Magnetic Resonance Imaging in the management of prostate cancer: What the Radiologists need to know?

Transcription

1 Magnetic Resonance Imaging in the management of prostate cancer: What the Radiologists need to know? Poster No.: C-0889 Congress: ECR 2014 Type: Educational Exhibit Authors: S. S. Deshpande, N. Sable, M. H. Thakur, G. K. Bakshi ; Mumbai, MAHARASHTRA/IN, Mumbai/IN Keywords: Neoplasia, Cancer, Imaging sequences, Diagnostic procedure, Contrast agent-intravenous, MR-Spectroscopy, MR-Diffusion/ Perfusion, MR, Pelvis, Genital / Reproductive system male DOI: /ecr2014/C-0889 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 50

2 Learning objectives To describe the normal MR anatomy of the prostate gland. To learn the staging and treatment of the prostate malignancy with the imaging findings those decide the management issues. To elaborate on the MRI protocol that gives the optimal information required by the clinicians. To portray the various imaging appearances of prostate malignancy and the role of different MRI sequences in the final radiological diagnosis Page 2 of 50

3 Background Prostate cancer is a common tumor with good clinical prognosis if diagnosed and treated early [1]. So early detection and accurate staging of the disease is mandatory for optimal disease management. Digital rectal examination (DRE) and Prostate Specific Antigen (PSA) have long been used as screening tools which raise the suspicion of prostate malignancy. Various radiological modalities contribute to Confirm the diagnosis Guidance for core biopsy for histopathological confirmation and Gleason grading Loco-regional staging of prostate malignancy- size of the tumor, lobes involved, extracapsular spread, neurovascular bundle involvement and seminal vesicle involvement. Nodal and distant metastases MRI is one of the modalities which can depict not only the morphological details but also functional characteristics of the tumor. For the appropriate interpretation of MRI performed for evaluation of clinically suspected cases of prostate malignancy, the radiologists should be aware of the Normal MR anatomy of prostate Staging of prostate cancer and hence the radiological features that change the stage of the disease and consequently the management The conventional and functional MRI in evaluation of the disease Page 3 of 50

4 Findings and procedure details Anatomy [2]: Prostate gland is conical in shape with its base abutting the bladder outlet cranially, while its apex abutting the urogenital diaphragm caudally. Anteriorly, it is separated from the pubic symphysis by the retropubic fat and periprostatic veins; while posteriorly it is separated from the rectum by the fascia of Denonvilliers (Figure 1). Fig. 1: Diagram of a Sagittal section to demonstrate the relations of prostate in the pelvis. Page 4 of 50

5 References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Prostate is composed of glandular and nonglandular tissue. The glandular prostate is divided into the transition zone (occupies 5%), central zone (occupies 25%) and the peripheral zone (occupies 70%) (Figure2). Fig. 2: Diagram showing the zonal anatomy of prostate- transition zone (TZ), central zone (CZ), peripheral zone (PZ) and the anterior fibromuscular stroma (FMS) with respect to the prostatic urethra (PU) and the ejaculatory ducts (ED). Page 5 of 50

6 References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN The glandular tissue is deficient anteriorly and is replaced by a thick fibromuscular stroma. The junction between the transition zone and the peripheral zone is marked by the surgical or the pseudocapsule. The true capsule surrounds the peripheral zone. The prostatic urethra courses through the anterior third of prostate. The ejaculatory ducts course through the central zone towards the verumontanum. The neurovascular bundles (NVB) are seen posterolateral to the peripheral zone, embedded in the periprostatic fat. MR appearance: On SE T1-weighted images, the zonal anatomy is not well demonstrated. The prostate shows homogeneous low to intermediate signal intensity (Figure 3). Page 6 of 50

7 Fig. 3: Axial T1 weighted image depicting the prostate gland (arrow) which shows low to intermediate signal intensity. The zonal anatomy of prostate is not well appreciated. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN The zonal anatomy is well appreciated on T2-weighted images (Figure 4 A, B). Fig. 4: Axial T2 weighted image showing the prostate gland. The zonal anatomy of prostate is well appreciated (A) Peripheral zone appears hyperintense (long arrow) as compared to the central gland (thick arrow). The true capsule appears as a hypointense rim (short arrow). The prostatic urethra is seen as a central hyperintense area with a hypointense rim (asterix). (B) Caudal axial T2 weighted image which shows prostatic urethra (long arrow) with anterior fibromuscular stroma (short arrow) (C) Seminal vesicles are seen as lobulated hyperintense structures with hypointense rim (arrow) References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN The normal peripheral zone appears hyperintense on T2 weighted images. The central and transition zones show similar signal intensity. Anatomical location forms the basis of their differentiation on MRI. They both show lower signal intensity as compared to the peripheral zone. The anterior fibromuscular band demonstrates homogenous low signal intensity. The prostatic capsule is seen as a thin rim of low signal intensity around the peripheral zone. The proximal urethra is rarely appreciated on MRI. The distal portion is seen as a low signal intensity ring at the apex. The ejaculatory ducts appear hyperintense running obliquely across the central gland. The seminal vesicles are multilobulated structures located postero-superior to the prostate which show hyperintense glandular tissue with hypointense rim. The NVB appears as a hypointense foci posterolateral to the prostate. The levator ani muscles demonstrate homogenous low to intermediate signal intensity as compared to the peripheral zone. Staging and treatment of prostate malignancy: Page 7 of 50

8 Change in the stage of the disease drastically changes the management decisions and hence, accurate staging of a tumor forms the basis of appropriate management. Prostate adenocarcinoma is commonly staged according to the TNM system (Figure 5) [3]. Fig. 5: TNM system for prostate cancer staging References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN The various management strategies those are available for treating prostate cancer are [4, 5, 6] Watchful waiting coupled with active surveillance Surgery Radiation therapy Chemotherapy Hormone therapy Biologic therapy Bisphosphonate therapy Page 8 of 50

9 Other techniques - High intensity focused ultrasound (HIFU), cryosurgery etc. Once accurately diagnosed and staged, the disease can be treated using appropriate treatment modalities, in various combinations at various stages. The treatment depends on the stage of the tumor, Gleason grade, PSA levels, age of the patient, the life expectancy and the other co-morbid conditions. Radiological evaluation: Primary tumor ('T') According to the staging system, the imaging features that need to be addressed in any MRI of the prostate are Detection, delineation and characterization of the lesion Extra capsular spread (ECS) Seminal vesicle (SV) involvement Adjacent organ involvement Detection, delineation and characterization of the lesion: PSA and DRE have long been the most accepted screening methods for prostate malignancy. Raised PSA levels or palpable abnormality on DRE are indications for further investigation with TRUS and guided biopsy. However the yield of the traditional sextant TRUS guided biopsy is not satisfactory [7-9]. Hence, MRI is indicated in cases of high clinical suspicion of malignancy and negative biopsy results. It not only helps to confirm the findings, but also can act as a localizing tool for directed biopsies required for Gleason grading. MRI can also accurately document loco-regional spread [5,6]. Conventional MRI: Prostatic adenocarcinoma predominantly arises in the peripheral zone. Conventional MRI sequences that are used are T1 and multi-planar T2 weighted images [6]. Page 9 of 50

10 T1 weighted images- predominantly used to distinguish post biopsy hemorrhage within the prostate which may mimic tumor on T2 weighted images. T2 weighted images- obtained in three orthogonal planes (axial, coronal and Sagittal). Prostatic adenocarcinoma appears hypointense on the background of the hyperintense peripheral zone (Figure 6). Fig. 6: (A) Axial and (B) Coronal T2 weighted images showing hypointense lesions(arrow)in the peripheral zone.these were found to be malignant on further biopsy evaluation. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN It is difficult to delineate the central gland tumors on conventional T2 weighted images. The imaging features which support central gland tumors are homogeneous low T2 signal intensity of the central gland, ill-defined edges of the suspicious lesion, deficient lowsignal-intensity rim commonly seen in association with BPH, infiltration of the prostatic urethra or the fibromuscular stroma, and lenticular shape [10, 11]. Further data that is contributed by T2W images - Extra capsular spread (ECS), Neurovascular bundle (NVB) involvement, Seminal vesicle (SV) and adjacent organ infiltration. Extra capsular spread (ECS): This changes the stage of the disease and hence the management significantly. Thus accurate communication of this detail to the clinician becomes mandatory. Table: The radiological signs of ECS [2, 6]: Page 10 of 50

11 Irregular capsular bulge ( Figure 7) Obliteration of the recto-prostatic angle ( Figure 8) Asymmetry of the neurovascular bundle Breech of the capsule with evidence of direct tumor extension ( Figure 9) Focal capsular retraction and thickening Broad (> 12 mm) capsular tumour contact (Figure 10) Page 11 of 50

12 Fig. 7: Axial T2 weighted image showing a well defined hypointense lesion involving the right lobe of prostate (arrow), causing focal capsular bulge. HPR proved extracapsular spread. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Fig. 8: Axial T2 weighted image showing obliteration of the recto-prostatic angle by the tumor suggestive of extra-capsular spread of the tumor. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Page 12 of 50

13 Fig. 9: Axial T2 weighted image showing breech of the hypointense prostate capsule with direct extracapsular extension of the tumor References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Page 13 of 50

14 Fig. 10: Axial T2 weighted image showing hypointense lesion in the right peripheral zone with wide tumor-capsule contact (arrow). Histopathological evaluation showed ECS. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Seminal vesicular invasion Table: The radiological signs of seminal vesicle involvement [2]: Direct tumour extension into and around the seminal vesicles ( Figure 11) Tumour extension along the ejaculatory ducts into the seminal vesicles (Figure 12 )they appear of low signal intensity on T2-weighted images. Page 14 of 50

15 Fig. 11: Axial T2 weighted image showing hypointense right seminal vesicle (arrow) in a case of prostate cancer suggestive of seminal vesicle invasion. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Page 15 of 50

16 Fig. 12: Coronal T2 weighted image showing extension of the prostate tumor into the left seminal vesicle (arrow)suggestive of seminal vesicle invasion. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Adjacent organ involvement ( Figure 13 ) [2]: Break in the T2 hypointense line of the muscular wall Direct extension of the tumor visualized into the organ Page 16 of 50

17 Fig. 13: Sagittal T2 weighted image showing a large lobulated prostate mass with obvious extracapsular spread causing anterior rectal wall infiltration (arrow). References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Functional MRI techniques: MRI has a good sensitivity; however the specificity for prostate malignancy is low [6]. This is because; few other conditions also lead to T2 hypointense lesions in the peripheral zone. They are - post-biopsy hemorrhage, post-radiation or hormone therapy, post-inflammatory changes and dystrophic changes [5, 6]. It is also difficult to detect the lesions arising from the central or transition zone on SE T2 weighted images since they also show low to intermediate signal Page 17 of 50

18 intensity on T2W images. Also, the heterogeneity of the central and transition zone increases as the age advances due to BPH [12]. Prostatic malignancy being as disease of the old, this forms a confounding factor. Due to these issues, we use various functional MRI techniques to compliment the conventional MRI and improve diagnostic accuracy since no single sequence is sufficient to completely characterize prostate malignancy. They also, to some extent, behave as surrogate markers of the aggressiveness of the tumor and hence aid in risk stratification and determining the prognosis. Dynamic post contrast (DCE) MRI Diffusion weighted imaging Spectroscopy Dynamic post contrast (DCE) MRI: This method capitalizes on 'tumor neo-angiogenesis'. The tumor vessels are more permeable, heterogeneous and disorganized. As a result, prostate cancer shows early and more marked enhancement as compared to the normal prostate tissue and early wash out. These characteristics of the tumor tissue showing early and high peak enhancement with early wash out, aids in evaluating the presence and extent of the primary tumor and recurrence. DCE techniques use 3D T1-weighted fast spoiled gradient-echo MRI sequences after administration of a bolus of IV contrast agent. 3D image data is obtained sequentially every few seconds for up to 5#10 minutes. Ideally, the acquisitions should be obtained approximately every 5 seconds to allow the detection of early enhancement; to a maximum of 15 seconds. Image analysis can be done in three ways- Qualitative, semi-quantitative and quantitative (Figure 14) [11]. Page 18 of 50

19 Fig. 14: (A) Axial T2 weighted image showing hypointense lesions in both the prostatic lobes, predominantly on the left (arrow). (B), (C) and (D) Representative early DCE images showing early and marked enhancement of the prostatic lesions (arrow). This is indicative of malignant lesions. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Qualitative- or visual analysis of the post contrast serial dynamic acquisition. The tumor shows early and pronounced enhancement with early wash out as compared to the slow and progressive enhancement of normal prostate tissue. Semi-quantitative- or Curveology The images are post processed to acquire the time-enhancement curves. Type I-- persistent and progressive increase in enhancement Type II--plateau type Type III-- rapid enhancement and rapid wash out- considered the most suspicious for prostate cancer, however, type 1 and 2 curves can be found in prostate cancer as well Page 19 of 50

20 Quantitative- calculation of K trans and k ep Both these parameters can be acquired by post-processing software. They are increased in malignant tissue. Due to the complexity of the acquisition and analysis of the fully quantitative data, the qualitative and the semi-quantitative methods are more commonly used. Diffusion weighted imagingthis method capitalizes on the reduction in the diffusion of water protons in malignancy. As a results, the infiltrated areas show restricted diffusion on DWI with reduced ADC values (Figure 15) [13]. Page 20 of 50

21 Fig. 15: (A) Diffusion weighted image with (B) ADC map showing restricted diffusion (arrows) in a lesion noted in the left lobe of prostate on (C) T2 weighted image. This is indicative of malignant lesion. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN This especially helps in central gland tumors which can camouflage with the surrounding gland on conventional MRI (Figure 16). Page 21 of 50

22 Fig. 16: (A) Axial T2 weighted image showing central gland lesion which is well depicted on (B) DWI and (C) ADC images- which show restricted diffusion and reduced ADC values respectively. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Also, the ADC values have been correlated with the Gleason score and tumor volume [13]. There has been a significant overlap in the various groups due to which a consistent classification of the tumors according to the aggressiveness and respective ADC values is not possible. Despite this, the ADC values do form a surrogate marker of the aggressiveness of the tumor and the total tumor volume [13]. Spectroscopy: Spectroscopy capitalizes on the changes in the metabolites in the tumor as compared to the normal prostate tissue. Various techniques are applied to acquire spectroscopic data, the commonest used is the chemical shift imaging. Multivoxel data can be acquired in single or multiple sections (Figure 17). Page 22 of 50

23 Fig. 17: Multivoxel Spectroscopy showing metabolic map References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN The metabolites that are analyzed in prostate spectroscopy are- choline (3.2 ppm), creatine (3 ppm), polyamines (3.1 ppm) and citrate (2.6ppm). The creatine peak is close to that of choline, and hence the ratio of Choline + creatine: citrate (Ch+Cr/Ci) is used in practice. The normal prostate gland produces high levels of citrate and polyamines. In prostate tumors, the citrate and polyamines are decreased, while the choline increases due to increased cell turnover (Figure 18) [8]. Page 23 of 50

24 Fig. 18: Spectrum from a representative voxel showing increase in Ch: Ci and Ch+Cr: Ci ratio References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Decreased polyamines and increased Ch: Ci and Ch+Cr: Ci ratio is highly suspicious of prostate cancer. The metabolic maps obtained by post processing technique depict the distribution of the metabolic changes and hence the extent of involvement of the prostate and the locoregional spread of the disease (Figure 19) [8]. Page 24 of 50

25 Fig. 19: Multivoxel Spectroscopy showing localizing image and the metabolic maps showing the distribution of the metabolic changes and hence the extent of involvement of the prostate References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN It gives an objective evidence and so reduces the inter-observer variability. As DWI, linear correlation has been found between the aggressiveness of the tumor and increasing choline and decreasing citrate levels [8]. Nodal involvement (N): Page 25 of 50

26 The involvement of pelvic nodes is diagnosed when pelvic lymph nodes are larger than 10 mm (Figure 20). Fig. 20: (A) Axial T2 weighted (B) Axial post contrast T1 weighted image showing enlarged right common iliac node References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN CT and MRI have similar sensitivities to detect pelvic lymph nodes. The sensitivity and specificity of MRI for detection of nodal metastases was found to be 36% and 97% respectively [14]. Newer techniques like using lymphotropic superparamagnetic nanoparticles have improved the accuracy of detection of nodal metastases [15]. Metastases (M): The commonest site of metastases from prostate cancer is the bones. Prostate cancer commonly leads to sclerotic bone lesions. Bone scintigraphy is generally used to evaluate for the same. On MRI, characteristic sclerotic prostate metastases are seen as hypointense osseous lesions on both T1 and T2 weighted images (Figure 21). Page 26 of 50

27 Fig. 21: Axial (A) T1 weighted (B)T2 weighted (C) Post contrast T1 weighted image showing focal lesions in the left pubic bone and the left femoral neck suggestive of metastases. References: DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL Mumbai/IN Visceral metastases too can be detected on abdomino-pelvic MRI. Page 27 of 50

28 Images for this section: Fig. 1: Diagram of a Sagittal section to demonstrate the relations of prostate in the pelvis. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 28 of 50

29 Fig. 2: Diagram showing the zonal anatomy of prostate- transition zone (TZ), central zone (CZ), peripheral zone (PZ) and the anterior fibromuscular stroma (FMS) with respect to the prostatic urethra (PU) and the ejaculatory ducts (ED). DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 29 of 50

30 Fig. 3: Axial T1 weighted image depicting the prostate gland (arrow) which shows low to intermediate signal intensity. The zonal anatomy of prostate is not well appreciated. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Fig. 4: Axial T2 weighted image showing the prostate gland. The zonal anatomy of prostate is well appreciated (A) Peripheral zone appears hyperintense (long arrow) as compared to the central gland (thick arrow). The true capsule appears as a hypointense rim (short arrow). The prostatic urethra is seen as a central hyperintense area with a Page 30 of 50

31 hypointense rim (asterix). (B) Caudal axial T2 weighted image which shows prostatic urethra (long arrow) with anterior fibromuscular stroma (short arrow) (C) Seminal vesicles are seen as lobulated hyperintense structures with hypointense rim (arrow) DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Fig. 5: TNM system for prostate cancer staging DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 31 of 50

32 Fig. 6: (A) Axial and (B) Coronal T2 weighted images showing hypointense lesions(arrow)in the peripheral zone.these were found to be malignant on further biopsy evaluation. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 32 of 50

33 Fig. 7: Axial T2 weighted image showing a well defined hypointense lesion involving the right lobe of prostate (arrow), causing focal capsular bulge. HPR proved extracapsular spread. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 33 of 50

34 Fig. 8: Axial T2 weighted image showing obliteration of the recto-prostatic angle by the tumor suggestive of extra-capsular spread of the tumor. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 34 of 50

35 Fig. 9: Axial T2 weighted image showing breech of the hypointense prostate capsule with direct extracapsular extension of the tumor DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 35 of 50

36 Fig. 10: Axial T2 weighted image showing hypointense lesion in the right peripheral zone with wide tumor-capsule contact (arrow). Histopathological evaluation showed ECS. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 36 of 50

37 Fig. 11: Axial T2 weighted image showing hypointense right seminal vesicle (arrow) in a case of prostate cancer suggestive of seminal vesicle invasion. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 37 of 50

38 Fig. 12: Coronal T2 weighted image showing extension of the prostate tumor into the left seminal vesicle (arrow)suggestive of seminal vesicle invasion. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 38 of 50

39 Fig. 13: Sagittal T2 weighted image showing a large lobulated prostate mass with obvious extracapsular spread causing anterior rectal wall infiltration (arrow). DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 39 of 50

40 Fig. 14: (A) Axial T2 weighted image showing hypointense lesions in both the prostatic lobes, predominantly on the left (arrow). (B), (C) and (D) Representative early DCE images showing early and marked enhancement of the prostatic lesions (arrow). This is indicative of malignant lesions. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 40 of 50

41 Fig. 15: (A) Diffusion weighted image with (B) ADC map showing restricted diffusion (arrows) in a lesion noted in the left lobe of prostate on (C) T2 weighted image. This is indicative of malignant lesion. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 41 of 50

42 Fig. 16: (A) Axial T2 weighted image showing central gland lesion which is well depicted on (B) DWI and (C) ADC images- which show restricted diffusion and reduced ADC values respectively. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 42 of 50

43 Fig. 17: Multivoxel Spectroscopy showing metabolic map DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 43 of 50

44 Fig. 18: Spectrum from a representative voxel showing increase in Ch: Ci and Ch+Cr: Ci ratio DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 44 of 50

45 Fig. 19: Multivoxel Spectroscopy showing localizing image and the metabolic maps showing the distribution of the metabolic changes and hence the extent of involvement of the prostate DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 45 of 50

46 Fig. 20: (A) Axial T2 weighted (B) Axial post contrast T1 weighted image showing enlarged right common iliac node DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Fig. 21: Axial (A) T1 weighted (B)T2 weighted (C) Post contrast T1 weighted image showing focal lesions in the left pubic bone and the left femoral neck suggestive of metastases. DEPARTMENT OF RADIODIAGNOSIS, TATA MEMORIAL HOSPITAL - Mumbai/IN Page 46 of 50

47 Conclusion MRI is an extremely useful modality for evaluation of prostate cancer at various steps of patient management. Conventional MRI has a good sensitivity but low specificity for detection of malignancy. The various limitations of conventional MRI are overcome largely by the newer functional MRI techniques. Multi-parametric MRI contributes to the diagnosis, extent evaluation and follow up of prostate cancer. Hence, the radiologists should be aware of the imaging techniques, radiological appearances and the image interpretation of the conventional and the functional MRI sequences. Page 47 of 50

48 Personal information S.S.Deshpande -Department of Radiodiagnosis, Tata Memorial Hospital, Dr. E. Borges Road, Parel, Mumbai , India. N.Sable - Department of Radiodiagnosis, Tata Memorial Hospital, Dr. E. Borges Road, Parel, Mumbai , India. M.H.Thakur - Department of Radiodiagnosis, Tata Memorial Hospital, Dr. E. Borges Road, Parel, Mumbai , India. G.K.Bakshi - Department of Surgical Oncology, Tata Memorial Hospital, Dr. E. Borges Road, Parel, Mumbai , India. Page 48 of 50

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50 15. Harisinghani MG, Barentsz J, Hahn PF et al. Noninvasive detection of clinically occult lymph-node metastases in prostate cancer. N Engl J Med Jun 19; 348(25): Page 50 of 50