What is Multiparametric-MRI of the Prostate and Why Do We Need It?

This is the final version of the article. It first appeared from iMedPub via http://interventional-radiology.imedpub.com/what-is-multiparametricmriof-the-prostate-and-why-do-weneed-it.pdfPost-Prostate cancer is the second leading cause of cancer death in men. Prostate-specific antigen (PSA) testing has led to an over-diagnosis of relatively indolent disease, which has been further compounded by the limitations of traditional diagnosis by transrectal ultrasound-guided biopsy. Improvements in MRI technique and, in particular, functional imaging have enabled the radiologist to play a key role in the risk stratification and management of patients, with a drive to utilizing MRI early in the diagnostic pathway. However, the technique remains challenging both in the acquisition of images and in their interpretation, highlighting the need for the recent push towards greater standardisation. The benefits and limitations of MRI are discussed, along with future directions in the field.The author acknowledges research support from National Institute of Health Research Cambridge Biomedical Research Centre, Cancer Research UK, Cancer Research UK and the Engineering and Physical Sciences Research Council Imaging Centre in Cambridge and Manchester and the Cambridge Experimental Cancer Medicine Centre

Functional Imaging to enable more accurate localisation and characterisation of prostate tumours

Abstract Prostate cancer is the leading cause of cancer death in men after skin cancer, with an incidence expected to double by 2030 mainly due to the ageing population. However, many more men die with prostate cancer rather than from the disease, highlighting the indolent nature of many tumours. Therefore, the development of non-invasive imaging methods to stratify prostate cancer is important for patient management. Recently, multiparametric MRI has revolutionised the work-up of prostate cancer, becoming a routine part of clinical practice and migrating earlier in the diagnostic pathway. However, the technique remains challenging, with patient-related factors, intrinsic insensitivity of MRI, protocol differences, and radiologist experienced all combining to limit its overall accuracy. Anatomical T2-weighted imaging is limited by the non-specific nature of its findings and improvements have mainly been driven by the addition of functional sequences such as diffusion-weighted imaging, dynamic contrast-enhanced MRI and spectroscopy. In the absence of validated circulating biomarkers, only functional imaging currently offers the potential for further improvements in lesion detection and characterisation, with the additional advantages of providing whole gland coverage of the prostate and being non-invasive. This thesis addresses the issues of prostate tumour localisation and characterisation using functional imaging techniques. Chapter 2 assesses whether simple pre-imaging interventions relating to patient preparation can help improve MRI quality. Chapter 3 evaluates the potential for two novel functional MR sequences to differentiate tumour from normal prostate tissue. Chapter 4 investigates whether non-proton sodium MRI can offer functional information reflecting cell membrane integrity and cell viability. Chapter 5 evaluates whether the PET/CT tracer 11C-acetate can offer additive information on primary prostate tumours. Tristan Barret

Case 267: Cecureterocoele Manifesting in a Man with Infertility.

History A 28-year-old man presented with lifelong anejaculation, which had become an issue because of family planning. The patient had a history of normal erections and experienced the sensation of orgasm without ever ejaculating. On physical examination, both testes were present in the scrotum, with normal dimensions and a normal epididymis bilaterally. The patient had a slightly tender left testicle, and digital rectal examination findings were normal. The patient underwent further investigation for the possibility of retrograde ejaculation with urine cytology, the results of which were negative. Genetic testing was performed to exclude Y chromosome microdeletions. Serum-luteinizing and follicle-stimulating hormone levels were normal, with a borderline low level of testosterone (7.6 nmol/L; normal range, 8.0-29.0 nmol/L). All other pertinent laboratory results were noncontributory. Pelvic MRI was requested to exclude an anatomic cause of anejaculation. MRI was performed in accordance with the standard clinical prostate protocol, with a dynamic contrast material-enhanced study. CT of the upper abdomen was also performed. The patient subsequently underwent cystoscopy, which revealed an intravesicular fluid-filled mass near the left ureteric orifice

A method for mapping and quantifying whole organ diffusion-weighted image distortion in MR imaging of the prostate.

A computational algorithm was designed to produce a measure of DW image distortion across the prostate. This algorithm was tested and validated on virtual phantoms incorporating known degrees and distributions of distortion. A study was then carried out on DW image volumes from three sets of 10 patients who had been imaged previously. These volumes had been radiologically assessed to have, respectively, 'no distortion' or 'significant distortion' or the potential for 'significant distortion' due to susceptibility effects from hip prostheses. Prostate outlines were drawn on a T2-weighted (T2W) image 'gold-standard' volume and on an ADC image volume derived from DW images acquired over the same region. The algorithm was then applied to these outlines to quantify and map image distortion. The proposed method correctly reproduced known distortion values and distributions in virtual phantoms. It also successfully distinguished between the three groups of patients: mean distortion in 'non-distorted' image volumes, 1.942 ± 0.582 mm; 'distorted', 4.402 ± 1.098 mm; and 'hip patients' 8.083 ± 4.653 mm; P < 0.001. This work has demonstrated and validated a means of quantifying and mapping image distortion in clinical prostate MRI cases

Evaluation of image‐based prognostic parameters of post‐prostatectomy urinary incontinence: A literature review

Abstract: Prostate cancer is the second most common male cancer, and radical prostatectomy is a highly effective treatment for intermediate and high‐risk disease. However, post‐prostatectomy urinary incontinence remains a major functional side‐effect in patients undergoing radical prostatectomy. Despite recent improvements in preoperative imaging quality and surgical techniques, it remains challenging to predict or prevent occurrence of this complication. The aim of this research was to review the current published literature on pre‐ and postoperative imaging evaluation of the prostate and pelvic structures, to identify added value in the prediction of post‐prostatectomy urinary incontinence. A computerized bibliographic search of the PubMed library was carried out to identify imaging‐based articles evaluating the pelvic floor and surrounding structures pre‐ and/or postradical prostatectomy to predict post‐prostatectomy urinary incontinence. A total of 32 articles were included. Of these, 29 papers assessed the importance of magnetic resonance imaging evaluation, with a total of 16 parameters evaluated. The most common parameters were intravesical protrusion, the membranous urethral length, prostatic volume and periurethral fibrosis. Preoperative membranous urethral length and its preservation after surgery showed the strongest correlation with urinary incontinence. Three studies evaluated ultrasound, with all carried out postoperatively. This technique benefits from a dynamic evaluation, and the results are promising for proximal urethral hypermobility and the degree of bladder neck funneling on the Valsalva maneuver. Several imaging studies evaluated the predictors of post‐prostatectomy urinary incontinence, with preoperative membranous urethral length offering the most promise. However, the current literature is limited by the single‐center nature of studies, and the heterogeneity in patient populations and methodologies used

Multiparametric Prostate Magnetic Resonance Imaging and Cognitively Targeted Transperineal Biopsy in Patients With Previous Abdominoperineal Resection and Suspicion of Prostate Cancer.

OBJECTIVE: To report our experience with a combination of prostate magnetic resonance imaging (MRI) and transperineal ultrasound biopsy for evaluating the prostate in patients with elevated prostate-specific antigen (PSA) who have previously undergone abdominoperineal resection (APR). PATIENTS AND METHODS: We reviewed the records of 11 patients with a history of APR and clinical suspicion of prostate cancer due to elevated PSA levels over a 5-year period. All patients underwent multiparametric MRI at our institution prior to biopsy. MR diagnoses were validated either by transperineal ultrasound biopsy (Likert 3-5) guided by visual registration or clinical follow-up >6 months (Likert 1-2). RESULTS: All 7 cases with highly suspicious lesions (Likert 4-5) on MRI demonstrated cancer-1 case of Gleason 3 + 3 and 6 cases of Gleason ≥3 + 4 disease. Two cases with Likert 3 MR lesions revealed benign tissue upon biopsy. Two patients with no suspicious lesions on MRI were followed-up clinically, with PSA levels remaining stable over a mean period of 17.5 months (range 7-28 months). CONCLUSION: The use of prebiopsy multiparametric prostate MRI and subsequent cognitively targeted transperineal biopsy guided by visual registration can aid in the diagnostic pathway of patients with APR and a suspicion of prostate cancer.Author 1 has received a research grant from RWTH Aachen University Hospital (Aachen, Germany). Author 6 acknowledges support from Cancer Research UK, National Institute of Health Research Cambridge Biomedical Research Centre, Cancer Research UK and the Engineering and Physical Sciences Research Council Imaging Centre in Cambridge and Manchester and the Cambridge Experimental Cancer Medicine Centre.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.urology.2016.04.03

A head-to-head comparison of the inter- and intraobserver agreement of COVID-RADS and CO-RADS grading systems in a population with high estimated prevalence of COVID-19

Purpose To evaluate the inter- and intraobserver agreement of COVID-RADS and CO-RADS reporting systems among differently experienced radiologists in a population with high estimated prevalence of COVID-19. Materials and Methods Chest CT scans of patients with clinically-epidemiologically diagnosed COVID-19 were retrieved from an open-source MosMedData dataset, randomised, and independently assigned COVID-RADS and CO-RADS grades by an abdominal radiology fellow, thoracic imaging fellow and a consultant cardiothoracic radiologist. The inter- and intraobserver agreement of the two systems were assessed using the Fleiss’ and Cohen’s kappa coefficients, respectively. Results A total of 200 studies were included in the analysis. Both systems demonstrated moderate interobserver agreement, with kappa values of 0.51 (95% CI: 0.46-0.56) and 0.55 (95% CI: 0.50-0.59) for COVID-RADS and CO-RADS, respectively. When COVID-RADS and CO-RADS grades were dichotomised at cut-off values of 2B and 4 to evaluate the agreement between grades representing different levels of clinical suspicion for COVID-19, the interobserver agreement became substantial with kappa values of 0.74 (95% CI: 0.66-0.82) for COVID-RADS and 0.73 (95% CI: 0.65-0.81) for CO-RADS. The median intraobserver agreement was considerably higher for CO-RADS reaching 0.81 (95% CI: 0.43-0.76) compared with 0.60 (95% CI: 0.43-0.76) of COVID-RADS. Conclusions COVID-RADS and CO-RADS showed comparable interobserver agreement, which was moderate when grades were compared head-to-head and substantial when grades were dichotomised to better reflect the underlying levels of suspicion for COVID-19. The median intraobserver agreement of CO-RADS was, however, considerably higher compared with COVID-RADS. Advances in knowledge This paper provides a comprehensive review of the newly introduced COVID-19 chest CT reporting systems, which will help radiologists of all sub-specialties and experience levels make an informed decision on which system to use in their own practice.Acknowledgments: The authors acknowledge support from Cancer Research UK, National Institute of Health Research Cambridge Biomedical Research Centre, Cancer Research UK and the Engineering and Physical Sciences Research Council Imaging Centre in Cambridge and Manchester and the Cambridge Experimental Cancer Medicine Centre

Case 267.

History A 28-year-old man presented with lifelong anejaculation, which had become an issue because of family planning. The patient had a history of normal erections and experienced the sensation of orgasm without ever ejaculating. On physical examination, both testes were present in the scrotum, with normal dimensions and a normal epididymis bilaterally. The patient had a slightly tender left testicle, and digital rectal examination findings were normal. The patient underwent further investigation for the possibility of retrograde ejaculation with urine cytology, the results of which were negative. Genetic testing was performed to exclude Y chromosome microdeletions. Serum-luteinizing and follicle-stimulating hormone levels were normal, with a borderline low level of testosterone (7.6 nmol/L; normal range, 8.0-29.0 nmol/L). All other pertinent laboratory results were noncontributory. Pelvic MRI was requested to exclude an anatomic cause of anejaculation. MRI was performed in accordance with the standard clinical prostate protocol, with a dynamic contrast material-enhanced study ( Figs 1 - 3 ). CT of the upper abdomen was also performed ( Fig 4 ). The patient subsequently underwent cystoscopy, which revealed an intravesicular fluid-filled mass near the left ureteric orifice ( Fig 5 ). Figure 1a: (a) Coronal and (b, c) axial fast spin-echo T2-weighted MR images of the pelvis, with b being superior to c. Figure 1b: (a) Coronal and (b, c) axial fast spin-echo T2-weighted MR images of the pelvis, with b being superior to c. Figure 1c: (a) Coronal and (b, c) axial fast spin-echo T2-weighted MR images of the pelvis, with b being superior to c. Figure 2a: (a) Coronal T2-weighted (repetition time msec/echo time msec, 4574/86.5) MR image of the pelvis. (b) Axial T2-weighted (3000/85.4) MR image of the pelvis. Figure 2b: (a) Coronal T2-weighted (repetition time msec/echo time msec, 4574/86.5) MR image of the pelvis. (b) Axial T2-weighted (3000/85.4) MR image of the pelvis. Figure 3: Unenhanced axial fat-saturated T1-weighted (6.2/3.1) MR images. Figure 4: Coronal CT urogram. Figure 5: Image obtained at cystoscopy

The physicality of sound production on acoustic instruments

This thesis presents practical research into sound production on instruments, working collaboratively with players, in order to build an understanding of the sounds available. I have explored the way in which instrumental technique can be extended in such a way as to function as the basis for musical material. The function of ‘figuration’ has also be brought into question, by employing seemingly primitive, residual material pushed to such a degree that it is possible to hear what happens underneath a gesture. Research in this area has been conducted by, among others, Helmut Lachenmann and Rebecca Saunders; I am drawn to the way their work highlights the tangible quality of sound. The exploration of the physicality of sound production inevitably encounters the problem that the finished work becomes a catalogue of extended techniques. My research has drawn on the work of these composers and has attempted to resolve this problem by exploring the way in which texture can suggest ‘line’ and the structural implications of sculpting self-referential material through angular and polarized divisions. This facilitates a Braille-like reading of a sound’s progress by foregrounding a non-thematic sound-surface of resonance and decay. This takes a positive and active approach to the problems of musical language, by questioning the functions and expectations put upon music. The possible solutions have been worked through in a series of works for mixed chamber ensembles, in order to investigate the palette possibilities of fusing instruments in intimate settings.EThOS - Electronic Theses Online ServiceArts and Humanities Research CouncilGBUnited Kingdo