Common Pelvic And Urinary MRI Flashcards
Zones of the prostate gland
Base, mid-gland, Apex
4 histological zones
- Anterior fibromuscular stromatolites
- Transitional zone (TZ) - surrounds the urethra (5% glandular tissue)
- central Zone (CZ =) - surrounds the ejactlatory ducts (20% glandular tissue)
-outer peripheral zone (PZ)(80% glandular tissue)
What is Prostate cancer and its rates within the PZ and TZ zones?
Uncontrolled division of glandular cells:
70-75% PZ
20-25% - TZ
Detection of Prostate cancer
Screening with PSA test - (PSA= prostate specific antigen)
DRE - rectal exam - hard irregular lumps in the prostate
Biopsy - Gleason score
Imaging to stage (NM, CT, MR)
Indications for prostate MRI
PSA > 4 ng/l
Abnormal DRE
Surveillance
What scale is used to grade prostate cancer?
Sequences assessed and each lesion graded on PI-RADs scale.
- 1 - 5 (1 very low to 5 very high likelihood of cancer)
PI - RADS = prostate imaging reporting and data system
What are the Sequences used for Prostate cancer?
T2 w - sag, cor and ax
DWI
T1W ax
T1 FS dynamic with gad contrast ax
How does a T2 prostate lesion appear?
Hypointesnse
What is Buscopan?
Antispasmodic
What are the Challenges of Prostate MRI?
Magnetic susceptibility - DWI
Motion artefact - peristalsis or respiration
What are the 2 parts of the Cervix?
what types of cells do they contain?
Internal os/ endocervix - columnar epithelial cells
External os / ectocervix - squamous epithelial cells
Between the two is the transformational zone - squamocolumnar cells
Where is cervical cancer usually found
Transformational zone
Cervical cancer
Most common in women < 45
Associated with HPV
Screening 25 - 64 every 3-5 years
Colposcopy/ biopsy
HPV vaccination - 2008
What are the Indications for cervix MRI?
Based on British gynaecological cancer society (BGCS) and RCR
- cytogically proven cancer
- response to chemo
- reoccurance
How many days post biopsy can we scan?
What are the cervix MRI protocol?
7-10 days post biopsy to allow for healing
T1W - to ashes para-aortic and pelvic lymph nodes - presence of hydronephrosis
T2w - assess size, position and local tissue invasion
What are the specific challenges of cervical imaging?
Biopsy trauma can mimic Ca
Positioning of T2w axial coronal obliques - due to the nature of uterus positions
What are the 3 layers of the Uterus ?
Perimetrium - double membrane continuous with abdominal peritoneum
Myometrium - thick layer of muscle, which expands during pregnancy
Endometrium - in a mucous membrane, most superficial layer is shed during menstruation
Endometrial cancer
- uncontrolled proliferation of the endometrium
- Most common, gynological cancer
- Most common imposter, menopausal women
- Increase prevalence due to obesity
- Symptoms, post menopause, bleeding
- symptomatic disease - no screening program
What are the indications for endometrial MRI?
Based on BGCS guidelines
- PMB - post-menopausal, bleeding
- confirmed endometrial cancer - to decide treatment options
- Staging to assess myometrial invasion and lymph nodes
- Advanced disease- avoid hysterectomy, if no possibility of cure
What are the protocols for Endometrial MRI?
T2W - to assess size position and local tissue invasion into myometrium, cervical stroma, parametric and Adnexa.
DWI - to asscess extent of myometrial invasion
T1FS - precontrast
T1FS - dynamic post contrast - to assess myometrium invasion
T1W ax - assess hilar abdominal and pelvic nodes
What are the Challenges of endometrial MRI?
Biopsy trauma mimic Ca
Position of T2w ax / coronal obliques due to position of uterus
What is Endometriosis?
Material tissue implants outside of the uterus, either with the female reproductive system or distant organs
: Such as bladder, bowel, lungs brain, skin
Most commonly on ovaries, where it forms endometriomas (chocolate cysts)
During the menstrual cycle, and the tissue breakdown and bleeds.
Patients experience , heavy bleeding, pelvic pain and infertility
What are the Indications for an MRI for Endometriosis?
NICE guidelines
Not used as a primary tool yet but to assess deep endometriosis involving bladder, bowel and ureter
Surgical planning
What are the protocols for endometriosis?
What are they assessing on the MRI?
T2w, T1W and T1FS
Asses for Adenomyosis, endometrial plaques/ foci, endometriomas, hydrosalpinx and hydronephrosis
What are the Specific challenges for diagnosing endometriosis?
Negative us and MRI can’t rule out endometriosis
Renal cancer
RCC - renal cell carcinoma - 9/10 cancers
primary malignant adenocarcinoma
Commonly from epithelium within the renal tubules of the medulla
- 70% - 80% clear cell (proximal convoluted tubules)
- 13% - 20% Papillary RCC (distal convoluted tubules)
How are Renal cancers diagnosed?
Usually by CT - lower cost and greater capacity compared to MRI
MRI - marginally better than CT as it can indicate subtype and presence of thrombus in renal vein/ IVC - expensive and less available
What are the indications for an RCC MRI?
Staging of RCC with venous invasion
When CT iodinated contrast can’t be used
Pregnancy
What are the MRI protocols for RCC?
T1W Ax - to observe primary tumour, venous invasion, lymph nodes involvement
T2w ax
T1wFS ax
T1FS ax post contrast ax - 20s, 50s, 80s
(20s - arterial supply to inform partial nephrectomy , 80 sec - nephrogenic phase)
T1W sag and cor
What are the Specific challenges of renal scanning?
Respiratory artefact
Metal artefact
Peristalsis
What are the causes of Renal artery stenosis?
How do we diagnose RAS?
75% - atherosclerosis
20 % - fibromuscular dysplasia
Diagnosis on MRI or CT
What is RAS - fibromuscular dysplasia?
The muscle and fibre tissues in the arteries thicken, causing the vessels to narrow- string of beads, appearances
Causing stenosis, aneurysms and dissections to small, medium sized arteries
Can lead to severe hypertension, ischaemic or haemorrhagic stroke
What are the Indications for renal artery MRI?
Hypertension that is resistant to medication or of late onset with no family history
Poor renal function
What are the Renal artery MRI protocols?
T2w HASTE
T1W FLASH 3D - pre and post con
Or TWIST - 3D MRA with gad which acquires multiple images through the arterial mixed and venous phases which can be reconstructed into MIPS
What does MIP stand for?
Maximum intensity projection
Rectal cancer facts
2nd most common cancer in uK
Affects males > females
Most commonly affects 60-80 years old
Screening program 60-74
Symptomatic - pain, blood in stools, change in bowel habit, anaemia
What is Rectal cancer?
Uncontrolled proliferation of epithelial cells (surface of mucosa)
98% adenocarcinomas which form from malignant transformation of polyps ( benign, adenomas)
Malignant cells invade layers of rectum, and can invade beyond to lymph nodes and distant organs, such as liver and lungs.
What are the indications for Rectal cancer MRI?
Staging local disease in upper rectal and sigmoid cancers
Surveillance
What are the Rectal cancer Protocols?
T2w sag - to measure distance from anal verge and length of tumour
T2w axial - to look for pelvic disease outside of the mesorectum
T2w ax oblique ( perpendicular to long axis of rectum) - to measure tumour and assess spread within the mesorectum( L5, S1)
T2w coronal oblique ( parallel to the long axis of the rectum) - to measure tumour and spread within the mesorectum ( L5 - S1)
Report to stage TNM
