Diagnostic value of T2 and diffusion-weighted imaging (DWI) in local staging of endometrial cancer

BackgroundEndometrial cancer (EC) is the eighth most prevalent cancer globally. T2-weighted magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) help anatomical localization and local staging of lesions. The present study was performed to assess the diagnostic value of the simultaneous use of T2 and DWI techniques in EC evaluation.MethodsSeventy-eight histopathological-proven EC cases were included in this study. Patients were assessed using a complete MRI exam, including T2 and DWI. The myometrial invasion, cervical, serosal or adnexal, vaginal or parametrial, and pelvic lymph node involvements and accuracy, sensitivity, specificity, and positive and negative predictive values were evaluated in each sequence distinctly and was compared with the pathology findings and full standard protocol using post-contrast multiphasic contrast-enhanced series.ResultsDeep myometrial invasion in EC cases was detected in 38.5% by T2-DWI and 37.2% by pathology. The pathology diagnosed cervical, serosal, and vaginal involvements and pelvic lymph node metastases in 20.5%, 7.7%, 6.4% and 11.5% of cases respectively, while the numbers for T2-DWI were 26.9%, 7.7%, 7.7%, and 15.4%, respectively. The accuracy, sensitivity, specificity, PPV, and NPV of T2-DWI in the diagnosis of myometrial invasion were 93.5%, 93.1%, 93.8%, 90%, and 93.8%, respectively. A slightly higher Kappa coefficient of DWI (0.973) in the diagnosis of myometrial invasion was identified compared to T2 (0.946). The T2-DWI technique had a 52.6% intraclass correlation coefficient in the diagnosis of IA stage.ConclusionThe simultaneous consideration of T2 and DWI technique may signify a noninvasive, rapid, safe, and accurate approach for precisely assessing myometrial invasion and EC staging. Elimination of intravenous contrast material result in prevention of contrast related side effects beside significant cost reduction for health care systems and patients with a comparable result to contrast enhanced MRI.     

Computed tomography and magnetic resonance imaging findings of metastatic rectal linitis plastica from prostate cancer: A case report and review of literature

Linitis plastica is a rare condition showing circumferentially infiltrating intramural anaplastic carcinoma in a hollow viscus, resulting in a tissue thickening of the involved organ as constricted, inelastic, and rigid. While most secondary rectal linitis plastica (RLP) is caused by metastasis from stomach, breast, gallbladder, or bladder cancer, we report an extremely rare and unique case of secondary RLP due to prostate cancer with computed tomography (CT) and magnetic resonance imaging (MRI) findings, including diffusion weighted imaging (DWI). A 78-year-old man presented with approximately a 2-mo history of constipation and without cancer history. On sigmoidoscopy, there was a luminal narrowing and thickening of rectum with mucosa being grossly normal in its appearance. On contrast-enhanced CT, marked contrast enhancement with wall thickening of rectum was noted. On pelvic MRI, rectal wall thickening showed a target sign on both T2-weighted imaging and DWI. A diffuse infiltrative lesion was suspected in the prostate gland based on low signal intensity on T2-weighted imaging and restricted diffusion. A transanal full-thickness excisional biopsy revealed metastasis from a prostate adenocarcinoma invading the submucosa to the muscularis propria consistent with metastatic RLP. We would like to emphasize the CT and MRI findings of metastatic RLP due to prostate cancer.     

High b value diffusion-weighted imaging is more sensitive to white matter degeneration in Alzheimer's disease

It has been reported that diffusion-weighted imaging (DWI) can detect white matter degeneration in the Alzheimer's disease (AD) brain. We hypothesized that imaging of the slow diffusion component using high b value DWI is more sensitive to AD-related white matter degeneration than is conventional DWI, and therefore we studied the effects of high b value on lesion-to-normal contrast and contrast-to-noise ratio (CNR). Seven AD patients and seven age-matched normal subjects were studied with full-tensor DWI at three different b values (1000, 2000, and 4000 s/mm(2)) without changing echo time or diffusion time, and the mean diffusivities in the parietal and occipital regions were measured. Statistical analyses revealed that use of higher b values significantly improves both lesion-to-normal contrast and CNR. We concluded that high b value DWI is more sensitive to AD-related white matter degeneration than is conventional DWI.     

盆腔MRI平扫、钆喷酸葡胺增强扫描及扩散加权成像对盆腔脓肿患者的诊断价值:64例患者前瞻性研究

目的探讨盆腔MRI平扫、钆喷酸葡胺增强扫描及扩散加权成像（DWI）对盆腔脓肿患者的诊断效能。方法选择2018年1月~2019年6月收治的64例拟诊为盆腔脓肿的患者作为研究对象,全部患者均经MRI平扫、增强扫描及DWI检查。以活检或手术病理作为金标准,评估MRI平扫、增强扫描及DWI检查诊断盆腔脓肿的结果,并比较各检查方法的效能指标（灵敏度、特异度、准确率、阳性预测值、阴性预测值）,绘制ROC曲线比较各检查方法诊断曲线下面积,观察盆腔脓肿的MRI表现。结果增强扫描、DWI敏感度、特异度和准确率与MRI平扫对比差异均无统计学意义（P > 0.05）;增强扫描与DWI敏感度、特异度和准确率对比差异均无统计学意义（P > 0.05）。DWI和增强扫描ROC曲线下面积高于MRI平扫（P < 0.05）,增强扫描与DWI的曲线下面积对比差异无统计学意义（P > 0.05）。MRI平扫准确诊断39例,多数为囊实性包块、形态不规则、边界清晰、可见包膜、有明显分隔;T1WI序列显示包块总体呈低信号,T2WI序列显示包块呈不均匀的高信号和稍高信号。DWI检查显示多数病灶呈高信号,低ADC值,扩散明显受限。增强扫描显示多数病灶表现为渐进性强化,部分病灶分隔壁出现不同程度的强化。结论盆腔MRI、钆喷酸葡胺增强扫描及DWI诊断盆腔脓肿均效能良好,其中增强扫描效能最高。      

MRI对宫颈癌宫旁浸润的诊断价值

目的：探讨MRI在宫颈癌宫旁浸润中的临床应用价值。材料与方法连续入组58例经手术病理证实的宫颈癌患者,将术前磁共振成像检查结果与手术病理结果对照,评价T2WI、T2WI结合DWI、T2WI结合增强扫描、T2WI结合DWI及增强扫描四种不同的序列组合判断宫旁浸润的准确性。结果58例宫颈癌中有8例存在宫旁浸润,T2WI判断宫旁浸润的敏感度、特异度、阳性预测值、阴性预测值及准确度分别为87.5%、90.0%、58.3%、97.8%、89.7%,T2WI结合DWI判断宫旁浸润的敏感度、特异度、阳性预测值、阴性预测值及准确度分别为87.5%、96.0%、77.8%、98.0%、94.8%,T2WI结合增强扫描判断宫旁浸润的敏感度、特异度、阳性预测值、阴性预测值及准确度分别为62.5%、100.0%、100.0%、94.3%、94.8%,T2WI结合DWI及增强扫描判断宫旁浸润的敏感度、特异度、阳性预测值、阴性预测值及准确度分别为87.5%、100.0%、100.0%、98.0%、98.3%。结论磁共振成像T2WI结合DWI及增强扫描判断宫旁浸润的能力优于其他三种序列组合。     

肝脏转移瘤消融术后疗效的影像学评价进展

肝转移瘤消融术后边缘局部残留或复发很常见。MRI功能成像包括扩散加权成像(diffusion weighted imaging,DWI)、多b值DWI、动态对比增强(dynamic contrast enhanced,DCE)成像、影像组学等在消融后早期显示病灶残留、鉴别术后炎症增生改变与残留或复发灶等方面的价值较大。该文就上述影像学方法在肝脏转移瘤消融术后疗效评价中的应用作一综述。     

分段读出扩散加权成像在鼻咽癌检查中的价值

目的探讨分段读出扩散加权成像(RS-EPI DWI)相对于单次激发平面回波扩散加权成像(SS-EPI DWI)在鼻咽癌检查中的价值。方法收集30例经病理证实的未做任何治疗的鼻咽癌患者,采用Siemens 3.0 T Skyra磁共振扫描仪对患者常规平扫加增强扫描基础上加做鼻咽的轴位RS-EPI DWI及SS-EPI DWI序列,分别计算出鼻咽肿瘤区域的信噪比(SNR)、对比噪声比(CNR),以T_1增强轴位图像为参考,计算鼻咽层面图像的变形百分比,测量鼻咽肿瘤长、短径,比较SS-EPI DWI、RS-EPI DWI图像上肿瘤大小的准确性,比较颅底层面磁敏感伪影幅度。结果RS-EPI DWI较SS-EPI DWI图像的SNR(t=34.074,P0.01)、CNR(t=23.120,P0.01)值高,图像变形较轻,相同解剖层面,RS-EPI DWI图像测出的肿瘤大小更接近增强后T1轴位上病灶大小,颅底层面RS-EPI DWI图像磁敏感伪影明显较弱(b值为0 s/mm~2时t=10.634,P0.01,b值为1000 s/mm~2时t=8.219,P0.01),两名医师分别对SS-EPI DWI、RS-EPI DWI的ADC图病灶区进行测值,两组测值在判断病灶扩散受限上统计学差异(t=0.00,P=1.000.05)。结论分段读出扩散加权成像较传统的弥散加权成像图像质量更佳,其临床应用更有价值,对于诊断的准确性具有积极的作用。     

Diffusion-weighted MR imaging of the kidneys and the urinary tract

There is currently a growing interest in applications of diffusion-weighted imaging (DWI) in the abdomen and pelvis. DWI provides original functional information where the signal and contrast are determined by the microscopic mobility of water. DWI can provide additional information over conventional MR sequences, and could potentially be used as an alternative to contrast-enhanced sequences in patients with chronic renal insufficiency at risk of nephrogenic systemic fibrosis. We provide an overview on basic physics background on DWI applied to the kidneys, and we summarize the current available data, including our recent experience.     

MR弥散张量成像在中枢神经系统的临床应用

DWI是一种较新的MR成像技术,图像对比与组织内水分子运动的不同有关,水分子的运动用表观扩散系数表示,DWI对急性脑缺血的早期诊断有重要的临床价值;DTI可用于评估各向同性及各向异性扩散.DTI主要用于评估影响脑白质尤其是白质纤维束完整性的疾病.本文主要对DWI、尤其是DTI在中枢神经系统中的临床应用现状作一综述.     

Nongynecologic findings on pelvic ultrasound: focus on gastrointestinal diseases

Ultrasound (US) is considered the first-line imaging modality of choice in women presenting with pelvic complaints. Although imaging is focused on detecting abnormalities of the uterus and adnexa, occasionally nongynecologic findings are detected, which may or may not explain the patient's symptoms. Many of these findings are related to the gastrointestinal (GI) tract. Although most of these GI abnormalities are better diagnosed with computed tomography (CT), symptoms are often nonspecific and US may be the first imaging modality requested by referring clinicians. Sonographers should be aware of the possibility of nongynecologic diseases in patients with pelvic symptoms, particularly if US evaluation of the female reproductive tract does not provide an answer to the clinical question. Careful attention to the bowel when performing a pelvic US may allow the sonographer to diagnose GI pelvic diseases such as appendicitis, diverticulitis, colitis, bowel obstruction, mesenteric adenitis, epiploic appendagitis, Crohn disease, and even GI malignancy. As concerns grow regarding the radiation dose of pelvic CT, the use of iodinated contrast material, and imaging costs, US examination may be increasingly requested as an initial imaging study in patients in whom GI diseases is primarily suspected in the pelvis, and familiarity with the various sonographic manifestations will aid considerably in establishing the correct diagnosis.     

DWI序列在早期子宫内膜癌肌层浸润的评估价值

目的探讨磁共振动态增强(DCE)和扩散加权成像(DWI)对早期子宫内膜癌的肌层浸润深度的评估价值。方法选取2014年1月~2016年12月于我院手术病理证实为早期子宫内膜癌的患者68例。所有患者术前均进行了磁共振检查,包括DCE和DWI两种序列。以术后病理结果为准,比较两种检查序列对早期子宫内膜癌的肌层浸润深度的诊断准确率。结果有关肌层浸润方面评估,磁共振DCE序列的整体准确率为75.00%(51/68),DWI序列的整体准确率为91.18%(62/68),DWI序列准确率要高于DCE序列,差异有统计学意义(χ~2=6.332,P0.05)。DWI浸润Ⅰ级的灵敏度高于DCE序列,差异有统计学意义(χ~2=4.418,P0.05)。DWI序列判断宫颈浸润的准确率高于DCE序列,差异有统计学意义(χ~2=4.955,P0.05)。结论在子宫内膜癌肌层浸润深度评估方面,磁共振DWI较DCE序列均有更高的诊断符合率,具有检查时间短、无需对比剂等优点,应作为首选序列。     

DWI及DCE-MRI对卵巢肿瘤的应用研究进展

卵巢肿瘤是危害女性健康的常见疾病之一,肿瘤组织的良、恶性的准确定性对患者的治疗方案的制定及预后尤其关键。MRI是良好观察卵巢肿瘤并能协助定性诊断的有效检查方法。其中,扩散加权成像(DWI)和动态对比增强MRI(DCE-MRI)以其自身优势亦逐步应用于肿瘤的研究当中。作者就DWI及DCEMRI在卵巢肿瘤的应用进展展开综述。     

磁共振弥散加权成像检测肝内小病灶的临床应用

目的评估弥散加权成像(DWI)检测肝内小病灶能力.方法对103例有肝脏局灶性病变(直径均≤2 cm)的患者行DWI、常规MRI平扫及动态增强,分别计数DWI与常规MRI检出≤2 cm肿瘤结节的个数.计算在DWI与T2WI上病灶与肝组织之间的对比噪声比(CNR)并予以比较.结果 DWI共显示肝内小病变425个,T2WI显示217个,增强MRI显示211个,T1WI显示155个,DWI显示的小病灶的数目明显多于T2WI、增强与T1WI (P<0.05).在DWI及T2WI序列,小病灶与肝组织之间的CNR分别为10.45±3.16和7.58±2.60(P<0.05).结论与常规MRI比较,DWI能更敏感地检测肝内小病灶.     

CT指数及MR成像对盆腔淋巴结转移诊断价值的研究

目的探讨CT指数及MR成像对盆腔淋巴结转移诊断价值。材料与方法 2011年9月到2015年2月选择在湖北省十堰市房县人民医院肿瘤科就诊的56例宫颈癌初诊患者,都进行CT指数及MRI成像检测与对比,并且进行了病理分析。结果在56例患者中,手术病理判断为淋巴结转移38例,转移阳性率为67.9%。CT检测显示淋巴结转移阳性患者的淋巴结多为原型、中心有坏死、多合并存在包膜外侵,并且大小明显高于淋巴结转移阴性患者(P0.05)。MRI DWI图像显示淋巴结转移阳性患者的ADC值明显低于淋巴结转移阴性患者(P0.05),而eADC值明显高于淋巴结转移阴性患者(P0.05)。与手术病理结果对比,CT与MR诊断淋巴结转移的敏感性为97.4%和100.0%,特异性都为100.0%,对比差异都无统计学意义(P0.05)。结论宫颈癌盆腔淋巴结转移在临床上比较常见,可导致CT影像图特征的变化与MR成像参数的改变,CT指数及MRI成像对盆腔淋巴结转移都是非常敏感与特异的检测手段,值得在临床上推广应用。     

MRCP+DWI联合CT增强对恶性胆道梗阻性疾病的诊断价值

目的:探讨磁共振胰胆管成像(MRCP)、扩散加权成像(DWI)联合CT增强对恶性胆道梗阻性疾病的诊断价值.方法:回顾性分析69例恶性胆道梗阻的影像表现,24例研究对象仅行MRCP+DWI检查,20例研究对象仅行CT增强检查,25例研究对象行MRCP+DWI联合CT增强检查,所有影像诊断结果与临床病理结果对照.结果:MR...     

Utility of diffusion-weighted MR imaging in the diagnosis of placenta accreta spectrum abnormality

Purpose

The aim of this study was to evaluate the utility of added DWI sequences as an adjunct to traditional MR imaging in the evaluation of abnormal placentation in patients with suspicion for placenta accreta spectrum abnormality or morbidly adherent placenta (MAP).

Materials and methods

The study was approved by local ethics committee. The subjects included pregnant women with prenatal MRI performed between July 2013 to July 2015. All imaging was performed on a Philips 1.5T MR scanner using pelvic phased-array coil. Only T2-weighted and diffusion-weighted imaging (DWI) series were compiled for review. Two randomized imaging sets were created: set 1 included T2-weighted series only (T2W); set 2 included T2W with DWI series together (T2W + DWI). Three radiologists, blinded to history and pathology, reviewed the imaging, with 2 weeks of time between the two image sets. Sensitivity, specificity, and overall accuracy for MAP were calculated and compared between T2W only and T2W + DWI reads. Associations between imaging findings and invasion on pathology were tested using the Chi-squared test. Confidence scores, inter-reader agreement, and systematic differences were documented.

Results

A total of 17 pregnant women were included in the study. 8 cases were pathologically diagnosed with MAP. There were no significant differences in the diagnostic accuracy between T2W and T2W + DWI in the diagnosis of MAP in terms of overall accuracy (62.7% for T2W vs. 68.6% for T2W + DWI, p = 0.68), sensitivity (70.8% for T2W vs. 95.8% for T2W + DWI, p = 0.12), and specificity (55.6% for T2W vs. 44.4% for T2W + DWI, p = 0.49). There was no significant difference in the diagnostic confidence between the review of T2W images alone and the T2W + DWI review (mean 7.3 ± 1.8 for T2W vs. 7.5 ± 1.8 for T2W + DWI, p = 0.37).

Conclusion

With the current imaging technique, addition of DWI sequence to the traditional T2W images cannot be shown to significantly increase the accuracy or reader confidence for diagnosis of placenta accreta spectrum abnormality. However, DWI does improve identification of abnormalities in the placental–myometrial interface.

     

体素内不相干运动扩散加权成像在肺部的应用进展

扩散加权成像(diffusion weighted imaging,DWI)技术无需对比剂即可获得组织的水分子扩散情况.然而单指数DWI无法区分组织内单纯水分子扩散和微循环灌注信息,体素内不相干运动扩散加权成像(intravoxel incoherent motion-diffusion weighted imagin...     

盆腔良恶性肿瘤鉴别中磁共振表观扩散系数值的诊断价值

目的 探讨磁共振检查中定量参数表观扩散系数值在盆腔良性、恶性肿瘤诊断、鉴别中价值。 方法 选择2015年2月~2016年5月期间在我院接受诊治,且经手术病理学检查被确诊为良恶性肿瘤的48例患者作为对象,其中20例良性肿瘤患者作为良性组,28例恶性肿瘤患者作为恶性组,对2组患者磁共振检查相关资料进行回顾性分析。 结果 良性组患者肿瘤病变磁共振弥散加权成像信号存在多样性,可表现为高、较高、等信号,恶性组患者病变磁共振弥散加权成像信号多数表现为高信号;在表观扩散系数值比较上,恶性组显著低于良性组（P<0.05）。 结论 表观扩散系数值对盆腔病变表现出较高的敏感,该值可为盆腔良恶性肿瘤早期临床鉴别诊断提供可靠参考依据。       

椎体转移瘤扩散加权成像与MRI增强扫描的比较研究

目的比较扩散加权成像(DWI)与MRI增强扫描对MRI增强扫描有强化的椎体转移病灶的诊断价值.方法搜集恶性肿瘤合并脊柱转移病例57例,行常规MRI(T1WI,T2WI,STIR,MR增强扫描)及DWI扫描,113个病灶有强化;测量DWI与MR增强扫描对比噪声比(CNR),计算病灶表观弥散系数(ADC)值和骨髓对比率,比较病变椎体在DWI和MR增强扫描的信号,进行统计学分析.结果DWI和MR增强扫描序列的CNR无显著差异;椎体转移灶ADC值平均为(1.37±0.56)×10-3 mm2/s,正常椎体ADC值(0.64±0.22)×10-3 mm2/s,两者ADC值具有显著性差异(P＜0.05).DWI和MR增强扫描病灶骨髓对比率平均为(1.54±1.39)和(0.64±0.54),二者有良好相关性(P=0.01),DWI骨髓对比率高于MR增强扫描.结论DWI在显示病灶方面有一定优势,病灶骨髓对比率高于MR增强扫描.临床上应用DWI结合ADC值,可以提高对椎体转移病灶的诊断.     

磁共振弥散加权成像对肝脏常见占位性病变诊断应用价值的研究

目的 探讨磁共振弥散加权成像(DWI)在筛选和鉴别肝脏良恶性病变中的临床应用价值.方法 对70例肝脏占位性病灶(肝癌30例,肝转移瘤20例,肝血管瘤20例)行DWI检查,并测量表观弥散系数(ADC)值来进行判断肝脏占位病变的良恶性.结果 DWI在显示恶性病灶,特别是显示多发小病灶转移瘤,要比CT增强扫描更有优势.肝细胞癌和转移瘤的ADC值均低于血管瘤的ADC值,并且差异具有统计学意义(P<0.05).结论 DWI及ADC值的应用大大提高了MR对肝脏恶性肿瘤的诊断和鉴别诊断能力.