目的 在3.0 T MR上观察各向同性矢状面多回波数据合成成像(MEDIC)序列结合开放源图像处理软件OsiriX半自动定量测量猪膝关节软骨体积的可重复性及准确性.方法 使用水激发各向同性矢状面MEDIC序列短时重复扫描30个猪膝关节,扫描完毕立即解剖剥离软骨,用量筒水替代法测量获得软骨体积;然后由A和B 2名观察者分别在苹果笔记本电脑上使用开放源图像处理软件OsiriX半自动测量2次扫描图像的软骨体积,使用配对t检验比较A和B观察者间2次测量均值及A观察者的2次测量值差异,并计算变异系数的均方根来评估量化测量方法的可重复性;最后以解剖测量体积为参照标准,对图像测量体积进行技术校准,使用配对t检验比较A观察者的2次测量均值与解剖测量体积值,并计算随机配对差异、系统配对差异及相关系数,评估量化图像测量的准确性.记录同一个观察者手工及半自动测量用时,进行用时比较.结果 使用软件半自动测量软骨体积平均用时(4.0 ±1.5)rain,较手工测量用时(16.0±0.9)min减少约75%.A和B观察者间可重复性差异:髌骨测量均值A为(2.66±0.82)ml,B为(2.61 ±0.81)ml(t=0.24,P=0.81);内侧髁测量均值A为(2.40 ±0.69)ml,B为(2.49±0.85)ml(t=-0.45,P=0.65);外侧髁测量均值A为(2.28±0.74)ml,B为(2.41±0.78)ml(t=-0.66,P=0.51);股骨滑车测量均值A为(3.43±1. 28)ml,B为(3.51±1.08)ml(t=-0.26,P=0.79).A观察者内两次测量可重复性差异:髌骨测量值第1次(2.64 ±0.62)ml,第2次(2.67±0.60)ml(t=-0.19,P=0.85);内侧髁测量值第1次(2.43 ±0.60)ml,第2次(2.39±0.59)ml(t=0.26,P=0.80);外侧髁测量值第1次(2.26 ±0.56)ml,第2次(2.30±0.57)ml(t=-0.27,P=0.78);滑车软骨测量值第1次(3.40±1.20)ml,第2次(3.47±1.11)ml(t=-0.23,P=0.82).解剖测量值髌骨(2.73±0.97)ml,内侧髁(2.28±0.66)ml,外侧髁(2.18±0.55)ml,滑车(3.39±1.31)ml,A观察者测量均值与解剖测量值有较高的相关性[髌骨r=0.95(t=16.10,P<0.05),内侧髁r=0.92(t=12.42,P<0.05),外侧髁r=0.94(t=14.58,P<0.05),股骨滑车r=0.98(t=26.06,P<0.05)].结论 使用半自动分割软件,定量测量各向同性矢状面MEDIC图像软骨体积有较高可重复性和准确性,且图像采集及后处理用时较少,利于临床定量分析各种关节病变的软骨改变.
目的 在3.0 T MR上觀察各嚮同性矢狀麵多迴波數據閤成成像(MEDIC)序列結閤開放源圖像處理軟件OsiriX半自動定量測量豬膝關節軟骨體積的可重複性及準確性.方法 使用水激髮各嚮同性矢狀麵MEDIC序列短時重複掃描30箇豬膝關節,掃描完畢立即解剖剝離軟骨,用量筒水替代法測量穫得軟骨體積;然後由A和B 2名觀察者分彆在蘋果筆記本電腦上使用開放源圖像處理軟件OsiriX半自動測量2次掃描圖像的軟骨體積,使用配對t檢驗比較A和B觀察者間2次測量均值及A觀察者的2次測量值差異,併計算變異繫數的均方根來評估量化測量方法的可重複性;最後以解剖測量體積為參照標準,對圖像測量體積進行技術校準,使用配對t檢驗比較A觀察者的2次測量均值與解剖測量體積值,併計算隨機配對差異、繫統配對差異及相關繫數,評估量化圖像測量的準確性.記錄同一箇觀察者手工及半自動測量用時,進行用時比較.結果 使用軟件半自動測量軟骨體積平均用時(4.0 ±1.5)rain,較手工測量用時(16.0±0.9)min減少約75%.A和B觀察者間可重複性差異:髕骨測量均值A為(2.66±0.82)ml,B為(2.61 ±0.81)ml(t=0.24,P=0.81);內側髁測量均值A為(2.40 ±0.69)ml,B為(2.49±0.85)ml(t=-0.45,P=0.65);外側髁測量均值A為(2.28±0.74)ml,B為(2.41±0.78)ml(t=-0.66,P=0.51);股骨滑車測量均值A為(3.43±1. 28)ml,B為(3.51±1.08)ml(t=-0.26,P=0.79).A觀察者內兩次測量可重複性差異:髕骨測量值第1次(2.64 ±0.62)ml,第2次(2.67±0.60)ml(t=-0.19,P=0.85);內側髁測量值第1次(2.43 ±0.60)ml,第2次(2.39±0.59)ml(t=0.26,P=0.80);外側髁測量值第1次(2.26 ±0.56)ml,第2次(2.30±0.57)ml(t=-0.27,P=0.78);滑車軟骨測量值第1次(3.40±1.20)ml,第2次(3.47±1.11)ml(t=-0.23,P=0.82).解剖測量值髕骨(2.73±0.97)ml,內側髁(2.28±0.66)ml,外側髁(2.18±0.55)ml,滑車(3.39±1.31)ml,A觀察者測量均值與解剖測量值有較高的相關性[髕骨r=0.95(t=16.10,P<0.05),內側髁r=0.92(t=12.42,P<0.05),外側髁r=0.94(t=14.58,P<0.05),股骨滑車r=0.98(t=26.06,P<0.05)].結論 使用半自動分割軟件,定量測量各嚮同性矢狀麵MEDIC圖像軟骨體積有較高可重複性和準確性,且圖像採集及後處理用時較少,利于臨床定量分析各種關節病變的軟骨改變.
목적 재3.0 T MR상관찰각향동성시상면다회파수거합성성상(MEDIC)서렬결합개방원도상처리연건OsiriX반자동정량측량저슬관절연골체적적가중복성급준학성.방법 사용수격발각향동성시상면MEDIC서렬단시중복소묘30개저슬관절,소묘완필립즉해부박리연골,용량통수체대법측량획득연골체적;연후유A화B 2명관찰자분별재평과필기본전뇌상사용개방원도상처리연건OsiriX반자동측량2차소묘도상적연골체적,사용배대t검험비교A화B관찰자간2차측량균치급A관찰자적2차측량치차이,병계산변이계수적균방근래평고양화측량방법적가중복성;최후이해부측량체적위삼조표준,대도상측량체적진행기술교준,사용배대t검험비교A관찰자적2차측량균치여해부측량체적치,병계산수궤배대차이、계통배대차이급상관계수,평고양화도상측량적준학성.기록동일개관찰자수공급반자동측량용시,진행용시비교.결과 사용연건반자동측량연골체적평균용시(4.0 ±1.5)rain,교수공측량용시(16.0±0.9)min감소약75%.A화B관찰자간가중복성차이:빈골측량균치A위(2.66±0.82)ml,B위(2.61 ±0.81)ml(t=0.24,P=0.81);내측과측량균치A위(2.40 ±0.69)ml,B위(2.49±0.85)ml(t=-0.45,P=0.65);외측과측량균치A위(2.28±0.74)ml,B위(2.41±0.78)ml(t=-0.66,P=0.51);고골활차측량균치A위(3.43±1. 28)ml,B위(3.51±1.08)ml(t=-0.26,P=0.79).A관찰자내량차측량가중복성차이:빈골측량치제1차(2.64 ±0.62)ml,제2차(2.67±0.60)ml(t=-0.19,P=0.85);내측과측량치제1차(2.43 ±0.60)ml,제2차(2.39±0.59)ml(t=0.26,P=0.80);외측과측량치제1차(2.26 ±0.56)ml,제2차(2.30±0.57)ml(t=-0.27,P=0.78);활차연골측량치제1차(3.40±1.20)ml,제2차(3.47±1.11)ml(t=-0.23,P=0.82).해부측량치빈골(2.73±0.97)ml,내측과(2.28±0.66)ml,외측과(2.18±0.55)ml,활차(3.39±1.31)ml,A관찰자측량균치여해부측량치유교고적상관성[빈골r=0.95(t=16.10,P<0.05),내측과r=0.92(t=12.42,P<0.05),외측과r=0.94(t=14.58,P<0.05),고골활차r=0.98(t=26.06,P<0.05)].결론 사용반자동분할연건,정량측량각향동성시상면MEDIC도상연골체적유교고가중복성화준학성,차도상채집급후처리용시교소,리우림상정량분석각충관절병변적연골개변.
Objective To investigate the accuracy and reproducibility of multi echo data imagine combination (MEDIC) sequence with water excitation at 3. 0 T in swine knee cartilage. Methods Sagittal MEDIC sequences (0.6 mm slice thickness, isotropic) were acquired twice at 3. 0 T MRI in 30 swine knees. The knee cartilage was then removed and the volume was directly measured with water substitution method. The cartilage volume was also determined with a validated open source image software OsiriX by two observers ( A and B). The cartilage volumes obtained by two methods were compared. The reproducibility of MEDIC for quantitative measurement was accessed by the root-mean-square (RMS) of variation coefficient. Interobserver and intraobserver precision errors were compared using a paired students t-test. The accuracy of MEDIC for quantitative measurement was determined by the random pairwise differences, systematic pairwise differences and the Pearson correlation coefficients. Time of semiautomatic and manual segmentation were recorded. Results Time was saved about 75% by using semiautomatic segmentation methods [(4.0 ±1.5) min] versus manual segmentation [(16.0 ±0.9) min]. Interobserver precision errors (RMS CV%for paired analysis) between A and B for cartilage volume measurement were (2. 66 ±0. 82) ml and(2. 61 ±0.81) ml, t=0.24, P=0. 81 (patella); (2.40 ±0.69) ml and(2.49 ±0. 85) ml, t= -0.45,P =0. 65 (medial femoral condyle) ;(2. 28 ±0.74) ml and(2.41 ±0. 78) ml, t = -0. 66, P = 0. 51 (lateral femoral condyle);(3.43±1.28) ml and(3. 51 ±1. 08) ml, t= -0.26, P=0.79 (femora trochlea) with sagittal MEDIC. Intraobserver precision errors ( RMS CV% for paired analysis) of observer A for the first and second cartilage volume measurement were(2. 64 ±0. 62) ml and(2. 67 ±0. 60) ml, t = -0.19, P =0. 85(patella); (2.43 ±0.60) ml and(2. 39 ±0.59) ml, t =0.26, P = 0. 80 (medial femoral condyle);(2. 26 ±0. 56) ml and (2. 30 ±0. 57) ml, t = - 0.27, P = 0. 78 (lateral femoral condyle); (3.40 ±1.20) ml and(3.47 ±1. 11) ml, t = -0.23, P = 0. 82 (femora trochlea) with sagittal MEDIC. The cartilage volume of direct measurement were (2.73 ±0.97 ) ml ( patella ) , (2. 28 ±0. 66 ) ml ( medial femoral condyle) ,(2. 18 ±0. 55) ml (lateral femoral condyle) and (3. 39 ±1.31) ml (femora trochlea).Correlation coefficients between MEDIC and direct measurement for cartilage volume measurement were high [r = 0.95, t = 16. 10, P<0.05 ( patella); r=0.92, t = 12.42, P<0.05 (medial femoral condyle); r =0.94, t = 14.58, P < 0.05 (lateral femoral condyle) and r = 0.98, t = 26.06, P < 0. 05 (femora trochlea) ]. Conclusion Using image software OsiriX, sagittal MEDIC sequence permits accurate and precise measurement of cartilage volume at reasonable acquisition and segmentation time at 3.0 T MRI in swine knee.
