L3 - Pelvic Imaging Flashcards
PELVIC IMAGING MODALITIES
i) what are the two most commonly used modalities?
ii) name two adv and two disadv of MRI
iii) name two disadv for using CT in pelvic imaging
i) MRI and ultrasound
ii) adv = no ionising radiation and good soft tissue contrast
disadv = longer exam time and more expensive
iii) CT has poor soft tissue contrast and can get artefact from the pelvic girdle
THE MALE PELVIS
i) label A-I
ii) is the scan T1 or T2 weighted? which modality? which view?
iii) where is a common side for rectcal cancer to spread?
iv) what is the action of the obturator internus? where does it insert?
A = pubic symphysis, B = femoral head, C = prostate D = rectum, E = ischio-rectal fossae, F = obturator internus G = rectus sheath, H = bladder, I = seminal vesicle
ii) T1 weighted axial MRI
iii) rectal cancer can spread to ischio rectal fossa
iv) obturator internus = lateral rotation and abduct of hip
- inserts into greater troch of the femur
THE FEMALE PELVIS
i) what are the three layers of the uterus? label A-C
ii) how does the ovary appear on T2 weighted MRI? why?
iii) label 1-4
i) A = endometrium = innermost
B = junctional zone = bet endo and myomet
C = myometrium = muscle layer
ii) ovary appears bright white on T2 weight as it has fluid filled cysts (fluid is bright white on T2)
iii) 1 = ovary, 2 = bladder, 3 = cervix, 4 = rectum
SAGITTAL MRI
label 1-5
1 = cervix, 2 = rectum, 3 = bladder, 4 = uterus, 5 = vagina 6 = pubic symphysis
THE OVARY
i) which ligament is the fallopian tube contained within? name the four parts
ii) what may the person with scan A be experiencing? what may have caused this?
iii) what happens in a hysterosalpingogram? when is this most commonly used?
i) the broad ligament
- infundibulum (fimbrae), ampulla, isthmus, intramural (enters uterine cavity)
ii) infertility due to collapsed endomet cavity
- can happen post pelvic infection > scarring
iii) hysterosalpingogram involves injecting contrast into the uterine cavity
- can be used to investigate fertility (primary) when all other causes have been ruled out
THE PERITONEUM
i) name the two pouches made by peritoneal reflections in females - label A and B
ii) where does the peritoneum run in relation to the rectus sheath?
iii) which pouch is formed by peritoneal reflec in males?
iv) what can happen in the pouches during intra ab infection? name two situations this may happen and one complication that can arise from this?
v) which pouch is aka pouch of douglas?
i) vesico-uterine pouch = between bladder and uterus
recto-uterine pouch = between rectum and uterus
A = vesico uterine, B = recto uterine
ii) peritoneum runs under the rectus sheath
iii) males = vesicorectal pouch - between bladder and rectum
iv) fluid can pool in the pouches and cause abscess
- can be due to post op or pelvic inflam disease
- sepsis is a complication
v) rectouterine pouch = POD
PELVIC ULTRASOUND
i) name three advantages and two disadv
ii) name the two many approaches and what each may be used for
iii) what does a bladder full of urine aid?
iv) which type of US may be used for prostate imaging/biopsy in men?
i) adv = fast/cheap, no ionising rad, non invasive
disadv = operator dep and bone/gas may obscure image
ii) transabdominal - good at looking at pelvic strucs eg bladder
transvaginal - gynae assess for uterus/ovary
iii) bladder full of urine makes an acoustic window and is good at transmitting to structures behind it eg uterus
iv) trans rectal US
TYPES OF ULTRASOUND
i) what may a transabdo US be used for? is frequency and image resol low or high? best with full or empty bladder?
ii) is frequency and resolution of transvaginal US high or low? best with full or empty bladder?
iii) label tranvag US A-D
iv) name three roles of an antenatal US
i) transabdo for foetal imaging
- low freq and image resol
- best with a full bladder (acoustic window)
ii) transvag = high freq and resol
- best with empty bladder
iii) A = fundus of uterus, B = cervix, C = myometrium, D = endometrium
iv) look for congen abnorms, growth rate (bone length and estim weight) and expected delivery date
DUPLEX US
i) which system is it used to image?
ii) what does it measure overall?
iii) name four things it can assess
iv) name two pathological things that can be looked for
v) when may it be used?
i) vascular system
ii) measures the highest velocity in an artery
iii) can assess flow, stenosis, aneurysm and plaque
iv) can see turbulent flow (bruit) and post stenotic dilatation
v) may be used before/after vascular surgery
ANGIOGRAM
i) which type of contrast may be injected in a CT angio? how will it be injected?
ii) name three occassions a catheter angiogram may be used
iii) where is a catheter angio inserted? what is the name of the technique?
iv) what are the four steps of the above technique?
i) iodinated iv contrast through a peripheral cannula
ii) patients with peripheral vasc disease (look for blockage), emergency bleeding and in post partum haemmorhage (block arteries to uterus)
iii) insert catheter to femoral artery and feed to aorta/artery
- seldinger technique
iv) needle puncture by US guidance > insert guidewire > remove needle > adv catheter or sheath over wire
IMAGING THE VASCULAR SYSTEM
i) which technique is A-C, label 1
ii) which branch of the common iliac supplies a) pelvic organ/glutes, b) runs under inguinal lig and becomes femoral
iii) what level does the aorta bifurcate? what level does the IVC divide?
iv) which vessel does the right common iliac artery cross? what condition is this significant in?
i) A = duplex US, B = CT angiogram, C = catheter angiogram (1= iliac artery)
ii) int iliac to pelvis and glutess
ext illiac runs under ing lig and becomes femoral
iii) aorta bifurcates at L4 and IVC and L5
iv) right CI crosses the left common iliac vein which is important in may-thurner syndrome
MAY THURNER SYNDROME
i) what is it?
ii) what is it a rare cause of? which vessel is affected?
ii) what causes it?
iii) how is it treated? (3)
i) an iliac vein compression syndrome
ii) rare cause of DVT in the left iliac vein
ii) caused by the right common iliac artery running over the left iliac vein and pulsating/compressing it causing scarring
iii) treated by trying to open the vein, remove the DVT and stent
which condition is depicted here?
may thurner syndrome
ILIAC/FEMORAL ARTERIES
i) which organs does the anterior division of the int iliac supply?
ii) name the three branches of the post division of int iliac?
iii) what is depicted in picture A? what caused it
i) ant int iliac supplies pelvic organs
ii) post int iliac = iliolumbar, lateral sacral and superior gluteal
iii) pseudoaneurysm due to patient bleeding from an artery (collection of blood)
SAGITTAL MRI
label diagrams
A = bladder, B = pubic symphysis. C = prostate, D = sigmoid colon, E = rectum, F = seminal vesicle, G = anal canal
1 = rectouterine pouch (POD), 2 = vesicouterine pouch, 3 = vagina, 4 = perineum
