Brendan Koo

Defining the learning curve for multiparametric magnetic resonance imaging (MRI) of the prostate using MRI-transrectal ultrasonography (TRUS) fusion-guided transperineal prostate biopsies as a validation tool

To determine the accuracy of multiparametric magnetic resonance imaging (mpMRI) during the learning curve of radiologists using MRI targeted, transrectal ultrasonography (TRUS) guided transperineal fusion biopsy (MTTP) for validation.

Definitions of terms, processes and a minimum dataset for transperineal prostate biopsies: a standardization approach of the Ginsburg Study Group for Enhanced Prostate Diagnostics.

To define terms and processes and agree on a minimum dataset in relation to transperineal prostate biopsy procedures and enhanced prostate diagnostics. To identify the need for further evaluation and establish a collaborative research practice.

Multicentre evaluation of targeted and systematic biopsies using magnetic resonance and ultrasound image-fusion guided transperineal prostate biopsy in patients with a previous negative biopsy.

To evaluate the detection rates of targeted and systematic biopsies in magnetic resonance imaging (MRI) and ultrasound (US) image‐fusion transperineal prostate biopsy for patients with previous benign transrectal biopsies in two high‐volume centres.

Current diagnostic approaches to subarachnoid haemorrhage

Over the past decade, significant advances have been made in the field of subarachnoid haemorrhage (SAH). Prompt diagnosis with high-resolution CT and intensive critical care support remain key aspects of good patient management. Early identification and definitive treatment of underlying ruptured aneurysms is generally advocated to reduce the risk of re-bleeding, a complication with high mortality and morbidity. Although intra-arterial digital subtraction angiography (DSA) is still considered the gold standard for sourcing aneurysms, CT angiography, especially with the evolution of multi-slice technology, is slowly gaining acceptance as a rapid, accessible and minimally invasive method which appears likely to replace DSA as first-line modality in the future. Furthermore, the advent of Guglielmi detachable coils and the ISAT trial have revolutionised the treatment of ruptured aneurysms, with a significant trend towards endovascular coiling away from operative clipping. Improvements in clinical experience, coiling technology and assistive devices now allow interventionalists to potentially treat the majority of aneurysms, including wide-necked or complex lesions. The uncertain long-term results of coiling, however, still fuel strong debate and controversy. This review summarises current diagnostic approaches to SAH from a radiological perspective, with an emphasis on aneurysmal SAH and an evidence-based approach to the role of imaging and interventional radiology in diagnosis, treatment and follow-up.

Utility of an ultrafast magnetic resonance imaging protocol in recent and semi-recent strokes

Objective: To evaluate the technical feasibility of an integrated ultrafast head magnetic resonance (MR) protocol using a sensitivity encoding (SENSE) technique for depicting parenchymal ischaemia and vascular compromise in patients with suspected recent stroke. Methods: 23 patients were evaluated with the ultrafast MR protocol using T2, T1, fluid attenuated inversion recovery (FLAIR), 3D time of flight magnetic resonance angiography (MRA), and diffusion weighted imaging (DWI) sequences. These were compared with routine conventional MR sequences. Results: One patient could not tolerate conventional imaging, although imaging using the three minute head SENSE protocol was diagnostic. Both conventional and ultrafast protocols were of similar diagnostic yield in the remaining patients. There were no significant differences in clinical diagnostic quality for the T1, T2, FLAIR, and DWI sequences. One MRA examination was of better quality when SENSE was used, owing to reduced motion artefacts and shorter imaging time. Conclusions: It is possible to undertake a comprehensive MR examination in stroke patients in approximately three to five minutes. Ultrafast imaging may become a useful triage tool before thrombolytic therapy. It may be of particular benefit in patients unable to tolerate longer sequences. Further work is necessary to confirm these findings in hyperacute stroke.

The influence of prostate-specific antigen density on positive and negative predictive values of multiparametric magnetic resonance imaging to detect Gleason score 7-10 prostate cancer in a repeat biopsy setting

To evaluate the influence of prostate‐specific antigen density (PSAD) on positive (PPV) and negative (NPV) predictive values of multiparametric magnetic resonance imaging (mpMRI) to detect Gleason score ≥7 cancer in a repeat biopsy setting.

The Prostate Health Index adds predictive value to multi-parametric MRI in detecting significant prostate cancers in a repeat biopsy population

Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5–30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI.

Investigating the ability of multiparametric MRI to exclude significant prostate cancer prior to transperineal biopsy

INTRODUCTION We characterized false negative prostate magnetic resonance imaging (MRI) reporting by using histology derived from MRI-transrectal ultrasound (TRUS)-guided transperineal (MTTP) fusion biopsies. METHODS In total, 148 consecutive patients were retrospectively reviewed. Men underwent multiparametric MRI (mpMRI), reported by a consultant/attending radiologist in line with European Society of Urogenital Radiology (ESUR) standards. MTTP biopsy of the lesions was performed according to the Ginsburg recommendations. Cases with an MRI-histology mismatch were identified and underwent a second read by an experienced radiologist. A third review was performed with direct histology comparison to determine a true miss from an MRI-occult cancer. Statistical analysis was performed with McNemars test. RESULTS False negative lesions were identified in 29 MRI examinations (19.6%), with a total of 46 lesions. Most false negative lesions (21/46) were located in the anterior sectors of the prostate. The second read led to a significant decrease of false-negative lesions with 7/29 further studies identified as positive on a patient-by-patient basis (24.1% of studies, p = 0.016) and 11/46 lesions (23.9%; p = 0.001). Of these, 30 lesions following the first read and 23 lesions after the second read were considered significant cancer according to the University College London criteria. However, on direct comparison with histology, most lesions were MRI occult. CONCLUSION We demonstrate that MRI can fail to detect clinically relevant lesions. Improved results were achieved with a second read but despite this, a number of lesions remain MRI-occult. Further advances in imaging are required to reduce false negative results.

Progression and treatment rates using an active surveillance protocol incorporating image‐guided baseline biopsies and multiparametric magnetic resonance imaging monitoring for men with favourable‐risk prostate cancer

To assess early outcomes since the introduction of an active surveillance (AS) protocol incorporating multiparametric magnetic resonance imaging (mpMRI)‐guided baseline biopsies and image‐based surveillance.

Modern myths of percutaneous renal tumour mass biopsy.

An international systematic review published in 2012 (based on publications between 2004 and 2011) involving over 1300 biopsied tumours, found the sensitivity and specificity of PRTB for the diagnosis of malignancy to be 86–100% and 100%, respectively [2]. A previous literature review in 2008 of almost 2500 biopsied tumours, found diagnostic accuracy (a combination of test sensitivity and specificity) of 94% for those stratified as performed after 2001 [3]. The only two UK-based series (although perhaps biased by tertiary centre expertise) have reported a diagnostic accuracy of 100% [4]. Over the last decade, considerable and undeniable improvements have occurred in radiology (imaging guidance, biopsy technique expertise) and pathology (immunohistochemical, molecular and perhaps even genetic support for the interpretation of specimens), resulting in a consistent high standard of reported accuracy.