胡友強(qiáng)，陳晨，陳勇，解超蓮，李勇，曾南林，陳天武，張小明

常規(guī)MRI與彌散加權(quán)成像測(cè)量的腫瘤容積對(duì)直腸癌TN分期的診斷價(jià)值

胡友強(qiáng)，陳晨，陳勇，解超蓮，李勇，曾南林，陳天武，張小明*

目的探討常規(guī)MRI與彌散加權(quán)成像(DWI)測(cè)量的腫瘤容積對(duì)直腸癌TN分期的診斷價(jià)值。材料與方法對(duì)經(jīng)腸鏡確診的74例直腸癌患者行盆腔3.0 T MRI檢查。分析MRI對(duì)直腸癌術(shù)前TN分期的準(zhǔn)確性，用Kappa檢驗(yàn)評(píng)價(jià)MRI術(shù)前TN分期與病理分期的一致性。用單因素方差分析評(píng)價(jià)DWI (b=1000 s/mm2) 測(cè)量的腫瘤容積與病理TN分期的相關(guān)性。結(jié)果MRI診斷直腸癌T、N分期的準(zhǔn)確率分別為87.8% (66/74)、66.2% (49/74)；病理學(xué)和MRI對(duì)T分期診斷有較好的一致性(Kappa=0.78，P=0.000)、對(duì)N分期診斷一致性較差(Kappa=0.33，P=0.000)。在DWI上測(cè)量腫瘤容積≤T2期、T3期、T4期分別為 (4145.13±718.00) mm3、(14939.73±3591.38) mm3、(22714.76±4251.71) mm3；N0期、N1期、N2期分別為(14367.15±6425.83) mm3、(17967.69±5259.88) mm3、(19464.00±3588.77) mm3。DWI測(cè)腫瘤容積越大直腸癌T分期越高，差異有統(tǒng)計(jì)學(xué)意義 (F=75.189，P=0.000)；腫瘤容積與直腸癌不同N分期間差異有統(tǒng)計(jì)學(xué)意義(F=3.545，P=0.034)。結(jié)論MRI評(píng)價(jià)直腸癌T分期準(zhǔn)確率較高，對(duì)N分期也有一定診斷價(jià)值。MR腫瘤容積測(cè)量對(duì)直腸癌TN分期有重要參考價(jià)值。

直腸腫瘤；腺癌；磁共振成像；彌散加權(quán)成像；腫瘤容積；分期

結(jié)直腸癌是常見(jiàn)的惡性腫瘤之一，發(fā)病率在所有腫瘤中占第三位，其中直腸癌占50%～70%[1]。目前，直腸癌的主要治療手段為外科手術(shù)治療結(jié)合相應(yīng)階段的輔助放化療，而手術(shù)治療仍是其主要治療方法，全直腸系膜切除術(shù)(total mesorectal excision，TME)成為直腸癌外科手術(shù)的金標(biāo)準(zhǔn)[2]。直腸癌術(shù)前分期是選擇治療方案的必要條件，在直腸癌術(shù)前評(píng)估的基礎(chǔ)上，不同分期可選擇相應(yīng)的治療方案，因此準(zhǔn)確的術(shù)前分期對(duì)選擇治療方式、判斷預(yù)后情況都有一定的指導(dǎo)意義[3]。目前，臨床上用于診斷直腸癌的主要方法包括結(jié)直腸鏡、鋇劑灌腸、CT 、MRI。雖然結(jié)直腸鏡、鋇灌腸能確診直腸癌，但是這些腔內(nèi)技術(shù)無(wú)法觀察腫瘤大小、浸潤(rùn)范圍及淋巴結(jié)轉(zhuǎn)移。與CT相比，MRI無(wú)放射線輻射、有卓越的軟組織分辨率、可提供功能成像及進(jìn)行多平面成像，尤其是薄層高分辨率 MRI的應(yīng)用，它能更好地顯示直腸腸壁的各層結(jié)構(gòu)和直腸系膜筋膜，分期準(zhǔn)確性較高[4-5]。MRI也能評(píng)價(jià)新輔助化療療效及診斷局部腫瘤復(fù)發(fā)情況[6-7]，有文獻(xiàn)報(bào)道，在MR圖像上測(cè)量直腸癌容積可較好地評(píng)價(jià)直腸癌新輔助化療(neoadjuvant chemotherapy，NACT) 及后續(xù)化療反應(yīng)情況[8-9]。但有關(guān)腫瘤容積與直腸癌T分期相關(guān)性的研究尚未見(jiàn)報(bào)道。筆者通過(guò)常規(guī)磁共振成像序列對(duì)直腸癌進(jìn)行術(shù)前TN分期的同時(shí)，進(jìn)一步研究DWI測(cè)量的腫瘤容積與直腸癌TN分期的相關(guān)性，為臨床醫(yī)師提供更多治療依據(jù)。

1 材料與方法

1.1 一般資料

本研究獲得川北醫(yī)學(xué)院附屬醫(yī)院倫理委員會(huì)批準(zhǔn)，所有病例均簽署知情同意書(shū)。2014年9月至2016年2月期間在我院收治74例未行術(shù)前放化療且經(jīng)腸鏡確診的直腸腺癌患者行盆腔3.0 T MRI檢查。入組標(biāo)準(zhǔn)：MRI檢查前經(jīng)腸鏡確診為直腸腺癌；MRI檢查前未行放化療；檢查后1周內(nèi)行TME并成功獲得病理TN分期結(jié)果；有完整MRI資料且圖像清晰可辨；無(wú)MRI禁忌證(如心臟起搏器、神經(jīng)刺激器、動(dòng)脈瘤夾、胰島素泵、人工耳蝸等)。74例有完整影像及臨床資料患者入選本組實(shí)驗(yàn)，其中男48例，女26例，年齡38～84歲，平均為61.5歲。

1.2 MRI檢查技術(shù)

使用美國(guó)GE公司的DV 750 3.0 T超導(dǎo)性磁共振成像掃描儀，32通道相控陣表面線圈?；颊卟捎米阆冗M(jìn)方式，對(duì)所有患者行常規(guī)MRI及多b值DWI檢查。所有患者檢查前均未做清潔胃腸道準(zhǔn)備。檢查前15～20 min肌內(nèi)注射山莨菪堿注射液 (654-2) 20 mg，以減少腸蠕動(dòng)。行TSE T1WI橫斷面、TSE T2WI橫斷面、T2WI SPAIR橫斷面 (FOV 360 mm ×360 mm，矩陣：384×384，層厚6 mm)。TSE T2WI矢狀面 (FOV 160 mm×160 mm，矩陣384×384，層厚4 mm)；小FOV T2WI橫斷面(FOV 240 mm×240 mm，矩陣360×224，層厚4 mm)；DWI橫斷面(FOV 380 mm×380 mm，矩陣160×192，層厚4 mm，b=0、100、300、500、800、1000、1500 s/mm2)。

1.3 圖像分析及統(tǒng)計(jì)分析

根據(jù)美國(guó)癌癥聯(lián)合會(huì)(AJCC)直腸癌TNM分期系統(tǒng)標(biāo)準(zhǔn)[10]，T分期標(biāo)準(zhǔn)：T1腫瘤侵及黏膜及黏膜下層；T2腫瘤侵及腸壁固有肌層；T3腫瘤侵及肌層穿入漿膜下，或侵及無(wú)腹膜覆蓋的腸旁組織；T4腫瘤穿透腹膜臟層或者直接侵犯或粘連于周?chē)鞴倩蚪Y(jié)構(gòu)。N分期標(biāo)準(zhǔn)：N0無(wú)淋巴結(jié)轉(zhuǎn)移； N1有1～3枚淋巴結(jié)轉(zhuǎn)移；N2有4枚以上淋巴結(jié)轉(zhuǎn)移。由于T1與T2期直腸癌在MRI上難以分辨， 臨床治療方法也相似， 因此本研究將兩期合并為≤T2期進(jìn)行研究。

由2名有5年以上MRI診斷經(jīng)驗(yàn)的醫(yī)師對(duì)盆腔MR圖像進(jìn)行分析判斷，并作出TN分期，分析的圖像資料包括T1WI、T2WI、DWI。對(duì)有異議的結(jié)果則由2名醫(yī)師討論取得一致意見(jiàn)后作為最終結(jié)果。2名醫(yī)師除已知腸鏡確診為直腸腺癌外，未知病變大小、位置及術(shù)后病理結(jié)果等其他信息。常規(guī)序列中若淋巴結(jié)短徑≥0.6 cm、形態(tài)不規(guī)整則視為轉(zhuǎn)移[11]；高b值DWI 上為明顯高信號(hào)，且形態(tài)不規(guī)整則視為轉(zhuǎn)移淋巴結(jié)。在軸面DWI (b=1000 s/mm2)上，2名MRI醫(yī)師勾畫(huà)出不規(guī)則的腫瘤感興趣區(qū)面積，然后與層厚(0.4 cm)相乘，如此逐層測(cè)量，最后相加得出腫瘤容積。直到2名醫(yī)師測(cè)量值相差10%以?xún)?nèi)，則計(jì)算平均值作為最終結(jié)果。

表1 直腸癌MRI T分期與病理T分期結(jié)果對(duì)照Tab. 1 The comparison between pathologic and MRI tumor T staging

表2 直腸癌MRI N分期與病理N分期結(jié)果對(duì)照Tab. 2 The comparison between pathologic and MRI tumor N staging

表3 直腸癌不同T分期的DWI腫瘤容積比較Tab. 3 The comparison of diffusion-weighted MR tumor volumetry between pathologic T stage

表4 直腸癌不同N分期的DWI腫瘤容積比較Tab. 4 The comparison of diffusion-weighted MR tumor volumetry between pathologic N stage

1.4 統(tǒng)計(jì)學(xué)方法

運(yùn)用SPSS 17.0軟件進(jìn)行數(shù)據(jù)分析。2名觀察者之間的一致性及MRI TN分期與病理TN分期的一致性采用Kappa檢驗(yàn)，Kappa≤0.40時(shí)，表明一致性較差；0.40＜Kappa≤0.60時(shí)，表明中度一致；0.60＜Kappa≤0.80時(shí)，表明有較高一致性；Kappa＞0.80時(shí)，表明有很好的一致性。應(yīng)用單因素方差分析評(píng)價(jià)腫瘤容積與直腸癌T分期、N分期的相關(guān)性。P＜0.05認(rèn)為差異有統(tǒng)計(jì)學(xué)意義。

2 結(jié)果

2.1 病理結(jié)果

74例患者M(jìn)RI檢查后2周內(nèi)均完成手術(shù)，術(shù)中切除原發(fā)腫瘤，遠(yuǎn)切緣術(shù)中冰凍及病理切片報(bào)告均為陰性。病理T分期：≤T2期8例、T3期49例、T4期17例；N0期52例，N1期16例，N2期6例。

2.2 直腸癌MRI TN分期與術(shù)后病理TN分期結(jié)果比較

2名醫(yī)師對(duì)直腸癌T分期結(jié)果一致性為Kappa=0.82 (P＜0.001)。直腸癌T分期MRI的診斷準(zhǔn)確率為87.8%(66/74)，過(guò)高分期5例，2例T2期誤診為T(mén)3期，3例T3期誤診為T(mén)4期，過(guò)低分期4例均為T(mén)4期誤診為T(mén)3期。病理學(xué)和MRI對(duì)直腸癌T分期診斷二者一致性較好(表1)。2名醫(yī)師對(duì)直腸癌N分期結(jié)果一致性為Kappa=0.79 (P＜0.001)。N分期的診斷準(zhǔn)確率為66.2% (49/74)，過(guò)高分期17例，其中有7例N0期誤診為N2期，5例N0期誤診為N1期，5例N2期誤診為N1期，過(guò)低分期8例，6例N1期誤診為N0期，1例N2期誤診為N0期，1例N2期期誤診為N1期。病理學(xué)和MRI對(duì)N分期診斷一致性較差(表2)。典型MR圖像見(jiàn)圖1～4。

2.3 DWI直腸癌容積與術(shù)后T、N分期的相關(guān)性

2名醫(yī)師在DWI上測(cè)量的腫瘤容積的結(jié)果一致性為Kappa=0.78(P＜0.001)。在DWI上所測(cè)量的≤T2期、T3期、T4期腫瘤容積分別為(4145.13±718.00) mm3、(14939.73±3591.38) mm3、(22714.76±4251.71) mm3；N0期、N1期、N2期腫瘤容積分別為(14367.15±6425.83) mm3、(17967.69± 5259.88) mm3、(19464.00±3588.77) mm3。直腸癌DWI測(cè)量腫瘤容積越大其T分期越高，差異有顯著統(tǒng)計(jì)學(xué)意義(P=0.000)(表3)。不同N分期與腫瘤容積間差異有統(tǒng)計(jì)學(xué)意義(P=0.034)(表4)。典型MR圖像見(jiàn)圖5。

3 討論

MRI是目前結(jié)直腸癌分期的重要檢查方法，在對(duì)腫瘤定位、判斷腫瘤浸潤(rùn)深度、決定切除范圍方面，準(zhǔn)確度較高[12]。相關(guān)研究結(jié)果提示，應(yīng)用相控陣線圈高分辨MRI顯示直腸癌T分期總的診斷準(zhǔn)確率分別為85.7%(36/42)和89.5%(85/95)[13-14]，與本研究綜合常規(guī)MRI及DWI顯示T分期總體準(zhǔn)確率87.8%(66/74)基本一致。本研究中T2期誤診為T(mén)3期主要MRI表現(xiàn)為腫瘤周?chē)鹃g隙欠清晰，可見(jiàn)條索狀長(zhǎng)T2異常信號(hào)影。有報(bào)道表明判斷直腸癌T分期最主要的困難在于T2期與T3期的鑒別，由于腫瘤周?chē)w維化、炎癥、感染或血管病變會(huì)對(duì)T2、T3期的診斷造成影響[15-16]。T3期誤診為T(mén)4期主要MRI表現(xiàn)為腫瘤周?chē)鹃g隙不清，其內(nèi)可見(jiàn)片狀異常信號(hào)影并與臨近盆壁及肌肉分界不清。分析原因多為感染、炎癥范圍較大致腸壁與周?chē)Y(jié)構(gòu)產(chǎn)生類(lèi)似腫瘤浸潤(rùn)征象。T3期誤診為T(mén)4期MRI表現(xiàn)為腫瘤浸潤(rùn)范圍較廣，與鄰近充盈欠佳的膀胱壁或肛提肌分界不清，似有受侵。但病理結(jié)果顯示均未侵及鄰近器官，可能因腫瘤生長(zhǎng)，推擠壓迫鄰近組織，使局部分界不清。MRI對(duì)臨界期腫瘤的T分期的診斷存在一定的難度，而在實(shí)際工作中， 聯(lián)合觀察軸位、矢狀位、冠狀位圖像對(duì)于減少直腸癌分期錯(cuò)誤有一定的幫助[15]。

圖1 A為T(mén)2期直腸腺癌軸面DWI，顯示后壁不均勻增厚，外緣光整，周?chē)鹃g隙尚清；B為同一患者不同層面軸面T2WI圖2 A為T(mén)3期直腸腺癌軸位DWI，顯示右前壁明顯不均勻增厚，腫瘤累及肌層及周?chē)窘M織，外緣部分呈結(jié)節(jié)狀隆起；B為同一患者軸面T2WI圖3 A為T(mén)4期直腸腺癌軸面DWI，顯示腸壁廣泛增厚，穿透腹膜臟層，脂肪間隙不清，周?chē)?jiàn)結(jié)節(jié)狀、條片狀高信號(hào)影，并累及雙側(cè)盆壁筋膜，B為同一患者不同層面軸面T2WI圖4 A為直腸腺癌軸面DWI，顯示直腸右后方1枚腫大淋巴結(jié), 邊界清，DWI上明顯高信號(hào)，病理學(xué)顯示淋巴結(jié)為增生性反應(yīng)，B為同一患者不同層面軸面T2WI圖5 患者男，61歲，病理證實(shí)為T(mén)3期直腸腺癌，A～D為DWI (b=1000 s/mm2)，顯示沿腫瘤邊緣手動(dòng)勾畫(huà)腫瘤面積，最后計(jì)算出腫瘤容積Fig. 1 A is axial DWI of a patient with T2 staging of rectal adenocarcinoma. It displays the back wall is thick and the edges became smooth and clear (arrow represents the location of rectal adenocarcinoma). B is axial T2WI of the same patient with 1A.Fig. 2 A is axial DWI of a patient with T3 staging of rectal adenocarcinoma. It displays the right front wall is obvious uneven thicking (arrow represents the location of rectal adenocarcinoma). B is axial T2WI of the same patient with 2A.Fig. 3 A is axial DWI of a patient with T4 staging of rectal adenocarcinoma. It displays the rectal wall is extensive thicking (arrow represents the location of rectal adenocarcinoma). B is axial T2WI of the same patient with 3A.Fig. 4 A is axial DWI of a patient with rectal adenocarcinoma. It displays a pelvic lymph node with high signal behind the rectum,but pathology shows that lymph nodes are proliferative (arrow represents the location of lymph node). B is axial T2WI of the same patient with A.Fig. 5 A 61-year-old male patient, and the pathology conf i rmed the stage is T3. A—D: Tumor area is manually drawn along margin of tumor, and value of this area on axial DWI (b=1000 s/mm2), then calculate the tumor volume.

MRI診斷淋巴結(jié)轉(zhuǎn)移的符合率差別較大，但大多數(shù)文獻(xiàn)報(bào)道其診斷符合率為50%～70%[17]，與本研究結(jié)果基本一致。本研究過(guò)高分期病例MRI上顯示直腸周?chē)⒛c系膜間多發(fā)淋巴結(jié)腫大影，DWI上呈高信號(hào)，但邊緣較規(guī)則，多數(shù)淋巴直徑大于1.0 cm。但病理學(xué)顯示淋巴結(jié)反應(yīng)性增生，不含有腫瘤細(xì)胞，原因可能是直腸癌導(dǎo)致淋巴結(jié)炎性增大。Brown等[18]報(bào)道，在同一直腸癌標(biāo)本中轉(zhuǎn)移性淋巴結(jié)與炎性增大淋巴結(jié)經(jīng)常難以區(qū)分。誤診為N0期的7例患者中有6例MRI上未發(fā)現(xiàn)淋巴結(jié)影，僅1例患者病變腸旁可見(jiàn)小淋巴結(jié)顯示，直徑小于0.5 cm，信號(hào)較均勻。但病理結(jié)果顯示淋巴結(jié)內(nèi)有腫瘤細(xì)胞。Monig等[19]通過(guò)132枚轉(zhuǎn)移淋巴結(jié)研究發(fā)現(xiàn)，53%轉(zhuǎn)移淋巴結(jié)直徑小于0.5 cm，應(yīng)用0.5 cm 作為鑒別良、惡性淋巴結(jié)的閾值僅僅具有中等度的敏感性和特異性。事實(shí)上，較小的轉(zhuǎn)移淋巴結(jié)非常普遍，有研究發(fā)現(xiàn)在MRI上小于0.5 cm的淋巴結(jié)15%屬于轉(zhuǎn)移淋巴結(jié)，沒(méi)有淋巴結(jié)大小的限制可以排除轉(zhuǎn)移淋巴結(jié)[16]。因此，基于淋巴結(jié)大小的標(biāo)準(zhǔn)，MRI對(duì)直腸癌術(shù)前淋巴結(jié)淋巴結(jié)轉(zhuǎn)移的診斷準(zhǔn)確性較低[19-22]。結(jié)合本組病例術(shù)中所見(jiàn)發(fā)現(xiàn)，多發(fā)小淋巴結(jié)位于與腸壁融合的區(qū)域，MRI上難以辨別。通過(guò)形態(tài)學(xué)觀察鑒別轉(zhuǎn)移淋巴結(jié)因主觀性太大，不同觀察者間差異較大導(dǎo)致可靠性低，而利用超微型超順磁性氧化鐵顆粒(USPIO)增強(qiáng)掃描，則可提高轉(zhuǎn)移淋巴結(jié)檢出的特異性[23]。但國(guó)內(nèi)USPIO尚用于實(shí)驗(yàn)階段。

直腸癌的研究表明DWI可以提高病變的檢出，在T2WI的基礎(chǔ)上運(yùn)用DWI對(duì)直腸癌的診斷敏感性從82%～84%提高到93%～95%[24]。Curvo-Semedo等[25]報(bào)道，應(yīng)用DWI和T2WI測(cè)量的腫瘤容積有較好的一致性，但在DWI上測(cè)量的容積較T2WI測(cè)量值稍小，鑒于DWI應(yīng)用越來(lái)越廣泛，可能成為制定放療計(jì)劃和GTV勾畫(huà)的重要參考[26]。而在高b值的DWI上，直腸癌呈高信號(hào)，病變顯示較好，故本研究選擇b值為1000 s/mm2DWI圖像測(cè)量腫瘤容積。相關(guān)文獻(xiàn)報(bào)道，通過(guò)MR腫瘤容積測(cè)量區(qū)別直腸癌新輔助化療反應(yīng)好壞與組織病理學(xué)對(duì)比一致性達(dá)68%～78%[8-9，27]，表明 MRI腫瘤容積測(cè)量是評(píng)價(jià)直腸癌術(shù)前NACT及后續(xù)化療的較好方法。但目前對(duì)于測(cè)量腫瘤容積與直腸癌T分期相關(guān)性的研究尚未見(jiàn)報(bào)道。筆者發(fā)現(xiàn)直腸癌DWI上測(cè)量容積越大其T分期越高，其原因可能是隨腫瘤容積的增大，浸潤(rùn)直腸壁的深度隨之增加，故T分期越高。因此在觀察腫瘤浸潤(rùn)深度顯示欠清或不確切時(shí)，可通過(guò)測(cè)量腫瘤容積，對(duì)直腸癌進(jìn)行T分期診斷。對(duì)于直腸癌N分期的MRI研究，多集中在淋巴結(jié)大小、形態(tài)、DWI信號(hào)、強(qiáng)化程度及ADC值等方面，本研究通過(guò)測(cè)量直腸癌原發(fā)腫塊大小，探討其與N分期的相關(guān)性，期望為臨床治療提供更多依據(jù)。研究發(fā)現(xiàn)DWI上測(cè)量腫瘤容積越大，其N(xiāo)分期越高。其發(fā)生機(jī)制可能是，原發(fā)腫瘤體積越大，血供越豐富，腫瘤細(xì)胞通過(guò)直接浸潤(rùn)淋巴管或經(jīng)細(xì)胞外間隙滲入淋巴管而發(fā)生淋巴結(jié)轉(zhuǎn)移的數(shù)量也越多[28]。多個(gè)研究表明，口咽癌、舌癌、食管鱗狀上皮細(xì)胞癌在CT或MRI上測(cè)量腫瘤容積大小可以幫助預(yù)測(cè)淋巴結(jié)轉(zhuǎn)移[29-31]，與本研究在直腸癌上基本一致。腫瘤容積大小對(duì)直腸癌TN分期的診斷可以作出良好的補(bǔ)充。

本研究存在一些不足之處，可能使數(shù)據(jù)統(tǒng)計(jì)結(jié)果出現(xiàn)偏倚。首先，本研究病例偏少，分期、分組不均；其次，2名醫(yī)師的經(jīng)驗(yàn)也會(huì)影響TN分期的準(zhǔn)確性；最后，雖然腫瘤容積的測(cè)量要求2名醫(yī)師測(cè)量值相差10%以?xún)?nèi)，但仍不能完全反映腫瘤真實(shí)容積。

綜上所述，常規(guī)MRI聯(lián)合DWI檢查能夠較準(zhǔn)確地診斷直腸癌TN分期，但是對(duì)于直腸癌轉(zhuǎn)移淋巴結(jié)的鑒別不夠準(zhǔn)確。DWI腫瘤容積測(cè)量對(duì)直腸癌TN分期的診斷有良好的參考價(jià)值，可協(xié)助臨床提供較合理的治療方案。在對(duì)直腸癌進(jìn)行術(shù)前分期時(shí)，推薦結(jié)合測(cè)量腫瘤容積大小。

[References]

[1] Rebecca L, Siegel MP, Kimberly D, et al. Cancer statistics, 2016. CA Cancer J Clin, 2016, 66(1): 7-30.

[2] Piso P, Dahlke MH. Total mesorectal excision for middle and lower rectal cancer: a sine institution with 337 consecutive patients. J surg Oncol, 2004, 86(3): 115-121.

[3] Wieder HA, Rosenberg R, Lordick F, et al. Rectal cancer: MR imaging before neoadjuvant chemotherapy and radiation therapy for prediction of tumor-free circumferential resection margin and longterm survival. Radiology, 2007, 243(3): 744-751.

[4] Yamada I, Yoshino N, Tetsumura A, et al. Colorectal carcinoma: local tumor staging and assessment of lymph node metastasis by highresolution MR imaging in surgical specimens. Int J Biomed Imaging, 2009, 2009: 659836.

[5] Videhult P, Smedh K, Lundin P, et al. Magnetic resonance imaging for preoperative staging of rectal cancer in clinical practice: high accuracy in predicting circumferential margin with clinical benef i t. Colorectal Dis, 2007, 9(5): 412-419.

[6] Kim SH, Lee JM, Park HS, et al. Accuracy of MRI for predicting the circumferential resection margin, mesorectal fascia invasion, and tumor response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer. J Magn Reson Imaging, 2009, 29(5): 1093-1101.

[7] Schaefer O, Langer M. Detection of recurrent rectal cancer with CT,MRI and PET/CT. Eur Radiol, 2007, 17(8): 2044-2054.

[8] Nougaret S, Fujii S, Addley HC, et al. Neoadjuvant chemotherapy evaluation by MRI volumetry in rectal cancer followed by chemoradiation and total mesorectal excision: initial experience. J Magn Reson Imaging, 2013, 38(3): 726-732.

[9] Aiba T, Uehara K, Nihashi T, et al. MRI and FDG-PET for assessment of response to neoadjuvant chemotherapy in locally advanced rectal cancer. Ann Surg Oncol, 2014, 21(6): 1801-1808.

[10] Edge SB, Compton CC. The American Joint Committee on Cancer: the 7th edition of the AJCC cancer staging manual and the future of TNM. Ann Surg Oncol, 2010, 17(6): 1471-1474.

[11] Brown G, Riehards CJ, Neweombe RG, et al. Rectal carcinoma: thin-section MRI imaging for staging 28 patients. Radiology, 1999, 211(1): 215-221.

[12] Schmoll HJ, van Cutsem E, Stein A, et al. Esmo consensus guidelines for management of patients with colon and rectal cancer: a personalized approach to clinical decision making. Ann Oncol, 2012, 23(10): 2479-2516.

[13] Cong GM, Qin MW, He D, et al. Assessment of High -Resolution Magnetic Resonance Imaging on TNM Stage and Circumferential Resection Margin in Rectal Cancer. Chin J Bases Clin General Surg, 2010, 17(3): 894-900.叢冠寧, 秦明偉, 賀丹, 等. 高分辨MRI對(duì)直腸癌TNM分期及環(huán)周切緣的評(píng)估. 中國(guó)普外基礎(chǔ)與臨床雜志, 2010, 17(3): 894-900.

[14] Tang N, Shang NJ, Zhang HX. The value of 3.0 T high resolution MRI in preoperative T staging of rectal cancer. J Chin Clin Med Imaging, 2016, 27(8): 562-564.唐娜, 尚乃艦, 張紅霞. 3.0 T高分辨率MRI在直腸癌術(shù)前T分期中的價(jià)值. 中國(guó)臨床醫(yī)學(xué)影像雜志, 2016, 27(8): 562-564.

[15] Zhang XP, Sun YS. CT and MRI in the diagnosis of rectal cancer staging. Chin J Pract Surg, 2010, 30(10): 831-834.張曉鵬, 孫應(yīng)實(shí). CT與MRI在直腸癌分期診斷中的應(yīng)用. 中國(guó)實(shí)用外科雜志, 2010, 30(10): 831-834.

[16] Mulla M, Deb R, Singh R. MRI in T staging of rectal cancer: How effective is it. Indian J Radiol Imaging, 2010, 20(2): 118-121.

[17] Zhang XP, Sun YS. Preoperative MRI evaluation of low rectal cancer in the total mesorectal excision. Chin J Pract Surg, 2009, 24(4): 296-299.張曉鵬, 孫應(yīng)實(shí). 中低位直腸癌診斷和綜合治療: 中低位直腸癌全直腸系膜切除術(shù)前MRI評(píng)價(jià). 中國(guó)實(shí)用外科雜志, 2009, 24(4): 296-299.

[18] Brown G, Richards CJ, Bourne MW, et al. Morphologic predictors of lymph node status in rectal cancer with use of high spatial-resolution MR imaging with histopathologic comparison. Radiology, 2003, 227(2): 371-377.

[19] Monig SP, Baldus SE, Zirbes TK, et al. Lymph node size and metastatic inf i ltration in colon cancer. Ann Surg Oncol, 1999, 6(6): 579-581

[20] Tveit KM, Kataja VV. ESMO minimum clinical recommendations for diagnosis, treatment and follow-up of rectal cancer. Ann Oncol, 2005, 16(1): 120-121.

[21] Klessen C, Rogalla P, Taupitz M. Local staging of rectal cancer: the current role of MRI. Eur Radiol, 2007, 17(2): 379-389.

[22] Bipat S, Glas AS, Slors FJ, et al. Rectal cancer: local staging and assessment of lymph node involvement with endoluminal US, CT, and MR imaging: a meta-analysis. Radiology, 2004, 232(3): 773-783. [23] Lahaye MJ, Engelen SM, Kessels AG, et al. USPIO-enhanced MR imaging for nodal staging in patients with primary rectal cancer: predictive criteria. Radiology, 2008, 246(3): 804-811.

[24] Rao SX, Zeng MS, Chen CZ, et al. The value of diffusion-weighted imaging in combination with T2-weighted imaging for rectal cancer detection. Eur J Radiol, 2008, 65(2): 299-303.

[25] Curvo-Semedo L, Lambregts DM, Maas M, et al. Rectal cancer: assessment of complete response to preoperative combined radiation therapy with chemotherapy conventional MR volumetry versus diffusion-weighted MR imaging. Radiology, 2011, 260(3): 734-743.

[26] Regini F, Gourtsoyianni S, Cardoso De Melo R, et al. Rectal tumour volume (GTV) delineation using T2-weighted and diffusionweighted MRI: implications for radiotherapy planning. Eur J Radiol, 2014, 83(5): 768-772.

[27] Birlik B, Obuz F, Elibol FD, et al. Diffusion-weighted MRI and MR-volumetry-in the evaluation of tumor response after preoperative chemoradiotherapy in patients with locally advanced rectal cancer. Magn Reson Imaging, 2015, 33(2): 201-212.

[28] Liu LL, Li YM. MSCT and MRI research progress of preoperative evaluation for colon cancer. Chin J Med Imaging, 2013, 18(6): 475-477.劉麗麗, 李詠梅. 多層螺旋CT和MRI對(duì)結(jié)腸癌術(shù)前評(píng)估的研究進(jìn)展. 中國(guó)醫(yī)學(xué)影像學(xué)雜志, 2013, 18(6): 475-477.

[29] Kimura Y, Sumi M, Ichikawa Y, et al. Volumetric MR imaging of oral, maxillary sinus, oropharyngeal, and hypo-pharyngeal cancers: correlation between tumor volume and lymph node metastasis. AJNR Am J Neuroradiol, 2005, 26(9): 2384-2389.

[30] Kuriakose MA, Loree TR, Hicks WL, et al. Tumour volume estimated by computed tomography as a predictive factor in carcinoma of the tongue. Br J Oral Maxillofac Surg, 2000, 38(5): 460-465.

[31] Li R, Chen TW, Hu JN, et al. Tumor volume of resectable adenocarcinoma of the esophagogastric junction at multidetector CT: association with regional lymph node metastasis and N stage. Radiology, 2013, 269(1): 130-138.

Value of magnetic resonance imaging combined with diffusionweighted MR tumor volumetry in the diagnosis of TN staging for rectal cancer

HU You-qiang, CHEN Chen, CHEN Yong, XIE Chao-lian, LI Yong, ZENG Nan-lin, CHEN Tian-wu, ZHANG Xiao-ming*
Sichuan Key Laboratory of Medical Imaging and Department of Radiology, Aff i liated Hospital, North Sichuan Medical College, Nanchong 637000, China
*Correspondence to: Zhang XM, E-mail: cjr.zhxm@vip.163.com

Objective:To investigate the value of magnetic resonance imaging (MRI) in the diagnosis of preoperative TN staging for rectal cancer and the correlation between diffusion-weighted MR tumor volumetry and TN staging.Materials and Methods:Between September 2014 and February 2016, 74 patients with histologically proven rectal cancer by the colonoscopic biopsy in our hospital was performed by pelvic 3.0 T MRI. We analyzed the preoperative MRI TN staging of rectal cancer diagnosis accuracy. Concordance between MRI TN staging of tumor and pathologic reporting was assessed by means of theKappastatistic. The correlation between diffusion-weighted MR tumor volumetry and TN staging was analyzed byone-wayanalysis of variance.Results:The accurate rate for T-staging of rectal cancer using MRI was 87.8% (66/74). There was a good correlation between pathologic and MRI tumor staging (Kappa=0.78,P=0.000). The accurate rate for N-staging of rectal cancer using MRI was 66.2% (49/74). There was a poor correlation between pathologic and MRI tumor staging (Kappa=0.33,P=0.000). The tumor volume of rectal cancer at DWI in ≤T2, T3and T4 staging rectal cancer was (4145.13±718.00) mm3, (14939.73±3591.38) mm3and (22714.76±4251.71) mm3. The tumor volume of rectal cancer at DWI in N0, N1 and N2 staging was (14367.15±6425.83) mm3,(17967.69±5259.88) mm3and (19464.00±3588.77) mm3. The greater of the tumor volume, the higher of the T-staging of rectal cancer, and the discrepancies were statistically different (F=75.189,P=0.000). The discrepancies between tumor volume and N-stagings of rectal cancer were statistically different (F=3.545,P=0.034).Conclusions:MRI has a good concordance with pathologic T-staging of rectal cancer, and has a certain clinical value in the N-staging. DWI tumor volumetry contributes a lot to diagnosis of TN-staging of rectal cancer.

Rectal neoplasms; Adenocarcinoma; Magnetic resonance imaging; Diffusion-weighted imaging; Tumor volume; Staging

國(guó)家衛(wèi)生和計(jì)劃生育委員會(huì)公益性行業(yè)科研專(zhuān)項(xiàng)基金(編號(hào)：201402019)

川北醫(yī)學(xué)院附屬醫(yī)院放射科 醫(yī)學(xué)影像四川省重點(diǎn)實(shí)驗(yàn)室，南充 637000

張小明，E-mail：cjr.zhxm@vip.163. com

2016-09-26

接受日期：2017-01-06

R445.2；R735.37

A

10.12015/issn.1674-8034.2017.03.010

胡友強(qiáng), 陳晨, 陳勇, 等. 常規(guī)MRI與彌散加權(quán)成像測(cè)量的腫瘤容積對(duì)直腸癌TN分期的診斷價(jià)值. 磁共振成像, 2017, 8(3): 214-219.

Received 26 Sep 2016, Accepted 6 Jan 2017

ACKNOWLEDGMENTSThis article was supported by the National Health and Family Planning Commission public welfare industry research under special funding (No. 201402019).