1. Body CT Modules: CT of the Ovaries and Uterus Sean Stanley MS3 OHSU Fall 2006

2. Sources CT of the Ovaries and Uterus Siddall KA. Multidetector CT of the female pelvis. Radiol Clin North Am. 01-NOV-2005; 43(6): 1097-118 Casillas J, Joseph RC, Guerra JJ Jr. CT appearance of uterine leiomyomas. Radiographics. 1990 Nov;10(6):999-1007. Foshager MC, Walsh JW. CT anatomy of the female pelvis: a second look. Radiographics. 1994 Jan;14(1):51-64; Outwater EK, Siegelman ES, Hunt JL. Ovarian teratomas: tumor types and imaging characteristics. Radiographics. 2001 Mar-Apr;21(2):475-90. Pannu, HK, et al. MD CT Evaluation of Cervical Cancer: Spectrum of Disease. Radiographics 2001; 21:1155–1168 Rha SE, et al. CT and MR imaging features of adnexal torsion. Radiographics. 2002 Mar- Apr;22(2):283-94. Roberts JL, Dalen K, Bosanko CM, Jafir SZ. CT in abdominal and pelvic trauma. Radiographics. 1993 Jul;13(4):735-52. Roobolamini, SA. Imaging of Pregnancy-related Complications. Radiographics 1993; 13:753-770. Saksouk FA, Johnson SC. Recognition of the ovaries and ovarian origin of pelvic masses with CT. Radiographics. 2004 Oct;24 Suppl 1:S133-46. Sam JW, Jacobs JE, Birnbaum BA. Spectrum of CT findings in acute pyogenic pelvic inflammatory disease. Radiographics. 2002 Nov-Dec;22(6):1327-34. Yang DM. Retroperitoneal cystic masses: CT, clinical, and pathologic findings and literature review. Radiographics. 2004 Sep-Oct;24(5):1353-65. Buy, J-N, et al. Cystic Teratoma of the Ovary: CT Detection. Radiology 1989; 171:697-701

3. Purpose of this Presentation Familiarize the student with looking at the amorphous world of CT-visualized pelvic anatomy. Familiarize the student with CT-visualized pelvic anatomical changes over the female lifecourse. Expose the student to a few common pathologies one might see on a pelvic CT. Give student practice using “CT speak” and the “radiology approach”. **Caveats: it would probably be best to come to this presentation knowing a few basics about CT and about general anatomy. If you have never seen a CT or pelvic anatomy, check out some other basic resources first.

4. Table of Contents Normal Anatomy Anatomic Change Over the Lifecourse Example Pathologies –Non-neoplasm –Neoplasms CT of the Ovaries and Uterus Discerning pelvic pathology from pelvic anatomy can be as hard as separating the weeds from the flowers in this field. Alpine Meadow, Mt Hood

5. Quick review of normal anatomy! Ovary Fallopian Tube Uterus Cervix Vaginal Canal CT of the Ovaries and Uterus BUT THAT’S JUST A DRAWING!! Normal Anatomy

6. Quick review of normal anatomy! Uterus Fallopian Tube Ovary Cervix (out of plane) Vaginal Canal (out of plane) CT of the Ovaries and Uterus Here’s the real thing! But unless you’re a surgeon, you’ll never see this.

7. Normal Anatomy Ovaries Fallopian Tubes Uterus Cervix Vaginal Canal CT of the Ovaries and Uterus This is what you’ll see: a normal axial pelvic CT. Each image is a visual slice through the pelvis R L

8. Normal Anatomy Ovaries Fallopian Tubes Uterus Cervix Vaginal Canal CT of the Ovaries and Uterus R L Which basically yields a radiographic visualization of pelvic anatomy.

9. Normal Anatomy Ovaries: -paired organs -ovoid/almond shaped -normally up to 4cm in length -lie on either side of the uterus -variable size/density depending on what’s going on hormonally a) fluid density (like blood) b) soft-tissue density (like uterus) c) physiologic cysts (fluid with a border around it) -don’t enhance greatly with contrast CT of the Ovaries and Uterus R L These ovaries are relatively easy to see. Many times they are not so easy to see, as they can be displaced by the mobile abdominal contents or other masses. Look at lateral surfaces of uterus, up and down through planes to find them!

10. Normal Anatomy Fallopian Tubes (oviducts): -normally difficult to visualize on CT, unless pathology -project from lateral aspect of ovaries to uterine fundus -Soft-tissue density (usually similar to uterine tissue) -0.1 to 0.5cm in diameter at isthmus -1 cm in diameter at ampulla CT of the Ovaries and Uterus R L Hmmm. A bit harder to find?

11. Normal Anatomy CT of the Ovaries and Uterus Uterus: -pear-shaped -about the size of human fist (8x5x2.5cm) -soft tissue density (it’s mostly a big muscle - compare to pelvic muscle.) -triangular endometrial cavity within (fluid filled/density), viewed in only certain planes -varies in size/density depending on age/parity of woman R L Don’t confuse this with the uterus, it’s the bladder, note the density -> fluid density (urine).

12. Flowers at Mt.Hood Are you starting to discern things? You must learn how to look before you can see.

13. The Approach During the “Lifecourse” and “Pathologies” parts of this presentation we will use a repetitive 3- slide approach to each CT image. Slide a: Describe what you see (using CT terminology - “density”, “mass”, “heterogeneous”, and other words that lead to understanding without jumping to a diagnosis - CT is an aid to diagnosis, to be weighed alongside clinical and other lab data, not necessarily a diagnosis clincher.) Slide b: Read an example description, and brainstorm possible diagnoses that could present radiographically like that given description. Slide c: Find out the answer and read a bit about it! CT of the Ovaries and Uterus

14. The Approach A quick CT terminology reference: (CT is all about description - you can’t really tell what something is by one glance at a CT, but you can tell how it looks!) Attenuation (density) –Fat Attenuation (“fat density” - same density as fat on CT) –Fluid attenuation (same density as fluid on CT - kind of nonspecific - better to say “blood attenuation”[a little denser than average fluid due to cellular contents] or “water attenuation”[a little less dense than average fluid due to lack of cellular or proteinaceous content]) –Soft-tissue attenuation (same density as muscle on CT) –Bone attenuation (same density as bone on CT) Contents: Heterogeneous v. Homogenous Wall: Thin-walled v. Thick-walled Border: Well-circumscribed v. Indistinct Borders Internal borders: Septated External Contour: Smooth v. Lobulated (lobed) Path: Tortuous (serpiginous) Size: enlarged v. atrophied Contrast: enhancing (lights up with contrast) v. non-enhancing (doesn’t) Location –Absolute - “in the cervical canal” –Relative - “posterior to the left ovary”, “medial to the right sacral wing” CT of the Ovaries and Uterus

15. Normal Anatomic Change Over the Female Lifecourse Because the ovaries and uterus are part of the reproductive system, their function changes as the individual matures and ages. Functional changes are reflected in the anatomy as visualized by CT. CT of the Ovaries and Uterus

16. Lifecourse - case 1a Describe what you see inside the outline. CT of the Ovaries and Uterus 4 year old This is where you should say, “I see a small soft-tissue density uterine tissue in the mid- pelvis, between a bladder filled with homogeneous fluid density…blah blah blah” Normal Anatomic Change Over the Female Lifecourse

17. Lifecourse - case 1b Sample Description: - “Narrow strip of soft-tissue attenuation uterine tissue, nestled between a normal fluid-attenuated bladder (‘b’), and a normal stool-filled rectum (‘r’). Oviducts and Ovaries are indistinguishable from soft-tissue density uterus.” CT of the Ovaries and Uterus b r 4 year old Why might the uterus look that way? Normal Anatomic Change Over the Female Lifecourse

18. Lifecourse - case 1c “Premenarchal Stage” -OVARIES: :: are 1/3 of adult size (therefore difficult to visualize) :: have less mature follicles, therefore are more dense - closer to soft-tissue than fluid :: if visualized, ovaries can have normal microcysts up to 0.9cm -UTERUS: :: small :: non-engorged, therefore enhances less with contrast CT of the Ovaries and Uterus 4 year old uterus Normal Anatomic Change Over the Female Lifecourse

19. Lifecourse - case 2a Describe what you see. CT of the Ovaries and Uterus 33 year old Again, here is where you should say, “I see a larger soft-tissue density uterine tissue in the mid-pelvis with some regions of hyperdensity…etc and so forth” Normal Anatomic Change Over the Female Lifecourse

20. CT of the Ovaries and Uterus 33 year old Lifecourse - case 2b Sample Description: - “Engorged, greater-than-soft-tissue- attenuation, contrast-enhancing uterine tissue, flanked by normal sized ovaries having some heterogeneities of fluid- or soft-tissue attenuation.” Why might the uterus and ovaries look that way? Normal Anatomic Change Over the Female Lifecourse

21. Lifecourse - case 2c “Premenstrual/Menstrual Stage” -UTERUS: :: enlarges to more globular shape, due to endometrial proliferation :: becomes more vascular (note higher attenuation than pelvic muscle) -OVARIES: :: enlarge to a length of up to 7cm. :: still consist of normal ovarian tissue (just possibly more of it!) CT of the Ovaries and Uterus 33 year old Normal Anatomic Change Over the Female Lifecourse

22. Lifecourse - case 3a Describe what you see. CT of the Ovaries and Uterus Normal Anatomic Change Over the Female Lifecourse

23. CT of the Ovaries and Uterus Lifecourse - case 3b Sample Description: -“highly dilated uterine tissue of mildly contrast-enhancing soft-tissue density, containing at its center a cavity mainly of fluid-density attenuation, but containing some peripheral regions of heterogeneously enhancing soft- tissue attenuation and amorphous central foci of bone-attenuation.” Why might the uterus look that way? Normal Anatomic Change Over the Female Lifecourse

24. Lifecourse - case 3c “Parous/Pregnant” Stage: (it’s a baby!) -UTERUS: :: the uterine cavity enlarges and is filled with fetal material and amniotic fluid. :: placenta is visible at the rim of uterine endometrium, and has the attenuation somewhere in between soft tissue and fluid/blood (think about the purpose of the placenta!) CT of the Ovaries and Uterus Normal Anatomic Change Over the Female Lifecourse

25. Lifecourse - case 4a Describe what you see. CT of the Ovaries and Uterus 27 year old Normal Anatomic Change Over the Female Lifecourse

26. CT of the Ovaries and Uterus Lifecourse - case 4b Sample Description: -“enlarged, heterogeneous uterine tissue of soft-tissue attenuation without general contrast- enhancement, but with peripheral scattered regions of enhancement” 27 year old Why might the uterus look that way? Normal Anatomic Change Over the Female Lifecourse

27. Lifecourse - case 4c “Post-partum stage” (She just had a baby!) -UTERUS: :: enlarged, avg size of 9x12x14cm. :: may still have engorged vessels. :: small amounts of intrauterine fluid or blood are normal in the first 24 hrs post- delivery :: small amounts of intrauterine air occurs in ~25% of post-partum women :: Uterine size returns to normal in 6-8 weeks after delivery CT of the Ovaries and Uterus Here’s another post-partum uterus, note the small amount of free air 27 year old Normal Anatomic Change Over the Female Lifecourse

28. Lifecourse - case 5a Describe what you see. CT of the Ovaries and Uterus 66 year old Normal Anatomic Change Over the Female Lifecourse

29. CT of the Ovaries and Uterus 66 year old Lifecourse - case 5b Sample Description: -“normal sized uterine tissue of soft- tissue attenuation with some small foci of contrast-enhancement, flanked by small, dense ovaries of soft-tissue attenuation, without significant fluid enhancement.” Why might the uterus and ovaries look that way? Normal Anatomic Change Over the Female Lifecourse

30. Lifecourse - case 5c “Post-menopausal stage” -UTERUS: :: size decreases (due to uterine endometrium atrophy) :: loses its cyclic engorgement -OVARIES: :: small :: featureless (the follicles are no longer under hormone stimulation) :: uniformly soft-tissue density CT of the Ovaries and Uterus 66 year old Normal Anatomic Change Over the Female Lifecourse

31. Pathologies Continue to next presentation: CT of the Ovaries and Uterus- Part 2 Pathology