基于磁共振分級(jí)的膝關(guān)節(jié)骨關(guān)節(jié)炎關(guān)節(jié)軟骨T2圖

胡 娜，張 燕，盛 敏，吳志宏，金 今，包 飛，孟 薇，徐 進(jìn)，姜 波，劉 東，金征宇

1四川大學(xué) 華西醫(yī)院放射科，成都 610041中國醫(yī)學(xué)科學(xué)院 北京協(xié)和醫(yī)學(xué)院 北京協(xié)和醫(yī)院 2 放射科 3骨科 4針灸科，北京 100730

·論著·

基于磁共振分級(jí)的膝關(guān)節(jié)骨關(guān)節(jié)炎關(guān)節(jié)軟骨T2圖

胡 娜1，2，張 燕2，盛 敏2，吳志宏3，金 今3，包 飛4，孟 薇2，徐 進(jìn)2，姜 波2，劉 東2，金征宇2

1四川大學(xué) 華西醫(yī)院放射科，成都 610041
中國醫(yī)學(xué)科學(xué)院 北京協(xié)和醫(yī)學(xué)院 北京協(xié)和醫(yī)院2放射科3骨科4針灸科，北京 100730

目的探討T2圖在膝關(guān)節(jié)骨關(guān)節(jié)炎關(guān)節(jié)軟骨成像的表現(xiàn)與運(yùn)用。方法對(duì)38例健康組和53例膝關(guān)節(jié)骨關(guān)節(jié)炎(OA)患者進(jìn)行西安大略和麥克馬斯特大學(xué)骨關(guān)節(jié)炎指數(shù)(WOMAC)評(píng)分和脛股關(guān)節(jié)軟骨矢狀位T2圖成像，測(cè)量軟骨10個(gè)亞區(qū)的T2值。OA組另行矢狀位脂肪抑制三維快速擾相梯度回波成像和修訂的全器官磁共振成像評(píng)分(WORMS)，按修訂的磁共振Recht分級(jí)分成輕度(OA1)和重度(OA2)兩組，比較各亞區(qū)T2值在健康組、OA1和OA2組間的差異、T2值與WORMS及WOMAC評(píng)分的相關(guān)性和T2值測(cè)量的觀察者內(nèi)和觀察者間信度。結(jié)果健康組、OA1組和OA2組脛股關(guān)節(jié)軟骨各亞區(qū)的T2值分別為43.9～53.6、41.1～55.0和45.6～56.1 ms。OA2組T2值在股骨內(nèi)側(cè)中區(qū)、脛骨內(nèi)及外側(cè)中區(qū)高于健康組，在股骨內(nèi)側(cè)中區(qū)、脛骨內(nèi)側(cè)前及中區(qū)高于OA1組(P<0.05)。除股骨外側(cè)后區(qū)外，OA組的T2值與WORMS評(píng)分呈正相關(guān)(R=0.307～0.811，P<0.01)，與WOMAC總分及亞領(lǐng)域評(píng)分無相關(guān)性。除OA組的脛骨外側(cè)前區(qū)觀察者間外，T2值測(cè)量在觀察者內(nèi)和觀察者間具有可信度(R>0.740，P<0.05)。結(jié)論T2圖能區(qū)分基于磁共振分級(jí)的OA嚴(yán)重程度，是膝關(guān)節(jié)OA病情監(jiān)測(cè)的敏感手段。

膝關(guān)節(jié)；骨關(guān)節(jié)炎；關(guān)節(jié)軟骨；磁共振成像；T2圖

膝關(guān)節(jié)骨關(guān)節(jié)炎(osteoarthritis，OA)是中國人常見的關(guān)節(jié)炎，多發(fā)于中年以后，以脛股關(guān)節(jié)軟骨退變、破壞和骨質(zhì)增生為主要特征，臨床主要表現(xiàn)為關(guān)節(jié)疼痛、晨僵和功能障礙[1-3]。T2圖是當(dāng)前研究相對(duì)廣泛的關(guān)節(jié)軟骨生理性定量磁共振成像方法，體外實(shí)驗(yàn)揭示T2值有望成為OA早期診斷和病情監(jiān)測(cè)的敏感標(biāo)記[4]。然而臨床研究中，T2值反映膝關(guān)節(jié)OA的陽性結(jié)果并不顯著，例如T2值在健康人與患者間[5]、不同病情間差異無統(tǒng)計(jì)學(xué)意義[6]，或患者T2值僅高出健康人幾毫秒[7-8]，或縱向觀察T2值變化無顯著性差異[9-10]等。不相符的原因可能與觀察期過短、樣本量偏小、軟骨全層T2值敏感性低和重復(fù)測(cè)量一致性弱等有關(guān)[11]。但主要原因可能是絕大多數(shù)研究采用Kellgren-Lawrence(KL)分級(jí)衡量嚴(yán)重程度[12-13]，其重復(fù)性和敏感性較差[14-18]，并存在“假陽性”[19-20]，可能無法真實(shí)反映各級(jí)別的病變差異，從而無法客觀論證T2圖的應(yīng)用價(jià)值。本研究假設(shè)磁共振分級(jí)能更準(zhǔn)確反映各組病變嚴(yán)重程度的差別，即T2值在各組間差異具有統(tǒng)計(jì)學(xué)意義，在此基礎(chǔ)上探討T2圖在膝關(guān)節(jié)OA關(guān)節(jié)軟骨成像的表現(xiàn)和運(yùn)用。

對(duì)象和方法

對(duì)象收集2008年12月至2009年4月40～59歲的38例健康人(healthy，H)和53例OA患者膝關(guān)節(jié)：H組(49±1)歲，男性11例、女性27例；OA組(52±1)歲，男性13例、女性40例。H組為無任何關(guān)節(jié)癥狀的健康人，排除膝關(guān)節(jié)既往、查體異?；?個(gè)月內(nèi)用過緩解病情藥物者；OA組符合中華醫(yī)學(xué)會(huì)膝關(guān)節(jié)OA診斷標(biāo)準(zhǔn)(2003年)[1]，排除其他膝關(guān)節(jié)疾病或治療史者。研究對(duì)象均接受西安大略和麥克馬斯特大學(xué)骨關(guān)節(jié)炎指數(shù)(Western Ontario and McMaster Universities Osteoarthritis Index，WOMAC)[21-22]評(píng)分，并簽署知情同意書。

方法采用美國GE公司Signa EXCITE Twin Speed HD 1.5T 磁共振成像系統(tǒng)和兩個(gè)3英寸表面線圈，對(duì)脛股關(guān)節(jié)行矢狀位T2圖成像，采取快速恢復(fù)快速自旋回波序列(fast recovery fast spin echo，F(xiàn)RFSE)，重復(fù)時(shí)間1340.0 ms，回波時(shí)間17.5～105.0 ms，回波鏈長度6，層厚4.0 mm，視野14 cm×11 cm或15 cm×12 cm，矩陣320×256，激勵(lì)次數(shù)3，掃描時(shí)間13.9 min。OA組另行矢狀位脂肪抑制三維快速擾相梯度回波(fat-suppressed three-dimensional fast spoiled gradient echo，F(xiàn)S-3D-FSPGR)成像，重復(fù)時(shí)間 10.6 ms，回波時(shí)間2.5 ms，層厚2.0 mm，視野14 cm×14 cm，矩陣256×256，偏轉(zhuǎn)角10°，掃描時(shí)間5.4 min。

圖像評(píng)估由兩名放射科醫(yī)師經(jīng)培訓(xùn)后獨(dú)立完成，在脛股關(guān)節(jié)軟骨的內(nèi)、外側(cè)各選定1個(gè)最佳層面測(cè)量，利用AW 4.2/Functool軟件生成T2偽彩圖，可信度取95%，并刪除第1自旋回波的數(shù)據(jù)[23]。根據(jù)膝關(guān)節(jié)OA全器官磁共振成像評(píng)分(Whole-Organ Magnetic Resonance Imaging Score，WORMS)[24]的規(guī)定，將每側(cè)軟骨分為10個(gè)亞區(qū)，每區(qū)T2值連測(cè)3次并取平均值。對(duì)OA組FS-3D-FSPGR圖像行修訂的磁共振Recht分級(jí)[25]和修訂的WORMS評(píng)分，規(guī)定Recht 0～Ⅰ級(jí)為輕度(OA1組)，Ⅱ～Ⅲ級(jí)為重度(OA2組)。OA1組共6例(男性3例、女性3例)，OA2組47例(男性10例、女性37例)，平均年齡分別為(50±2)和(52±1)歲。剔除運(yùn)動(dòng)偽影嚴(yán)重或感興趣區(qū)T2值≥200 ms者、H組有明顯骨贅、WOMAC總分>5分者或OA組Recht Ⅳ級(jí)者[7,26-27]。

統(tǒng)計(jì)學(xué)處理采用SPSS 16.0統(tǒng)計(jì)軟件，計(jì)量資料用均數(shù)±標(biāo)準(zhǔn)差表示，所有檢驗(yàn)均采用雙側(cè)檢驗(yàn)，可信度95%，顯著性水平0.05。用SNK法比較各亞區(qū)T2值在健康組、OA1和OA2 組間的差異；用Pearson簡單相關(guān)系數(shù)檢驗(yàn)評(píng)價(jià)OA組T2值和WORMS及WOMAC評(píng)分的相關(guān)性；用簡單相關(guān)系數(shù)R值聯(lián)合兩樣本配對(duì)T檢驗(yàn)評(píng)價(jià)T2值測(cè)量的觀察者間及觀察者內(nèi)信度。

結(jié) 果

健康組、OA1組和OA2組脛股關(guān)節(jié)軟骨各亞區(qū)T2值分別為43.9～53.6、41.1～55.0和45.6～56.1 ms，健康軟骨T2圖見圖1A，OA異常分為3類：(1)局灶性升高(圖1B)；(2)全層性普遍升高(圖1C)，表現(xiàn)為軟骨色階增高；(3)全層T2值異質(zhì)性增大(圖1B、C)，信號(hào)強(qiáng)度雜亂不均，部分見非全層缺損，此外OA組的T2值標(biāo)準(zhǔn)差普遍增高。

脛骨內(nèi)側(cè)前及中區(qū)、股骨內(nèi)側(cè)中區(qū)和脛骨外側(cè)中區(qū)的T2值在各組間差異具有統(tǒng)計(jì)學(xué)意義(P<0.05)(表1)。除股骨外側(cè)后區(qū)外，OA組的T2值和WORMS評(píng)分具有相關(guān)性(R=0.307～0.811，P<0.01)，與WOMAC總分及亞領(lǐng)域評(píng)分均無相關(guān)性。除OA組的脛骨外側(cè)前區(qū)觀察者間外，T2值測(cè)量在觀察者內(nèi)和觀察者間均具有可信度(R>0.740，P<0.05)。

討 論

本研究未采用傳統(tǒng)的X線平片分級(jí)方法，改用磁共振分級(jí)來評(píng)價(jià)OA關(guān)節(jié)軟骨的嚴(yán)重程度，并實(shí)現(xiàn)了T2圖對(duì)OA軟骨嚴(yán)重程度的辨別，同時(shí)采用FS-3D-FSPGR序列對(duì)軟骨實(shí)行磁共振半定量評(píng)分，并結(jié)合臨床WOMAC指數(shù)，綜合探討了T2圖和FS-3D-FSPGR序列在膝關(guān)節(jié)OA關(guān)節(jié)軟骨成像上的運(yùn)用和關(guān)系。

本研究OA脛股關(guān)節(jié)軟骨的T2值與國內(nèi)外相關(guān)報(bào)道類似[7-8,28-29]。T2值局灶性升高提示病灶可能是OA的早期表現(xiàn)，其異質(zhì)性升高則在一定程度上反映了軟骨膠原結(jié)構(gòu)和水分子移動(dòng)的異質(zhì)性升高[30]。如果軟骨缺損區(qū)域殘存關(guān)節(jié)液，會(huì)加重界面的容積效應(yīng)，導(dǎo)致T2值更高(圖1C、E)。薄層高場(chǎng)強(qiáng)掃描結(jié)合快速成像技術(shù)[31-34]可提高信噪比和空間分辨率，節(jié)約掃描時(shí)間。

Li等[35]的小樣本研究(n=10)顯示用磁共振分級(jí)區(qū)分輕、重度OA時(shí)，T2值差異具有統(tǒng)計(jì)學(xué)意義。本研究通過擴(kuò)大樣本含量，顯示T2值在輕-重度OA間以及健康-重度OA間的差異均具有統(tǒng)計(jì)學(xué)意義，并隨病情加重增高。關(guān)節(jié)軟骨退變是OA早期和主要的病理生理變化[35]。選擇不敏感的KL分級(jí)可能導(dǎo)致“輕度OA”晚于實(shí)際情況，無法從軟骨退變的角度區(qū)分病情，而磁共振分級(jí)則能更敏感反映。建議在縱向觀察和評(píng)估療效時(shí)改用磁共振分級(jí)。另外，T2值差異最大的區(qū)域主要在承重區(qū)，并隨病情加重而升高，和David-Vaudey等[36]近期的病理研究結(jié)果類似，體現(xiàn)了軟骨退變的漸變過程，支持了膝關(guān)節(jié)軟骨的受損機(jī)制。

表 1 各亞區(qū)T2值在H、OA1和OA2組間的比較

H：健康人；OA：骨關(guān)節(jié)炎；與H組比較，aP<0.05；與OA1組比較，bP<0.05

H:healthy; OA:osteoarthritis;aP<0.05 compared with group H;bP<0.05 compared with group OA1

T2圖可作為OA關(guān)節(jié)軟骨病情評(píng)價(jià)的敏感方法，尤其適用于早期，測(cè)量承重區(qū)和局灶性信號(hào)異常區(qū)的T2值更有意義。然而健康人和輕度OA間差異無統(tǒng)計(jì)學(xué)意義，可能與輕度OA病例數(shù)過小有關(guān)，需要加大輕度OA的例數(shù)。

T2值和WORMS評(píng)分的普遍相關(guān)性提示，磁共振Recht分級(jí)符合軟骨的大體形態(tài)學(xué)改變，支持用磁共振分組假設(shè)的合理性。臨床可根據(jù)具體需求選擇成像方法：T2圖適用于OA的隨訪和療效評(píng)估，若僅需要粗略觀察軟骨形態(tài)學(xué)改變時(shí)可選用磁共振半定量評(píng)價(jià)系統(tǒng)。

與國外縱向調(diào)查[9,37]類似，本研究橫斷面的T2值和臨床表現(xiàn)之間無聯(lián)系。除關(guān)節(jié)軟骨外，膝關(guān)節(jié)其他多種結(jié)構(gòu)含有感覺神經(jīng)[38]。觀察性研究提示臨床癥狀與關(guān)節(jié)內(nèi)多種結(jié)構(gòu)的磁共振表現(xiàn)有一定關(guān)系[39-45]或尚存爭論[37,46-49]，表明OA是器官的整體性疾病[50]，最后綜合導(dǎo)致多種臨床表現(xiàn)。雖然軟骨是其最重要的磁共振特征，但其他異常也應(yīng)評(píng)價(jià)[51]，有助于更全面分析致病機(jī)制和監(jiān)測(cè)療效。

綜上，T2圖能區(qū)分基于磁共振分級(jí)的OA嚴(yán)重程度，是膝關(guān)節(jié)OA關(guān)節(jié)軟骨病變病情監(jiān)測(cè)的敏感手段。下一步研究方向是評(píng)價(jià)T2圖與OA的血清學(xué)指標(biāo)、關(guān)節(jié)鏡和軟骨病理學(xué)之間的關(guān)系，并探討在療效監(jiān)測(cè)上的運(yùn)用，重點(diǎn)觀察承重區(qū)和治療干預(yù)區(qū)。

(本文圖1見插圖第5頁)

[1] 中華醫(yī)學(xué)會(huì)風(fēng)濕病學(xué)分會(huì).骨關(guān)節(jié)炎診治指南(草案)[J].中華風(fēng)濕病學(xué)雜志,2003, 7(11):702-704.

[2] Haq I, Murphy E, Dacre J. Osteoarthritis [J]. Postgrad Med J, 2003, 79(933):377-383.

[3] David TF. Osteoarthritis of the knee [J]. NEJM, 2006, 354(8):841-848.

[4] Blumenkrantz G, Majumdar S. Quantitative magnetic resonance imaging of articular cartilage in osteoarthritis [J]. Eur Cells Mater, 2007, 13(5):75-86.

[5] Li X, Han ET, Ma CB, et al.Invivo3T spiral imaging based multi-slice T1ρ mapping of knee cartilage in osteoarthritis [J]. Magn Reson Med, 2005, 54(4):929-936.

[6] Koff MF, Amrami KK, Kaufman KR. Clinical evaluation of T2 values of patellar cartilage in patients with osteoarthritis [J]. Osteoarthr Cartilage, 2007, 15(2):198-204.

[7] Dunn TC, Lu Y, Jin H, et al. T2 relaxation time of cartilage at MR imaging: comparison with severity of knee osteoarthritis [J]. Radiology, 2004, 232(2):592-598.

[8] 楊海濤,王仁法,李鋒,等.膝關(guān)節(jié)骨關(guān)節(jié)炎軟骨磁共振T2-mapping成像與X線分級(jí)的對(duì)照研究[J].放射學(xué)實(shí)踐,2007, 22(11):1158-1160.

[9] Stahl R, Blumenkrantz G, Carballido-Gamio J, et al. MRI-derived T2 relaxation times and cartilage morphometry of the tibio-femoral joint in subjects with and without osteoarthritis during a 1-year follow-up [J]. Osteoarthr Cartilage, 2007, 15(11):1225-1234.

[10] Blumenkrantz G, Lindsey CT, Dunn TC, et al. A pilot, two year longitudinal study of the interrelationship between trabecular bone and articular cartilage in the osteoarthritic knee [J]. Osteoarthr Cartilage, 2004, 12(12):997-1005.

[11] Eckstein F, Burstein D, Link TM. Quantitative MRI of cartilage and bone: degenerative changes in osteoarthritis [J]. NMR Biomed, 2006, 19(7): 822-854.

[12] Kellgren JH, Lawrence J. Radiological assessment of osteoarthritis [J]. Ann Rheum Dis, 1957, 16(4):494-502.

[13] The Department of Rheumatology and Medical Illustration, University of Manchester and Manchester Royal Infirmary and the Empire Rheumatism Council’s Field Unit. Atlas of standard radiographs of arthritis [EB/OL]. [2009-05-28]. http://rheumatology.oxfordjournals.org/cgi/reprint/44/suppl_4/iv43.pdf.

[14] Dieppe PA, Cushnaghan J, Shepstone L. The Bristol ‘OA500’ study: progression of osteoarthritis (OA) over 3 years and the relationship between clinical and radiographic changes at the knee joint [J]. Osteoarthr Cartilage, 1997, 5(2):87-97.

[15] Mcalindon T, Cooper C, Kirwan J, et al. Determinants of disability in osteoarthritis of the knee [J]. Ann Rheum Dis, 1993, 52(4):258-262.

[16] Rosemann T, Joos S, Koerner T, et al. Comparison of AIMS2-SF, WOMAC, x-ray and a global physician assessment in order to approach quality of life in patients suffering from osteoarthritis [J]. BMC Musculoskeletal Disord, 2006, 7(1):6.

[17] Chang CB, Seong SC, Kim TK. Evaluations of radiographic joint space-do they adequately predict cartilage conditions in the patellofemoral joint of the patients undergoing total knee arthroplasty for advanced knee osteoarthritis [J]. Osteoarthr Cartilage, 2008, 16(10):1160-1166.

[18] Raynauld JP. Quantitative magnetic resonance imaging of articular cartilage in knee osteoarthritis [J]. Curr Opin Rheumatol, 2003, 15(5):647-650.

[19] Chan WP, Lang P, Stevens MP, et al. Osteoarthritis of the knee: comparison of radiography, CT, and MR imaging to assess extent and severity [J]. AJR, 1991, 157(4):799-806.

[20] 黃加張，顧湘杰，潘哲爾，等.半月板突出在膝骨性關(guān)節(jié)炎關(guān)節(jié)間隙狹窄中的作用[J].中國臨床康復(fù)，2005，9(2)：22-23.

[21] Xie F, Li SC, Goeree R, et al. Validation of Chinese Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in patients scheduled for total knee replacement [J]. Qual Life Res, 2008, 17(4):595-601.

[22] Faik A, Benbouazza K, Amine B, et al. Translation and validation of Moroccan Western Ontario and Mc Master Universities (WOMAC) osteoarthritis index in knee osteoarthritis [J]. Rheumatol Int, 2008, 28(7):677-683.

[23] Maier CF, Tan SG, Hariharan H, et al. T2 quantitation of articular cartilage at 1.5 T [J]. J Magn Reson Imaging, 2003, 17(3):358-364.

[24] Peterfy CG, Guermazi A, Zaim S, et al. Whole-Organ Magnetic Resonance Imaging Score (WORMS) of the knee in osteoarthritis [J]. Osteoarthr Cartilage, 2004, 12(3):177-190.

[25] Recht MP, Piraino DW, Paletta GA, et al. Accuracy of fat-suppressed three-dimensional spoiled gradient-echo FLASH MR imaging in the detection of patellofemoral articular cartilage abnormalities [J]. Radiology, 1996, 198(1):209-212.

[26] Dardzinski BJ, Mosher TJ, Li S, et al. Spatial variation of T2 in human articular cartilage [J]. Radiology, 1997, 205(2):546-550.

[27] Mosher TJ, Smith H, Dardzinski BJ, et al. MR imaging and T2 mapping of femoral cartilage:invivodetermination of the magic angle effect [J]. AJR Am J Roentgenol, 2001, 177(3):665-669.

[28] Hannila I, R?in?, SS, Tervonen O, et al. Topographical variation of T2 relaxation time in young adult knee cartilage at 1.5T [J]. Osteoarthr Cartilage, 2009, 17(12):1570-1575.

[29] 鄭紅偉，李小明，羅敏，等.MR T2-mapping成像對(duì)診斷早期膝關(guān)節(jié)骨關(guān)節(jié)軟骨損傷的臨床應(yīng)用價(jià)值 [J].醫(yī)學(xué)影像學(xué)雜志,2008, 18(5):532-534.

[30] Blumenkrantz G, Stahl R, Carballido-Gamio J, et al. The feasibility of characterizing the spatial distribution of cartilage T2 using texture analysis [J]. Osteoarthr Cartilage, 2008, 16(5):584-590.

[31] Lammentausta E, Kiviranta P, Nissi MJ, et al. T2 relaxation time and delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of human patellar cartilage at 1.5 T and 9.4 T: relationships with tissue mechanical properties [J]. J Orthop Res, 2006, 24(3):366-374.

[32] Quaia E, Toffanin R, Guglielmi G, et al. Fast T2 mapping of the patellar articular cartilage with gradient and spin-echo magnetic resonance imaging at 1.5 T: validation and initial clinical experience in patients with osteoarthritis [J]. Skeletal Radiol, 2008, 37(6):511-517.

[33] Deoni SC, Rutt BK, Peters TM. Rapid combined T1 and T2 mapping using gradient recalled acquisition in the steady state[J]. Magn Reson Med, 2003, 49(3):515-526.

[34] Deoni SC, Peters TM, Rutt BK. High-resolution T1 and T2 mapping of the brain in a clinically acceptable time with DESPOT1 and DESPOT2[J]. Magn Reson Med, 2005, 53(1):237-241.

[35] Li X, Ma CB, Link TM, et al.InvivoT1ρ and T2 mapping of articular cartilage in osteoarthritis of the knee using 3 T MRI [J]. Osteoarthr Cartilage, 2007, 15(7):789-797.

[36] David-Vaudey E, Ghosh S, Ries M, et al. T2 relaxation time measurements in osteoarthritis [J]. Magn Reson Imaging, 2004, 22(5):673-682.

[37] Phan CM, Link TM, Blumenkrantz G, et al. MR imaging findings in the follow-up of patients with different stages of knee osteoarthritis and the correlation with clinical symptoms [J]. Eur Radiol, 2006, 16(3):608-618.

[38] Hirasawa Y, Okajima S, Ohta M, et al. Nerve distribution to the human knee joint: anatomical and immunohistochemical study [J]. Int Orthop, 2000, 24(1):1-4.

[39] Cicuttini F, Wluka A, Wang Y, et al. The determinants of change in patella cartilage volume in osteoarthritic knees [J]. J Rheumatol, 2002, 29(12):2615-2619.

[40] Lindsey CT, Narasimhan A, Adolfo JM, et al. Magnetic resonance evaluation of the interrelationship between articular cartilage and trabecular bone of the osteoarthritic knee [J]. Osteoarthr Cartilage, 2004, 12(2):86-96.

[41] Wluka AE, Wolfe R, Stuckey S, et al. How does tibial cartilage volume relate to symptoms in subjects with knee osteoarthritis [J]. Ann Rheum Dis, 2004, 63(3):264-268.

[42] Mosher TJ, Dardzinski BJ, Smith MB. Human articular cartilage: influence of aging and early symptomatic degeneration on the spatial variation of T2: preliminary findings at 3 T [J]. Radiology, 2000, 214(1):259-266.

[43] Bombardier C, Melfi CA, Paul J, et al. Comparison of a generic and a disease-specific measure of pain and physical function after knee replacement surgery [J]. Med Care, 1995, 33(4 Suppl):AS131-AS144.

[44] Bhattacharyya T, Gale D, Dewire P, et al. The clinical importance of meniscal tears demonstrated by magnetic resonance imaging in osteoarthritis of the knee [J]. J Bone Joint Surgery Am, 2003, 85-A(1):4-9.

[45] Hill CL, Seo GS, Gale D, et al. Cruciate ligament integrity in osteoarthritis of the knee [J]. Arthritis Rheum, 2005, 52(3):794-799.

[46] Davisa AM, Badley EM, Beaton DE, et al. Rasch analysis of the Western Ontario McMaster (WOMAC) Osteoarthritis Index: results from community and arthroplasty samples [J]. J Clin Epidemiol, 2003, 56(11):1076-1083.

[47] Cicuttini FM, Baker J, Hart DJ, et al. Association of pain with radiological changes in different compartments and views of the knee joint [J]. Osteoarthr Cartilage, 1996, 4(2):143-147.

[48] Kornaat PR, Bloem JL, Ruth YT, et al. Osteoarthritis of the knee: association between clinical features and MR imaging findings [J]. Radiology, 2006, 239(3):811-817.

[49] Felson DT, Chaisson CE, Hill CL, et al. The association of bone marrow lesions with pain in knee osteoarthritis [J]. Ann Intern Med, 2001, 134(7):541-549.

[50] Felson DT, Lawrence RC, Dieppe PA, et al. Osteoarthritis: new insights. Part 1: the disease and its risk factors [J]. Ann Intern Med, 2000, 133(8):635-646.

[51] Peterfy C, Woodworth T, Altman R. Workshop for consensus on osteoarthritis imaging: MRI of the knee [J]. Osteoarthr Cartilage, 2006, 14(1):44-45.

T2MappingofArticularCartilageinKneeOsteoarthritisUsingAMagneticResonanceStaging

HU Na1，2, ZHANG Yan2, SHENG Min2，WU Zhi-hong3, JIN Jin3, BAO Fei4,MENG Wei2, XU Jin2, JIANG Bo2, LIU Dong2, JIN Zheng-yu2

1Department of Radiology, West China Hospital, Sichuan University, Chengdu 610041, China
2Department of Radiology,3Department of Orthopedics,4Department of Acupuncture-Moxibustion,
PUMC Hospital, CAMS and PUMC, Beijing 100730, China

JIN Zheng-yu Tel: 010-65295441, E-mail: jin_zhengyu@163.com

ObjectiveTo evaluate T2 mapping of articular cartilage in knee osteoarthritis (OA).MethodsTotally 38 healthy subjects (group H) and 53 OA patients

scoring with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and underwent T2 mapping of tibiofemoral articular cartilages. The T2 values in 10 subregions of the cartilages were measured. Patients in the OA group were further divided into OA1 group and OA2 group using the modified Magnetic Resonance Recht Grading System. In OA group, the fat-suppressed three-dimensional fast spoiled gradient echo MRI was performed to obtain the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS). The differences of T2 values among group H, group OA1, and group OA2 were compared. The correlation between T2 value and WORMS/WOMAC scores was analyzed. The intra- and inter-observer reproducibility of measurement was calculated.ResultsThe T2 values in all the subregions ranged 43.9-53.6ms in group H, 41.1-55.0 ms in group OA1, and 45.6-56.1ms in group OA2. T2 values in group OA2 were significantly higher in central medial femoral subregion, central medial, and lateral tibial subregions compared with group H, also significantly higher in central medial femoral subregion, anterior and central medial tibial subregions compared with group OA1 (P<0.05). T2 values were significantly correlated with WORMS scores (R=0.307-0.811,P<0.01) except in posterior lateral femoral subregion, but not with WOMAC scores. The correlation coefficients for intra- and inter-observer measurement showed good reproducibility (R>0.740,P<0.05) except in anterior lateral tibial subregion for inter-observer of measurement.ConclusionT2 mapping can differentiate the OA severity of knee cartilage using a magnetic resonance staging, and therefore can be a sensitive technique for monitoring the severity of OA.

knee joint; osteoarthritis; articular cartilage; magnetic resonance imaging; T2 mapping

ActaAcadMedSin，2011,33(2)：169-174

金征宇 電話：010-65295441，電子郵件：jin_zhengyu@163.com

R684.3；R445.2

A

1000-503X(2011)02-0169-06

10.3881/j.issn.1000-503X.2011.02.014

2010-01-14)