[It is about time for fundamental research of the Dutch disciplinary law]. / Hoog tijd voor fundamenteel onderzoek naar tuchtrecht.

The report 'Future-proof disciplinary law: Learning from disciplinary procedures en team- and network responsibilities in disciplinary law in healthcare' is discussed. The aim of the Dutch Disciplinary law is to foster and monitor the quality of professional practice. In the report it is stated that this goal is achieved through learning. A myriad of recommendations how learning can be improved is provided. However, the disciplinary system is under discussion because many drawbacks and the confidence in the system among professionals is decreasing. Professionals feel the urge for a fundamental research if and how the law contributes to quality of care. Learning from the law has never been proved and the contribution of the proposals in the report cannot be assessed. Focus on Implementation and evaluation of the proposals will distract attention from the necessary research to the functioning of the law.

Cancer Detection Rates of Systematic and Targeted Prostate Biopsies after Biparametric MRI.

OBJECTIVE: To compare prostate cancer detection rates (CDRs) and pathology results with targeted prostate biopsy (TB) and systematic prostate biopsy (SB) in biopsy-naive men. METHODS: An in-patient control study of 82 men undergoing SB and subsequent TB in case of positive prostate MRI between 2015 and 2017 in the Jeroen Bosch Hospital, the Netherlands. RESULTS: Prostate cancer (PCa) was detected in 54.9% with 70.7% agreement between TB and SB. Significant PCa (Gleason score ≥7) was detected in 24.4%. The CDR with TB and SB was 35.4% and 48.8%, respectively (p=0.052). The CDR of significant prostate cancer with TB and SB was both 20.7%. Clinically significant pathology upgrading occurred in 7.3% by adding TB to SB and 22.0% by adding SB to TB. CONCLUSIONS: There is no statistically significant difference between CDRs of SB and TB. Both SB and TB miss significant PCas. Moreover, pathology upgrading occurred more often by adding SB to TB than vice versa. This indicates that the omission of SB in this study population might not be justified.

The added value of systematic biopsy in men with suspicion of prostate cancer undergoing multiparametric MRI-targeted biopsy.

PURPOSE: Incorporation of multiparametric magnetic resonance imaging (mpMRI) and targeted biopsy (TBx) in the diagnostic pathway for prostate cancer (CaP) is rapidly becoming common practice. In men with a prebiopsy positive mpMRI a TBx only approach, thereby omitting transrectal ultrasound-guided systematic biopsy (SBx), has been postulated. In this study we evaluated the additional clinical relevance of SBx in men with a positive prebiopsy mpMRI (Prostate Imaging Reporting and Data System [PI-RADS] ≥ 3) undergoing TBx for CaP detection, Gleason grading and CaP localization. MATERIAL AND METHODS: Prospective data of 255 consecutive men with a prebiopsy positive mpMRI (PI-RADS ≥ 3) undergoing 12-core SBx and subsequent MRI-transrectal ultrasound fusion TBx in 2 institutions between 2015 and 2018 was obtained. The detection rate for significant CaP (Gleason score [GS] ≥ 3 + 4) for TBx and SBx were compared. The rate of potentially missed significant CaP by a TBx only approach was determined and GS concordance and CaP localization by TBx and SBx was evaluated. RESULTS: TBx yielded significant CaP in 113 men (44%) while SBx yielded significant CaP in 110 men (43%) (P = 0.856). Insignificant CaP was found in 21 men (8%) by TBx, while SBx detected 34 men (13%) with insignificant CaP (P = 0.035). A TBx only approach, omitting SBx, would have missed significant CaP in 13 of the 126 men (10%) with significant CaP on biopsy. Ten of the 118 men (8%), both positive on TBx and SBx, were upgraded in GS by SBx while 11 men (9%) had higher maximum tumor core involvement on SBx. Nineteen of the 97 men (20%) with significant CaP in both TBx and SBx were diagnosed with unilateral significant CaP on mpMRI and TBx while SBx demonstrated bilateral significant CaP. CONCLUSIONS: In men with a prebiopsy positive mpMRI, TBx detects high-GS CaP while reducing insignificant CaP detection as compared to SBx. SBx and TBx as stand-alone missed significant CaP in 13% and 10% of the men with significant CaP on biopsy, respectively. A combination of SBx and TBx remains necessary for the most accurate assessment of detection, grading, tumor core involvement, and localization of CaP.

Prostate Cancer Risk Assessment in Biopsy-naïve Patients: The Rotterdam Prostate Cancer Risk Calculator in Multiparametric Magnetic Resonance Imaging-Transrectal Ultrasound (TRUS) Fusion Biopsy and Systematic TRUS Biopsy.

BACKGROUND: The value of multiparametric magnetic resonance imaging (mpMRI) and targeted biopsy (TBx) remains controversial for biopsy-naïve men when compared to transrectal ultrasound (TRUS)-guided systematic biopsy (SBx). Risk-based patient selection could help to selectively identify men with significant prostate cancer (PCa) and thus reduce unnecessary mpMRI and biopsies. OBJECTIVES: To compare PCa detection rates for mpMRI TBx with SBx and to determine the rate of potentially avoided mpMRI and biopsies through risk-based selection using the Rotterdam Prostate Cancer Risk Calculator (RPCRC). DESIGN, SETTING, AND PARTICIPANTS: Two-hundred consecutive biopsy-naïve men in two centres underwent mpMRI scanning, 12-core SBx, and subsequent MRI-TRUS TBx in the case of suspicious lesion(s) (Prostate Imaging-Reporting and Data System v.2 score ≥3). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We measured the detection rate for high-grade (Gleason score ≥ 3+4) PCa for TBx and SBx. We carried out a retrospective stratification according to RPCRC biopsy advice to determine the rate of mpMRI and biopsies that could potentially be avoided by RPCRC-based patient selection in relation to the rate of high-grade PCa missed. RESULTS AND LIMITATIONS: TBx yielded high-grade PCa in 51 men (26%) and low-grade PCa in 14 men (7%), while SBx yielded high-grade PCa in 63 men (32%) and low-grade PCa in 41 men (21%). Four out of 73 men (5%) with negative RPCRC advice and 63 out of 127 men (50%) with positive advice had high-grade PCa. Upfront RPCRC-based patient selection for mpMRI and TBx would have avoided 73 out of 200 (37%) mpMRI scans, missing two out of 51 (4%) high-grade PCas. Limitations include the RPCRC definition of high- and low-grade PCa and different mpMRI techniques. CONCLUSIONS: mpMRI with TBx detected PCa with high Gleason score and avoided biopsy in low-grade PCa, but failed to detect all high-grade PCa when compared to SBx among biopsy-naïve men. Risk-based patient selection using the RPCRC can avoid one-third of mpMRI scans and SBx in biopsy-naïve men. PATIENT SUMMARY: Men with a suspicion of prostate cancer are increasingly undergoing a magnetic resonance imaging (MRI) scan. Although promising, MRI-targeted biopsy is not accurate enough to safely replace systematic prostate biopsy for now. Individualised assessment of prostate cancer risk using the Rotterdam Prostate Cancer Risk Calculator could avoid one-third of MRI scans and systematic prostate biopsies.

[Abdominal splenosis]. / Abdominale splenose.

Splenosis is a common benign finding that occurs after splenic trauma or after splenectomy. It is auto-transplantation of splenic tissue and can be seen intra-abdominally, intra-thoracically and even subcutaneously. Splenosis is usually found incidentally at laparoscopy, laparotomy or on radiological examination and is mostly asymptomatic. Treatment is only required if a patient complains of abdominal pain, obstruction or bleeding. On radiological examination splenosis can mimic a metastatic malignant disease. For this reason it is important to recognise splenosis and know the patient's medical history concerning splenic trauma or splenectomy, thus avoiding diagnostic laparoscopy or ultrasound guided biopsy. This paper presents two patients with splenosis. Additionally, we describe how to diagnose this entity by scintigraphy with (99m) Technetium-labelled heat-denatured erythrocytes.

Reduction of contrast medium volume in abdominal aorta CTA: multiphasic injection technique versus a test bolus volume.

OBJECTIVE: The purpose of this study is to reduce the administered contrast medium volume in abdominal CTA by using a test bolus injection, with the preservation of adequate quantitative and qualitative vessel enhancement. STUDY DESIGN: For this technical efficacy study 30 patients, who were referred for a CTA examination of the abdominal aorta, were included. Randomly 15 patients were assigned to undergo a multiphasic injection protocol and received 89 mL of contrast medium (Optiray 350) (protocol I). Fifteen patients were assigned to the test bolus injection protocol (protocol II), which implies injection of a 10 mL test bolus of Optiray 350 prior to performing CTA with a 40 mL of contrast medium. Quantitative assessment of vascular enhancement was performed by measuring the amount of Hounsfield Units in the aorta at 30 positions from the celiac trunk to the iliac arteries in both groups. Qualitative assessment was performed by three radiologists who scored the images at a 5-point scale. RESULTS: Quantitative assessment showed that there was no significant difference in vascular enhancement for patients between the two protocols, with mean attenuation values of 280.9 ± 50.84 HU and 258.60 ± 39.28 HU, respectively. The image quality of protocol I was rated 4.31 (range: 3.67/5.00) and of protocol II 4.11 (range: 2.67/5.00). These differences were not statistically significant. CONCLUSION: This study showed that by using a test bolus injection and the administration of 50 mL of contrast medium overall, CTA of the abdominal aorta can reliably be performed, with regard to quantitative and qualitative adequate vessel enhancement.

Reduced contrast medium in abdominal aorta CTA using a multiphasic injection technique.

PURPOSE: The purpose of this study was to determine if with a multiphasic injection technique the administered amount of contrast medium for abdominal computerized tomographic angiography (CTA) can be decreased, whilst improving CT image quality. MATERIALS AND METHODS: In 30 patients a multiphasic injection method was compared to the standard uniphasic contrast medium injection protocol. Fifteen patients underwent abdominal CTA with a standard uniphasic injection protocol (protocol I) receiving 100mL of a non-ionic radiopaque contrast agent (Ioversol). The second group of 15 patients underwent CTA with a multiphasic injection protocol (protocol II) receiving a total of 89 mL Ioversol. Vascular contrast enhancement and difference in enhancement uniformity were assessed quantitatively and image quality was assessed by three independent radiologists. RESULTS: Quantitative assessment of the vascular contrast enhancement showed that there was no significant difference in enhancement uniformity for patients between the protocols. The image quality was rated as being good to excellent in 81.8% and 88.0% of the scans, for protocol I and protocol II, respectively. However these differences were not statistically significant. CONCLUSION: By using a multiphasic injection technique with CTA of the abdominal aorta a reduction of 11 percent of contrast medium can be realized. Enhancement patterns are quantitatively as well as qualitatively comparable to the standard contrast medium injection protocol.

Value of PET/CT and MR lymphography in treatment of prostate cancer patients with lymph node metastases.

PURPOSE: To determine the clinical value of two novel molecular imaging techniques: (11)C-choline positron emission tomography (PET)/computed tomography (CT) and ferumoxtran-10 enhanced magnetic resonance imaging (magnetic resonance lymphography [MRL]) for lymph node (LN) treatment in prostate cancer (PCa) patients. Therefore, we evaluated the ability of PET/CT and MRL to assess the number, size, and location of LN metastases in patients with primary or recurrent PCa. METHODS AND MATERIALS: A total of 29 patients underwent MRL and PET/CT for LN evaluation. The MRL and PET/CT data were analyzed independently. The number, size, and location of the LN metastases were determined. The location was described as within or outside the standard clinical target volume for elective pelvic irradiation as defined by the Radiation Therapy Oncology Group. Subsequently, the results from MRL and PET/CT were compared. RESULTS: Of the 738 LNs visible on MRL, 151 were positive in 23 of 29 patients. Of the 132 LNs visible on PET/CT, 34 were positive in 13 of 29 patients. MRL detected significantly more positive LNs (p < 0.001) in more patients than PET/CT (p = 0.002). The mean diameter of the detected suspicious LNs on MRL was significantly smaller than those detected by PET/CT, 4.9 mm and 8.4 mm, respectively (p < 0.0001). In 14 (61%) of 23 patients, suspicious LNs were found outside the clinical target volume with MRL and in 4 (31%) of 13 patients with PET/CT. CONCLUSION: In patients with PCa, both molecular imaging techniques, MRL and (11)C-choline PET/CT, can detect LNs suspicious for metastasis, irrespective of the existing size and shape criteria for CT and conventional magnetic resonance imaging. On MRL and PET/CT, 61% and 31% of the suspicious LNs were located outside the conventional clinical target volume. Therefore, these techniques could help to individualize treatment selection and enable image-guided radiotherapy for patients with PCa LN metastases.

[3-D ultrasound of the breast: less dependent on the investigator]. / 3D-echografie van de mamma: minder afhankelijk van onderzoeker.

Three-dimensional (3-D) ultrasound is a technique, in which almost the entire breast is automatically scanned. Data sets can be stored and reviewed at a later date. This almost completely eliminates the subjective character of conventional ultrasound, enabling a more reliable review and follow-up. 3-D ultrasound can be implemented in daily radiological practice and could possibly be used in population screening programmes for breast cancer.

Intratendinous ganglion of the long head of the biceps tendon: US and MRI features (2010: 9b). Intratendinous ganglion.

We present a case report and literature review of the ultrasound (US) and magentic resonance imaging (MRI) features of an intratendinous ganglion originating from the long head of the biceps tendon. Intratendinous ganglia are very rare entities and intratendinous ganglion of the long head of the biceps tendon has only been described once. To the best of our knowledge, this is the first case report presenting the sonographic features of an intratendinous ganglion originating from the long head of the biceps tendon.

Ultrasound detection of rotator cuff tears: observer agreement related to increasing experience.

OBJECTIVE: Ultrasound of the rotator cuff is considered to be operator-dependent with its accuracy being related to the operator's level of experience. This study was conducted to test the hypothesis that ultrasound performed by operators with different levels of experience will give nonreproducible results. SUBJECTS AND METHODS: Two radiologists, one general radiologist with no experience in musculoskeletal ultrasound and one experienced musculoskeletal radiologist, independently performed ultrasound on 200 shoulders in 183 consecutive patients. Agreement was assessed. Cohen's kappa values with standard errors were calculated. In 71 patients the ultrasound findings could be related to surgical findings. RESULTS: The diagnoses of full-thickness and partial-thickness rotator cuff tears were made with agreements of 98% (κ-value: 0.95 [standard error, 0.03]) and 90% (κ-value: 0.79 [0.05]), respectively. Agreement for full-thickness tears was constant; the agreement for partial-thickness tears improved from 80% to 98% in the last quarter of the study period. Based on the 71 patients who underwent shoulder surgery, sensitivity, specificity, and accuracy for detecting full-thickness tears by the experienced and general radiologists were 94%, 94%, and 94% and 89%, 91%, and 90%, respectively. Sensitivity, specificity, and accuracy for detecting partial-thickness tears by the experienced and general radiologists were 100%, 32%, and 57% and 84%, 35%, and 53%, respectively. CONCLUSION: The hypothesis that ultrasound of the shoulder is operator-dependent and related to experience was refuted. In this study, there was excellent agreement for the detection of rotator cuff tears, which only slightly improved with the increasing experience of the general radiologist. Accuracy of rotator cuff tear detection was high and in accordance with the results in the literature.

Unsuspected sonographic findings in patients with posttraumatic shoulder complaints.

PURPOSE: To prospectively assess the frequency of abnormal sonographic findings in patients with posttraumatic shoulder pain and/or disability in whom ultrasound (US) was not considered and to assess the effect of sonographic findings on working diagnosis and therapeutic strategy, to analyze the possible role of US in the diagnostic workup of these patients. METHODS: A survey was performed under general practitioners and orthopedic surgeons. They were requested to refer patients with persistent posttraumatic complaints for an US examination of the shoulder and to fill out a questionnaire concerning working diagnosis and therapy. In 50 patients examinations were performed separately by two radiologists. Findings were confirmed with additional radiographs and/or MRI and/or surgery. Four weeks after the US examination, the survey was repeated to inquire about changes in diagnosis and/or treatment that resulted from US. RESULTS: US showed relevant pathology in 45 (90%) of 50 patients, a proximal humerus fracture in 25 (50%) patients, and a rotator cuff tear in 43 (86%) patients. Twenty-three (92%) fractures were accompanied by a rotator cuff tear, and 23 (54%) rotator cuff tears were accompanied by a fracture. Ten fractures were initially missed radiographically. US findings changed the working diagnosis and therapeutic strategy in 37 (74%) and 26 (52%) patients, respectively. CONCLUSION: In patients with posttraumatic shoulder complaints, US showed a high rate (90%) of relevant pathology. This changed the initial working diagnosis in 74% of the patients and the therapeutic strategy in more than half of the patients. Active referral for US examination may identify these abnormalities in an earlier phase and improve clinical outcome.

Detection of rotator cuff tears: the value of MRI following ultrasound.

OBJECTIVE: To evaluate the need for additional magnetic resonance imaging (MRI) following ultrasound (US) in patients with shoulder pain and/or disability and to compare the accuracy of both techniques for the detection of partial-thickness and full-thickness rotator cuff tears (RCT). METHODS: In 4 years, 5,216 patients underwent US by experienced musculoskeletal radiologists. Retrospectively, patient records were evaluated if MRI and surgery were performed within 5 months of US. US and MRI findings were classified into intact cuff, partial-thickness and full-thickness RCT, and were correlated with surgical findings. RESULTS: Additional MR imaging was performed in 275 (5.2%) patients. Sixty-eight patients underwent surgery within 5 months. US and MRI correctly depicted 21 (95%) and 22 (100%) of the 22 full-thickness tears, and 8 (89%) and 6 (67%) of the 9 partial-thickness tears, respectively. The differences in performance of US and MRI were not statistically significant (p = 0.15). CONCLUSIONS: MRI following routine shoulder US was requested in only 5.2% of the patients. The additional value of MRI was in detecting intra-articular lesions. In patients who underwent surgery, US and MRI yielded comparably high sensitivity for detecting full-thickness RCT. US performed better in detecting partial-thickness tears, although the difference was not significant.

[An invasive process in the pancreas: sometimes lymphoma]. / Een ruimte-innemend proces in het pancreas: soms een lymfoom.

An invasive process in the pancreas was found in a 60-year-old woman and a 50-year-old man with abdominal symptoms. Generally, such findings turn out to be adenocarcinoma. However, these patients had lymphoma. Primary pancreatic lymphoma or localization of lymphoma in the pancreas are rare and chemotherapy may be curative. Therefore, obtaining tissue for histopathological confirmation of the diagnosis is very important. Both patients underwent chemotherapy. The first patient was in complete remission one month after the last chemotherapy cycle. In the second, the disease went into remission, but he suddenly died of sepsis after the fourth chemotherapy cycle.

Cost-effectiveness of MR lymphography for the detection of lymph node metastases in patients with prostate cancer.

PURPOSE: To apply a decision analytic model to determine whether the addition of magnetic resonance (MR) lymphography to the diagnostic workup of patients with intermediate or high probability of lymph node metastases is cost effective from a health care perspective. MATERIALS AND METHODS: The data that were used for the decision analytic model were obtained from an empiric study population of 375 patients. As the input of the decision analytic model was made given prospective patient data from several hospitals, the ethics review board of each hospital approved the study. Written consent was obtained from all patients. To investigate possible differences between strategies that utilize MR lymphography and those that do not (pelvic lymph node dissection [PLND]), two outcome measures were examined and combined in an incremental cost-effectiveness ratio (ICER) of health care resources consumed and quality-adjusted life-years (QALYs). Probabilistic and one-way sensitivity analyses were performed. RESULTS: The PLND strategy is dominated by the MR lymphography strategy. Probabilistic sensitivity analysis showed that in 63% of simulations, MR lymphography was cost saving and resulted in better patient outcome for patients with prostate cancer and intermediate or high probability of lymph node metastases. The probability of MR lymphography being inferior (more expensive and worse patient outcome) is less than 3%. CONCLUSION: MR lymphography is an efficient strategy in the detection of lymph node metastases of prostate cancer when compared with the PLND strategy.

Prostate cancer: detection of lymph node metastases outside the routine surgical area with ferumoxtran-10-enhanced MR imaging.

PURPOSE: To prospectively evaluate the feasibility of magnetic resonance (MR) imaging with ferumoxtran-10 in patients with prostate cancer to depict lymph node metastases outside the routine pelvic lymph node dissection (PLND) area. MATERIALS AND METHODS: The study was approved by the institutional review boards at all four hospitals; patients provided written informed consent. Two hundred ninety-six consecutive men (mean age, 67 years; range, 47-83 years) with prostate cancer and an intermediate-to-high risk for nodal metastases (prostate-specific antigen level >10 ng/mL, Gleason score >6, or stage T3 disease) were enrolled. MR lymphography of the pelvis was performed 24 hours after intravenous drip infusion of ferumoxtran-10. Positive nodes at MR lymphography were indicated to be inside or outside the routine dissection area (RDA). On the basis of MR lymphography computed tomographic (CT)-guided biopsy, routine PLND, or MR imaging-guided minimal extended PLND was performed. RESULTS: MR lymphography findings were positive in 58 patients. Of these, 44 had histopathologic confirmation of lymph node metastases. In 18 of 44 patients (41%), MR lymphography findings showed nodes exclusively outside the RDA, which were confirmed with MR lymphography-guided extended PLND (n = 13) and CT-guided biopsy (n = 5). In another 18 patients (41%), positive nodes were located both inside and outside the RDA at MR lymphography. In these 18 patients, routine PLND was used to confirm the nodes inside the RDA (n = 11); CT-guided biopsy was used to confirm nodes outside the RDA (n = 7). In the remaining eight patients, MR lymphography findings showed only nodes inside the RDA, which was confirmed with PLND (n = 5) and CT-guided biopsy (n = 3). In 14 of the 58 patients (24%), there was no histologic confirmation. CONCLUSION: In 41% of patients with prostate cancer, nodal metastases outside the area of routine PLND were detected by using MR imaging with ferumoxtran-10.

Glenohumeral joint injection: a comparative study of ultrasound and fluoroscopically guided techniques before MR arthrography.

To assess the variability in accuracy of contrast media introduction, leakage, required time and patient discomfort in four different centres, each using a different image-guided glenohumeral injection technique. Each centre included 25 consecutive patients. The ultrasound-guided anterior (USa) and posterior approach (USp), fluoroscopic-guided anterior (FLa) and posterior (FLp) approach were used. Number of injection attempts, effect of contrast leakage on diagnostic quality, and total room, radiologist and procedure times were measured. Pain was documented with a visual analogue scale (VAS) pain score. Access to the joint was achieved in all patients. A successful first attempt significantly occurred more often with US (94%) than with fluoroscopic guidance (72%). Leakage of contrast medium did not cause interpretative difficulties. With US guidance mean room, procedure and radiologist times were significantly shorter (p < 0.001). The USa approach was rated with the lowest pre- and post-injection VAS scores. The four image-guided injection techniques are successful in injection of contrast material into the glenohumeral joint. US-guided injections and especially the anterior approach are significantly less time consuming, more successful on the first attempt, cause less patient discomfort and obviate the need for radiation and iodine contrast.

MRI with a lymph-node-specific contrast agent as an alternative to CT scan and lymph-node dissection in patients with prostate cancer: a prospective multicohort study.

BACKGROUND: In patients with prostate cancer who are deemed to be at intermediate or high risk of having nodal metastases, invasive diagnostic pelvic lymph-node dissection (PLND) is the gold standard for the detection of nodal disease. However, a new lymph-node-specific MR-contrast agent ferumoxtran-10 can detect metastases in normal-sized nodes (ie, <8 mm in size) by use of MR lymphoangiography (MRL). In this prospective, multicentre cohort study, we aimed to compare the diagnostic accuracy of MRL with up-to-date multidetector CT (MDCT), and test the hypothesis that a negative MRL finding obviates the need for a PLND. METHODS: We included consecutive patients with prostate cancer who had an intermediate or high risk (risk of >5% according to routinely used nomograms) of having lymph-node metastases. All patients were assessed by MDCT and MRL, and underwent PLND or fine-needle aspiration biopsy. Imaging results were correlated with histopathology. The primary outcomes were sensitivity, specificity, accuracy, NPV, and PPV of MRL and MDCT. This study is registered with ClinicalTrials.gov, number NCT00185029. FINDINGS: The study was done in 11 hospitals in the Netherlands between April 8, 2003, and April 19, 2005. 375 consecutive patients were included. 61 of 375 (16%) patients had lymph-node metastases. Sensitivity was 34% (21 of 61; 95% CI 23-48) for MDCT and 82% (50 of 61; 70-90) for MRL (McNemar's test p<0.05). Specificity was 97% (303 of 314; 94-98) for MDCT and 93% (291 of 314; 89-95) for MRL. Positive predictive value (PPV) was 66% (21 of 32; 47-81) for MDCT and 69% (50 of 73; 56-79) for MRL. Negative predictive value (NPV) was 88% (303 of 343; 84-91) for MDCT and 96% (291 of 302; 93-98) for MRL (McNemar's test p<0.05). Of the 61 patients with lymph-node metastases, 50 were detected by MRL, of which 40 (80%) had metastases in normal-sized lymph nodes. The high sensitivity and NPV of MRL imply that in patients with a negative MRL, the chance of positive lymph nodes is less than 11/302 (4%). INTERPRETATION: MRL had significantly higher sensitivity and NPV than MDCT for patients with prostate cancer who had intermediate or high risk of having lymph-node metastases. In such patients, after a negative MRL, the post-test probability of having lymph-node metastases is low enough to omit a PLND.