子宫良性肿瘤的MRI检查和诊断

目的：分析各种子宫良性肿瘤ＭＲＩ 图像,探讨ＭＲＩ 在子宫良性肿瘤中的诊断价值。材料和方法：共收集本院１９９４ － １９９９ 年临床疑子宫良性肿瘤病人３９ 例。ＭＲＩ 检查在ＧＥ Ｖｅｃｔｒａ０ ．５Ｔ 和ＧＥｓｉｇｎａ Ｈｏｒｉｚｏｎ１ ．５Ｔ 超导成像仪上进行,采集矢状面ＦＳＥ Ｔ２ ＷＩ 像,横断面ＳＥ Ｔ１ ＷＩ 像和ＦＳＥ Ｔ２ ＷＩ 像,并对各种病变所致子宫和宫颈的位置、大小、外形与其各层结构变化进行仔细观察和分析,与手术病理对照,以确定ＭＲＩ 的诊断价值。结果：３９例ＦＳＥ Ｔ２ ＷＩ 图像均清晰显示子宫及宫颈诸层结构;矢状面更可清楚显示子宫位置和大小。３９ 例病变均经病理证实,２３ 例为子宫肌瘤,子宫形态均增大,连结层和内膜层可受压,其中１７ 例Ｔ１ ＷＩ 和Ｔ２ ＷＩ 上表现为低信号影,６ 例为低到高不均匀信号影。１２ 例为子宫腺肌瘤,Ｔ２ ＷＩ 上连结层结构不清及较低信号,且增厚。１ 例为纳氏囊肿,Ｔ１ ＷＩ 上为子宫颈后壁内低信号囊状影,边缘光滑,Ｔ２ ＷＩ 上为均匀高信号影。本组有１ 例多发性肌瘤出血ＭＲＩ 上被误诊为子宫腺肌瘤;有２ 例子宫浆膜下肌瘤似游离于盆腔内,而漏诊。结论：ＭＲＩ 横断面及矢状面ＦＳＥ Ｔ２ ＷＩ 能清晰显示     

快速序列动态增强MRI对前列腺癌的诊断价值

目的 研究快速成像序列动态增强对前列腺癌的检出和定性价值。方法 对经活检证实的２５例,临床证实的６例,共３１例前列腺癌患者作了前瞻性增强ＭＲＩ研究。先行ＳＥＴ１ＷＩ、快速自旋回波（ＦＳＥ）Ｔ２Ｗ序列扫描,然后行快速多怪面干扰梯度回波（ＦＭＰＳＰＧＲ）序列团注增强扫描,共４个回合,研究病灶增强情况,并对增强后图像与常规ＦＳＥＴ２ＷＩ进行比较。结果 ＦＭＰＳＰＧＲ增强后扫描,共发现病灶２９个,可疑病灶     

颈动脉体瘤的MRI和MRA表现

目的 探讨颈动脉体瘤的ＭＲＩ及ＭＲＡ表现。材料与方法 １３例１５个颈动脉体瘤术前ＳＥＴ１ＷＩ检查,其中行２ＤＴＯＦ ＭＲＡ检查者１２个,ＳＥＴ１ＷＩ增强检查者１０个。结论 １５个颈动脉体瘤均位于颈动脉分叉水平,１３个骑跨于颈动脉分叉（８６．６６％）。Ｔ１ＷＩ表现为等或略高信号,Ｔ２ＷＩ表现为混合高信号。ＳＥＴ１Ｗ１３个肿块内可见流空信号（８６．６６％）,ＦＳＥ Ｔ２ＷＩ均可见流空信号（１００％）。     

烟雾病的磁共振成像诊断

目的：回顾分析８例烟雾病的磁共振成像表现，探讨磁共振成像对烟雾病的诊断价值。方法：８例烟雾病中男女各４例。年龄４～４９岁，平均２０．４岁。磁共振成像应用Ｓｉｅｍｅｎｓ１．０ＴＭＲ系统和头表面线圈。均有ＳＥ序列Ｔ１ＷＩ和Ｔ２ＷＩ，７例有三维时间飞跃法磁共振血管造影（３Ｄ－ＴＯＦＭＲＡ），１例有ＤＳＡ。结果：ＳＥ序列ＭＲＩ均见丘脑－基底节区（单侧２例，双侧６例）有扩张的烟雾血管，其中以Ｔ１ＷＩ显示更为清楚直观。７例３Ｄ－ＴＯＦＭＲＡ和１例ＤＳＡ均见ＩＣＡ上端、ＭＣＡ和ＡＣＡ近端闭塞以及丘脑－基底节区的烟雾血管。这些病理血管分布侧别与ＳＥ序列磁共振成像所见一致。结论：ＳＥ序列磁共振成像和３Ｄ－ＴＯＦＭＲＡ是诊断烟雾病的有效方法。Ｔ１ＷＩ显示丘脑－基底节区烟雾血管优于Ｔ２ＷＩ。３Ｄ－ＴＯＦＭＲＡ尚适用于烟雾病血管旁路术后随诊及其高危人群普查。     

强直性脊柱炎骶髂关节影像学分析：附24例骶髂关节平片,CT和MR…

目的：旨在评估强直性脊柱炎（ＡＳ）患者骶髂关节炎的ＭＲ影像特征，并比较Ｘ线平片、ＣＴ和ＭＲ影像在诊断骶髂关节炎中的作用。材料与方法：搜集２４例ＡＳ患者，分别行Ｘ线平片、ＣＴ和ＭＲＩ检查。增强前ＭＲ扫描序列包括ＳＥ Ｔ１ＷＩ、ＦＳＥ Ｔ２ＷＩ和梯度回波的准Ｔ２ＷＩ（ＧＲ Ｔ２＾＊ＷＩ）。增强后ＭＲ扫描序列参数与增强前ＳＥ Ｔ１ＷＩ相同。另选９例志愿者，行ＭＲ平扫检查。结果：８例志愿者１６个骶髂关节的     

磁共振动态增强和脂肪抑制技术在胰腺癌诊断中的价值

目的 了解磁共振动态增强和脂肪抑制技术在胰腺诊断中的价值。材料与方法 １８例经手术病理证实的胰腺癌患者进行了磁共振检查,采用在磁共振序列分别为：ＳＥＴ１ＷＩ、ＦＳＥＴ２ＷＩ、脂肪抑制技术ＳＥＴ１ＷＩ和动态增强ＦＭＰＳＰＧＲ等。结果 １８例胰腺癌肿瘤病灶,在ＳＥＴ１ＷＩ上呈低信号者１０例,等信号者６例,高信号者２例;ＦＳＥＴ２ＷＩ上高信号者８例,等信号者６例,低信号者４例;脂肪抑制技术ＳＥＴ１ＷＩ上     

MRI快速自旋回波T2WI三维重建技术在内耳病变中的应用

目的 研究快速自旋回波（ＦＳＥ）Ｔ２ＷＩ三维（３Ｄ）重建技术（以下简称３ＤＦＳＥ Ｔ２ＷＩ）在显示内耳和内听道正常结构和病变中的应用价值．方法 １０例健康志愿者和２０例听力下降患者行３ＤＦＳＥ Ｔ２ＷＩ和二维（２Ｄ）ＦＳＥ Ｔ２ＷＩ,比较分析２种技术显示正常结构和病变的优缺点;６例内淋巴囊扩大和１例Ｍｏｎｄｉｎｉ畸形患者同时行ＣＴ扫描,比较ＣＴ与３ＤＦＳＥ Ｔ２ＷＩ的显示结果。结果 ３Ｄ ＦＳＥＴ     

髌股关节软骨退变的临床MRI研究

目的：以关节镜为标准,比较多序列ＭＲＩ对髌股关节软骨退变的诊断价值。材料与方法：４８个膝关节行关节镜检查及Ｖｏｌｕｍｅ－ＦＦＥ－Ｔ１ＷＩ矢状位ＳＥ－Ｔ１ＷＩ断位、ＦＦＥ－Ｔ、ＷＩ断位扫描。３Ｄ－Ｖｏｌｕｍｅ－ＦＦＥ－Ｔ１ＷＩ矢状位行多平面重建（ＭＰＲ）处理。１０例无症状志原者仅行ＭＲＩ扫描。ＭＲＩ图像每以关节分内、外有面、股骨滑车面与关节镜图像逐一对照分析。统计各序列诊断软骨病变的敏感性、特异性。     

Moyamoya病的MRI和MRA诊断(附15例报告)

探讨ＭＲＩ和ＭＲＡ对Ｍｏｙａｍｏｙａ病的诊断价值。材料与方法；１５例Ｍｏｙａｍｏｙａ病患者中男６例，女９例。年龄４－４９岁２０岁以下者１１例。应用 Ｓｉｅｍｅｒｎｓ １．０Ｔ超导型ＭＲ系统行ＳＥ序列ＭＲＩ和三维时间飞跃法ＭＲＡ。均有ＳＥ序列Ｔ１Ｗ１和Ｔ２ＷＩ，１４例有３Ｄ－ＴＯＦ ＭＲＡ，１例有ＤＳＡ，６例有平扫ＣＴ。     

MRI诊断Maisonneuve骨折骨间膜断裂范围的研究

目的 探讨Ｍａｉｓｏｎｎｅｕｖｅ骨折（ＭＦＦ）骨间膜损伤及损伤范围的ＭＲＩ表现。方法 １２例急诊收治的ＭＦＦ患者术前进行ＭＲＩ检查。采用膝关节线圈对小腱全长分２段进行检查以获得骨间膜全长的图像。采用轴面Ｔ１ＷＩ（ＴＲ５００ｍｓ,ＴＥ４０ｍｓ）、Ｔ１脂肪抑制（ＳＴＩＲ）像、Ｔ２ＷＩ（ＴＲ３０００～４０００ｍｓ,ＴＥ１８０～２００ｍｓ）,３例行双侧对比,５例术中探查骨间膜。结果 １２例患者均存在骨间膜     

T2-weighted MR imaging of prostate cancer: multishot echo-planar imaging vs fast spin-echo imaging

The aim of the present study was to assess the performance of pre-biopsy T2-weighted MR imaging using multishot echo-planar imaging (EPI) sequence for visualization of prostate cancer and to compare image quality with that of fast spin-echo (FSE) sequence. Thirty-nine patients with suspected prostate cancer and one healthy male volunteer were examined on a 1.5-T MR scanner equipped with a pelvic phased-array coil. Axial MR images were obtained using multishot EPI sequence with a multishot number of 16 and FSE sequence without fat suppression. Paired EPI and FSE images were independently evaluated by three radiologists. Furthermore, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were compared between EPI and FSE images of 12 pathologically proven lesions of prostate cancer. Delineation of the periprostatic venous plexus, prostate zonal anatomy, and seminal vesicle on EPI was graded to be superior/inferior to FSE in 15.8/0, 14.6/0, and 21.5/4.3% of cases, respectively. On the other hand, delineation of the neurovascular bundle was superior/inferior to FSE in 2.6/13.2% of cases. The SNR and CNR of prostate cancer on EPI were significantly higher than those on FSE (7.99±2.51 vs 3.36±0.58, p<0.0001, and 5.51±2.02 vs 2.21±0.79, p<0.0001, respectively). In conclusion, multishot EPI has higher quality of contrast resolution for imaging of prostate cancer compared with FSE and would have the potential usefulness in the detection of prostate cancer, although these results obtained with a phased-array coil cannot be extrapolated to examinations performed with an endorectal coil.     

Magnetic resonance imaging of the primary site in stage I cervical carcinoma: A comparison of endovaginal coil with external phased array coil techniques at 0.5T

OBJECTIVE: To compare endovaginal with pelvic phased array coil magnetic resonance imaging (MRI) in detection of Stage I cervical carcinoma by correlating the findings with histopathology. Patients and METHODS: Forty consecutive patients with Stage I cervical carcinoma confirmed histologically were studied using an endovaginal coil alone immediately followed by a pelvic phased array coil. T1-W transverse and T2-W FSE sagittal images made with each coil were analyzed independently by two radiologists noting the presence and size of a mass within the cervix and any parametrial extension or involvement of adjacent organs. Tumor volumes were measured using the electronic calliper to compute tumor area on each slice and multiplying by the slice thickness. Thirty patients underwent radical hysterectomy, one a trachylectomy, one simple hysterectomy and four extended cone biopsies. Four patients had radiotherapy to the primary tumor. Following surgery, histopathologic findings were recorded and tumor volumes measured. RESULTS: Tumor volumes ranged from 0-106 cm(3)(median 1.4 cm(3), mean 9 +/- 19.4 cm(3)). Thirty-six patients had correlation of the primary site with the surgical specimen. Agreement between observers was excellent for both endovaginal (k = 0.90) and pelvic phased array (k = 0.96) techniques. Combined sensitivity and specificity for both observers of endovaginal MR imaging for detection of tumor was 96% and 70%, respectively; for pelvic phased array imaging sensitivity was substantially less at 54%. Specificity was higher at 83.7%, probably because small abnormalities were seldom visible. In patients treated surgically, early parametrial involvement in four women on endovaginal MRI was confirmed histologically in two. Pelvic phased array imaging showed early parametrial involvement in four women and was confirmed in one. CONCLUSION: Endovaginal MRI adds substantially to information from pelvic phased array images in the preoperative assessment of patients with early cervical cancer. J. Magn. Reson. Imaging 2000;12:1020-1026.     

Endorectal surface coil MR imaging of prostatic carcinoma with the inversion-recovery sequence

The value of inversion-recovery (IR) sequences in the diagnosis and staging of prostatic carcinoma with magnetic resonance (MR) imaging was studied. Twenty-six patients with carcinoma of the prostate were imaged at 1.5 T with an endorectal surface coil and with a variety of IR sequences and a set of spin-echo (SE) sequences for comparison. Ex vivo prostate specimens were imaged again at the same field strength. The two images were correlated with histologic sections. Cancer was identified with MR imaging in 96% of patients. Of the tumors more than 4 mm in diameter, 87% were identified on T2-weighted SE images, whereas only 26% were identified on IR images. However, IR images may be more useful in local staging of carcinoma. Gross capsular infiltration was present in only two patients; however, it was detectable (and excluded in five other patients) by means of IR images. It was not detectable on SE images. The high quality of images obtained with the endorectal coil was confirmed. The authors conclude that addition of the IR sequence to MR imaging with the endorectal coil may improve the usefulness of this examination.     

Multiparametric MR imaging of the prostate at 1.5-T without endorectal coil using an 8 channel pelvic phased array: Is it still a viable option?

IntroductionThe purpose of our work was to evaluate the feasibility of prostate multiparametric MR imaging at 1.5-T without endorectal coil using an 8 channel pelvic phased array coil.Material and methodsA total of 154 patients who underwent mp-MRI were retrospectively included. Patients received a standardized mp-MRI, compliant with 2012 European Society of Uro-Radiology guidelines, with 1·5 T magnetic field strength and an 8 channel pelvic phased-array coil.Two blinded readers graded the image quality of mp-MRI on a three-point scale and they scored the prostate lesions according to PI-RADS v2. All PI-RADS of 4 or 5 underwent biopsy. A third radiologist and a pathologist verified the correspondence between the MRI images and the results of the biopsy.Results64 (41.6%) patients showed a Pi-rads of 4 or 5. At biopsy, 79.7% showed a Gleason score ≥7, 12.5% showed a Gleason score of 6 and 7.8% showed a negative biopsy. In the group of Pi-rads ≤ 3, 12 patients underwent a biopsy with the following results: negative biopsy in 33.3%, atypical Small Acinar Proliferation in 16.7%, prostatic intraepithelial neoplasia in 25% and indolent PCa 25%. Mp-MRI in the identification of clinically significant cancer provided a low percentage of false positive (7.8%) while in 79.7% of cases it was capable to detect clinically significant prostate cancer. In 92.2% of patients mp-MRI identified a prostate cancer with a Gleason score ≥6. The inter-reader agreement was excellent in defining both the quality of the examination and the PI-RADS category (k = 0.83 and k = 0.70, respectively).Conclusionsmp-MRI at 1.5-T without endorectal coil using an 8 channel phased array is an appropriate tool for early detection of clinically significant prostate cancer.Implications for practice8 channel pelvic phased array is still an appropriate tool for early detection of clinically significant prostate cancer and for obtaining a reduction in overdiagnosis of indolent PCa.     

SENSE心脏阵列线圈在前列腺MRI检查中的初步应用研究

目的 对灵敏度编码(SENSE)心脏阵列线圈和直肠腔内线圈在前列腺MRI检查中的图像质量进行对比研究,初步评价SENSE心脏阵列线圈在前列腺MRI检查中的价值.资料与方法 选取前列腺病变患者50例.在相同扫描参数下,均使用SENSE心脏阵列线圈和直肠腔内线圈进行前列腺MRI常规检查,对使用两种线圈所分别获得的前列腺轴位(TRA)小视野、薄层T2WI图像的均匀度、对比信噪比(CNR)进行对比分析.结果 采用SENSE心脏阵列线圈所获得的图像均匀度优于采用直肠腔内线圈者(配对t检验,P＜0.05);采用SENSE心脏阵列线圈所获得的图像CNR亦优于采用直肠腔内线圈者(配对t检验,P＜0.05).结论 SENSE心脏阵列线圈在图像均匀度和CNR这两个图像评价指标方面都取得了较好的成像效果,在一定程度上可以替代直肠腔内线圈进行前列腺小视野、薄层、高分辨率T2W成像.     

Comparison of MRI with CT for the radiotherapy planning of prostate cancer: a feasibility study

This feasibility study was performed to evaluate the suitability of MRI in defining appropriate pelvic radiotherapy treatment volumes, and to compare MRI sequences with CT for prostate cancer radiotherapy. Five patients with localized prostate cancer, imaged with four MRI sequences (spin echo (SE) T1, turbo SE (TSE) T2, high resolution TSE (HR) T2, and FLASH 3D (F3D)), compared with their corresponding CT planning scans. Segmentation ability of the following pelvic structures: prostatic apex (PA), prostate, rectum, bladder and seminal vesicles (SV), were evaluated by three independent observers. They used a five point grading scale based on the anatomical definition of the organ boundary, tissue contrast and multiplanar display. Results were averaged for the group and for each sequence. There was no significant interobserver variation in the assessed scores (p > 0.1). The average scores (+/- 1 SD) for all pelvic structures assessed by each imaging sequence were CT 1.3 +/- 0.6; SE T1 2.4 +/- 0.9; TSE T2 2.4 +/- 0.7; HR T2 2.2 +/- 0.7 and F3D 3.4 +/- 0.6. Compared with CT, the average MR score for each assessed pelvic structure was higher with a trend for all transaxial MR sequences to provide improved segmentation of the PA and rectum. The F3D sequence scored highest as it provided multiplanar views and avoided the problem of partial volume averaging. MRI, compared with CT, appears to provide improved definition of pelvic treatment volumes but further work is required to confirm this and to address the issues of MRI associated distortion and dosimetry before MRI can be used routinely for pelvic radiotherapy planning.     

In vivo prostate magnetic resonance imaging and magnetic resonance spectroscopy at 3 Tesla using a transceive pelvic phased array coil: preliminary results

Magnetic resonance (MR) systems operating at 3 Telsa (T) and above have demonstrated considerable potential in human studies, offering improved signal-to-noise ratio and spectral resolution. However, because of radiofrequency limitations and concerns, and the lack of large volume body coils, most studies have been limited to the head. In this study we describe the design and construction of a transceive pelvic phased array coil with which MR images and spectra of the human prostate at 3 T have been obtained. Comparison with 1.5 T instruments with different hardware configurations is difficult; however, in a preliminary comparison the signal-to-noise ratio is improved in phantoms and humans when compared with a 1.5 T receive-only pelvic phased array coil, and high quality spectral resolution is demonstrated through the delineation of the citrate quadruplet in localized 1H prostate spectra. Higher fields offer the potential for MR prostate studies without the use of an endorectal coil.     

不同MRI序列在显示颞叶内侧硬化的对照研究

目的比较各序列在颞叶内侧硬化病人显示海马信号强度增加的作用。材料与方法对３０例临床及脑电图或脑地形图诊断为颞叶癫痫的病人采用双回波常规自旋回波（ＳＥ）序列、快速自旋回波（ＦＳＥ）序列和液体衰减反转恢复（ＦＬＡＩＲ）序列进行ＭＲＩ检查，并通过目测观察和信号强度测量等方法对图像进行处理。结果ＳＥ序列质子密度加权像判别海马信号强度增加的准确度最差（４３．３％）；ＦＳＥ序列次之（６２．２％）；ＳＥ序列Ｔ２加权像和ＦＬＡＩＲ序列判别海马信号强度增加的准确度很高，且ＦＬＡＩＲ序列（８８．９％）较ＳＥ序列Ｔ２加权像（７７．８％）更为准确。结论在诊断颞叶内侧硬化方面ＦＬＡＩＲ序列有可能成为常规ＳＥ序列的替代者     

Value of fat-suppressed proton-density-weighted turbo spin-echo sequences in detecting meniscal lesions: comparison with arthroscopy

Purpose: To evaluate fat-suppressed (FS) proton-density-weighted (PDw) turbo spin-echo (TSE) magnetic resonance imaging (MRI) compared to arthroscopy in the detection of meniscal lesions.

Material and Methods: In a prospective study, 31 knee joints were imaged on a 1.5T MR scanner before arthroscopy using the following sequences: (a) coronal and sagittal FS-PDw TSE (TR/TE: 4009/15 ms); (b) coronal T1w SE (TR/TE: 722/20 ms), and sagittal PDw TSE (TR/TE: 3800/15 ms). Other imaging parameters were: slice thickness 3 mm, FOV 160 mm, matrix 256×256. A total of 186 meniscal regions (62 menisci; anterior horn, body, posterior horn) were evaluated. Standard of reference was arthroscopy. Sensitivity, specificity, negative predictive value (npv), positive predictive value (ppv), and accuracy were calculated.

Results: Arthroscopically, meniscal lesions were detected in 55/186 segments (35 medial and 20 lateral meniscal lesions). Sensitivity, specificity, npv, ppv, and accuracy for combination of coronal and sagittal FS PDw TSE were 91.4%, 98.3%, 95%, 97%, and 93.5% for the medial meniscus, and 90%, 98.6%, 97.3%, 94.7%, and 96.8% for the lateral. The results were comparable to the combination of coronal T1w SE and sagittal PDw TSE for the medial (88.6%, 98.3%, 93.4%, 96.9%, 91.4%) and the lateral (90%, 95.9%, 97.2%, 85.7%, 92.5%) meniscus.

Conclusion: FS PDw TSE-MR sequences are an excellent alternative for the detection of meniscal lesions in comparison with diagnostic arthroscopy.     

Magnetic resonance with endorectal coil in the local staging of prostatic carcinoma. Comparison with histologic macrosections in 40 cases]

PURPOSE: Endorectal coil MRI is widely used in the diagnostic workup of prostate cancer, but diagnostic accuracy rates reported in the literature are quite variable. We report our personal experience with endorectal coil MRI in the local staging of prostate carcinoma. MATERIAL AND METHODS: Forty consecutive patients with histologically proved prostate carcinoma were examined with endorectal coil MRI at high field strength (1.5 T). All patients underwent a sagittal T1-weighted SE location sequence (TR 400, TE 20), an axial T1-weighted SE (TR 400, TE 20), two axial T2-weighted FSE sequences (TR 3000, TE 102, ETL 8) with and without fat suppression, and a coronal T2-weighted FSE sequence (TR 3000, TE 102, ETL 8); an axial Fast Multiplanar Spoiled Gradient Recalled (FMSPGR) dynamic sequence after Gd-DTPA injection was also performed in 18 patients. MR staging of local tumor spread was done according to the current literature criteria. All patients were submitted to radical prostatectomy, and histologic macrosections on the same plane as MR images were obtained from surgical specimens. MR and histologic staging were compared to assess MR accuracy in detecting capsular infiltration, seminal vesicles and apex involvement. The diagnostic yield of Gd-DTPA was also investigated. RESULTS: MRI correctly staged 31 of 40 cases (77.5%). MR accuracy was 80% in detecting capsular infiltration (85.7% sensitivity and 73.6% specificity), 90% in seminal vesicle involvement (91.6% sensitivity, 89.2% specificity) and 72.5% in apex involvement (79.1% sensitivity, 62.5% specificity). Dynamic studies with Gd-DTPA did not improve staging accuracy in any case. DISCUSSION AND CONCLUSIONS: In agreement with most of the current literature, MRI showed moderate overall accuracy in the local staging of prostate carcinoma. Particularly, MRI had good accuracy in detecting seminal vesicle involvement but moderate sensitivity and specificity in demonstrating capsular infiltration and apex involvement. Due to its high cost, MRI should not be routinely used in prostate cancer staging but should be reserved to the patients whose clinical and serological data suggest extraprostatic tumor spread, whose preoperative demonstration could avoid noncurative surgery.