Diffusion-weighted MRI Findings Research Articles

Role of Adding Diffusion-Weighted MR Imaging to Conventional MR Imaging in Evaluation of Ovarian Masses

Abstract Background: Ovarian cancer is a leading cause of death among gynecological malignancies and the fifth most common cause of cancer deaths in women. Aim of Study: To determine whether the addition of DW sequences to a conventional MR imaging protocol can help in the prediction of the nature of suspicious ovarian masses which are detected previously by conventional ultrasound. Patients and Methods: Thirty-five female patients with initial undetermined ovarian lesions were included in this study during the period from December 2019 to September 2020. Women who present with an ovarian mass on previous US examination and were referred to the Radiology Department of Alexandria Main University Hospital and Radiology De-partment of Ain Shams University Hospitals for further assessment and characterization by MRI imaging with adding DW-MR imaging Sequence. Results: In the current study, the mean patient age was 41.00±13.37 years. 17 (48.57%) of 35 ovarian masses were benign, and 12 (34.29%) were malignant, and 6 (17.14%) were borderline. Diffusion-weighted MRI findings of the different histopathological types showed restricted diffusion in 83.3% of borderline lesions and 91.7% of malignant lesions while only 17.6% of benign lesions showed restriction diffusion with a statistically significant difference at p-value 0.025*. DWI had shown 91.7% sensitivity and low specificity 82.4%. Combined DWI and conventional MRI sequences had the highest accuracy 93.1%, and sensitivity at 95.3%. Conclusion: Our results concluded that the DWI can help and increase the confidence of MRI in assessment or exclude potential malignancy in ovarian masses.

Parotid gland tumors: comparison of conventional and diffusion-weighted MRI findings with histopathological results.

The aim of this study was to investigate the relationship between pathological classification of parotid gland tumors and conventional MRI - diffusion-weighted imaging findings and also contribute the possible effect of apparent diffusion coefficient (ADC) to diagnosis. 60 patients with parotid masses diagnosed using histopathology and/or cytology were enrolled in this retrospective study. All patients were evaluated using a 1.5 T MRI. Demographic features, conventional MRI findings, and ADC values (mean, minimum, maximum, and relative) were recorded. MRI findings and ADC values were compared between benign-malignant groups and pleomorphic adenoma vs Warthin's tumor groups. 60 tumors (48 benign, 12 malignant) were evaluated in a total of 60 patients (39 males, 21 females). The mean age was 59 (±14, 18-86) years old; the mean lesion size was 26 (±10, 11-61) mm. On the texture of conventional MRI, T2 dominantly hyperintense/with hypointensity signal was seen in 87% of pleomorphic adenomas and T2 dominantly hypointense/with hyperintesity signal was encountered in 64% of all Warthin's tumors. Seven (28%) Warthin's tumors were misdiagnosed as pleomorphic adenomas and two others (8%) as malignant tumors. The commonly used mean ADC value was 1.6 ± 0.6 × 10-3 mm2 s-1 for benign tumors, 0.8 ± 0.3 × 10-3 mm2 s-1 for malign tumors, 1 (0.9-1.8) × 10-3 mm2 s-1 for Warthin's tumors, and 1.9 ± 0.3 × 10-3 mm2 s-1 for pleomorphic adenomas. There was a statistically significant difference in ADC values between benign-malignant tumors and pleomorphic adenomas-Warthin's tumors. Warthin's tumor may occasionally be misdiagnosed as pleomorphic adenoma and malignant tumor because of variable morphologic features. In addition to benign-malignant differentiation, the added ADC measurement may also be useful for differentiating Warthin's tumors from pleomorphic adenomas.

Investigation of Brain Impairment Using Diffusion-Weighted and Diffusion Tensor Magnetic Resonance Imaging in Experienced Healthy Divers.

BackgroundThe aim of this study was to understand the changes of decompression illness in healthy divers by comparing diffusion-weighted (DWI) and diffusion tensor MRI findings among healthy professional divers and healthy non-divers with no history of diving.Material/MethodsA total of 26 people were recruited in this prospective study: 11 experienced divers with no history of neurological decompression disease (cohort) and 15 healthy non-divers (control). In all study subjects, we evaluated apparent diffusion coefficient (ADC) and type of diffusion tensor metric fractional anisotropy (FA) values of different brain locations (e.g., frontal and parieto-occipital white matter, hippocampus, globus pallidus, putamen, internal capsule, thalamus, cerebral peduncle, pons, cerebellum, and corpus callosum).ResultsADC values of hippocampus were high in divers but low in the control group; FA values of globus pallidus and putamen were lower in divers compared to the control group. DWI depicted possible changes due to hypoxia in different regions of the brain. Statistically significant differences in ADC values were found in hypoxia, particularly in the hippocampus (p=0.0002), while FA values in the globus pallidus and putamen were statistically significant (p=0.015 and p=0.031, respectively). We detected forgetfulness in 6 divers and deterioration in fine-motor skills in 2 divers (p=0.002 and p=0.17, respectively). All of them were examined using neuro-psychometric tests.ConclusionsRepeated hyperbaric exposure increases the risk of white matter damage in experienced healthy divers without neurological decompression illness. The hippocampus, globus pallidus, and putamen are the brain areas responsible for memory, learning, navigation, and fine-motor skills and are sensitive to repeated hyperbaric exposure.

Man-in-the-barrel’ syndrome with Delayed Diffusion-weighted MRI Findings (P3.072)

Man-in-the-barrel’ syndrome with Delayed Diffusion-weighted MRI Findings (P3.072)

Outcomes between 30 Days and 1 Year after Carotid Artery Stenting Using FilterWire EZ: Clinical Results and Diffusion-weighted MRI Findings in 262 Consecutive Patients

Outcomes between 30 Days and 1 Year after Carotid Artery Stenting Using FilterWire EZ: Clinical Results and Diffusion-weighted MRI Findings in 262 Consecutive Patients

Diffusion-weighted MRI findings in Sjögren's syndrome: a preliminary study.

Parotid glands diffusion-weighted imaging (DWI) in Sjögren's syndrome patients have provided conflicting results currently. To determine if parotid gland DWI using a small region of interest (ROI) can provide diagnosis and assess therapeutic efficacy in Sjögren's syndrome. Twenty-three women with Sjögren's syndrome, five with dry mouth who did not meet diagnostic criteria for Sjögren's syndrome, and 11 healthy volunteers (controls) were evaluated with DWI. All participants received routine T1-weighted (T1W) imaging and T2-weighted (T2W) fat-suppressed imaging, and DWI. The SI ratios (SIRs) and ADC ratios (ADCRs) for parotid gland/spinal cord were then calculated. Approximately 8-10 round ROIs measuring approximately 5 mm(2) were placed on each lobe of the parotid gland, and the signal intensity (SI) was measured while avoiding fat, ducts, and blood vessels. A ROI encompassing the entire lobe of the parotid gland was also used to measure SI. Using 5 mm(2) ROIs significantly higher DWI SIRs were noted in participants with Sjögren's syndrome compared with either participants with dry mouth without Sjögren's syndrome or healthy volunteers (all, P <0.001). The difference was not related to the presence of fat. No differences were noted when the larger ROI was used. In addition, parotid gland from untreated Sjögren's participants showed significantly higher SIRs compared with those from treated participants (P = 0.015). A small ROI DWI can provide morphological and functional information on the parotid gland in Sjögren's syndrome patients, and can aid in the diagnosis and evaluation of therapeutic efficacy.

Diffusion-weighted MRI findings and clinical correlations in sporadic Creutzfeldt-Jakob disease.

The objective of this study is to investigate the hyperintense lesions on diffusion-weighted magnetic resonance imaging (DWI) and its clinical correlation in sporadic Creutzfeldt-Jakob disease (sCJD). Patients who suffered from sCJD and followed up at the Department of Neurology at the General Hospital of the People's Liberation Army during the period of June 1, 2007 to July 1, 2014 were reviewed. The location of the hyperintense lesions on DWI, apparent diffusion coefficient (ADC) values of the hyperintense lesions were correlated with symptoms and clinical course. A total of 58 sCJD patients and ten healthy controls were included. Hyperintense lesions on DWI were observed in all the patients. The patients with basal ganglia (BG) hyperintense lesions on DWI had shorter disease duration and higher incidence of myoclonus (92 versus 44 %) than those without BG hyperintense lesions. The patients with occipital cortex hyperintense lesions on DWI had shorter disease duration between symptom onset and akinetic mutism than those without these lesions. The lower of the BG ADC value the faster presence of akinetic mutism and the shorter disease duration the patients will have. The presence of BG and occipital cortex hyperintense lesions on DWI and BG ADC values is correlated with the clinical course and clinical symptoms.

Abstract W P114: Pure Pontine versus Pontine Plus Infarction Assessed by Diffusion Weighted MRI: Etiological and Clinical Differences

Pontine infarction is often associated with extrapontine infarcts. We aimed to elucidate differences in clinical characteristics and stroke mechanisms between the isolated pontine (IP) and pontine plus (PP) infarcts. We studied consecutively admitted patients with acute ischemic stroke (&lt; 7 days after the symptom) occurring in the pons between 2004 and 2013. All patients were assessed by diffusion weighted MRI (DWI) and MR angiography. According to DWI findings, we divided the patients into the IP and PP groups. In addition, pontine lesions were categorized as upper, middle and low according the previous report (Kim JS et al. Stroke 1995). Lesions were also categorized as focal vs. extensive and unilateral vs. bilateral. Functional outcome was measured by modified Rankin scale (mRS) at discharge. There were 834 (504 male) patients, 675 in the IP group and 159 in the PP group. The most commonly involved extrapontine territory was the posterior inferior cerebellar artery territory (54.1%) followed by superior cerebellar artery territory (42.1%) and occipital lobe (35.2%). As compared to the IP group, the pontine lesions in the PP group were more often located in the rostral (upper (67.3%), middle (61.6%), upper plus middle (40.3%)) level (p &lt; 0.001). Lesions involving more than 2 levels (40.3% vs. 10.5% p&lt;0.001), extensive (20.8% vs. 2.7%, &lt;0.001) and bilateral (37.1%, vs. 2.8%, p&lt;0.001) infarcts were more frequent in the PP group. The PP group had a higher prevalence of symptomatic stenosis (26.7% vs. 72.2%, p&lt;0.001), large artery disease (60.5% vs 25.9%) and cardioembolism (16.0% vs. 2.1%, &lt;0.001) than the IP group. In multivariable analysis, atrial fibrillation (OR: 3.87, 95% CI: 2.16-7.08) was significantly associated with PP. mRS at discharge was higher in the PP than IP group (median 3 (IQR 2-5) vs. 2 (IQR 1-3), &lt;0.001). PP groups have more extensive and rostral pontine lesions, and are more often associated with large artery artherosclerosis, cardioembolism, and worse functional outcome. Prevention and therapeutic strategies should differ between the two groups.

Diffusion-weighted MRI findings of treated and untreated retroperitoneal fibrosis.

We aimed to evaluate diffusion-weighted imaging (DWI) findings in patients with treated and untreated retroperitoneal fibrosis (RPF). We analyzed magnetic resonance imaging examinations of 44 RPF patients (36 male, 8 female), of which 15 were untreated and 29 were under therapy. Qualitative DWI and T1 postcontrast signal intensities and the largest perivascular extent of RPF were compared between treated and untreated groups and correlated to erythrocyte sedimentation rate and C-reactive protein values. Quantitative DWI signal intensities and apparent-diffusion-coefficients were calculated in regions-of-interest, together with a relative index between signal intensities of RPF and psoas muscle in 15 untreated patients and 14 patients under treatment with remaining perivascular fibrosis of more than 5 mm. The extent of RPF in untreated patients was significantly larger compared with the extent of RPF in treated patients (P <0.0001). DWI signal intensities were significantly higher in untreated patients than in patients under therapy (mean, 27 s/mm2 vs. 20 s/mm2; P = 0.009). The calculated DWI-index was significantly higher in untreated patients than in patients under therapy (P = 0.003). Our data show significant differences in the DWI findings (b800 signal intensities and relative DWI-index) of patients with treated and untreated RPF. DWI is a promising technique in the assessment of disease activity and the selection of patients suitable for medical therapy.

Alveolar echinococcosis of the liver: Diffusion-weighted MRI findings and potential role in lesion characterisation

PurposeTo report the diffusion-weighted MRI findings in alveolar echinococcosis (AE) of the liver and evaluate the potential role of apparent diffusion coefficients (ADCs) in the characterisation of lesions. Materials and methodsWe retrospectively included 22 patients with 63 AE liver lesions (≥1cm), examined with 3-T liver MRI, including a free-breathing diffusion-weighted single-shot echo-planar imaging sequence (b-values=50, 300 and 600s/mm2). Two radiologists jointly assessed the following lesion features: size, location, presence of cystic and/or solid components (according to Kodama's classification system), relative contrast enhancement, and calcifications (on CT). The ADCtotal, ADCmin and ADCmax were measured in each lesion and the surrounding liver parenchyma. ResultsThree type 1, 19 type 2, 17 type 3, three type 4 and 21 type 5 lesions were identified. The mean (±SD) ADCtotal, ADCmin and ADCmax for all lesions were 1.73±0.50, 0.76±0.38 and 2.63±0.76×10−3mm2/s, respectively. The mean ADCtotal for type 1, type 2, type 3, type 4 and type 5 lesions were 1.97±1.01, 1.76±0.53, 1.73±0.41, 1.15±0.42 and 1.76±0.44×10−3mm2/s, respectively. No significant differences were found between the five lesion types, except for type 4 (p=0.0363). There was a significant correlation between the presence of a solid component and low ADCmin (r=0.39, p=0.0016), whereas an inverse correlation was found between the relative contrast enhancement and ADCtotal (r=−0.34, p=0.0072). ConclusionThe ADCs of AE lesions are relatively low compared to other cystic liver lesions, which may help in the differential diagnosis. Although ADCs are of little use to distinguish between the five lesion types, their low value reflects the underlying solid component.

Use of DWI-only MR protocol for screening stroke mimics

PurposePatients presenting with focal neurological symptoms may suffer from stroke or stroke mimics. Diffusion weighted MRI (DWI) is highly sensitive for identifying acute ischemia. Therefore, we aimed to explore whether a DWI-only protocol would help differentiate stroke from stroke mimics. MethodsWe identified all patients with possible but not definite stroke that underwent DWI-only MRI between 6/2010 and 8/2011. Patients with a positive DWI lesion were compared to those with negative DWI findings on demographics, risk factor profile, final discharge diagnoses, and outcome. ResultsA total of 124 patients were included with a median age of 63.5 (53% male). DWI MRI was positive for acute ischemia in 46 patients (37%). The most frequent stroke mimics were peripheral vertigo (n=19), acute confusion (n=10), seizures (n=9) and migraine with aura (n=8). Most ischemic lesions were small on DWI (<2cm) and patients had minor disability (mean NIHSS 4.9±3.9) with 81% of patients having good outcomes (modified Rankin Score≤2) at 3months. On univariate analysis patients with positive DWI studies had higher frequencies of having more than one clinical symptom (56% vs. 13% respectively; P<0.001) and this variable remained a significant predictor for stroke on multivariate analysis (OR 9.4 95% CI 3.8–23.5). ConclusionsA short DWI-only MRI protocol can effectively differentiate stroke from stroke mimics and could be used in settings of the emergency department as well as later on for diagnostic purposes. The chances for finding positive DWI lesions are increased in patients with multiple symptoms and signs.

Abstract TP231: Clinical Characteristics of TIA with Atrial Fibrillation

Objectives: Patients with transient ischemic attack (TIA) are at high risk of early stroke, indicating a need for urgent diagnostic workup and treatment. Atrial fibrillation (AF) is one of important causes for TIA. The purpose of this study was to investigate characteristics of TIA patients with AF, using data of a multicenter retrospective study. Methods: The subjects of this study were TIA patients admitted to 13 stroke centers within 7 days after onset between 2008 and 2009. The definition of TIA used in this study was that of clinical symptoms lasting less than 24 hours, regardless of imaging findings. We compared baseline characteristics and diffusion weighted-MRI (DWI) findings between patients with AF and those without AF. Results: A total of 464 patients (69 ± 13 years in age, 172 women) were enrolled. We diagnosed 79 patients (17%) as having AF. TIA patients with AF were older (74 ± 9 vs. 67 ± 14 years old, P = 0.0001) and more likely to have a longer length of hospital stay (15 ± 9 vs. 14 ± 20 days, P = 0.046) than those without AF. Of 464 TIA patients, 458 patients (99%) underwent head MRI. DWI lesion was detected in 96 (21%) patients. There was no difference of DWI positivity rate between patients with or without AF (28% vs. 20%, P = 0.10). Compared to patients without AF, patients with AF were more likely to have a single lesion on DWI (86% vs. 51%, P = 0.005). DWI lesion of ≥15 mm was found more frequently in TIA patients with AF than in those without AF (45% vs. 22%, P = 0.04). Conclusions: This study demonstrated that TIA patients with AF were older and had a longer length of hospital stay than those without AF. In addition, characteristics of DWI findings differed between TIA patient with AF and those without AF; TIA patients with AF were more likely to have a single lesion with a size of ≥15 mm.

Neuropsychiatric Symptoms as a Putative Crescendo Warning of a Striatocapsular Infarct?

Neuropsychiatric Symptoms as a Putative Crescendo Warning of a Striatocapsular Infarct?

Investigation into Causes of Abnormal Cerebral MRI Findings Following PVAC Duty‐Cycled, Phased RF Ablation of Atrial Fibrillation

Left atrial catheter ablation of the pulmonary veins (PVs) is an established option for patients with atrial fibrillation (AF). Asymptomatic cerebral emboli (ACE) detected by diffusion weighted MRI (DW-MRI) following AF ablation has been reported at varying rates. This variability may be linked to procedural variables and demographic risk factors. Animal studies with the multielectrode pulmonary vein ablation catheter (PVAC) have identified potential sources of emboli, including air introduced during PVAC introduction, inadequate anticoagulation, and high current densities when the distal (E1) and proximal (E10) electrodes are in contact. We sought to evaluate the incidence, size, and number of DW-MRI findings with procedural modifications that potentially reduce the embolic load. Thirty-seven AF patients (59 ± 10 years, 73% male, all with paroxysmal AF, left atrial [LA] diameter 44 ± 7 mm, left ventricular ejection fraction 57 ± 7%) underwent MRI sequences preceding ablation, within 24 hours postablation, and at 4-6 weeks. During the procedure all patients were on uninterrupted phenprocoumon, an attempted activated clotting time (ACT) level >300 seconds, had the PVAC introduced under saline, and antral ablation was started with a 2:1 bipolar/unipolar mode. Files from the ablation unit (GENius v14.4) were retrospectively analyzed to determine the relationship between E1 and E10 in close proximity and DW-MRI findings. Post procedure, 10/37 patients (27%) were positive for new DWI cerebral lesions. Nine of 10 patients had a single lesion, and 1/10 patient had 2 lesions. Average lesion size was 3.1 ± 3.9 mm (2-14 mm). One of 10 (10%) had lesions at MRI follow-up. No neurological symptoms were observed. Eighteen of 37 (49%) of procedures had evidence of E1/E10 interaction. In the subgroup of patients with and without E1 and E10 in close proximity, the DW-MRI rate was 8/18 (44%) and 2/19 (11%), respectively (P = 0.029). The source of positive DW-MRI findings in LA ablation involves several factors. Controlling anticoagulation and careful sheath management helps to reduce the number and size of DW-MRI lesions. With the PVAC catheter, an ablation with the E1 and E10 in close proximity increases the risk of a DW-MRI finding. In the future, electrodes E1 and E10 should be kept apart to help reduce the incidence of acute ACE.

Maple syrup urine disease: diffusion-weighted MRI findings during acute metabolic encephalopathic crisis

Maple syrup urine disease (MSUD) is caused by a genetic defect of branched-chain amino acids, which include leucine, isoleucine and valine. We report diffusion-weighted imaging (DWI) findings in a newborn child with MSUD who presented with acute metabolic encephalopathic crisis. DWI (b = 1,000 s/mm(2)) showed high signal localized within the myelinated white matter (WM) areas including the cerebellar white matter, pons, bulbus, cerebral peduncles, lentiform nucleus, posterior limbs of the internal capsules, corona radiata and bilateral perirolandic cortex. The apparent diffusion coefficient values of these regions were markedly low in the affected areas. The presence of these findings was considered cytotoxic or intramyelinic edema evidenced by restricted water diffusion. In conclusion, our findings suggest that during the acute phase and early encephalopathic crisis stage of MSUD, DWI can demonstrate the involvement of myelinated WM in newborns.

Diffusion-weighted MRI Findings in a Patient with Pituitary Abscess

Diffusion-weighted MRI Findings in a Patient with Pituitary Abscess

Appearances of colorectal hepatic metastases at diffusion-weighted MRI compared with histopathology: initial observations

To describe the appearances of colorectal liver metastases on diffusion-weighted MRI (DW-MRI) and to compare these appearances with histopathology. 43 patients with colorectal liver metastases were evaluated using breath-hold DW-MRI (b-values 0, 150 and 500 s mm(-2)). The b=500 s mm(-2) DW-MRI were reviewed consensually for lesion size and appearance by two readers. 18/43 patients underwent surgery allowing radiological-pathological comparison. Tissue sections were reviewed by a pathologist, who classified metastases histologically as cellular, fibrotic, necrotic or mixed. The frequency of DW-MRI findings and histological features were compared using the χ(2) test. 84 metastases were found in 43 patients. On b=500 s mm(-2) DW-MRI, metastases showed three high signal intensity patterns: rim (55/84), uniform (23/84) and variegate (6/84). Of the 55 metastases showing rim pattern, 54 were >1 cm in diameter (p<0.01, χ(2) test). 25/84 metastases were surgically resected. Of these, 11/22 metastases >1 cm in diameter showed rim pattern and demonstrated central necrosis at histopathology (p=0.04, χ(2) test). No definite relationship was found between uniform and variegate patterns with histology. Rim high signal intensity was the most common appearance of colorectal liver metastases >1 cm diameter on DW-MRI at b-values of 500 s mm(-2), a finding attributable to central necrosis.

Serial diffusion-weighted MRI and SPECT findings in a Creutzfeldt–Jakob disease patient with V180I mutation

We report serial changes of diffusion-weighted imaging (DWI) and single photon emission computed tomography (SPECT) in a patient with Creutzfeldt–Jakob disease with V180I mutation (CJD180). DWI abnormalities in our patient were more predominantly observed in the left cerebral cortex than left basal ganglia. Hemilateral abnormalities progressed over 5 months to involve the contralateral side with increasing DWI signals. At 6 months, SPECT showed hypoperfusion in the left parietal and frontal lobes and the hypoperfusion region spread to the bilateral basal ganglia, right parietal and frontal lobes. SPECT imaging revealed marked cerebral blood flow reduction, predominantly in the cerebral cortex corresponding to brain areas with high-intensity DWI signals. During the follow-up period of CJD180, DWI was more sensitive than conventional FLAIR and T2-weighted images (T2WI) to detect and monitor the progression of abnormal hyperintense lesions. We suggest that serial DWI and SPECT findings are useful for not only early diagnosis of CJD but also for monitoring disease progression.

The association of tethered cord, syringomyelia, diasto - metamyelia, spinal epidermoid, spinal lipoma and dermal sinus tract in a child

We report on a 5-year-old boy presenting with tethered cord, diastometamyelia, spinal dysraphism, terminal lipoma, spinal epidermoid, and dermal sinus tract with CT, conventional MRI, and diffusion-weighted MRI findings. To the best of our knowledge, our case has the property to be the first case in the literature showing the association of these pathologies all together.

Comparative study of multiparametric MRI of intraprostatic lesion detection: Correlation with transrectal ultrasound-guided and template biopsies.

e15003 Background: Multiple MRI techniques (T2W, dynamic contrast enhancement (DCE), diffusion-weighted (DW) and spectroscopic imaging (MRSI)) can detect the intraprostatic location of cancer. This study compares the diagnostic performance of each alone and in combination for detecting cancer in men with raised serum PSA levels. Methods: 20 patients (PSA 6.5ng/ml; range 4.5- 47.9ng/ml; previous negative systematic TRUS=11) underwent multifunctional MRI studies. T2W, DCE, DW and MRSI MRI findings were correlated with TRUS or template biopsies. Each prostate was divided in multiple sectors according to biopsy site. For TRUS biopsy correlations, only the posterior 1.5cm (needle length) of each gland was evaluated. A radiologist blinded to biopsy results evaluated each sequence, scoring each sector 1(definite normal)-5(definite cancer) using literature based criteria. ROC analysis was used to compare diagnostic performance of each technique alone and in combination. Results: 329 biopsies from 100 sectors were reviewed (median 3/sector; range 1-12). 15 sectors had cancers (prevalence 15%; pre-test likelihood). 2 sectors had Gleason 3+4 cancer and 13 sectors had Gleason 3+3 cancer. Only T2W (AUC 0.67, P=0.03; sen 40%, spec 94%) and DW-MRI (AUC 0.72, p=0.005; sen 67%, spec 69%) were able to detect cancer. DCE-MRI and MRSI were poor at cancer detection (p=NS). Combining T2W+DW-MRI was not better than DW-MRI alone (AUC 0.71, p=0.008; sen 60%, spec 76%). The post-test likelihood of cancer being present/sector (positive predictive value) increased by 45%, 10% & 15% for T2W, DW-MRI & T2W+DW-MRI respectively. 8 of 9 T2W/DW false negative sectors had small volume tumor (length less or equals 2mm/involved core). Negative predictive value (NPV)/sector was high for T2W/DW-MRI (increasing by 5% to 90% for both). Presumed tumor foci in non-biopsied TRUS regions were seen in 3/16 patients (diameter 8mm-20 mm). Conclusions: Only T2W and DW-MRI are useful for detecting cancers in patients with previous negative systematic TRUS prostate biopsies and persistently raised PSA levels. The high NPV/sector suggests a role for MRI in guiding biopsies. No significant financial relationships to disclose.