Evolution of apparent diffusion coefficient, diffusion-weighted, and T2-weighted signal intensity of acute stroke

BACKGROUND AND PURPOSE: Serial study of such MR parameters as diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC), ADC with fluid-attenuated inversion recovery (ADC(FLAIR)), and T2-weighted imaging may provide information on the pathophysiological mechanisms of acute ischemic stroke. Our goals were to establish the natural evolution of MR signal intensity characteristics of acute ischemic lesions and to assess the potential of using specific MR parameters to estimate lesion age. METHODS: Five serial echo-planar DWI studies with and without an inversion recovery pulse were performed in 27 patients with acute stroke. The following lesion characteristics were studied: 1) conventional ADC (ADC(CONV)); 2) ADC(FLAIR); 3) DWI signal intensity (SI(DWI)); 4) T2-weighted signal intensity (SI(T2)), and 5) FLAIR signal intensity (SI(FLAIR)). RESULTS: The lesion ADC(CONV) gradually increased from low values during the first week to pseudonormal during the second week to supranormal thereafter. The lesion ADC(FLAIR) showed the same pattern of evolution but with lower absolute values. A low ADC value indicated, with good sensitivity (88%) and specificity (90%), that a lesion was less than 10 days old. All signal intensities remained high throughout follow-up. SI(DWI) showed no significant change during the first week but decreased thereafter. SI(T2) initially increased, decreased slightly during week 2, and again increased after 14 days. SI(FLAIR) showed the same initial increase as the SI(T2) but remained relatively stable thereafter. CONCLUSION: Our findings further clarify the time course of stroke evolution on MR parameters and indicate that the ADC map may be useful for estimating lesion age. Application of an inversion recovery pulse results in lower, potentially more accurate, absolute ADC values.     

Outcome analysis and rational management of enhancing lesions incidentally detected on contrast-enhanced MRI of the breast

OBJECTIVE: The purpose of our study was to assess the prevalence, characteristics, and clinical consequence of incidentally detected enhancing lesions on MRI of the breast. SUBJECTS AND METHODS. MRI of the breast (1.0-T scanner, dynamic gadolinium-enhanced T1-weighted three-dimensional gradient-echo sequence, double breast coil) was performed on 1273 women for different indications. Enhancing incidental lesions were defined as enhancing lesions on MRIs that were not expected from findings on the previous conventional imaging. They were classified in five assessment categories using a scoring system based on morphologic and kinetic enhancement characteristics. Detection of enhancing incidental lesions resulted in a review of mammograms and sonograms with the aim of also localizing these lesions on conventional imaging. The lesions were either biopsied or followed up. RESULTS: Twenty-five percent (274/1086) of all enhancing lesions detected in the study population were enhancing incidental lesions. Enhancing incidental lesions were found in 16% (210/1273) of all study patients. Forty-one percent (113/274) of the enhancing incidental lesions were histologically confirmed. Forty-eight percent (54/113) of the biopsied and 20% (54/274) of all enhancing incidental lesions were malignant. Eleven percent (54/508) of all malignant lesions occurring in the 1273 women were detected solely through additional MRI. Fifty-seven percent (31/54) of these MRI-detected malignant lesions could be identified on a reevaluation of sonograms and mammograms. CONCLUSION: Detection of enhancing incidental lesions should lead to a thorough reevaluation of mammograms and sonograms. If not reidentified, suspicious enhancing incidental lesions should be biopsied, and enhancing incidental lesions that are probably benign should be carefully followed up. Indeterminate enhancing incidental lesions should be histologically examined by minimally invasive techniques or, if they are small, followed up by another MRI 6 months later.     

Incidental enhancing lesions found on preoperative breast MRI: management and role of second-look ultrasound

Purpose

This study prospectively assessed second-look ultrasound (US) for the evaluation of incidental enhancing lesions identified on preoperative breast magnetic resonance imaging (MRI).

Materials and methods

Between 2004 and 2007, 182 patients with malignant breast lesions detected on US and/or X-ray mammography and confirmed by cytology/histology underwent preoperative breast contrast-enhanced (CE)-MRI. Patients with incidental lesions on breast MRI underwent second-look high-resolution US directed at the site of the incidental finding. Diagnosis of incidental lesions was based on biopsy or 24-month follow-up.

Results

Breast MRI detected 55 additional lesions in 46/182 (25.2%) patients. Forty-two of 55 (76.3%) lesions were detected on second-look US in 38/46 (82.6%) patients. Malignancy was confirmed for 24/42 (57.1%) correlate lesions compared with 7/13 (53.8%) noncorrelate lesions. Second-look US depicted 8/9 (88.8%) Breast Imaging Reporting and Data System (BI-RADS) 5, 16/22 (72.7%) BI-RADS 4 and 18/24 (75%) BI-RADS 3 lesions. Sensitivity, specificity, accuracy and positive and negative predictive values for lesion detection/diagnosis was 100%, 88.9%, 94.6%, 90.3% and 100% for MRI and 64.3%, 70.4%, 67.3%, 69.2% and 65.5% for second-look US. Improved performance for US was obtained when masslike lesions only were considered.

Conclusions

Second-look US is a confirmatory method for incidental findings on breast MRI, particularly for mass-like lesions.     

Whole-lesion histogram analysis metrics of the apparent diffusion coefficient as a marker of breast lesions characterization at 1.5 T

IntroductionTo retrospectively assess the role of whole-lesion apparent diffusion coefficient (ADC) in the characterization of breast tumors by comparing different histogram metrics.Methods49 patients with 53 breast lesions underwent magnetic resonance imaging (MRI). ADC histogram parameters, including the mean, mode, 10th/50th/90th percentile, skewness, kurtosis, and entropy ADCs, were derived for the whole-lesion volume in each patient. Mann–Whitney U-test, area under the receiver-operating characteristic curve (AUC) were used for statistical analysis.ResultsThe mean, mode and 10th/50th/90th percentile ADC values were significantly lower in malignant lesions compared with benign ones (all P < 0.0001), while skewness was significantly higher in malignant lesions P = 0.02. However, no significant difference was found between entropy and kurtosis values in malignant lesions compared with benign ones (P = 0.06 and P = 1.00, respectively). Univariate logistic regression showed that 10th and 50th percentile ADC yielded the highest AUC (0.985; 95% confidence interval [CI]: 0.902, 1.000 and 0.982; 95% confidence interval [CI]: 0.896, 1.000 respectively), whereas kurtosis value yielded the lowest AUC (0.500; 95% CI: 0.355, 0.645), indicating that 10th and 50th percentile ADC values may be more accurate for lesion discrimination.ConclusionWhole-lesion ADC histogram analysis could be a helpful index in the characterization and differentiation between benign and malignant breast lesions with the 10th and 50th percentile ADC be the most accurate discriminators.     

Preoperative histological grading of meningiomas using apparent diffusion coefficient at 3T MRI

Purpose

We assessed whether a high b-value DWI at b = 4000 s/mm² would discriminate the histopathological differentiation of the tumor grade of meningiomas, and also focused on the relationship between radiologic features and the tumor grade.

Materials and methods

We acquired DWI at 3T with b = 1000 and b = 4000 s/mm² in 77 patients (42, 31 and 4 patients were WHO grades I (G1), II (G2), and III (G3), respectively). The apparent diffusion coefficient (ADC) was measured by placing multiple regions of interest (ROIs) on ADC maps. The ADC values of each tumor were determined preoperatively from several ROIs, and expressed as the minimum (ADC_MIN), mean (ADC_MEAN), and maximum absolute values (ADC_MAX). We evaluated the relationship between ADCs and histological findings, and assessed the radiologic features such as tumor location, tumor size, presence/absence of peritumoral edema, shape of the tumor, presence/absence of bone destruction or hyperplasia, status of contrast enhancement, presence/absence of calcification and cyst.

Results

ADCs of the meningiomas were inversely correlated with the histological grade of meningiomas. According to results of the discriminant analysis, the apparent log likelihood value was greatest for ADC_MIN at b = 4000. Furthermore, only the ADC_MIN value at b = 4000 was significantly correlated with the histological grade of meningiomas when we performed a multiple logistic regression analysis to identify the significant independent factors such as shape of tumor, presence/absence of bone destruction, status of contrast enhancement, presence/absence of cyst and ADC_MIN at b = 4000.

Conclusion

A meningioma with a low ADC_MIN at a high b-value might imply a high-grade meningioma.     

MR扩散加权成像表观扩散系数在乳腺结节病变诊断中的应用价值

目的 评价ADC值及相对ADC值(rADC)在乳腺结节病灶检查中的应用价值.方法 对52例66个乳腺结节病灶行MR DWI扫描,b值分别为0、800、1000 s/mm2,测量乳腺结节及同侧、对侧乳头层面未受累乳腺实质组织ADC值,计算rADC1(病灶ADC值/同侧未受累乳腺实质ADC值)及rADC2(病灶ADC值/对侧未受累乳腺实质ADC值),对所获资料采用两独立样本t检验、x2检验进行统计学分析.所有病灶均经穿刺活检或手术病理证实.结果 52例患者中,浸润性导管癌18例,纤维腺瘤34例,DWI显示50例,共64个病灶.b=800s/mm2时,良、恶性结节平均ADC值、同侧rADC800-1及对侧rADC800-2分别为(1.54±0.28)×10-3、(1.01±0.09)×10-3 mm2/s和0.77±0.15、0.52±0.07,0.76±0.14、0.51±0.06;其差异均有统计学意义(t值分别为8.217、9.339、10.394,P值均＜0.01);以乳腺浸润性导管癌平均值95％参考值范围上限界值作为恶性病变上限阈值点,ADC值、rADC8o0-1及rADC800-2分别为1.05×10-3 mm2/s、0.55、0.53,诊断的敏感度分别为75.0％、65.0％、60.0％,特异度分别为100.0％、95.7％、97.8％,阳性预测值分别为100.0％、86.7％、92.3％,阴性预测值分别为90.2％、86.3％、84.9％,诊断符合率分别为92.4％、86.4％、86.4％.b=1000 s/mm2时,良、恶性结节平均ADC值、rADC1000-1及rADC1000-2分别为(1.45±0.28)×10-3、(0.93±0.08)×10-3mm2/s和0.75±0.16、0.53±0.09,0.74±0.15、0.52±0.07;其差异有统计学意义(t值分为11.844、5.820、8.082;P值均＜0.01);ADC值、rADC1ooo-1及rADC1000-2阈值点分别为0.97×10-3 mm2/s、0.58、0.55,诊断的敏感度均为70.0％,特异度分别为100.0％、95.7％、93.5％,阳性预测值分别为100.0％、87.5％、82.4％,阴性预测值分别为88.5％、88.0％、87.8％,诊断符合率分别为90.9％、87.9％、86.5％.以上6种诊断方法的敏感度及诊断符合率差异无统计学意义(x2值分别为1.232、2.263,P值分别为0.942、0.812).结论 ADC值与rADC值均为鉴别良恶性乳腺病变的重要参数,尤其是b= 800 s/mm2时的ADC值临床应用价值最高.     

脑梗死在扩散加权像上信号强度及表面扩散系数变化的时间过程

目的 探讨脑梗死在扩散加权像（ｄｉｆｆｕｓｉｏｎ ｗｅｉｇｈｔｅｄ ｉｍａｇｉｎｇ,ＤＷＩ）上信号强度、表面扩散系数（ａｐｐａｒｅｎｔ ｄｉｆｆｕｓｉｏｎ ｃｏｅｆｆｉｃｉｅｎｔ,ＡＤＣ）变化的时间过程及两者的关系。方法 ５６例脑梗死病人计１０７个病灶接受ＭＲ ＤＷＩ检查,计算病变的信号强度比值（ｓｉｇｎａｌ ｉｎｔｅｎｓｉｔｙ ｒａｔｉｏ,ＳＲ）、ＡＤＣ及相对ＡＤＣ（ｒＡＤＣ）,根据ＤＷＩ和Ｔ２     

Diffusion-weighted imaging of breast lesions: Region-of-interest placement and different ADC parameters influence apparent diffusion coefficient values

Objectives

To investigate the influence of region-of-interest (ROI) placement and different apparent diffusion coefficient (ADC) parameters on ADC values, diagnostic performance, reproducibility and measurement time in breast tumours.

Methods

In this IRB-approved, retrospective study, 149 histopathologically proven breast tumours (109 malignant, 40 benign) in 147 women (mean age 53.2) were investigated. Three radiologists independently measured minimum, mean and maximum ADC, each using three ROI placement approaches:1 – small 2D-ROI, 2 – large 2D-ROI and 3 – 3D-ROI covering the whole lesion. One reader performed all measurements twice. Median ADC values, diagnostic performance, reproducibility, and measurement time were calculated and compared between all combinations of ROI placement approaches and ADC parameters.

Results

Median ADC values differed significantly between the ROI placement approaches (p?<?.001). Minimum ADC showed the best diagnostic performance (AUC .928–.956), followed by mean ADC obtained from 2D ROIs (.926–.94). Minimum and mean ADC showed high intra- (ICC .85–.94) and inter-reader reproducibility (ICC .74–.94). Median measurement time was significantly shorter for the 2D ROIs (p?<?.001).

Conclusions

ROI placement significantly influences ADC values measured in breast tumours. Minimum and mean ADC acquired from 2D-ROIs are useful for the differentiation of benign and malignant breast lesions, and are highly reproducible, with rapid measurement.

Key Points

? Region of interest placement significantly influences apparent diffusion coefficient of breast tumours. ? Minimum and mean apparent diffusion coefficient perform best and are reproducible. ? 2D regions of interest perform best and provide rapid measurement times.

     

Inverse correlation between choline magnetic resonance spectroscopy signal intensity and the apparent diffusion coefficient in human glioma.

Magnetic resonance spectroscopy and diffusion magnetic resonance imaging (MRI) characteristics of human intracranial glioma were studied. Present knowledge suggests a hypothetical inverse relationship between the characteristic choline signal intensity elevation and the apparent diffusion coefficient (ADC) in glioma. Twenty cases of glioma were examined with diffusion-weighted echoplanar imaging and proton magnetic resonance spectroscopic imaging (1H-MRSI). A statistically significant inverse correlation between the choline signal intensity and the ADC was found (P = 0.0004) in radiologically defined tumor-containing regions. This study is the first in which diffusion MRI and 1H-MRSI were used to evaluate human intracranial glioma jointly. It provides insight into how to interpret choline signal intensity elevation in terms of tumor cellularity and proliferative potential when ADC images are also available.     

不同类型正常乳腺表观扩散系数值差异的研究

目的 研究不同类型正常乳腺表观扩散系数（ADC）值的差异，探讨ADC值与组织学分型之间的关系。方法 采用单次激发平面回波（EPI）技术，扩散敏感因子（b）值分别为0、500、1000s／mm^2，对62个正常乳腺（包括42例乳腺病变患者的对侧正常乳腺及10名健康志愿者20个乳腺）进行MR扫描及MR扩散加权成像（DWI）检查，计算62个正常乳腺分别在不同b值时的ADC值。将62个正常乳腺分为3型，比较3型之间ADC值的差异及不同b值时ADC值的差异。结果 42例乳腺病变患者对侧正常乳腺的DWI及ADC图与组织切片对比，不同类型乳腺组织学结构不同，其DWI及ADC图表现亦有差异。62个正常乳腺分为致密型10个，分叶斑点型42个及退化型10个。致密型和分叶斑点型乳腺随b值降低ADC值升高，而退化型乳腺随b值降低ADC值变化不明显。b=1000—0s／mm^2时，致密型、分叶斑点型、退化型乳腺ADC值分别为（1．70±0．37）、（1．93±0．46）、（1．18±0．65）×10^-3mm^2／s，3组间比较差异有统计学意义（F=12．998，P=0．000）。不同b值时每2种类型间进行单因素方差分析，致密型和分叶斑点型之间差异无统计学意义（F=2．167，P=0．147）；致密型和退化型之间、分叶斑点型和退化型之间差异均有统计学意义（F值分别为5．593、19．128，P值分别为0．029、0．000）。结论 3型正常乳腺ADC值受乳腺组织学结构的影响，致密型和分叶斑点型乳腺ADC值受b值高低的影响。     

液体衰减反转恢复技术对急性脑梗死表观扩散系数值及扩散加权成像信号的影响

表观扩散系数(ADC)值的变化反映了细胞微结构的改变,因而其定量研究具有重要的临床价值.     

Diagnostic interplay of proton magnetic resonance spectroscopy and diffusion weighted images with apparent diffusion coefficient values in suspicious breast lesions

Aim of the work

To study the diagnostic performance of combined single voxel 1H-MRS and DW-MRI with ADC values as a non-contrast diagnostic tool, compared to the DCE-MRI, in suspicious breast lesions.

表观扩散系数对乳腺肿块样和非肿块样强化病变的诊断价值

目的：探讨ADC值及相对ADC值（rADC）对乳腺肿块样和非肿块样强化病变的诊断价值。方法：回顾性分析术经手术病理证实的171例乳腺病变患者（共177个病灶）的术前 MRI和DWI（b＝0和800s／mm2）资料,测量并比较（t检验）乳腺肿块和非肿块样良、恶性病变的ADC值及rADC值,采用受试者工作特征曲线（ROC）分析ADC值及rADC值在乳腺良、恶性病变定性诊断中的效能。结果：177个乳腺病变中良性病变112个,恶性病变65个;按病变形态分组,肿块性病变144个,非肿块性病变33个。肿块性病变中恶性47个,平均 ADC 值及平均 rADC 值分别为（1．06±0．27）×10－3mm2／s和0．62±0．17;良性97个,平均ADC 值及 rADC 值分别为（1．58±0．26）×10－3mm2／s 和0．91±0．17;ROC分析显示,以ADC值和rADC值分别为1．23×10－3mm2／s和0．72作为阈值,鉴别肿块样乳腺良、恶性病变的敏感度和特异度分别为85．1％、92．8％和80．9％、89．7％。33个非肿块性病变中恶性18个,平均ADC值及rADC值分别为（1．25±0．40）×10－3mm2／s 和0．76±0．25;良性15个,平均 ADC 值和 rADC 值分别为（1．50±0．18）×10－3mm2／s 和0．89±0．12;ROC分析显示,以ADC和rADC值分别为1．36×10－3mm2／s、0．84作为阈值,鉴别非肿块样乳腺良、恶性病变的敏感度和特异度分别为77．8％、80．0％和77．8％、73．3％。结论：根据ADC和rADC值可以鉴别乳腺良、恶性病变,ADC值的诊断价值略高于rADC值,对乳腺肿块性和非肿块性病变应采用不同的ADC。     

Changes in apparent diffusion coefficient and T2 relaxation during radiotherapy for prostate cancer

Purpose:

To evaluate regional and temporal changes in apparent diffusion coefficient (ADC) and T₂ relaxation during radiation therapy (RT) in patients with low and intermediate risk localized prostate cancer.

Materials and Methods:

Seventeen patients enrolled on a prospective clinical trial where MRI was acquired every 2 weeks throughout eight weeks of image‐guided prostate IMRT (78 Gy/39 fractions). ADC and T₂ quantification used entire prostate, central gland, benign peripheral zone, and tumor‐dense regions‐of‐interest, and mean values were evaluated for common response trends.

Results:

Overall, the RT responses were greater than volunteer measurement repeatability, and week 6 appeared to be an optimum time‐point for early detection. RT effects on the entire prostate were best detected using ADC (5–7% by week 2, P < 0.0125), effects on peripheral zone were best detected using T₂ (19% reduction at week 6; P = 0.004) and effects on tumors were best detected using ADC (14% elevation at week 6; P = 0.004).

Conclusion:

ADC and T₂ may be candidate biomarkers of early response to RT warranting further investigation against clinical outcomes. J. Magn. Reson. Imaging 2013;37:909–916. © 2012 Wiley Periodicals, Inc.     

Region of interest demarcation for quantification of the apparent diffusion coefficient in breast lesions and its interobserver variability

PURPOSE

We aimed to compare two different methods of region of interest (ROI) demarcation and determine interobserver variability on apparent diffusion coefficient (ADC) in breast lesions.

METHODS

Thirty-two patients with 39 lesions were evaluated with a 3.0 Tesla scanner using a diffusion-weighted sequence with several b-values. Two observers independently performed the ADC measurements using: 1) a small fixed area of 10 mm² ROI within the area with highest restriction; 2) a large ROI so as to include the whole lesion. Differences were assessed using the Wilcoxon-rank test. Bland-Altman method and Spearman coefficient were applied for interobserver variability and correlation analysis.

RESULTS

ADC values measured using the two ROI demarcation methods were significantly different for both observers (P = 0.026; P = 0.033). There was no interobserver variability in ADC values using either method (large ROI, P = 0.21; small ROI, P = 0.64). ADC values of malignant lesions were significantly different between the two methods (P < 0.001). Variability in ADC was ≤0.008×10⁻³ mm²/s for both methods. When using the same method, ADC values were significantly correlated between the observers (small ROI: r=0.990, P < 0.001; large ROI: r=0.985, P < 0.001).

CONCLUSION

The choice of ROI demarcation method influences ADC measurements. Small ROIs show less overlap in ADC values and higher ADC reproducibility, suggesting that this method may improve lesion discrimination. Interobserver variability was low for both methods.Diffusion-weighted imaging (DWI) of the breast has been used to improve lesion diagnosis. However, due to lesion heterogeneity, differences between acquisition protocols, and lesion demarcation strategies, there is some overlap in apparent diffusion coefficient (ADC) values of different lesion types (1).Regarding lesion demarcation, different strategies can be found in the literature. Pereira et al. (2) suggest delimiting the whole lesion area, whereas others consider only its most solid part representing viable tumor (3, 4).A study focusing on the use of ADC minimum, average, and maximum to characterize breast lesions (5) has indirectly investigated the influence of region of interest (ROI) on ADC quantification, but has not specifically compared these two methods of demarcation. Here, we compare these two ROI demarcation methods and determine their interobserver variability in ADC quantification.     

Correlation between 3 T apparent diffusion coefficient values and grading of invasive breast carcinoma

PurposeThe aim of this study was to evaluate whether the apparent diffusion coefficient (ADC) provided by 3.0 T (3 T) magnetic resonance diffusion-weighted imaging (DWI) varied according to the grading of invasive breast carcinoma.Materials and methodsA total of 92 patients with 96 invasive breast cancer lesions were enrolled; all had undergone 3 T magnetic resonance imaging (MRI) for local staging. All lesions were confirmed by histological analysis, and tumor grade was established according to the Nottingham Grading System (NGS). MRI included both dynamic contrast-enhanced and DWI sequences, and ADC value was calculated for each lesion. ADC values were compared with NGS classification using the Mann–Whitney U and the Kruskal–Wallis H tests. Grading was considered as a comprehensive prognostic factor, and Rho Spearman test was performed to determine correlation between grading and tumor size, hormonal receptor status, HER2 expression and Ki67 index. Pearson's Chi square test was carried out to compare grading with the other prognostic factors.ResultsADC values were significantly higher in G1 than in G3 tumors. No significant difference was observed when G1 and G3 were compared with G2. Tumor size, hormonal receptor status, HER2 expression and Ki67 index correlated significantly with grading but there was a significant difference only between G1 and G3 related to the ER and PR status, HER2 expression and Ki67 index. There was no statistically significant difference in lesion size between the two groups.ConclusionADC values obtained on 3 T DWI correlated with low-grade (G1) and high-grade (G3) invasive breast carcinoma. 3 T ADC may be a helpful tool for identifying high-grade invasive breast carcinoma.     

MRI扩散加权成像表观弥散系数对肝脏转移瘤的诊断价值

目的 评价表观弥散系数(apparent diffusion coefficient,ADC)在不同组织来源的肝脏转移瘤的诊断价值.方法 回顾性分析45例经1.5T MRI检查的肝脏转移瘤患者的扩散加权图像,采用单因素方差分析276处肝脏转移瘤的ADC值,比较不同肿瘤组间的差异性.结果 来源于胃直肠癌、肝癌、乳腺癌的肝脏转移瘤的平均ADC值间的差异无统计学意义.来源于肺癌的肝脏转移瘤的平均ADC值低于其他来源的肝脏转移瘤,差异有统计学意义(P＜0.05).来源于胰腺癌的肝脏转移瘤的平均ADC值高于其他来源的肝脏转移瘤,差异有统计学意义(P＜0.05).结论 ADC值在肺癌和胰腺癌来源的肝脏转移瘤的诊断中有一定的价值.     

Reporting and management of breast lesions detected using MRI

Magnetic resonance imaging (MRI) is the most accurate technique for diagnosing and delineating the extent of both invasive and in-situ breast cancer and is increasingly being used as part of the preoperative work-up to assess the local extent of disease. It is proving invaluable in providing information that allows successful single-stage surgery. An inevitable consequence of the high sensitivity of MRI is that it will identify additional lesions that may or may not represent significant extra disease. This may complicate and delay the preoperative process. This paper outlines a strategy for managing MRI-detected lesions to optimize the benefits of breast MRI as a local staging tool while minimizing the false-positive diagnoses. It discusses the importance of good technique to reduce the number of indeterminate lesions. Methods to refine the patient pathway to minimize delays are discussed. The format of MRI reporting is discussed in detail as is the usefulness of discussion of cases at multidisciplinary meetings. Illustrative cases are used to clarify the points made.