1. MR IMAGING IN PROSTATE CANCER
A REVIEW OF DEPARTMENTAL CASES
Sarbesh Tiwari
2. INTRODUCTION
2nd most common malignant tumor in male.
95% are adenocarcinoma
Higher incidence in African Americans, incidence
raising in India
Age : 6th to 7th decade.
Symptoms: Dysuria, hematuria, urgency+/‐
frequency of micturition, bone pain
Diagnosis: Combination of DRE & PSA.
Confirmation of diagnosis-
Transrectal biopsy under Ultrasound guidance
5. ZONAL DISTRIBUTION OF PROSTATE CANCER
70 % prostate CA ------ In Peripheral Zone of Prostate
20 % prostate CA ------ In Transitional Zone of Prostate
10 % prostate CA ------ In Transitional Zone of Prostate
6. NORMAL MRI APPEARANCE
OF PROSTATE
Normal prostate has homogenous low signal
on T1WI
Zonal anatomy is best demonstrated on T2WI
Comprise of low signal central zone and
higher signal peripheral zone
TZ and CZ appears similar in SI and loosely
termed the central gland
8. MR IMAGING IN PROSTATE CA
INDICATION –
To stage the extent of prostate cancer once the
diagnosis is established
To identify the presence of recurrent disease
following treatment
Persistent raised PSA with repeated negative
TRUS biopsies.
MRI is not used in the primary diagnosis of prostate
cancer. This is usually established following biopsy at
TRUS
9. MR IMAGING PROTOCOL
MRI is usually performed on 1.5T or 3T MRI using
endorectal and pelvic phase array coil.
Standard Sequences :
1. Axial T1WI of pelvis
2. Axial + Sagittal + Coronal T2WI
3. MR Spectroscopy of selected volume of prostate
Others,
4. Diffusion Weighted Imaging
5. Dynamic contrast enhanced MRI.
10. CONVENTIONAL MRI FINDINGS
TIWI : Tumor is isointense relative to gland
T2WI : Tumor appears as a region of low signal
intensity within normal high signal peripheral
zone
Detection of extra capsular extension:
1. Asymmetry into neurovascular bundle
2. Obliteration of recto-prostatic angle
3. Irregular bulging or breech of prostate capsule
4. Invasion of bladder / rectum / seminal vesicle.
11. MRI FINDINGS CONTD…
Diffusion Weighted Imaging :
Restricted diffusion with reduced ADC value.
: Increased cellularity of malignant
lesions, with reduction of the extracellular space and
restriction of the motion of a larger portion of water
molecules to the intracellular space
Dynamic contrast enhanced MRI :
Early, rapid, and intense enhancement with quick
washout of contrast material
: Increased tumor neovascularsation
and thus increased micro vascular density as
compared to normal prostate.
12. MR SPECTROSCOPY OF
PROSTATE
NORMAL METABOLITE OF PROSTATE
Citrate : Produced by normal epithelial cells
of prostate
Normal Peak at 2.6 ppm
Choline : Precursor of phospholipids cell
membrane
Normal Peak at 3.2 ppm
Creatine : Involved in cellular energy
Normal peak at 3 ppm
14. MR SPECTROSCOPY OF
PROSTATE
Classic spectral signature of prostate cancer
consists of increased choline and decreased citrate
Ratio of (Choline + creatine)/ Citrate is usually
measured.
Normal range : 0.22 +/- 0.013, range upto 0.5.
Lower values for the Cho+cr /Cit ratio in the
peripheral areas than in the central glands.
Choline / creatine to citrate ratios:
> 0.5 : suspicious
> 1 : very suspicious
> 2 : abnormal
17. Case 1:
Clinical Detail : A 69 yrs old patient with post TURP status and biopsy
proven adenocarcinoma, presented for MR evaluation and staging of
the disease.
T1WI Axial T1WI Sagittal
20. DIAGNOSIS
PROSTATIC CA WITH EXTRACAPSULAR
EXTENSION INTO LEFT SEMINAL VESICAL
WITHOUT ANY LYMPHADENOPATHY.
BLADDER WALL HYPERTROPHY DUE TO
PREVIOUS BOO.
21. CASE 2
•56 yrs old male presenting with
difficulty in micturition, poor
urinary stream and back pain
• Raised serum PSA- 20ng/ml
T2WI - Axial
T2WI - Axial T2WI - Axial
25. DIAGNOSIS
Prostate ca arising from the peripheral zone
with extra capsular extension into left
posterolateral periprostatic fat with infiltration
of anterior rectal wall.
Associated secondary deposits noted in
sacrum and lumbar vertebra
26. CASE 3
62 yrs old male presenting with urgency and increased frequency of
micturition with pain in left hip joint
T2WI : Axial
27.
28.
29. DIAGNOSIS
BENIGN PROSTATIC HYPERPLASIA WITH
NORMAL SPECTROSCOPIC FINDINGS.
UNILATERAL PAGETS DISEASE OF LEFT
ILLIAC BONE.
30. CONCLUSION
MRI serves as a powerful modality for
localization and staging of prostate cancer
Non ionizing and non invasive.
Excellent soft tissue resolution, allows better
delineation of primary tumor and nearby
extension.
Combination MR + MRS: Sensitivity 91%
Specificity 95%
31. REFERANCE
1. David Bonekamp, Michael A. Jacobs et.al Advancements in
MR Imaging of the Prostate: From Diagnosis to Interventions.
RadioGraphics 2011;31:677–703
2. Textbook of radiology and imaging . Volume 2 David Sutton 7th
edition.
Notes de l'éditeur
Prostate cancer generally refers to adenocarcinoma of the prostate, which accounts for more than 98% of all prostate cancers. Less common prostatic malignancies include neuroendocrine tumors, squamous tumors, sarcomas, and transitional cell carcinomas.The only established risk factors for prostate cancer are age, race/ethinicity, and family history of prostate cancer.
In the axial plane, the prostate is divided into four zones: (a)the anterior fibromuscular stroma, which contains no glandular tissue; (b) the transition zone surrounding the urethra, which contains 5% of the glandular tissue; (c)the central zone, which contains 20% of the glandular tissue; and (d)the outer peripheral zone, which contains 70%–80% of the glandular tissue.
The prostate is supplied by branches from the inferior vesical, middle rectal and internal pedendal arteries. Rich plexus of vein are present to the side and base of prostate which communicates freely with internal pudendal and vertebral venous plexus, these ate valveless veins.
At the base of bladder: The anterior fibromuscular stroma (arrow) consists of nonglandular tissue and appears dark. Note the symmetric homogeneous muscular stroma layer (arrowheads) in the posterior prostate baseMidprostate level : Homogeneously bright peripheral zone (arrowheads) surrounding the central gland (white arrows). The central gland is composed of the transition zone and central zone, which cannot be resolved at imaging. Therefore, they are referred to jointly as the central gland. Note theneurovascular bundles at the 5-o’clock and 7-o’clock positions (black arrows).At prostate apex : The homogeneous peripheral zone (arrowheads) surrounding the urethra (U). Note that the volume of the peripheral zone increases from thebase to the apex.
Benign tissues in theperipheral zone show hyperintense signals in T2 weightedimaging, whereas malignant changes show hypointensesignals, of which the reason could be the cellular density aswell as the malfunction of the gland when the malignantchange had occurred
MR spectroscopic spectrum, obtained at 1.5 T shows a high citrate (Ci)peak (resonance at 2.6 ppm) and a low choline (Ch)peak (resonance at 3.2 ppm), characteristics of benign tissue. The choline and creatine (Cr)peaks are overlapping.At 3 T : Good separation of the choline (Cho)and creatine (Cr)peaks at higher magnetic field strength. The spectrum is normal, with a high concentration of citrate (Ci)and low concentration of choline.
