Report of diffusion-weighted MRI in two cases with different cerebral hydatid disease

Purpose: To present MRI findings in two cases of cerebral hydatid disease with an emphasis on diffusion-weighted imaging (DWI) findings of Echinococcus granulosus (EG) versus Echinococcus alveolaris (EA).

Results: EG lesions were isointense with cerebrospinal fluid in all sequences including DWI. On DWI, EA lesions remained hypointense on b=1000 s/mm² diffusion-weighted images. Apparent diffusion coefficient (ADC) values of EG and EA lesions were completely different from each other, 2.88±0.24×10^-3 s/mm² and 1.33±0.15×10^-3 s/mm², respectively.

Conclusion: The ADC values could not be used to discriminate from other differential diagnoses.     

Metachromatic leukodystrophy. Diffusion MR imaging and proton MR spectroscopy

Metachromatic leukodystrophy is characterized by dysmyelination caused by a deficiency of arylsulfatase-A. In a 17-month-old boy with metachromatic leukodystrophy, an echo-planar diffusion MR sequence revealed a restricted diffusion pattern in the deep white matter, manifested by high-signal on b = 1000 s/mm² images, and low ADC values (0.56 × 10^-3 mm²/s). Proton MR spectroscopy revealed a marked decrease in choline, a metabolite related to myelin turnover. These observations consisting of a restricted diffusion pattern on diffusion MR imaging, and decreased choline peaks on proton spectroscopy, likely represented dysmyelination in metachromatic leukodystrophy.     

Echo-planar and gradient-echo diffusion MRI of normal brain iron in the globus pallidus

The purpose of this study was to investigate effects of normal brain iron on proton diffusion and its quantification by diffusion MRI. The studies were undertaken in 24 cases ages ranging from 15 to 74 years (mean=45 years) with normal iron deposition in the globus pallidus to characterize the appearances on diffusion imaging with differing b values and on apparent diffusion coefficient (ADC) maps. Diffusion MRI was obtained by the spin-echo echo-planar imaging sequence (n=20 patients) or by the gradient-echo diffusion sequence, PSIF (n=4). In the PSIF sequence, pixel lens calculations were performed. In the echo-planar sequence, ADC value calculations were performed by using Stejskal–Tanner formula and by direct reading from automatically generated ADC maps. ADC values obtained from the normal appearing parenchyma were used as controls. Twenty patients with acute cerebral infarction were included for comparison of ADC values with those of iron deposition. The mean ADC value in the normal cerebral parenchyma was 0.85±0.11×10⁻³ mm²/s. In the globus pallidus, mean ADC value was 48±0.12×10⁻³ mm²/s. That of regions with acute infarction was 0.34±0.11×10⁻³ mm²/s. On b=0 or 50, b=500 and b=1000 s/mm² images of the echo-planar diffusion imaging globus pallidus appeared hypointense compared to surrounding parenchymal structures. Low signal and low pixel values were evident on the PSIF imaging. This study indicates that, on diffusion MRI, normal iron deposition reveals prominent low signal on all the images of the echo-planar diffusion imaging sequence with differing b values, as well as on the gradient-echo diffusion, PSIF sequence. Low signal on ADC maps and low ADC values are evident. These represent characteristic diffusion MRI features of normal iron deposition in the brain, reflecting susceptibility effects.     

Diffusion-weighted magnetic resonance imaging and magnetic resonance spectroscopy in the evaluation of focal cerebral tubercular lesions

Purpose: To review magnetic resonance (MR) diffusion-weighted imaging (DWI) and spectroscopy findings in patients with focal cerebral tuberculosis and to assess whether these techniques can adequately characterize focal cerebral tubercular lesions.

Material and Methods: Sixteen patients with single or multiple lesions were evaluated on a 1.5T MR system. DWI was performed with three 'b' values of 50, 500, and 1000 s/mm² and the apparent diffusion coefficient maps were calculated. MR spectroscopy was performed using the point-resolved single-voxel technique with 2 echo time values of 135 ms and 270 ms. The signal intensities of the tubercular lesions on diffusion images and the apparent diffusion coefficients (ADCs) of their centers, along with MR spectroscopy findings, were analyzed in relation to their T2-weighted MR appearances.

Results: DWI identified 17 of the 20 lesions evaluated. Increased signal intensity was seen in 9 of the 17 lesions. The ADCs of the lesions ranged from 0.406 to 2.64×10^-3 mm²/s (mean±SD: 1.038±0.609 mm²/s). Most of the lesions with hyperintense centers on T2-weighted images were of increased intensity on diffusion images, while those with hypointense centers on T2-weighted images were of decreased signal intensity on diffusion images. However, no statistical difference in the ADCs was found between lesions with increased and those with decreased signal intensity centers on T2-weighted images. MR spectroscopy revealed a lipid peak at 0.9-1.3 ppm in all of the 14 lesions evaluated. An increase in normalized choline:creatine ratio was found in all the lesions in which the spectra were obtained with the voxel, including a variable portion of the lesion wall.

Conclusion: DWI and MR spectroscopy help in determining the nature of cerebral tubercular lesions; however, since the findings are varied, they do not help in specific characterization.     

Value of apparent diffusion coefficient calculation in the differential diagnosis of parotid gland tumors

Background: The differential diagnosis of parotid gland tumors is often difficult with conventional magnetic resonance imaging.

Purpose: To determine whether the calculation of the apparent diffusion coefficient (ADC) is valuable for making the differential diagnosis of parotid tumors.

Material and Methods: Thirty parotid masses in 28 patients and 24 healthy parotid glands in 12 controls were examined in this prospective study. Diffusion-weighted magnetic resonance imaging with echo-planar spin-echo sequences was used to evaluate each subject. The ADC of each tumor and each healthy parotid gland was calculated. Tumor diagnoses were confirmed by the results of histopathologic analysis.

Results: The following types of masses were identified: 11 Warthin tumors, nine pleomorphic adenomas, seven malignant tumors, one basal cell adenoma, and two benign cysts. The mean ADC value for the Warthin tumors was 0.97±0.16×10^-3 mm²/s, for the pleomorphic adenomas was 1.74±0.37×10^-3 mm²/s, for the malignant tumors was 1.04±0.35×10^-3 mm²/s, and for the normal parotid glands was 0.34±0.20×10^-3 mm²/s. The respective ADC value for the single basal cell adenoma was 1.40×10^-3 mm²/s. Statistically significant differences were identified between the subjects with pleomorphic adenoma and those with another type of parotid tumor, and between subjects with healthy parotid glands and those with a tumor.

Conclusion: Calculating the ADC appears to be useful in differentiating pleomorphic adenomas from other types of parotid gland tumors.     

Diffusion-weighted and conventional MR imaging findings of neuroaxonal dystrophy

BACKGROUND AND PURPOSE: Neuroaxonal dystrophy is a rare progressive disorder of childhood characterized by mental deterioration and seizures. The diffusion-weighted and conventional MR imaging findings are reported for six cases. METHODS: Six patients aged 19 months to 9 years with proved neuroaxonal dystrophy (one with the infantile form, five juvenile forms) underwent imaging at 1.5 T. Echo-planar diffusion-weighted images were acquired with a trace imaging sequence in five patients and with a three-gradient protocol (4000/110) in one. Images obtained with a b value of 1000 s/mm2 and corresponding apparent diffusion coefficient (ADC) maps were studied. ADCs from lesion sites and normal regions (pons and temporal and occipital lobes) were evaluated. RESULTS: A hyperintense cerebellum (a characteristic of the disease) was evident on fluid-attenuated inversion recovery images in all cases. Four patients had associated cerebral changes. Diffusion-weighted images, especially ADC maps, showed an elevated diffusion pattern in the cerebellum in the five juvenile cases (normal images at b = 1000 s/mm2, ADCs of 1.30-2.60 x 10(-3) mm2/s). A restricted diffusion pattern was evident in the infantile case (hyperintensity at b = 1000 s/mm2, low ADCs of 0.44-0.55 x 10(-3) mm2/s). ADCs were normal in the pons and temporal and occipital lobes (0.64-1.00 x 10(-3) mm2/s). CONCLUSION: An elevated cerebellar diffusion pattern is a predominant feature of juvenile neuroaxonal dystrophy. Coexistent elevated and restricted diffusion patterns were evident in different brain regions in different forms of the disease. Dystrophic axons likely account the restricted diffusion, whereas spheroid formation (swelling) and abnormal myelination result in elevated diffusion.     

Quantitative study of prostate cancer using three dimensional fiber tractography

AIM:To investigate feasibility of a quantitative study of prostate cancer using three dimensional（3D）fiber tractography.METHODS:In this institutional review board approved retrospective study,24 men with biopsy proven prostate cancer underwent prostate magnetic resonance imaging（MRI）with an endorectal coil on a 1.5 T MRI scanner.Single shot echo-planar diffusion weighted images were acquired with b = 0.600 s/mm²,six gradient directions.Open-source available software Track Vis and its Diffusion Toolkit were used to generate diffusion tensor imaging（DTI）map and 3D fiber tracts.Multiple 3D spherical regions of interest were drawn over the areas of tumor and healthy prostatic parenchyma to measure tract density,apparent diffusion coefficient（ADC）and fractional anisotropy（FA）,which were statistically analyzed.RESULTS:DTI tractography showed rich fiber tract anatomy with tract heterogeneity.Mean tumor region and normal parenchymal tract densities were 2.53 and 3.37 respectively（P < 0.001）.In the tumor,mean ADC was 0.0011 × 10^-3 mm²/s vs 0.0014 × 10^-3 mm²/s in the normal parenchyma（P < 0.001）.The FA values for tumor and normal parenchyma were 0.2047 and 0.2259 respectively（P = 0.3819）.CONCLUSION:DTI tractography of the prostate is feasible and depicts congregate fibers within the gland.Tract density may offer new biomarker to distinguish tumor from normal tissue.     

Diffusion magnetic resonance imaging in infantile neuroaxonal dystrophy

A 7-month-old girl with infantile neuroaxonal dystrophy is reported. In diffusion MRI, the pyramidal tracts and dentate nuclei had high signal on b = 1,000 s/mm2 images and low apparent diffusion coefficient (ADC) values. This pattern likely reflected the presence of abnormal (dystrophic) axons with restricted mobility of water molecules. A reverse pattern was evident in the cerebellar cortex with high ADC values. This was likely a reflection of dysmyelination or lack of myelination.     

Wallenberg's lateral medullary syndrome: diffusion-weighted imaging findings

Purpose: To investigate the efficacy of diffusion-weighted imaging in patients with Wallenberg's lateral medullary syndrome.

Material and Methods: Thirteen patients with Wallenberg's lateral medullary syndrome were examined with conventional and echoplanar diffusion-weighted magnetic resonance (MR) imaging in a 1.5 T magnetic resonance unit. MR examinations were obtained in the acute or subacute stage of clinical syndrome, and diffusion-weighted imaging (DWI) was considered to be positive for infarction when an increase in signal was seen on b=1000 s/mm² images in the posterolateral medullary localization.

Results: DWIs were positive in 12 patients in the acute or subacute stages of this clinical syndrome. A false-negative result was obtained in only one patient examined within the first day, 10 h after onset of the symptoms. In the visual evaluation of the DWI, the contrast between normal and infarcted brainstem area was better in the high b-value images than in the apparent diffusion coefficient map images.

Conclusion: DWI is a valuable technique for examining patients presenting with the signs and symptoms of Wallenberg's syndrome and high b-value images can provide complementary data to T2-weighted images. However, because most of our case group were in either the acute or subacute stage, true sensitivity of the method in the hyperacute stage of the syndrome remains unclear.     

Treatment of long superficial femoral artery occlusions with excimer laser angioplasty: long-term results after 48 months

Purpose: To evaluate clinical and hemodynamical long-term results after laser angioplasty of long occlusions of the superficial femoral artery (SFA).

Material and Methods: In a prospective trial of 452 patients with long occlusions of the SFA, excimer percutaneous transluminal laser angioplasty (PTLA) for recanalization was applied. The average occlusion length of the SFA was 25.5 cm (range 16-38 cm). The recanalization attempt was done with the crossover technique in 398 patients, in 36 patients with the antegrade technique and in another 18 patients with the transpopliteal technique.

Results: The application of laser angioplasty demonstrated a successful recanalization of the SFA in 386/452 patients (85.5%). Recanalization with PTLA was not possible in 66 patients (14.5%). The main reason for the unsuccessful PTLAs was obstructing calcified material (n=28) resistant to PTLA application. After a follow-up period of 48 months there was a primary, primary-assisted, and secondary patency rate of 22.3%, 40.9%, and 43.2%, respectively.

Conclusion: Laser angioplasty of long occlusions of the SFA is a feasible procedure with a low failure rate. Long-term results are promising, but additional interventions are required in most patients if a patency rate of 43.2% is to be achieved after 4 years.     

Comparative study of fluorodeoxyglucose positron emission tomography and magnetic resonance imaging for the detection of spinal bone marrow infiltration in untreated patients with multiple myeloma

Background: The presence and extent of osteolytic bone lesions in untreated patients with multiple myeloma are important factors in the staging of the disease, and the extent of bone lesions in multiple myeloma cases significantly influences decisions regarding therapy. Recently, fluorodeoxyglucose positron emission tomography (FDG-PET) and magnetic resonance imaging (MRI) have been used to detect bone marrow involvement in patients with multiple myeloma.

Purpose: To compare the efficacy of FDG-PET and MRI for the detection of bone marrow infiltration into the spine in untreated patients with multiple myeloma.

Material and Methods: Twenty-two patients with multiple myeloma underwent both FDG-PET and spine MRI. The examined spinal regions by MRI included 21 thoracic and lumbar spines, one lumbar spine, and 12 cervical spines. The following imaging sequences were performed: T1-weighted spin-echo MRI with and without fat suppression, and T2-weighted spin-echo MRI in the sagittal plane. In the patients with bone marrow abnormalities, an additional contrast-enhanced T1-weighted spin-echo MR image and a fat-suppressed T1-weighted spin-echo MR image were obtained. Patients were divided into three groups on the basis of the criteria defined by Durie and Salmon: stage I (n=9), stage II (n=3), and stage III (n=10). The number and location of lesions detected in both FGD-PET and MRI were recorded, and the lesions were compared using the McNemar test. Bone marrow biopsy results, the patient's clinical examinations, and other imaging findings (MRI, FDG-PET, etc.) were used as references.

Results: In stages I and II (37 lesions in 12 patients), FDG-PET and MRI detected lesions in 78% (29 of 37 lesions) and 86% (32 of 37 lesions), respectively. However, the difference between the abilities of FDG-PET and MRI to detect lesions was not statistically significant (P=0.317). In stage III (101 lesions in 10 patients), FDG-PET and MRI detected lesions in 80% (81 of 101 lesions) and 92% (93 of 101 lesions), respectively. The difference between the abilities of FDG-PET and MRI to detect lesions was statistically significant (P=0.038).

Conclusion: MRI is superior to FDG-PET in detecting bone marrow involvement in the spine of patients with advanced multiple myeloma.     

Systemic-to-pulmonary venous shunt in superior vena cava obstruction: depiction on computed tomography venography

Purpose: To describe computed tomography (CT) venographic appearances of systemic-to-pulmonary venous shunts with CT venography and three-dimensional reconstruction images from patients with superior vena cava obstruction.

Material and Methods: From January 1994 to April 2002, CT venography was performed in 45 patients with superior vena cava obstruction using a single-detector helical CT scanner (n=38) and four-detector row CT scanner (n=7). Analysis of CT scan data included the cause and degree of venous obstruction, the presence of pleural thickening and enhancement, and the attenuation of pulmonary veins. The causative factor for systemic-to-pulmonary venous shunt was evaluated using the Fisher exact test.

Results: Systemic-to-pulmonary venous shunts were observed in four patients (9%) who had high-attenuated pulmonary veins and pleural enhancement on CT venography. Pleural thickening (P=0.01) and a history of pulmonary tuberculosis (P=0.034) are statistically significant risk factors.

Conclusion: CT venography showed strong pleural enhancement and high-attenuated pulmonary veins indicating systemic-to-pulmonary venous shunts. Radiologists should study the earlier enhancement of pulmonary veins in patients with superior vena cava obstruction.     

Pediatric multidetector computed tomography using tube current modulation and a patient image gallery

Background: Dose reduction is crucial in pediatric multidetector computed tomography (MDCT).

Purpose: To perform pediatric 16-slice MDCT using tube current modulations and to adjust prospectively the tube current using a patient image gallery (IG) providing simulated dose-reduced protocols; and to evaluate and compare the image quality of the IG and the clinical MDCT.

Material and Methods: 30 examinations (thorax, n=15; abdomen, n=8; pelvis, n=7) in 20 patients (nine male, age 8.05±7.33 years, weight 29.8±24.02 kg) were performed according to an IG on a 16-slice MDCT with additional use of online tube current modulation (CARE Dose). Three radiologists visually assessed image quality from the IG and actual 16-slice MDCT scans. For objective analysis, image noise was determined.

Results: Statistical analysis showed moderate concordance in objective (K =0.68-0.78) and subjective (K =0.33-0.64) image assessment between the IG and clinical 16-slice MDCT scans. Depending on the weight group and clinical question, no or only minor dose reductions in the chest, but moderate to considerable reductions in the abdominal/pelvic 16-slice MDCT scans compared to previously used pediatric protocols were achieved. Extra dose reduction was achieved due to additional use of CARE Dose depending on age group and scan region (mean 8.6-23.9%).

Conclusion: The IG enabled us to prospectively reduce the tube current and adapt the required image quality to the clinical question. Additional dose reduction was achieved with application of CARE Dose; nevertheless, the images are comparable to the simulated images of the IG.     

Detection of small implanted tumors growing during repeated magnetic resonance imaging of the rabbit liver: application of an interpretation model

Purpose: To apply experimentally and further develop a new image interpretation model based on repeated imaging and aimed at improving assessments of technical efficacy and diagnostic accuracy in the detection of small lesions.

Material and Methods: VX2 carcinoma was implanted in the liver of 14 rabbits as two 1.1-1.7 mm³ cores. Magnetic resonance imaging was performed before and 4 days after implantation and then every second day up to the 14th to 20th day. One T2-weighted sequence (TSE T2) and three T1-weighted sequences (SE T1, GE T1, and TFL T1) were used. Interpretation was performed stepwise: three readers independently interpreted image sequences chronologically (step 1). Tumors were included at the last examination (step 2). By concurrent interpretation of repeated examinations, the earliest day at which tumors became visible and tumor size were recorded (step 3). Records were corrected (step 4) and autopsy was performed (step 5). Two procedures for use in calculating repeated detection rates of tumors with different magnetic resonance imaging sequences are presented and discussed.

Results: Of 40 macroscopic tumors, 34 were included. They were mainly small (size range SE T1: 1-3 mm, TSE T2: 1.5-5 mm) when they became visible as determined at step 3, which was consistently earlier than observed at step 1. TSE T2, SE T1, and GE T1 did not differ significantly regarding earliest day of detection (step 3), while TFL T1 revealed the tumors later. The initial repeated detection rates were higher with TSE T2 than with the other sequences. Frequency of false positives varied over time, indicating fluctuating criteria for reporting tumors.

Conclusion: A theoretical image interpretation model previously described proved to be applicable for detection of experimental liver tumors. The model was improved by introducing calculations of repeated detection rates for initial image interpretation using an imaging reference standard.     

Magnetic resonance imaging with true fast imaging with steady-state precession and half-Fourier acquisition single-shot turbo spin-echo sequences in cases of suspected placenta accreta

Purpose: To present the magnetic resonance imaging (MRI) findings of placenta accreta in suspected cases of placenta accreta with true fast imaging with steady-state precession (True FISP) and half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequences.

Material and Methods: Five patients underwent MRI with HASTE (n=5) and/or True FISP (n=4) sequences for suspected placenta accreta. Retrospective review of MRI was performed to define the location and extent of the implantation abnormality.

Results: The uteroplacental interface was visualized as three layers; inner low signal intensity layer, middle high signal intensity layer of myometrium, and outer low signal intensity layer of uterine serosa. Three cases were diagnosed with placenta accreta on MRI and focal non-visualization of the inner layer was demonstrated.

Conclusion: The finding of focal non-visualization of the inner layer between the placenta and myometrium by MRI with True FISP and HASTE sequences was the diagnostic finding for placenta accreta.     

Effect of contrast media on vascular smooth muscle cells

Purpose: In order to alleviate the adverse effects of contrast media (CMs) on the vascular system, the role of Ca²⁺ in the viability of vascular smooth muscle cells (VSMCs) was investigated.

Material and Methods: VSMCs were obtained from swine thoracic aorta. The number of VSMCs was counted under a microscope using the trypan blue dye-exclusion method 24 h after culture in RPMI containing physiological saline (SAL) as control, iothalamate (IOT), or iohexol (IOH) at 10% by volume with CaCl₂ added at 0 to 2.0 mmol/l. Free Ca²⁺ in the above media was measured using an ion-selective electrode.

Results: Free Ca²⁺ was 0.4 to 1.5 mmol/l with ionic IOT and 0.4 to 1.8 mmol/l with non-ionic IOH as well as with control. The ratio of viable cells grown in the presence of CMs to those grown in the control was optimal at approximately 0.60 near 1 mmol/l Ca²⁺ and decreased markedly to 0.00 at 1.5 mmol/l Ca²⁺ in the presence of IOT and to 0.39 at 1.8 mmol/l Ca²⁺ in the presence of IOH, while the ratios decreased gradually to 0.28 in the presence of IOT and 0.53 in the presence of IOH at 0.4 mmol/l Ca²⁺.

Conclusion: Ionic IOT is more cytotoxic to VSMCs than non-ionic IOH. However, the cytotoxicity was minimal and similar between both CMs at 1 mmol/l Ca²⁺ in accordance with the sodium-calcium balance.     

Percutaneous transhepatic portal vein embolization: effectiveness of absolute ethanol infusion with balloon catheter in a pig model

Purpose: To evaluate the effectiveness of portal vein embolization (PVE) with absolute ethanol using multidetector-row computed tomography (CT) angiography in a pig model.

Material and Methods: Percutaneous transhepatic PVE with 10 ml absolute ethanol was performed in liver segments (n = 5) or subsegments (n = 5) in 10 pigs. CT images and volumetric data were qualitatively and quantitatively assessed to determine future liver remnant (FLR) hypertrophy and to correlate with histopathologic changes 2-6 weeks after PVE. Effectiveness evaluation was based on changes in absolute FLR size and ratio of FLR to total estimated liver volume (TELV).

Results: Occlusion of the embolized vessel was achieved immediately after injecting absolute ethanol within a range of 0.25-0.33 ml/kg. The TELV prior to PVE was 660.49±103.66 cm³ (range 527.22 to 833.70 cm³) and after PVE 769.51±29.36 cm³ (range 685.95 to 887.34 cm³). The mean FLR/TELV ratio increase after PVE was 14.2%. No statistically significant difference was found in the increase of TELV between segmental or subsegmental PVE. On microscopic observation, atrophy of the embolized liver was noted in all animals and was seen distinctly at 3 weeks after PVE in 2 animals.

Conclusion: Both regenerative response and histopathologic changes of the liver were seen after PVE with absolute ethanol with a mean FLR/TELV ratio of 14.2%.     

Computed tomography-guided pulmonary nodule localization before thoracoscopic resection

Purpose: To assess the success rate and complication rate of a CT-guided pulmonary nodule-marker system before thoracoscopic resection.

Material and Methods: In 24 patients (15 M, 9 F; age range, 18-71 years) a total of 25 pulmonary nodules (in 1 patient 2 lesions simultaneously) were marked with a special wire under CT-guidance and then thoracoscopically resected. We evaluated lesion size, lesion distance to the pleura, the time of intervention, complications, and thoracoscopic success rate.

Results: Mean lesion size was 7 mm (range 4-15 mm) and mean lesional distance to the pleura was 13 mm (range 2-31 mm). The pulmonary nodule-marker system was positioned successfully in all 25 pulmonary nodules within 5-11 min (mean 7.5 min). Minimal pneumothoraces were observed in five patients with no requirements of chest drains. In addition, no bleeding complications or hematothorax were observed. All 25 pulmonary nodules could be resected thoracoscopically. However, in one patient (4%), the guide-wire dislocated during thoracoscopy, but the lesion could be successfully resected during thoracoscopy.

Conclusion: The CT-guided placement of the pulmonary nodule-marker system used here offers a safe and accurate guide for the localization of small pulmonary nodules during thoracoscopic resection.     

ADC值联合T2WI纹理参数术前预测子宫内膜癌Ki-67表达水平的初步研究

目的 探讨表观扩散系数（ADC）值联合T₂WI纹理参数分析在术前预测子宫内膜癌（EC）Ki-67表达水平的价值。 方法 回顾性分析137例经手术病理证实为EC的女性病人,年龄27~79岁,平均（55.0±9.0）岁。根据Ki-67表达水平将病人分为高表达组（74例）和低表达组（63例）。所有病人术前均行常规MRI及扩散加权成像（DWI）（b值为0 、1 000 s/mm²）扫描,并测量ADC值。采用ITK-SNAP软件在横断面T₂WI影像逐层勾画兴趣区并获得EC全病灶的兴趣区体积（VOI）,通过GE Analysis Kit（A.K.）软件提取1 316个的三维纹理特征。采用独立样本t检验、Mann-Whitney U检验比较2组间ADC值和纹理参数的差异,对差异有统计学意义的参数进行多因素Logistic回归分析并建模。采用受试者操作特征（ROC）曲线分别评价各单一参数及联合参数（联合ADC和纹理参数）的预测模型对Ki-67表达水平的预测效能,采用Delong检验对多个预测模型的曲线下面积（AUC）进行比较。 结果 2组相比,Ki-67高表达组病理分期更晚,非子宫内膜样腺癌比例更高（均P<0.05）。最终筛出5个对EC病人Ki-67表达有较高诊断价值的纹理参数,分别为firstorder_90Percentile、firstorder_Minimum、glcm_InverseVariance、firstorder_Skewness和gldm_DependenceVariance。2组间ADC值及纹理参数比较,Ki-67低表达组的ADC值及firstorder_Skewness高于Ki-67高表达组,而其余4个纹理参数值均低于高表达组（均P<0.05）。将ADC值、单一纹理参数及联合参数分别建立预测模型,预测Ki-67表达的AUC分别为0.799、0.624、0.599、0.604、0.615、0.614、0.854。联合参数模型预测Ki-67表达水平的效能最高,AUC为0.854,均高于其他6种模型（均P<0.05）。 结论 ADC值联合T₂WI纹理分析有助于术前评估EC病人Ki-67表达的水平。