【摘要】：目的：通過對比分析雙源CT冠狀動脈成像（CT coronary angiography,CTA）前瞻性心電門控掃描與回顧性心電門控掃描的圖像質(zhì)量和輻射劑量，為低劑量、個性化CT冠狀動脈成像掃描方案的制定提供參考依據(jù)。 材料與方法：將90例行雙源CT冠狀動脈檢查的患者依據(jù)掃描方式不同分為兩組：前瞻掃描組40例，要求患者心率平穩(wěn)且≤70bpm，圖像采集時間窗為62-78%R-R間期，管電壓120KV,應(yīng)用自動管電流調(diào)制技術(shù)（automatic tube current modulation，ATCM），參考管電流為400mAs；回顧掃描組50例，采用ATCM技術(shù)、ECG管電流自動調(diào)制技術(shù)及螺距-心率自動匹配技術(shù)，管電壓120KV，參考管電流為400mAs。由兩位經(jīng)驗豐富的放射醫(yī)生對所有冠脈節(jié)段（直徑≥1mm）進行圖像質(zhì)量評分，意見不一致時協(xié)商確定。評分標準采用4分法（1分：優(yōu)秀；2分：輕度偽影或/和錯層；3分：中度偽影或/和錯層；4分：嚴重偽影或/和錯層），1-3分能用于圖像診斷，4分不能用于診斷。對兩組滿足診斷要求（≤3分）的冠脈節(jié)段及評價為優(yōu)（1分）的冠脈節(jié)段進行非參數(shù)秩和檢驗。計算所有患者CTA檢查的輻射劑量，兩組間比較采用配對t檢驗。 結(jié)果：（1）前瞻掃描組40例患者共評價冠脈554段，滿足診斷（≤3分）及評價為優(yōu)（1分）的冠脈節(jié)段比例分別為99.27%和96.93%�；仡檼呙杞M50例患者共評價冠脈645段，滿足診斷（≤3分）及評價為優(yōu)（1分）的冠脈節(jié)段比例分別為98.76%和88.99%。對兩組間滿足診斷的冠脈節(jié)段比例進行比較，有統(tǒng)計學差異（P=0.024）；評價為優(yōu)的冠脈節(jié)段比例前瞻掃描組明顯高于回顧掃描組，統(tǒng)計學差異明顯（P＜0.001）。（2）前瞻掃描組和回顧掃描組的有效輻射劑量分別為4.46mSv和6.61mSv，兩組間比較差異具有統(tǒng)計學意義（P＜0.001）。 結(jié)論：回顧性心電門控掃描應(yīng)用各種降低輻射劑量的措施后，可明顯降低輻射劑量；對于高心率及心律不齊患者有優(yōu)勢。前瞻性心電門控掃描是減少輻射劑量的有效方式，但較低且平穩(wěn)的心率是其獲得優(yōu)質(zhì)圖像的保證。臨床工作中應(yīng)根據(jù)患者不同情況選擇合適的掃描方式及參數(shù)，在保證圖像質(zhì)量的前提下，盡可能達到低劑量掃描。 第一節(jié)不完全心肌橋及完全性心肌橋的CT影像特征分析 目的：探討心肌橋的分型及不同類型心肌橋-壁冠狀動脈的CT影像特征。 材料和方法：收集50例行雙源CT冠狀動脈成像，診斷有心肌橋患者的影像學資料，所有患者采用回顧性心電門控掃描，重建顯示冠脈的最佳收縮期及舒張期圖像，重建層厚/層間距為0.75mm/0.5mm。根據(jù)冠狀動脈被心肌包繞程度分為兩組：不完全心肌橋組（冠狀動脈被心肌部分包繞，至少在1/2以上）和完全性心肌橋組（冠狀動脈完全被心肌包繞）。測量50例患者心肌橋的最佳舒張期及收縮期壁冠狀動脈最窄處、橋前段及橋后段正常血管的管徑，計算壁冠狀動脈的狹窄率，其差異的比較采用兩配對t檢驗。評價心肌橋患者橋前段冠脈伴發(fā)的粥樣硬化改變，兩組心肌橋間差異的比較采用卡方檢驗。 結(jié)果：50例患者中，冠脈CTA顯示58處心肌橋，平均長度為2.02cm，其中不完全心肌橋23處，完全性心肌橋35處。58處心肌橋中前降支中段32處（60%），前降支遠段17處（29.3%），前降支近段1處，第一對角支3處，第一鈍緣支4處，右冠后降支1處。不完全心肌橋組舒張期及收縮期壁冠狀動脈管徑及狹窄率分別為1.93mm、1.71mm、4.7%和20.4%，完全性心肌橋組舒張期及收縮期壁冠狀動脈管徑及狹窄率分別為2.21mm、1.63mm、8.1%和33.7%。兩組心肌橋舒張期及收縮期壁冠狀動脈管徑差值的差異具有統(tǒng)計學意義（P=0.008）；兩組心肌橋收縮期壁冠狀動脈狹窄率的比較，差異具有統(tǒng)計學意義（P=0.014）。8處不完全心肌橋及15處完全性心肌橋的橋前段冠脈伴發(fā)粥樣硬化病變，其差異無統(tǒng)計學意義（P=0.339）。 結(jié)論：完全性心肌橋?qū)Ρ诠跔顒用}的壓迫程度較不完全心肌橋嚴重，且持續(xù)時間更長。冠脈CTA成像能夠無創(chuàng)地顯示心肌橋的長度和厚度，評價壁冠狀動脈舒張期和收縮期的形態(tài)學變化及伴發(fā)的粥樣硬化改變，為臨床治療計劃提供客觀的依據(jù)。 第二節(jié)CT冠狀動脈成像診斷心肌橋的價值，與CAG對照 目的：對比分析冠脈CTA和CAG檢查患者的影像學資料，探討冠脈CTA對心肌橋診斷的臨床應(yīng)用價值。 材料和方法：收集83例同時行雙源CT冠狀動脈成像（冠脈CTA）及CAG檢查患者的影像學資料。圖像分析采用雙盲法，即由兩位放射科診斷醫(yī)生及兩位介入科醫(yī)生分別在不知道冠脈CTA及CAG診斷結(jié)果的前提下進行，兩種檢查手段對心肌橋的診斷分別由兩組醫(yī)生協(xié)商做出，計算CTA及CAG對心肌橋的檢出率并采用卡方檢驗進行比較。 結(jié)果：（1）83例患者中冠脈CTA顯示41例共48處心肌橋，檢出率為49.4%（41/83），28處為完全心肌橋，20處為不完全心肌橋。48處心肌橋中29處位于前降支中段，11處位于前降支遠段，2處位于右冠后降支，1處位于第一銳緣支，3處位于第一鈍緣支，1處位于中間支，1處位于第一對角支。41例患者中7例為2處心肌橋。（2）CAG顯示19例共19處冠脈“擠牛奶”效應(yīng)，即19例（19處）心肌橋，檢出率為22.9%（19/83）。19處心肌橋中16處位于前降支中段，，2處位于前降支遠段，1處位于右冠后降支。與CTA對照，CAG顯示的19處心肌橋與其位置一致，其中15處為完全性心肌橋，4處為不完全心肌。冠脈CTA對心肌橋的檢出率高于CAG，差異具有統(tǒng)計學意義（P＜0.001）。 結(jié)論：雙源CT冠狀動脈成像能多方位、直觀顯示冠狀動脈與心肌的解剖關(guān)系，對心肌橋的顯示優(yōu)于CAG，且具有無創(chuàng)性檢查的優(yōu)點；但CAG在顯示壁冠狀動脈血流動力學方面優(yōu)于CTA。 第三節(jié)單純性心肌橋患者心肌首過灌注成像的初步研究 目的以正常心肌首過灌注為對照，初步評估單純性前降支心肌橋患者相應(yīng)供血區(qū)的冠脈CTA心肌首過灌注情況，為臨床綜合評價心肌橋及臨床診治策略的制定提供參考依據(jù)。 材料和方法收集42例以胸痛就診、冠脈CTA診斷為單純前降支心肌橋的患者資料；病例組內(nèi)根據(jù)心肌橋類型分為完全性心肌橋組及不完全心肌橋組；根據(jù)收縮期壁冠狀動脈受壓程度分為收縮期狹窄≥50%組及收縮期狹窄＜50%組。20例冠脈CTA顯示冠脈無異常的體檢者作為正常對照組。所有患者均采用回顧性掃描，全劑量曝光時間窗30-75%R-R間期，重建最佳舒張期（65%-75%RR）及收縮期（30%-40%RR）圖像，重建層厚/間距為0.75mm/0.5mm。采用美國泰瑞工作站的心功能分析軟件獲得舒張期及收縮期時左室心肌17節(jié)段平均CT值。計算前降支供血區(qū)（1、2、7、8、13、14及17段）的平均CT值作為首過心肌灌注值。測量主動脈CT值，計算心肌平均CT值與主動脈平均CT值的比值為心肌首過灌注校正值（corrected MP, c-MP）。將主動脈平均CT值與心肌平均CT值進行相關(guān)性分析。心肌橋組和正常組的心肌平均CT值及c-MP行兩獨立樣本t檢驗。完全性心肌橋組及不完全心肌橋組、狹窄≥50%組及狹窄＜50%組和正常組間的心肌平均CT值及c-MP采用多組間比較。 結(jié)果(1)正常組主動脈平均CT值為367.1HU，心肌橋組主動脈平均CT值為398HU，均與心肌平均CT值呈明顯正相關(guān)（r=0.768-0.854，P＜0.001）。 (2)舒張期心肌橋組和正常組前降支供血區(qū)的平均CT值為94.0HU及96.0HU（P=0.216）、舒張期心肌橋組和正常組前降支供血區(qū)的c-MP為0.236及0.263（P＜0.001）；收縮期心肌橋組和正常組的前降支供血區(qū)平均CT值為89.3HU及94.6HU（P＜0.001）、收縮期心肌橋組和正常組的前降支供血區(qū)c-MP為0.225及0.259（P＜0.001）。 (3)完全性心肌橋組舒張期及收縮期的前降支供血區(qū)平均CT值為90.9HU及86.5HU，低于不完全心肌橋組（100.8HU及95.7HU），差異均有統(tǒng)計學意義（P＜0.05）。完全性心肌橋組的舒張期及收縮期c-MP為0.235及0.224，不完全心肌橋組為0.240及0.228，均明顯低于正常組，差異均具有統(tǒng)計學意義（P＜0.05）。 (4)狹窄≥50%組舒張期及收縮期的前降支供血區(qū)平均CT值為91.7HU及87.2HU，低于狹窄＜50%組（96.9HU及92.1HU），差異均有統(tǒng)計學意義（P＜0.05）。狹窄≥50%組的舒張期及收縮期c-MP為0.234及0.223，狹窄＜50%組為0.239及0.227，均明顯低于正常組，差異均具有統(tǒng)計學意義（P＜0.05）。 結(jié)論測量心肌橋患者冠脈CTA檢查時舒張期及收縮期首過灌注心肌CT值，能一定程度反應(yīng)相應(yīng)冠脈供血區(qū)的心肌血流灌注情況。以胸痛就診單純前降支心肌橋患者前降支供血區(qū)心肌平均CT值低于正常組，以收縮期更明顯，特別是完全性心肌橋并收縮期狹窄≥50%的患者，應(yīng)引起臨床關(guān)注。
[Abstract]:Objective: To compare the image quality and radiation dose of prospective ECG-gated and retrospective ECG-gated dual-source CT coronary angiography (CTA) in order to provide a reference for the development of low-dose, personalized CT coronary angiography scanning scheme.
Materials and Methods: 90 patients underwent dual-source CT coronary artery examination were divided into two groups according to different scanning methods: prospective scanning group (40 cases), patients with stable heart rate and < 70 bpm, image acquisition window for 62-78% R-R interval, tube voltage 120 KV, automatic tube current modulation (ATCM), reference tube. The current was 400 mAs. In the retrospective scan group, 50 patients were assessed by ATCM, ECG tube current automatic modulation and pitch-heart rate automatic matching. The tube voltage was 120 KV, and the reference tube current was 400 mAs. Quasi-four-point method (1:excellent; 2:mild artifacts or/and staggered layers; 3:moderate artifacts or/and staggered layers; 4:severe artifacts or/and staggered layers), 1-3 points can be used for image diagnosis, 4 points can not be used for diagnosis. Non-parametric rank sum test was performed on two groups of coronary artery segments that meet the diagnostic requirements (<3 points) and those that were evaluated as excellent (1 point). The radiation dose of all CTA patients was calculated. Paired t test was used in comparison between the two groups.
Results: (1) Forty patients in prospective scan group evaluated 554 segments of coronary artery, 99.27% satisfied the diagnosis (< 3 points) and 96.93% excellent (1 points). In retrospective scan group, 50 patients evaluated 645 segments of coronary artery, 98.76% satisfied the diagnosis (< 3 points) and 88.99% excellent (1 points), respectively. The proportion of coronary segments in the prospective scan group was significantly higher than that in the retrospective scan group (P < 0.001). (2) The effective radiation dose of the prospective scan group and the retrospective scan group were 4.46 mSv and 6.61 mSv, respectively. Academic meaning (P < 0.001).
Conclusion: Retrospective ECG-gated scan can significantly reduce radiation dose after various measures to reduce radiation dose, and has advantages for patients with high heart rate and arrhythmia.Prospective ECG-gated scan is an effective way to reduce radiation dose, but low and stable heart rate is the guarantee of obtaining high-quality images. Choose the appropriate scanning mode and parameters according to the different conditions of patients, and achieve low-dose scanning as far as possible on the premise of ensuring image quality.
Analysis of CT features of incomplete myocardial bridge and complete myocardial bridge in section I
Objective: To investigate the classification of myocardial bridge and CT imaging features of different types of myocardial bridge mural coronary artery.
Materials and Methods: The imaging data of 50 patients with myocardial bridge diagnosed by dual-source CT coronary angiography were collected. All patients underwent retrospective ECG-gated scanning to reconstruct the best systolic and diastolic images of the coronary artery. The reconstructed slice thickness/slice spacing was 0.75mm/0.5mm. The optimal diastolic and systolic diastolic diastolic diastolic diastolic diastolic diastolic and systolic wall diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic diastolic dia Two paired t-test was used to evaluate the changes of atherosclerosis associated with anterior bridge coronary artery in patients with myocardial bridge.
Results: Coronary CTA showed 58 myocardial bridges with an average length of 2.02 cm, including 23 incomplete myocardial bridges, 35 complete myocardial bridges, 32 (60%) middle anterior descending branches, 17 (29.3%) distal anterior descending branches, 1 proximal descending branch, 3 first diagonal branches, 4 first obtuse marginal branches and 1 posterior descending branch of right coronary artery. The diastolic and systolic wall coronary artery diameter and stenosis rates were 1.93 mm, 1.71 mm, 4.7% and 20.4% respectively in the two groups. The diastolic and systolic wall coronary artery diameter and stenosis rates in the complete myocardial bridge group were 2.21 mm, 1.63 mm, 8.1% and 33.7% respectively. There was significant difference in the incidence of coronary artery stenosis between the two groups (P = 0.014). There was no significant difference in the incidence of atherosclerosis between the anterior segment of coronary artery with incomplete myocardial bridge at 8 sites and with complete myocardial bridge at 15 sites (P = 0.339).
Conclusion: Complete myocardial bridges have more severe compression and longer duration than incomplete myocardial bridges. Coronary CT angiography can noninvasively display the length and thickness of myocardial bridges, evaluate the morphological changes of diastolic and systolic coronary arteries, and provide objective information for clinical treatment planning. The basis for it.
The value of second slice CT coronary angiography in diagnosing myocardial bridge, compared with CAG.
Objective: To compare and analyze the imaging data of coronary CTA and CAG in order to explore the clinical value of coronary CTA in the diagnosis of myocardial bridge.
Materials and Methods: The imaging data of 83 patients who underwent dual-source CT coronary angiography (CTA) and coronary angiography (CAG) at the same time were collected. The detection rate of myocardial bridge by CTA and CAG was calculated and compared by chi-square test.
Results: (1) Coronary CTA showed 48 myocardial bridges in 41 patients (49.4% (41/83), 28 complete myocardial bridges and 20 incomplete myocardial bridges. 29 of the 48 myocardial bridges were located in the middle of the anterior descending branch, 11 in the distal part of the anterior descending branch, 2 in the posterior descending branch of the right coronary artery, 1 in the first acute branch, 3 in the first obtuse branch, and 1 in the distal part of the anterior descending branch. (2) CAG showed 19 coronary "milking" effects in 19 cases (19 myocardial bridges). The detection rate was 22.9% (19/83). 16 of 19 myocardial bridges were located in the middle of the anterior descending branch, 2 in the distal part of the anterior descending branch and 1 in the posterior descending branch of the right coronary artery. The detection rate of myocardial bridge by coronary CTA was higher than that by CAG (P < 0.001).
Conclusion: Dual-source CT coronary angiography can visualize the anatomical relationship between coronary artery and myocardium in many directions, and is superior to CAG in displaying myocardial bridge, and has the advantage of non-invasive examination, but CAG is superior to CTA in displaying hemodynamics of mural coronary artery.
Preliminary study of myocardial first pass perfusion imaging in third patients with simple myocardial bridging
Objective To evaluate the first-pass perfusion of coronary CTA in patients with simple anterior descending branch myocardial bridge by comparing with normal myocardial first-pass perfusion.
Materials and Methods 42 patients with chest pain diagnosed by coronary CTA as simple anterior descending myocardial bridge were divided into complete myocardial bridge group and incomplete myocardial bridge group according to the type of myocardial bridge. All patients underwent retrospective scanning with a full-dose exposure window of 30-75% R-R interval, reconstruction of the best diastolic (65% -75% RR) and systolic (30% -40% RR) images, reconstruction of slice thickness/interval of 0.75 mm/0.5 mm. Average CT values of 17 segments of left ventricular myocardium during systolic and systolic periods were calculated. Average CT values of the anterior descending artery (1,2,7,8,13,14 and 17 segments) were calculated as the first pass myocardial perfusion values. Mean CT values were correlated. The mean CT values and c-MP values of the myocardium in the myocardial bridge group and the normal group were examined by two independent samples t test.
Results (1) The average CT value of aorta in normal group was 367.1 HU, and that of aorta in myocardial bridge group was 398 HU, which was positively correlated with the mean CT value of myocardium (r = 0.768-0.854, P < 0.001).
(2) The mean CT values of the anterior descending artery (ADB) in the diastolic myocardial bridge group and the normal group were 94.0HU and 96.0HU (P = 0.216), the c-MP values of the ADB in the diastolic myocardial bridge group and the normal group were 0.236 and 0.263 (P < 0.001), and the mean CT values of the ADB in the systolic myocardial bridge group and the normal group were 89.3HU and 94.6HU (P < 0.001), respectively. The c-MP of the anterior descending branch blood supply group and the normal group were 0.225 and 0.259 (P < 0.001).
(3) The mean CT values of the diastolic and systolic anterior descending artery were 90.9HU and 86.5HU in the complete myocardial bridge group, which were significantly lower than those in the incomplete myocardial bridge group (100.8HU and 95.7HU), respectively (P < 0.05). The diastolic and systolic c-MP values of the complete myocardial bridge group were 0.235 and 0.224, and those of the incomplete myocardial bridge group were 0.240 and 0.228, which were significantly lower than those of the incomplete myocardi The difference between the normal group and the control group was statistically significant (P < 0.05).
(4) The mean CT values of the diastolic and systolic blood supply areas of the anterior descending artery in the stenosis (>50%) group were 91.7 HU and 87.2 HU, lower than those in the stenosis (< 50%) group (96.9 HU and 92.1 HU), and the difference was statistically significant (P < 0.05). The diastolic and systolic c-MP values of the stenosis (>50%) group were 0.234 and 0.223, and that of the stenosis < 50% group was 0.239 and 0.227, which were significantly lower than those in the normal group Statistical significance (P < 0.05).
Conclusion Measuring the CT value of the first-pass perfusion myocardium in the diastolic and systolic phases of the patients with myocardial bridge can reflect the myocardial perfusion in the corresponding coronary artery supply area to a certain extent. Patients with muscular bridging and systolic stenosis of more than 50% should be clinically concerned.
【學位授予單位】：華中科技大學
【學位級別】：博士
【學位授予年份】：2012
【分類號】：R814.42

【參考文獻】

相關(guān)期刊論文 前10條

1 張雪梅;王健;黎川;李丹;;心肌橋的雙源CT診斷及臨床意義[J];第三軍醫(yī)大學學報;2008年20期

2 張龍江;盧光明;;冠狀動脈先天性異常的多層螺旋CT血管成像[J];放射學實踐;2008年08期

3 蒲曉群;心肌橋?qū)е氯毖孕呐K病二例[J];湖南醫(yī)科大學學報;1998年04期

4 龍丹;錢曉明;劉瑜;孫志遠;;雙源CT診斷心肌橋及心肌橋相關(guān)冠狀動脈病變的臨床分析[J];醫(yī)學研究生學報;2008年04期

5 鄭玲;張龍江;黃偉;蔡軍;盧光明;;雙源CT心肌橋的檢出率及其價值[J];臨床放射學雜志;2008年02期

6 劉巧玲;李永東;葛智平;代松魁;陳曉春;;心肌橋所致急性心肌梗死4例報告[J];臨床心血管病雜志;2010年09期

7 張文勝;內(nèi)皮細胞應(yīng)力反應(yīng)元件的研究進展[J];生物醫(yī)學工程學雜志;2001年03期

8 韓艷麗;王營;姜紅菊;左巖霞;朱靖;王健;劉芳;李繼福;陳玉國;;心肌橋與冠狀動脈粥樣硬化關(guān)系的探討[J];中國心血管病研究雜志;2006年03期

9 陳爾齊,楊亞安,邢衛(wèi)星;對壁冠狀動脈血流與形態(tài)關(guān)系的觀察分析[J];中國血液流變學雜志;2001年03期

10 王升平;肖湘生;劉士遠;;心肌橋及其影像學評價[J];醫(yī)學影像學雜志;2008年04期

本文編號：2182579