibial nerve,lateral and medial plantar nerves and their clinical significances in the diabetic foot (DF) patients.Methods Bilateral feet (DF group) of 33 patients diagnosed as type 2 diabetes mellitus with DF were examined with CT.Meanwhile,36 uninjured feet (NDF group) of patients with single-side foot wound were taken as the controls.CT findings of distal part of tibial nerve,medial plantar nerve and lateral plantar nerve on the same plane were observed with CT post-processing technique.The morphological measurements were done at the points of A1 (tibial nerve measuring position),A2 (proximal part of medial plantar nerve measuring position),A3 (distal part of medial plantar nerve measuring position) and A4 (lateral plantar nerve measuring position).Both of the anteroposterior and transverse diameters were measured and compared between DF and NDF groups.Results Plantar nerves (tibial nerve,medial plantar nerve and lateral plantar nerve) of DF patients were thick (52/66,78.79 ％),and the edges of nerve were indistinct (51/66,78.78％).The anteroposterior and transverse diameters of measurement points A1,A2 and A4 in DF group were larger than those in NDF group (all P＜0.01).There was no statistical difference of the anteroposterior and transverse diameters of point A3 between the two groups (both P＞0.05).Conclusion The plantar nerves of DF patient were thick with indistinct edges.The observation of continuous morphological characteristics and the diameter measurements of the plantar nerve can be performed with CT post-processing technique,which can provide more information for clinical diagnosis of DF.

Objective To estimate the application value of head-neck CT angiography (CTA) and whole brain CT perfusion (CTP) in patients with chronic cerebral ischemia by the correlation comparison study of head-neck CTA and brain CTP. Methods A total of 150 patients' CTA and CTP were analyzed for their correlations with the distribution of perfusion region, responsible blood vessels and perfusion abnormalities. Results The responsible vessels of 98.72% perfusion abnormal region were moderate vascular stenosis. With the aggravation of the degree of the stenosis of the responsible vessels, the proportion of abnormal region of perfusion was significantly increased. The degree of responsible vascular stenosis was moderately positively correlated with the staging of CTP in the pre-infarction stage. Conclusions Combined with the results of head-neck CTA and whole brain CTP, the degree of chronic ischemia in patients with chronic cerebral ischemia can be comprehensively evaluated, which is more conductive to the selection of clinical treatment.

ObjectiveTo explore the effect of Orthopedic Metal Artifact Reduction (O-MAR) technique in reducing dental metallic artifacts in head and neck CT examination.Methods65 patients with dental titanium prosthesis were conducted head and neck CT angiography scan. The patients were selected from Jan. to Dec. in 2014 of our hospital. The images were reconstructed by two different algorithms of O-MAR technique (group A) and traditional technique (group B). The regions of interest were placed in bilateral masseter muscles. Two groups’ standard deviation of the regions of interest was measured with paired t-test and image quality was subjectively scored. The image quality scores and demonstration of the oral cavity were conducted between two doctors, and analyzed with rank sum test andχ2test.Results The results of two doctors’ image quality scores are: ipsilateral masseter (z=-6.06,P<0.05); contralateral masseter (z=-4.79,P<0.05), the difference is statistically significant. Image quality score in group A is higher than that of group B (χ2=34.03,P<0.05), the difference is statistically significant; The standard deviation results are ipsilateral masseter (t=-9.34,P<0.05) and contralateral masseter (t=-4.06,P<0.05), the difference is statistically significant. There is no significant difference of bilateral masseter standard deviation in group A (t=1.48,P>0.05), while the difference of bilateral masseter standard deviation in group B (t=5.38,P<0.05) is statistically significant.Conclusion O-MAR technique is superior in decreasing the effect of high atomic number artifacts on image quality, and provides valuable information for clinical diagnosis.

Objective To evaluate the value of iterative reconstruction (idose4) for radiation dose reduction in screening of lung cancer through the comparative study between the reconstructed image of the filtered back projection (FBP) and idose4 (level 6).Methods Forty-two patients at high risk of lung cancer accepted CT scan with Philips ingenuity core 128 scanner. Al image were reconstructed by filtered back projection (FBP) (group A) and idose4(level 6) (group B). Four position which at the plane of bifurcation of trachea were chose to measure the CT value in both two groups, standard deviation (SD) of CT value were calculated to estimate the image quality Objective ly. Meanwhile, two radiologists assessed the quality of the image subjectively.Results Both the Objective and subjective Results show that the image quality of group B is better than group A.Conclusion The iterative reconstruction (idose4) for radiation dose reduction in screening of lung cancer can reduce the image noise and improve the image quality, it can also provide more accurate evidence to diagnose for the screening of lung cancer.