Prostate MRI: who, when, and how? Report from a UK consensus meeting.

The current pathway for men suspected of having prostate cancer [transrectal biopsy, followed in some cases by magnetic resonance imaging (MRI) for staging] results in over-diagnosis of insignificant tumours, and systematically misses disease in the anterior prostate. Multiparametric MRI has the potential to change this pathway, and if performed before biopsy, might enable the exclusion of significant disease in some men without biopsy, targeted biopsy in others, and improvements in the performance of active surveillance. For the potential benefits to be realized, the setting of standards is vital. This article summarizes the outcome of a meeting of UK radiologists, at which a consensus was achieved on (1) the indications for MRI, (2) the conduct of the scan, (3) a method and template for reporting, and (4) minimum standards for radiologists.

Imaging of triple-negative breast cancer.

Although triple-negative breast cancer (TNBC) has been studied extensively in the oncology and pathology literature, there are few reports on imaging features. Emerging data suggest that imaging features of TNBC are substantially different from other primary breast cancer immunotypes. In this work, we reviewed multi-modality imaging features of primary TNBC with emphasis on the appropriate niche for each technology in diagnosis, staging and management. TNBC lacks the typical suspicious mammographic features of breast cancer; namely irregular mass shape, spiculated margins and associated suspicious calcifications. Therefore, mammography alone is usually a sub-optimal tool for its initial diagnostic evaluation. Ultrasound has a much higher sensitivity, although its diagnostic capability may be impaired by associated benign features encountered in 21%-41% of TNBC lesions. Magnetic resonance imaging (MRI) consistently demonstrates the presence of all TNBC with a higher level of accuracy compared with other tumour sub-types, and provides a reliable baseline for neoadjuvant chemotherapy (NAC) follow-up. Preliminary studies also suggest that MRI may predict complete NAC response in TNBC more sensitively than other methods. [(18)F]2-fluoro-2-deoxy-D-glucose positron emission tomography ((18)F-FDG-PET) has a higher sensitivity for TNBC than estrogen-positive and human epidermal growth factor receptor 2-positive tumours, and axillary lymph node metastases are detected with more accuracy compared with other tumour molecular sub-types, although low FDG uptake of breast cancers in general may limit the routine clinical use of (18)F-FDG-PET in the initial diagnosis of TNBC patients and NAC follow-up.

Breast MRI at 3.0 T in a high-risk familial breast cancer screening cohort: comparison with 1.5 T screening studies.

OBJECTIVES: The sensitivity of X-ray mammography for the detection of breast malignancy in younger females is lower than that of breast MRI; consequently, guidelines recommend annual MRI for patients with a significantly elevated lifetime risk. The improved signal-to-noise ratio obtainable at 3.0 T should result in data superior to those obtainable at 1.5 T. However, breast imaging on higher field strength systems poses specific problems. As a result, caution has been urged in the implementation of breast MRI at 3.0 T. The aim of this study was to determine if it is appropriate to use 3.0 T MRI in the screening of patients by comparing the summary statistics achieved by this 3.0 T MRI programme against the published results of 1.5 T screening studies. METHODS: Over a 20-month period, 291 patients referred with an elevated familial risk of breast cancer were examined at 3.0 T. Resulting images were scored based on the Royal College of Radiologists Breast Group imaging classification. The reference standard was a combination of histology and follow-up imaging. RESULTS: Follow-up data were available in 267 patients. Analysis revealed positive and negative post-test probabilities of 28% [95% confidence intervals (CI); range, 10-60%] and 1% (95% CI; range, 0-2%), respectively. These results compared favourably against those of a recent meta-analysis [25.3% (95% CI; range, 18.4-33.8%) and 0.4% (95% CI; range, 0.2-0.9%), respectively]. CONCLUSION: Given the similar summary statistics between this work and the 1.5 T results, it would appear that screening of high-risk patients at 3.0 T has potential. Further studies should be undertaken to verify this result.

Multicentre randomised controlled trial examining the cost-effectiveness of contrast-enhanced high field magnetic resonance imaging in women with primary breast cancer scheduled for wide local excision (COMICE).

OBJECTIVES: To determine whether the addition of magnetic resonance imaging (MRI) to current patient evaluation by triple assessment would aid tumour localisation within the breast and thus reduce the reoperation rate in women with primary breast tumours who are scheduled for wide local excision (WLE), and to assess whether the addition of MRI would be cost-effective for the UK NHS. DESIGN: A multicentre, randomised controlled, open, parallel group trial with equal randomisation. The main design was supplemented with a qualitative study to assess patients' experiences of the treatment process and care pathway, and involved the development of a non-scheduled standardised interview (NSSI). SETTING: The study took place at 45 hospitals throughout the UK. PARTICIPANTS: Women aged 18 years or over with biopsy-proven primary breast cancer who had undergone triple assessment, were scheduled for WLE, and were capable of providing written informed consent. INTERVENTIONS: Patients were randomised to receive MRI or no MR1. Randomisation was performed using minimisation, incorporating a random element. All MRI was performed at 1.5 T or 1.0 T with a dedicated bilateral breast coil. MAIN OUTCOME MEASURES: The primary end point of the trial was the reoperation rate. Secondary outcome measures included discrepancies between imaging and histopathology, and the effectiveness of using both procedures; change in clinical management after using MRI; the clinical significance of MRI-only-detected lesions; the rate of interventions; the ipsilateral tumour recurrence rate; patient quality of life (QoL); and cost-effectiveness. RESULTS: From a total of 1623 patients, 816 were randomised to MRI and 807 to no MRI. No differences in reoperation rates were found between the two groups of patients [MRI patients 18.75%, no MRI 19.33%, difference 0.58%, 95% confidence interval (CI) -3.24 to 4.40]. Therefore, the addition of MRI to conventional triple assessment was not found to be statistically significantly associated with a reduced reoperation rate (odds ratio = 0.96, 95% CI 0.75-1.24, p = 0.7691). The best agreement between all imaging modalities and histopathology with regard to tumour size and extent of disease was found in patients over 50 years old with ductal tumours NST and who were node negative. In the imaging arm, mastectomy was found to be pathologically avoidable for 16 (27.6%) out of 58 patients who underwent the procedure. There were no significant differences between the groups regarding the proportion of patients receiving chemotherapy, radiotherapy or additional adjuvant therapies, as well as for local recurrence-free interval rates and QoL. An acceptable NSSI was developed for use in this population of patients. Economic analysis found no difference in outcomes between the two trial arms. CONCLUSIONS: The addition of MRI to triple assessment did not result in a reduction in operation rates, and the use of MRI would thus consume extra resource with few or no benefits in terms of cost-effectiveness or HRQoL. However, MRI showed potential to improve tumour localisation, and preoperative biopsy of MRI-only-detected lesions is likely to minimise the incidence of inappropriate mastectomy. TRIAL REGISTRATION: Current Controlled Trials ISRCTN57474502.

In vivo magnetic resonance spectroscopy of gynaecological tumours at 3.0 Tesla.

BACKGROUND: Magnetic resonance spectroscopy (MRS) uses the same hardware as MR imaging and allows us to analyse the biochemistry of tissues in vivo. Published data for gynaecological lesions are limited and are largely based on MRS carried out at the lower magnetic field strength of 1.5 Tesla (T). OBJECTIVE: The purpose of this study was to determine whether in vivo proton MRS could be performed at the higher magnetic field strength of 3 T to characterise the spectra of a variety of benign and malignant gynaecological lesions. DESIGN: Prospective, non-randomised study. SETTING: MRI department within a tertiary referral centre for gynaecological cancers. SAMPLE: All women with a pelvic mass under going 3T MRI. METHODS: We carried out MRS on nonrandomised women undergoing routine 3 T MRI within our MRI department during investigation for gynaecological lesions from February 2006 to April 2008. Only those women for whom histopathological data were available were included. MAIN OUTCOME MEASURES: The presence of choline detected by in vivo 3T MRS. RESULTS: Eighty-seven women underwent MRS, 57 of whom had newly diagnosed neoplasms. MRS data for 39 of these new women (18 were excluded because of technical errors or missing data) were used to detect the presence of choline, an indicator of basement membrane turnover. Overall, choline was present in 13 of the 14 ovarian cancers, 8 of the 11 cervical tumours and all 4 of the uterine cancers. There was no statistical significant difference between choline levels in various lesion types (P=0.735) or between benign and malignant disease (P=0.550). CONCLUSIONS: In vivo MRS can be performed at 3 T to provide biochemical information on pelvic lesions. The way in which this information can be utilised is less clear but may be incorporated into monitoring tissue response in cancer treatments.

The accurate staging of ovarian cancer using 3T magnetic resonance imaging--a realistic option.

OBJECTIVES: The aim of the study was to determine whether staging primary ovarian cancer using 3.0 Tesla (3T) magnetic resonance imaging (MRI) is comparable to surgical staging of the disease. DESIGN: A retrospective study consisting of a search of the pathology database to identify women with ovarian pathology from May 2004 to January 2007. SETTING: All women treated for suspected ovarian cancer in our cancer centre region. SAMPLE: All women suspected of ovarian pathology who underwent 3T MRI prior to primary surgical intervention between May 2004 and January 2007. METHODS: All women found to have ovarian pathology, both benign and malignant, were then cross checked with the magnetic resonance (MR) database to identify those who had undergone 3T MRI prior to surgery. The resulting group of women underwent comparison of the MR, surgical and histopathological findings for each individual including diagnosis of benign or malignant disease and International Federation of Gynecology and Obstetrics (FIGO) staging where appropriate. MAIN OUTCOME MEASURES: Comparisons were made between the staging accuracy of 3T MRI and surgical staging compared with histopathological findings and FIGO stage using weighted kappa. Sensitivity, specificity and accuracy were calculated for diagnosing malignant ovarian disease with 3T MRI. RESULTS: A total of 191 women identified as having ovarian pathology underwent imaging with 3T MR and primary surgical intervention. In 19 of these women, the ovarian disease was an incidental finding. The group for which staging methods were compared consisted of 77 women of primary ovarian malignancy (20 of whom had borderline tumours). 3T MRI was able to detect ovarian malignancy with a sensitivity of 92% and a specificity of 76%. The overall accuracy in detecting malignancy with 3T MRI was 84%, with a positive predictive value of 80% and negative predictive value of 90%. Statistical analysis of the two methods of staging using weighted kappa, gave a K value of 0.926 (SE +/-0.121) for surgical staging and 0.866 (SE +/-0.119) for MR staging. A further analysis of the staging data for ovarian cancers alone, excluding borderline tumours resulted in a K value of 0.931 (SE +/-0.136) for histopathological staging versus MR staging and 0.958 (+/-0.140) for histopathological stage versus surgical staging. CONCLUSION: Our study has shown that MRI can achieve staging of ovarian cancer comparable with the accuracy seen with surgical staging. No previous studies comparing different modalities have used the higher field strength 3T MRI. In addition, all other studies comparing radiological assessment of ovarian cancer have grouped the stages into I, II, III and IV rather than the more clinically appropriate a, b and c subgroups.

Recurrence rates after DCE-MRI image guided planning for breast-conserving surgery following neoadjuvant chemotherapy for locally advanced breast cancer patients.

BACKGROUND: Neoadjuvant therapy results in a significant increase in breast-conserving surgery. However, traditional imaging methods are unable to accurately predict the extent of viable residual disease leading to uncertainty in surgical planning and some previous studies have shown a disproportionately high incidence of locoregional recurrence. Dynamic contrast enhanced-MRI (DCE-MRI) has been shown to provide a potentially more accurate prediction of residual disease. RESULTS: Patients undergoing neoadjuvant chemotherapy for breast cancer in our unit are staged with the DCE-MRI of the breast performed at 1.5 T before, during and after treatment and the final result was used to plan surgery. Two hundred and four patients with breast cancer were treated with neoadjuvant chemotherapy between 1996 and April 2005. Eighteen of these patients had distant metastases at the time of initial diagnosis and so were excluded from the present study. Following neoadjuvant chemotherapy, 186 patients underwent surgical treatment. Of these, 68 patients had breast-conserving surgery. At a median follow up of 30 months (range: 5.6-72 months) 21 patients in this group developed subsequent recurrence (21/68 - 30%) of whom 9 (9/68 - 13%) had locoregional recurrence, 7 had local recurrence (7/68 - 10%), and 17 (17/68 - 25%) had distant recurrence. Logistic regression analysis revealed only vascular invasion (p=0.006) of the tumour to be significantly associated with overall recurrence. None of the pathological factors (ER, PR status, vascular invasion, lymph node metastases, pathological complete response to neoadjuvant chemotherapy) showed a significant association with locoregional recurrence. CONCLUSION: Breast-conserving surgery with DCE-MRI planning after neoadjuvant chemotherapy provides an acceptable level of local recurrence without the need for mastectomy.

A simple solution for reducing artefacts due to conductive and dielectric effects in clinical magnetic resonance imaging at 3T.

The quality of imaging obtained at high magnetic field strengths can be degraded by various artefacts due to conductive and dielectric effects, which leads to loss of signal. Various methods have been described and used to improve the quality of the image affected by such artefacts. In this article, we describe the construction and use of a simple solution that can be used to diminish artefacts due to conductive and dielectric effects in clinical imaging at 3T field strength and thereby improve the diagnostic quality of the images obtained.

Cost-effectiveness of screening with contrast enhanced magnetic resonance imaging vs X-ray mammography of women at a high familial risk of breast cancer.

Contrast enhanced magnetic resonance imaging (CE MRI) is the most sensitive tool for screening women who are at high familial risk of breast cancer. Our aim in this study was to assess the cost-effectiveness of X-ray mammography (XRM), CE MRI or both strategies combined. In total, 649 women were enrolled in the MARIBS study and screened with both CE MRI and mammography resulting in 1881 screens and 1-7 individual annual screening events. Women aged 35-49 years at high risk of breast cancer, either because they have a strong family history of breast cancer or are tested carriers of a BRCA1, BRCA2 or TP53 mutation or are at a 50% risk of having inherited such a mutation, were recruited from 22 centres and offered annual MRI and XRM for between 2 and 7 years. Information on the number and type of further investigations was collected and specifically calculated unit costs were used to calculate the incremental cost per cancer detected. The numbers of cancer detected was 13 for mammography, 27 for CE MRI and 33 for mammography and CE MRI combined. In the subgroup of BRCA1 (BRCA2) mutation carriers or of women having a first degree relative with a mutation in BRCA1 (BRCA2) corresponding numbers were 3 (6), 12 (7) and 12 (11), respectively. For all women, the incremental cost per cancer detected with CE MRI and mammography combined was pound28 284 compared to mammography. When only BRCA1 or the BRCA2 groups were considered, this cost would be reduced to pound11 731 (CE MRI vs mammography) and pound15 302 (CE MRI and mammography vs mammography). Results were most sensitive to the unit cost estimate for a CE MRI screening test. Contrast-enhanced MRI might be a cost-effective screening modality for women at high risk, particularly for the BRCA1 and BRCA2 subgroups. Further work is needed to assess the impact of screening on mortality and health-related quality of life.

Neoadjuvant chemotherapy in breast cancer: early response prediction with quantitative MR imaging and spectroscopy.

A prospective study was undertaken in women undergoing neoadjuvant chemotherapy for locally advanced breast cancer in order to determine the ability of quantitative magnetic resonance imaging (MRI) and proton spectroscopy (MRS) to predict ultimate tumour response (percentage decrease in volume) or to detect early response. Magnetic resonance imaging and MRS were carried out before treatment and after the second of six treatment cycles. Pharmacokinetic parameters were derived from T1-weighted dynamic contrast-enhanced MRI, water apparent diffusion coefficient (ADC) was measured, and tissue water:fat peak area ratios and water T2 were measured using unsuppressed one-dimensional proton spectroscopic imaging (30 and 135 ms echo times). Pharmacokinetic parameters and ADC did not detect early response; however, early changes in water:fat ratios and water T2 (after cycle two) demonstrated substantial prognostic efficacy. Larger decreases in water T2 accurately predicted final volume response in 69% of cases (11/16) while maintaining 100% specificity and positive predictive value. Small/absent decreases in water:fat ratios accurately predicted final volume non-response in 50% of cases (3/6) while maintaining 100% sensitivity and negative predictive value. This level of accuracy might permit clinical application where early, accurate prediction of non-response would permit an early change to second-line treatment, thus sparing patients unnecessary toxicity, psychological morbidity and delay of initiation of effective treatment.

Differentiation of benign from malignant breast disease associated with screening detected microcalcifications using dynamic contrast enhanced magnetic resonance imaging.

Dynamic Contrast Enhanced Magnetic Resonance Imaging (DCE-MRI) is an effective diagnostic modality for symptomatic breast disease. However, its role in evaluating clinically occult disease associated with mammographically detected microcalcification remains unclear. Women recalled following screening mammography with microcalcification had DCE-MRI examination of the breast. The data were evaluated subjectively and objectively using both empirical and 2-compartment pharmacokinetic modelling techniques to evaluate signal intensity parameters. Eighty-eight patients aged 50-75 years (median 58) were recruited. Comparing malignant and benign lesions, the mean values in arbitrary units for the enhancement index at 1 min in the most enhancing 9-pixel square +/-1 standard deviation were 0.61+/-0.40 vs. 0.22+/-0.26 p=<0.001 with sensitivity, specificity, PPV, NPV and accuracy of 80.0%, 82.4%, 57.1%, 93.3% and 81.8%, respectively. The corresponding values attained by the radiologist were 75.0%, 89.7%, 68.2%, 92.4% and 86.4%. DCE-MRI is able to differentiate malignant from benign clinically occult lesions associated with microcalcification and may therefore offer an alternative to open surgical biopsy for women with equivocal findings following initial triple assessment for microcalcification in the breast.

MRI and conservative treatment of locally advanced breast cancer.

AIMS: The objectives of this study were to compare the efficacy of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the response of primary breast carcinoma to neoadjuvant chemotherapy compared to conventional imaging modalities, and to see how surgical outcome was influenced as a result of these findings. METHODS: Thirty-four patients with locally advanced primary breast cancer underwent conventional imaging and DCE-MRI following six cycles of neoadjuvant chemotherapy prior to surgery. Changes in surgical management based on the post-chemotherapy DCE-MRI findings were recorded. RESULTS: Prior to neoadjuvant chemotherapy, 22 of the 34 patients were assessed as requiring mastectomy and the remaining 12 were considered inoperable. Following chemotherapy two patients were still considered inoperable. In 11 of the 34 patients, the final decision to proceed to either mastectomy or non-surgical management was based primarily on pre-treatment disease status or patient choice. DCE-MRI findings, therefore, contributed to the operative decision in 21 of 34 patients. Two of these 21 patients were spared surgery as DCE-MRI demonstrated complete response to chemotherapy and one declined surgery. The remaining 18 were able to undergo wide local excision, with only two patients subsequently requiring mastectomy for involved margins. CONCLUSIONS: DCE-MRI is able to accurately predict those patients suitable for breast conserving surgery following neoadjuvant chemotherapy and should be the imaging modality of choice in assessing the response of patients with primary breast carcinoma to neoadjuvant chemotherapy.

Dynamic contrast enhanced magnetic resonance imaging and magnetic resonance spectroscopy in diabetic mastopathy.

Diabetic mastopathy is a rare, benign clinico-pathological entity strongly associated with type I diabetes. X-ray mammography and ultrasonography are inadequate to distinguish this lesion from malignancy, leading to unnecessary excision biopsies. Dynamic contrast enhanced MRI and MR spectroscopy, powerful tools in the investigation of breast disease, can help solve this problem.

Differentiation of benign and malignant sub-1 cm breast lesions using dynamic contrast enhanced MRI.

The purpose of this work is to assess the additional benefit of MRI-based morphology and quantification of contrast enhancement in the differential diagnosis of sub-1cm breast lesions. Forty-three women with suspected breast cancer were examined using X-ray mammography, ultrasound mammography, and MRI. Dynamic contrast imaging was performed and relative enhancement at various time-points was calculated. The dynamic data was also processed using a two-compartment pharmacokinetic model. Radiological interpretation of high-resolution post-contrast images revealed a similar accuracy (69%) compared to X-ray mammography (69%) and ultrasound mammography (67%). The best individual parameter calculated from the dynamic images was found to be the exchange rate constant which revealed a diagnostic accuracy of 0.74 +/- 0.08. When information from the post-contrast images and dynamic data was combined in a logistic regression model a diagnostic accuracy of 0.92 +/- 0.03 was achieved. In conclusion, MR imaging of small breast lesions is feasible and the incorporation of quantitative MR derived parameters is beneficial.

Dynamic contrast enhanced magnetic resonance imaging aids the surgical management of invasive lobular breast cancer.

AIMS: Infiltrating Lobular Carcinoma (ILC) accounts for 5-10% of all breast cancers and is associated with subtle clinical and mammographic changes. It is also frequently multifocal and traditional diagnostic methods are unable to reliably detect this preoperatively. The aim of the study was to evaluate the efficacy of current imaging modalities compared with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the evaluation of ILC. METHODS: Data from women with ILC treated between 1996 and 2000 who had undergone preoperative triple assessment and DCE-MRI was analysed. The diagnostic accuracy and the detection of multifocal disease for each modality was assessed and any changes in clinical management following DCE-MRI were recorded. RESULTS: Twenty-one women (mean age 57, range 43-72 years) were recruited. The sensitivity of X-ray mammography, ultrasound, clinical assessment, fine needle aspiration cytology or core biopsy and DCE-MRI was 90.5, 87.5, 76.2, 85.7 and 95.2% respectively. DCE-MRI identified all the patients with subsequently histologically proven multifocal disease (n=11) with PPV and NPV of 100 and 95.2% respectively. X-ray mammography and ultrasound combined identified only 27% (n=3/11) with PPV and NPV of 100 and 55.6% respectively. Management was changed in 24% (5/21) of the cases following DCE-MRI. CONCLUSION: DCE-MRI has a higher sensitivity than other imaging modalities and is able to accurately delineate multifocal disease not evident on conventional imaging. DCE-MRI should therefore be used for accurate staging prior to surgery for invasive lobular breast cancer.

Current applications and future direction of MR mammography.

Compared with triple assessment for symptomatic and occult breast disease, magnetic resonance mammography (MRM) offers higher sensitivity for the detection of multifocal cancer, which is important in selecting patients appropriately for breast-conserving surgery. It is an ideal tool for the screening of patients with a high risk of breast cancer or where there is axillary disease or nipple discharge and conventional imaging has not revealed the primary focus. Techniques are now available to biopsy lesions only apparent on MRM. MRM can differentiate scar tissue from tumour; therefore, it is useful in patients in which there is possible recurrent disease. Clinical and X-ray mammographic assessment of response to neoadjuvant chemotherapy may be unreliable because of replacement of the tumour with scar tissue. MRM can identify responders and nonresponders with more accuracy. It is the modality of choice for the assessment of breast implants for rupture with accuracy higher than X-ray mammography and ultrasound. Advances in both spatial and temporal resolutions, the imaging sequences employed, pharmacokinetic modelling of contrast uptake, the use of dedicated and now phased-array breast coils, and gadolinium-based contrast agents have all played their part in the advancement of this imaging technique. Despite the limitations of patient compliance, scan-time and cost, this review describes how MRM has become a valuable tool in breast disease, especially in cases of diagnostic uncertainty. However, MRM must make the transition from research institutions into routine clinical practice.

Localisation of somatostatin and somatostatin receptors in benign and malignant ovarian tumours.

Somatostatin has been identified as having anti-proliferative, anti-angiogenic and pro-apoptotic actions in many tumour systems, and these effects are mediated through a family of five transmembrane G-protein coupled SRIF receptors. Ovarian cancer is the commonest gynaecological malignancy in the UK and maintenance therapy is urgently required. Native somatostatin expression and its receptors sst(1,2,3 and 5) were studied with immunohistochemistry in 63 malignant and 35 benign ovarian tumours of various histological types. Fifty-seven out of 63 (90%) of malignant and 26/35 (74%) benign tumours expressed somatostatin. Receptors sst(1,2,3 and 5) were expressed variably in epithelial, vascular and stromal compartments for both benign and malignant tumours. Somatostatin was found to correlate significantly with stromal sst(1) (P=0.008), epithelial sst(1) (P<0.001), stromal sst(2) (P=0.019), vascular sst(2) (P=0.026), epithelial sst(3) (P=0.026), stromal sst(5) (P=0.013) and vascular sst(5) (P=0.038). Increased expression of native somatostatin correlating with somatostatin receptors in malignant ovarian tumours raises the possibility that either synthetic somatostatin antagonists or receptor agonists may have therapeutic potential.

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS).

The UK national study of magnetic resonance imaging as a method of screening for breast cancer (MARIBS) is in progress. The study design, accrual to date, and related research projects are described. Revised accrual rates and expected recruitment are given. 15 cancers have been detected to date, from a total of 1236 screening measurements. This event rate and the tumour grades reported are compared with recent reports from other studies in women at high risk of breast cancer.

Comparison of quantitative T2 mapping and diffusion-weighted imaging in the normal and pathologic prostate.

In this study, diffusion-weighted images of the human prostate were successfully obtained, enabling quantification of apparent diffusion coefficients (ADCs) in normal and pathologic regions. A dual acquisition fast spin-echo sequence was used for accurate T2 calculation. T2 values were significantly higher in the peripheral zone than the central gland (P = 0.015). No significant correlations were found in either normal or pathologic tissue between ADC values and relaxation rates for all three gradient directions and the orientationally averaged water diffusion coefficient. Evidence suggesting that diffusional anisotropy is present in normal prostatic tissue is also detailed, with significant differences noted between the z-component and both the x- and y-components of the ADC for peripheral zone (P < 0.040) and central gland (P < 0.001).