Diffusion-weighted MR imaging of the normal pancreas: Reproducibility and variations of apparent diffusion coefficient measurement at 1.5- and 3.0-Tesla

PurposeTo evaluate reproducibility and variations in apparent diffusion coefficient (ADC) measurement in normal pancreatic parenchyma at 1.5- and 3.0-Tesla and determine if differences may exist between the four pancreatic segments.Materials and methodsDiffusion-weighted MR imaging of the pancreas was performed at 1.5-Tesla in 20 patients and at 3.0-Tesla in other 20 patients strictly matched for gender and age using the same b values (0, 400 and 800 s/mm²). Two independent observers placed regions of interest within the four pancreatic segments to measure ADC at both fields. Intra- and inter-observer agreement in ADC measurement was assessed using Bland-Altman analysis and comparison between ADC values obtained at both fields using non-parametrical tests.ResultsThere were no significant differences in ADC between repeated measurements and between ADC obtained at 1.5-Tesla and those at 3.0-Tesla. The 95% limits of intra-observer agreement between ADC were 2.3%–22.7% at 1.5-Tesla and 1%–24.2% at 3.0-Tesla and those for inter-observer agreement between 1.9%–14% at 1.5-Tesla and 8%–25% at 3.0-Tesla. ADC values were similar in all pancreatic segments at 3.0-T whereas the tail had lower ADC at 1.5-Tesla.ConclusionADC measurement conveys high degrees of intra- and inter-observer reproducibility. ADC have homogeneous distribution among the four pancreatic segments at 3.0-Tesla.     

Reproducibility of apparent diffusion coefficient measurement in normal prostate peripheral zone at 1.5T MRI

PurposeThe purpose of this study was to quantify the influence of factors of variability on apparent diffusion coefficient (ADC) estimation in the normal prostate peripheral zone (PZ).Materials and methodsFifty healthy volunteers underwent in 2017 (n = 17) or 2020 (n = 33) two-point (0, 800 s/mm²) prostate diffusion-weighted imaging in the morning on 1.5 T scanners A and B from different manufacturers. Additional five-point (50, 150, 300, 500, 800 s/mm²) acquisitions were performed on scanner B in the morning and evening. ADC was measured in PZ at midgland using ADC maps reconstructed with various b-value combinations. ADC distributions from 2017 and 2020 were compared using Wilcoxon rank sum test. ADC obtained in the same volunteers were compared using Bland Altman methodology. The 95% confidence interval upper limit of the repeatability/reproducibility coefficient defined the lowest detectable ADC difference.ResultsForty-nine participants with a mean age of 24.6 ± 3.8 [SD] years (range: 21–37 years) were finally included. ADC distributions from 2017 and 2020 were not significantly different and were combined. Despite high individual variability, there was no significant bias (10 × 10^?6 mm²/s, P = 0.58) between ADC measurements made on both scanners. On scanner B, differences in lowest b-values chosen within the 0–500 s/mm² range for two-point ADC computation induced significant biases (56-109 × 10^?6 mm²/s, P < 0.0001). ADC was significantly lower in the morning (bias: 33 × 10^?6 mm²/s, P = 0.006). The number of b-values had little influence on ADC values. The lowest detectable ADC difference varied from 85 × 10^?6 to 311 × 10^?6 mm²/s across scanners, b-value combinations and periods of the day.ConclusionsThe MRI scanner, the lowest b-value used and the period of the day induce substantial variability in ADC computation.     

表观弥散系数在前列腺良恶性病变中的应用

目的探讨表观弥散系数在前列腺良恶性病变中的鉴别诊断价值。方法收集笔者所在医院27例前列腺癌、16例前列腺炎以及32例良性前列腺增生患者的MR资料。测量病灶ADC值,对所得数值进行统计学分析。结果 b值为800s/mm2时,前列腺癌灶ADC值为（0.82±0.16）×10-3mm2/s,与炎症及前列腺增生结节比较,均有统计学意义（P〈0.05）。以0.84s/mm2作为诊断前列腺癌阈值,其敏感度为84.21%、特异度为86.54%、准确性为85.92%、阳性预测值为70.37%、阴性预测值为93.75%（Kappa=0.67,P〈0.01）。结论 ADC值测量在前列腺疾病鉴别诊断中具有重要作用。     

超声造影新技术鉴别诊断肝脏局灶性病变的研究

目的评价超声造影新技术鉴别诊断肝脏局灶性病变（FLL）的临床应用价值。方法采用六氟化硫微气泡造影剂和连续实时成像的对比脉冲序列技术,对505例FLL作超声造影检查。分析病灶增强开始时间、增强的水平、形态和随时相变化的特点。结果良、恶性FLL的增强开始时间和增强水平等表现均可相似,定性诊断最有意义的指标是增强随时相的变化。绝大多数恶性病变表现动脉期不同程度增强,至延迟期消退为低增强,良性病变则为动脉期增强后延迟期仍保持高增强或等增强,或整个造影过程均无增强。以此作为鉴别诊断的标准,诊断性试验显示超声造影诊断恶性FLL的敏感性、特异性、阳性预测值、阴性预测值和准确性分别为95．7％（313／327）、86．0％（153／178）、92．6％（313／338）、91.6％（153／167）和92．3％（466／505）。结论超声造影新技术鉴别诊断FLL,安全简便、准确性高,值得推广应用。     

Assessment of apparent diffusion coefficient in lumbar intervertebral disc degeneration

Objective

The aim of this study was to determine the relationship between the apparent diffusion coefficient (ADC) and lumbar intervertebral disc degeneration using diffusion-weighted magnetic resonance imaging (DWI).

Materials and methods

Using a 3 T magnetic resonance scanner, DWI of the lumbar spine was assessed in 109 patients, with a total of 545 lumbar discs analyzed. Apparent diffusion coefficient values were recorded for each disc, and all discs were visually graded by two independent observers using Pfirrmann’s grading system. Apparent diffusion coefficient values of disc were tested by correlation with qualitative clinical grading of degeneration severity, patient age, and sex. Correlations were investigated using Pearson’s and Spearman’s rank correlation analysis, and multiple regression analysis.

Results

Intervertebral disc degeneration was negatively correlated with ADC values of all levels (Spearman’s correlation coefficient ranged from ?0.381 to ?0.604, p < 0.001). There was a significant negative association between age and ADC values at all spinal levels (Pearson’s correlation coefficient ranged from ?0.353 to ?0.650, p < 0.001). When stepwise regression models were analyzed, both disc degeneration and age remained negatively associated with ADC values at each lumbar level (standardized coefficients ranged from ?0.231 to ?0.505, p < 0.01 and standardized coefficients ranged from ?0.179 to ?0.523, p < 0.05 respectively).

Conclusion

Apparent diffusion coefficient values obtained using DWI can assess lumbar intervertebral disc degeneration, and the ADC values were negatively correlated with the degree of disc degeneration.     

腰痛患者腰椎3.0T MR弥散加权成像腰椎间盘表观弥散系数与椎间盘退变分级的相关性

【摘要】 目的：分析腰痛患者腰椎3.0T MR弥散加权成像（diffusion weighted image,DWI）椎间盘的表观弥散系数（apparent diffusion coefficient,ADC）与椎间盘退变形态学分级的相关性。方法：2012年6月~2012年11月对60例腰痛患者行腰椎3.0T MR T2加权成像（T2 weighted image, T2WI）和DWI扫描。男30例,女30例,年龄19～66岁,平均42.5±11.9岁。在MR常规T2WI序列上对腰椎间盘按Pfirrmann标准进行形态学分级,在矢状面ADC图上对正中层面椎间盘进行ADC值测量。对腰椎间盘ADC值与Pfirrmann分级之间的相关性采用Spearman相关分析,并对椎间盘不同Pfirrmann分级的ADC值进行单因素方差分析,如有差异进一步进行LDS法两两检验。结果： 腰椎间盘Pfirrmann分级为Ⅰ级45个（15%）,Ⅱ级61个（20.3%）,Ⅲ级74个（24.7%）,Ⅳ级113个（37.7%）,Ⅴ级7个（2.3%）。Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ级椎间盘的ADC值分别为1.73±0.21、1.74±0.15、1.62±0.24、1.23±0.37、0.81±0.32（10-3mm2/s）。腰椎间盘不同Pfirrmann分级的ADC值有显著性差异（F=56.9,P=0.000）,不同分级间差异进一步行LDS法两两检验,Ⅰ级的ADC值与Ⅱ级比较无显著性差异（P＞0.05）,Ⅲ级、Ⅳ级、Ⅴ级分别与Ⅰ级、Ⅱ级比较均有显著性差异（P＜0.05）,Ⅲ级、Ⅳ级、Ⅴ级之间两两比较均有显著性差异（P＜0.05）。腰椎间盘ADC值与其Pfirrmann分级呈明显负相关（r=-0.624,P=0.000）。结论： 腰痛患者腰椎3.0T MR DWI腰椎间盘的ADC值与椎间盘退变分级呈负相关。     

表观扩散系数联合血清糖类抗原199、癌胚抗原在胰腺癌诊断及分期中的价值研究

目的：探讨磁共振扩散加权成像(DWI)、表观扩散系数(ADC)及血清糖类抗原199(CA199)、血清癌胚抗原(CEA)在胰腺癌诊断中的应用价值、诊断效能及其在临床分期中的相关性。方法：回顾性分析2020年3月—2021年9月在天津市南开医院行胰腺MRI检查的患者263例,根据纳排标准,最终入组胰腺癌患者83例(其中Ⅰ期21例、Ⅱ期30例、Ⅲ+Ⅳ期32例)、慢性胰腺炎患者56例及正常胰腺患者61例,分别进行DWI序列信号、ADC值及血清CA199、CEA水平检测。比较五组患者的ADC值、血清CA199、CEA值。绘制ADC值、血清CA199、CEA值及其三者联合诊断胰腺癌的ROC曲线图。分析ADC值及血清CA199值、CEA值与临床分期的相关性。结果：胰腺癌Ⅰ期的平均ADC值[(1.28±0.15)×10^-3 mm²/s]低于正常胰腺组[(1.52±0.14)×10^-3 mm²/s];胰腺癌Ⅱ及Ⅲ+Ⅳ期的平均ADC值[(1.09±0.07)×10^-3 mm²     

MRI issues for ballistic objects: information obtained at 1.5-, 3- and 7-Tesla

Background contextFew studies exist for magnetic resonance imaging (MRI) issues and ballistics, and there are no studies addressing movement, heating, and artifacts associated with ballistics at 3-tesla (T). Movement because of magnetic field interactions and radiofrequency (RF)-induced heating of retained bullets may injure nearby critical structures. Artifacts may also interfere with the diagnostic use of MRI.PurposeTo investigate these potential hazards of MRI on a sample of bullets and shotgun pellets.Study designLaboratory investigation, ex vivo.MethodsThirty-two different bullets and seven different shotgun pellets, commonly encountered in criminal trauma, were assessed relative to 1.5-, 3-, and 7-T magnetic resonance systems. Magnetic field interactions, including translational attraction and torque, were measured. A representative sample of five bullets were then tested for magnetic field interactions, RF-induced heating, and the generation of artifacts at 3-T.ResultsAt all static magnetic field strengths, non–steel-containing bullets and pellets exhibited no movement, whereas one steel core bullet and two steel pellets exhibited movement in excess of what might be considered safe for patients in MRI at 1.5-, 3- and 7-Tesla. At 3-T, the maximum temperature increase of five bullets tested was 1.7°C versus background heating of 1.5°C. Of five bullets tested for artifacts, those without a steel core exhibited small signal voids, whereas a single steel core bullet exhibited a very large signal void.ConclusionsBallistics made of lead with copper or alloy jackets appear to be safe with respect to MRI-related movement at 1.5-, 3-, and 7-T static magnetic fields, whereas ballistics containing steel may pose a danger if near critical body structures because of strong magnetic field interactions. Temperature increases of selected ballistics during 3-T MRI was not clinically significant, even for the ferromagnetic projectiles. Finally, ballistics containing steel generated larger artifacts when compared with ballistics made of lead with copper and alloy jackets and may impair the diagnostic use of MRI.     

Multiple parameters from ultrafast dynamic contrast-enhanced magnetic resonance imaging to discriminate between benign and malignant breast lesions: Comparison with apparent diffusion coefficient

PurposeThe purpose of this study was first to assess the diagnostic performance of ultrafast dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) parameters compared to apparent diffusion coefficient (ADC) for distinguishing benign from malignant breast lesions and second to investigate the complementarity of ultrafast DCE-MRI with DWI in that task.Materials and methodsA total of 142 women (mean age, 48.42 ± 11.03 [SD]) years; range: 14–78 years) with 150 breast lesions who underwent breast ultrafast DCE-MRI were prospectively recruited. Ultrafast DCE-MRI semi-quantitative parameters (maximum slope [MS], time to peak [TTP], time to enhancement [TTE], and initial area under curve in 60 s [iAUC]), ultrafast DCE-MRI quantitative parameters (K_ep, K_trans, and V_e), and the ADC were estimated and compared between benign and malignant breast lesions. Classification performances were assessed using area under the receiver operating characteristic curve (AUC) and compared using Delong test.ResultsThe ultrafast DCE-MRI semi-quantitative multiparameters (AUC, 0.913; 95% CI: 0.856–0.953) showed better classification performance than the quantitative multiparameters (AUC, 0.818; 95% CI: 0.747–0.876) (P = 0.022). No differences in AUC were found between ultrafast DCE-MRI semi-quantitative multiparameters and ADC (AUC, 0.912; 95% CI: 0.855–0.952) (P = 0.990). The combination of ultrafast DCE-MRI semi-quantitative multiparameters and ADC (AUC, 0.960; 95% CI: 0.915–0.985) showed better classification performance than the ultrafast DCE-MRI semi-quantitative multiparameters (P = 0.014) and quantitative multiparameters (P < 0.001).ConclusionUltrafast DCE-MRI can be used as an accurate method for discriminating benign from malignant breast lesions. The combination of ultrafast DCE-MRI and DWI significantly increases the diagnostic value of ultrafast DCE-MRI.     

不同致密度乳腺腺体的表观弥散系数与月经周期的关系

目的探讨不同致密度正常乳腺腺体的ADC值与月经周期的关系。方法将50名(100侧乳腺)女性志愿者按腺体致密度分为致密型(40侧)、中间型(36侧)、脂肪型(24侧),分别在月经期、增殖期及分泌期行T2WI-TIRM、DWI检查,并对各期乳腺腺体的ADC值进行测量,采用单因素方差分析、配对t检验比较各月经周期中不同腺体类型的ADC值及同一腺体类型在不同月经周期ADC值的差异。结果月经期时致密型、中间型及脂肪型腺体的ADC值分别为(2.08±0.07)×10-3 mm2/s、(2.09±0.09)×10-3 mm2/s、(1.90±0.35)×10-3 mm2/s;增殖期时各类腺体的ADC值分别为(1.97±0.16)×10-3 mm2/s、(2.00±0.17)×10-3 mm2/s、(1.81±0.54)×10-3 mm2/s;分泌期时各类腺体的ADC值分别为(2.01±0.08)×10-3 mm2/s、(2.02±0.05)×10-3 mm2/s、(1.82±0.21)×10-3 mm2/s;各腺体类型在月经期ADC值与增殖期及分泌期差异均有统计学意义(P均0.05),各月经周期脂肪型腺体的ADC值与致密型及中间型腺体ADC值差异均有统计学意义(P均0.01)。结论进行乳腺DWI检查时应考虑腺体致密度及月经周期对乳腺的影响,尽量选择月经结束后1周内完成。     

Predictors of pathological upgrading in low-risk prostate cancer patients without hypointense lesions on an apparent diffusion coefficient map of multiparametric magnetic resonance imaging

Purpose

To examine the clinicopathological features and identify the predictors of pathological upgrading in low-risk prostate cancer (PCa) patients without hypointense lesions on the apparent diffusion coefficient (ADC) map calculated from multiparametric magnetic resonance imaging.

Methods

We reviewed the medical records of 1905 PCa patients who underwent radical prostatectomy between 2007 and 2015. All ADC images were graded using the five-grade Likert scale; the positive hypointense lesions were graded 4–5. We analyzed 256 patients with low-risk classifications according to D’Amico criteria. Patients were classified into two groups according to the pathologic upgrading in the surgical specimens. The predictive factors for pathologic upgrading were evaluated using a multivariate logistic regression analysis.

Results

In 256 patients with low-risk PCa, the percentage of positive cores [odds ratio (OR) 1.09; 95 % confidence interval (CI) 1.02–1.16], the percentage of cancer in the positive cores (OR 1.07, 95 % CI 1.03–1.12), and the presence of hypointensity on an ADC map (OR 2.28; 95 % CI 1.23–4.22) were independent predictors of pathologic upgrading. Notably, 138 of low-risk patients (53.9 %) had no hypointense lesions on an ADC map. Of these 138 patients, the percentage of positive cores (OR 1.09; 95 % CI 1.01–1.18) and the percentage of cancer in the positive cores (OR 1.06; 95 % CI 1.01–1.12) remained independent predictors of pathologic upgrading.

Conclusions

In low-risk PCa patients without hypointense lesions on an ADC map, biopsy-related parameters such as the percentage of positive cores and the percentage of cancer in the positive cores were independent predictors of pathological upgrading following radical prostatectomy.

     

Differential diagnosis of the small renal masses: role of the apparent diffusion coefficient of the diffusion-weighted MRI

Introduction

Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies and more than 90% of neoplasms arising from the kidney. Uninformative percutaneous kidney biopsies vary from 10 to 23%. As a result, 7.5–33.6% of partial nephrectomies in patients with small renal masses (SRM) are performed on benign renal tumors. The aim of this study was to assess the feasibility of the apparent diffusion coefficient (ADC) of the diffusion-weighted imaging (DWI) of MRI, as RCC imaging biomarker for differentiation of SRM.

Method

Adult patients (n = 158) with 170 SRM were enrolled into this study. The control group were healthy volunteers with normal clinical and radiologic findings (n = 15). All participants underwent MRI with DWI sequence included.

Results

Mean ADC values of solid RCC (1.65 ± 0.38 × 10^?3 mm²/s) were lower than healthy renal parenchyma (2.47 ± 0.12 × 10^?3 mm²/s, p < 0.05). There was no difference between mean ADC values of ccRCC, pRCC and chRCC (1.82 ± 0.22 × 10^?3 vs 1.61 ± 0.07 × 10^?3 vs 1.46 ± 0.09 × 10^?3 mm²/s, respectively, p = ns). An inverse relationship between mean ADC values and Fuhrman grade of nuclear atypia of solid ccRCCs was observed: grade I—1.92 ± 0.11 × 10^?3 mm²/s, grade II—1.84 ± 0.14 × 10^?3 mm²/s, grade III—1.79 ± 0.10 × 10^?3 mm²/s, grade IV—1.72 ± 0.06 × 10^?3 mm²/s. This was significant (p < 0.05) only between tumors of I and IV grades. Significant difference (p < 0.05) between mean ADC values of solid RCCs, benign renal tumors and renal cysts was observed (1.65 ± 0.38 × 10^?3 vs 2.23 ± 0.18 × 10^?3 vs 3.15 ± 0.51 × 10^?3 mm²/s, respectively). In addition, there was a significant difference (p < 0.05) in mean ADC values between benign cysts and cystic RCC (3.36 ± 0.35 × 10^?3 vs 2.83 ± 0.21 × 10^?3 mm²/s, respectively).

Conclusion

ADC maps with b values of 0 and 800 s/mm² can be used as an imaging biomarker, to differentiate benign SRM from malignant SRM. Using ADC value threshold of 1.75 × 10^?3 mm²/s allows to differentiate solid RCC from solid benign kidney tumors with 91% sensitivity and 89% specificity; ADC value threshold of 2.96 × 10^?3 mm²/s distinguishes cystic RCC from benign renal cysts with 90% sensitivity and 88% specificity. However, the possibility of differentiation between ccRCC histologic subtypes and grades, utilizing ADC values, is limited.

     

乳腺磁共振扩散成像表观弥散系数值差异的比较研究

目的:通过比较乳腺癌病人健侧乳腺与正常人乳腺及良性病变病人的健侧乳腺的表观弥散系数(apparent diffusion coefficient,ADC)值差异,探讨不同类型乳腺的ADC值差异,绝经后与未绝经者乳腺的ADC值差异,分析不同因素对乳腺ADC值的影响.材料与方法:共84例对象被纳入本研究,全部行磁共振扩散加权成像检查及X线摄片检查.手术或穿刺活检证实39例为乳腺癌病人,45例为正常对照者或乳腺良性病变病人的乳腺,其中已绝经者29例.根据Wolf分型,将84例乳腺分为致密型、分叶串珠型和退化型.扩散敏感系数b值取1 000 s/mm2及600 s/mm2,同时测量乳腺组织的ADC值,进行比较.结果:致密型与退化型乳腺、分叶串珠型与退化型乳腺之间,ADC值差异具有统计学意义;乳腺癌病人健侧乳腺与正常及良性病变病人的健侧乳腺,ADC值差异具有统计学意义;取不同b值时,ADC值差异也具有统计学意义,乳腺ADC值随着b值的增大而减小.结论:ADC值随乳腺类型的不同,及是否曾患乳腺癌而有所变异;ADC值还随行MRI时所采用不同的b值而改变.     

腹腔镜保留十二指肠胰头切除术初步体会

目的总结腹腔镜保留十二指肠胰头切除术(laparoscopic duodenum preserving pancreatic head resection,LDPPHR)的经验。 方法回顾性分析2019年3月南方医科大学珠江医院肝胆二科1例行LDPPHR患者的临床资料。 结果患者顺利完成手术,手术时间280 min,术中出血量50 ml,未予输血。术后出现胆漏,予保守治疗后痊愈。无术后出血、胰漏、十二指肠瘘、胆总管狭窄等并发症。术后病理报告显示胰头慢性炎。 结论LDPPHR对于胰头良性病变的治疗是安全的、可行的,具有创伤小、恢复快、改善患者术后生活质量等优点,值得临床推广应用。     

Detection of parametrial invasion in women with uterine cervical cancer using diffusion tensor imaging at 1.5T MRI

Purpose: The purpose of this study was to prospectively evaluate the capability of diffusion tensor imaging (DTI) of the lumbosacral plexus to identify parametrial invasion by uterine cervical cancer.Materials and methods: Twenty-seven women with biopsy-proven cervical cancer were prospectively enrolled and underwent DTI at 1.5 TMRI. Fractional anisotropy (FA) values were calculated at the level of right and left L5 and S1 roots. The two sides of each patient were considered independently in two groups, according to the presence or absence of parametrial invasion. Differences between FA values of invaded parametria and those of non-invaded parametria were searched using Student t-test. Receiver operating characteristic (ROC) analysis was performed to identify the cut-off value of FA that yielded best sensitivity, specificity and accuracy for the diagnosis of parametrial invasion.Results: A total of 54 parametria in 27 participants (mean age, 52.9 ± 12 years; age range, 30–81 years) were analyzed. Invasion was present in 37/54 (68%) parametria and absent in 17/54 (31%) parametria. FA was greater in parametrial invasion (mean, 0.321 ± 0.036; range: 0.285–0.357) than in the absence of parametrial invasion (0.292 ± 0.02; range: 0.272–0.312) (P = 0.01). At ROC analysis, best cut-off value of FA for the diagnosis of parametrial invasion was >0.3099 (AUC, 0.681; 95% CI: 0.583– 0.768), yielding 62% sensitivity (95% CI: 50.3–73.64), 73% specificity (95% CI: 50.6–85.27) and 66% accuracy (95% CI: 54.62–73.91).Conclusion: Using >0.3099 as cut off-value for FA of L5-S1 roots, DTI has an accuracy of 73% in the diagnosis of parametrial invasion by uterine cervical cancer.     

MRI扩散加权成像表观扩散系数评估乳腺癌新辅助化疗疗效的价值

目的： 探讨MRI扩散加权成像表观扩散系数（ADC）的变化在预测乳腺癌新辅助化疗疗效中的价值。 方法： 回顾性分析2017年1月—2018年12月间收治的80例局部晚期乳腺癌患者临床资料。所有患者均行空芯针穿刺证实为乳腺癌并行新辅助化疗,在新辅助化疗第1周期前、手术前常规行乳腺MRI检查,记录新辅助治疗前与手术前肿瘤组织ADC值。分析肿瘤组织ADC值的变化（△ADC）与病理反应（MP分级）的关系,并通过ROC观察△ADC值判断新辅助化疗的效能。 结果： 全组患者中,新辅助化疗后病灶ADC值较化疗前增高（1.27×10-3 mm2/s vs. 0.98×10-3 mm2/s,P=0.000）;按类型分组分析显示,除三阴性乳腺癌ADC值化疗前后无统计学差异外（P>0.05）,其余类型的乳腺癌新辅助化疗后ADC值均较化疗前明显升高（均P<0.05）。组织学显著反应患者△ADC值明显大于组织学非显著反应患者（0.448×10-3 mm2/s vs. 0.209×10-3 mm2/s,P=0.004）。△ADC评价乳腺癌新辅助疗效的ROC曲线下面积为0.72,敏感度73.1%,特异度66.7%,当△ADC的截断值为0.239×10-3 mm2/s时,阳性预测值51.4%,阴性预测值83.7%,准确度68.8%。 结论： 在大多数乳腺癌中,ADC的变化对早期预测和评估新辅助化疗疗效有一定的价值。     

Determination of apparent diffusion coefficient to quantitatively study partial hepatic ischemia reperfusion injury in a rabbit model

Background

Animal models of partial hepatic ischemia-reperfusion injury (IRI) have potential benefits for decision making and clinical management after liver transplantation or massive hepatic resection. We evaluated changes in apparent diffusion coefficient (ADC) in rabbits with partial hepatic IRI using 3.0 T magnetic resonance diffusion-weighted imaging (DWI).

Methods

Rabbits underwent 60 minutes of left lobar ischemia followed by 0.5, 2, 6, 12, 24, or 48 hours of reperfusion (n = 6 each). DWI spin echo-echo planar imaging (SE-EPI) was performed with b values of 50, 100, 200, 300, 500, and 600 s/mm².

Results

There was a significant difference between the ADCs at 0.5 hour and sham groups when b values were <300 s/mm² and between the six hour and sham groups with b = 50 and 100 s/mm². The ADC values were lower in the 24-hour group with b values of 50, 100, 200, and 300 s/mm² (all P < .01) but significantly increased in the 48-hour group when b = 500 and 600 s/mm² compared with the sham group (all P < .01). ADC did not change significantly in the 2-hour and 12-hour groups compared with the control group.

Conclusions

In this study 3.0 T DWI dynamically monitored the pathological processes of liver IRI, revealing the microvascular disorder with a perfusion-sensitive ADC at the lower b values (<300 s/mm²), particularly in the early stages.