Imaging in Gynaecology Flashcards
Biophysics
US waves and frequency
Piezo-Electric crystals
Grows and shrinks depending on the voltage run through it
Running an alternative current through it causes it to vibrate at a high speed and to produce an US wave
Sound is then reflected back to the PE crystals converting sound into electrical energy and then photo energy
Doppler Waveform
Christian Johann Doppler
Doppler effect- shift between emitted and observed frequency of sound
Velocity and angle
Light moving away = red, light moving towards = blue
Blood cells – scatter – RBC
Endometrial: Uterus (Imaging in the normal menstrual cycle)
Shortly after menstruation, the endometrium appears as a thin white line
In the mid and late proliferative phase of the MC, the endometrium becomes thicker and manifests as a ‘triple-layer’ appearance
On the day before ovulation, the endometrium still has a ‘triple-layer’ appearance, but there is a thick white line surrounding it- this probably reflects some progesterone production from the dominant follicle
In the luteal phase, the endometrium is thick and homogenously hyperechoic (white)- echogenic
Ovarian- Follicle and Corpus Luteum
Early follicular phase = the follicles are small w less than 8mm in size and multiple
Mid-follicular phase = there is a dominant follicle ahead of the other follicles
Periovulatory follicle is about 17-23mm in size (ready to ovualte)
CL cystic or solid collapsed or full appearance w irregular edge and shadows w the cyst
Raised dopplers are classical- roughly day 21
Changes during the menstrual cycle
Doppler Wave form
Pulsed doppler pulsed echo system
Defines the rate at which data is collected
Resistance index: A-B/mean difference of the highest and lowest value divided by the mean in 1 cardiac cycle
Pulsatility index: A/B ratio indicated peripheral resistance
RI absent or reversal: increase peripheral resistance causes diminution and then loss of BF
3D and 4D
Coronal plane
Volume for review
TUI like MRI
SONOAVC
3D still image (dimensions)
4D: 3D in motion
Uterus issue to look our for:
ndometrial polyp = endometrial lining which has hypertrophied and has outgrown its endometrial attachment
No symptoms, bleeding between periods, history of miscarriage
If only lining = endometrial polyp
If there’s muscle = fibroid polyp
Fibroids = muscle lump
Cause heavy periods/bleeding between periods = fibroid is in the cavity
No symptoms if its outside the cavity
Uterine malformation
Location of pregnancy
SIS AND HYCOSY
see the appearance of polyp
- add saline liquid through a catheter: poly shows up
Hysteroscope
Camera used in the surgery of removing polyps
European society hysteroscopic classification of polyps
Type 0 = fibroid polyp
Type 1 = less than 50% within the myometrium
Type 2 = more than 50% within the myometrium
Uterus malformations
Arcuate uterus
The depth of the uterine muscle in the midline of the cavity indicates the degree of uterine septum or arcuate nucleus
Bicornuate uterus- both halves developed separately
Uterine septum- can be complete or partial
Usually cut the septum to increase the size of the cavity
If the septum is v muscular, don’t tend to do surgery
Unicornate uterus- one side didn’t develop
Uterine malformations often cause a breach presentation during pregnancy, resulting in an elective caesarean instead
Early Pregnancy
Main issues during pregnancy: sepsis, ectopic pregnancy
On US, ectopic = ‘bagel sign’ or ‘blob sign’
When it goes wrong
Cervical ectopic pregnancy- successfully treated w methotrexate (single dose, multiple dose, intra-amniotic). Sometimes treated with intra-amniotic KCl
LSCS scar ectopic pregnancy- most successfully treated w local methotrexate and/or KCl
Cornual/interstitial ectopic pregnancy- most treated w single dose methotrexate
Reasons for surgical management: pain, hemodynamically unstable, high hCG, viable ectopic pregnancy, large ectopic mass, hemoperitoneum
Sono-hysterography: should be used when an endometrial echo is not well visualised, or is not thin and distinct
Ovarian pathology: endometriosis, dermoid cyst, PCOS, cystadenoma, mucinous cyst
Endometriosis presentation = asymptomatic, pain before periods, difficulty conceiving, pain during sex
Can result in endometriotic cyst that fills w blood- ‘chocolate cyst’
Need to drain the blood and burn it off, but it means that part of the ovary is lost
When post-menopausal women have spotting, do an US and check endometrial lining- if thin and <4mm, not endometrial cancer. If thick and >5mm, then most likely endometrial cancer
A benign poly will just have 1 blood vessel, whereas a tumour will have many
Ultrasound in ART
Clinical application: assessment of uterus and ovaries, assessment of uterine cavity, tubal patency (hycosy), follicle growth, egg retrieval, embryo transfer
Luteal phase is constant- follicular phase is the one that varies e.g., PCOS
Progesterone makes endometrial mucus thick so the embryo can stick and implant
Transvaginal Ultrasound
Double thickness measurement of both endometrial
surfaces at the thickest point in the mid-sagittal view
* If fluid present: layers individually measured and summated
Sonohysterography
Should used when an endometrial
echo is not well visualized or is not thin and distinct
