Unit 2 10 Transaxial CT Images of the Male Pelvic Cavity 12 Coronal MRI images of the Female Pelvic Cavity There are no drawings with this unit The images of the male pelvis start just below the iliac crest, several cm lower than where the abdomen images left off. They continue in 1 cm increments through the pelvic cavity. The coronal images of the female pelvic cavity start posterior and continue anterior. First set of parenthesis, in bold, is page number for 3rd edition Second set of parenthesis, not bold, is page number for 4rd edition Unit 2 Reference 7 1 8 6 5 4 4 2 10 13 9 12 Ala of Rt. ilium Sacrum Male Images 1 & 2 Sacroiliac joints Psoas major muscles Lt. common iliac artery (381)(401) Lt. common iliac vein* Small bowel (with barium) Rt. iliacus muscle (478)(496) 9. Gluteus maximus muscle (476, 477)(494-495) 10. Gluteus medius muscle 11. Gluteus minimus muscle 12. Rt. common iliac vein** 13. Lt. ureter (with iodine contrast) (381)(401) 3 11 1. 2. 3. 4. 5. 6. 7. 8. * These pelvic sections begin below the aorta and IVC. Compare the appearance of the Rt. and Lt. common iliac vessels to plate 381 in Netter to appreciate why they are in this position, e.g. the artery on the right is medial to the vein, but on the left it is lateral. ** The elongated, apostrophe like shape of the Rt. iliac vein at this level is due to anastomosis of the internal and external iliac veins which are seen in image 3. Images 1-4 Reference Images 3 & 4 1. 2. 3. 4. Rt. external iliac artery (381-383)(401-403) Rt. external iliac vein Rt. internal iliac artery Rt. internal iliac vein 5. 6. 7. 8. 9. Body of bladder (348)(361) Rectosigmoid junction* (374, 348)(393-361) Rt. external iliac artery** Lt. external iliac vein*** Branches of the internal iliac veins (383)(403) & arteries**** 1 2 3 4 * Identified by its position behind this full bladder ** Rt. external iliac vein is against, but behind the artery *** Lt. external iliac artery is against, but in front of the vein. ****The internal iliac artery and vein are no longer identifiable. Numerous branch vessels are seen as spots or streaks. 5 7 8 6 9 1 Images 5 & 6 6 2 4 5 3 1. 2. 3. 4. 5. 6. Reference Bladder, with urine and iodine contrast Body of the Rt. ilium (468)(486) Rt. ureter* (348)(361) Lt. external iliac artery Lt. external iliac vein Rt. iliopsoas muscle** (478)(398) 7. Roof of Rt. acetabulum 8. Rt. femoral artery 9. Rt. femoral vein*** (253)(262) 10. Rectum**** 8 * 9 7 10 Seen as a streak, rather than a spot, because it has turned anterior toward the bladder. The Lt. ureter is not seen because at the moment in time it was imaged no contrast happened to be in it. ** The psoas major and iliacus muscles have merged into the iliospsoas. On image 4 the two can still be seen separately. *** The external iliac vessels become femorals when they pass through the inguinal canal, which is not seen. However, the level of the top of the acetabulum is close to the inguinal canal. ****The sigmoid colon crosses the top of the bladder, but posterior to it becomes the rectum. Images 5-8 Reference 6 1. 2. 3. 4. 5. 6. Greater trochanter of Lt. femur (469)(487) Coccyx Ureterovesical (ureterocystic) junctions Rt. & Lt. ampulla of vas deferens (367)(384) Rt. & Lt. seminal vesicle* Rt. & Lt. spermatic cords 3 1 4 5 7. Ischium bone 8. Pubic bone 9. Rt. & Lt. spermatic cords (241-243, 348) (249-251, 361) 10. Rt. & Lt. femoral veins** 11. Greater trochanter of the Rt. femur * Two spellings, vesicle (little bladder) and 11 vesical, (bladder shape) are similar, though “icle” is used for the seminal vesicles. ** Arteries are against, and anterior to the veins Images 7 & 8 2 9 10 8 7 Reference 1 1. Pubic symphysis 2. Prostate gland (367)(384) 3. Rt. Gluteus maximus muscle 2 4. Rt. ischial tuberosity (468)(385) 5. Proximal shaft of Lt. femur 3 Images 9 & 10 5 4 Images 9 & 10 MRI Coronal Images of the Female Pelvis 1 2 4 6 8 7 3 5 9 12 11 13 10 1. 2. 3. 4. 5. 6. 7. 8. Reference Adipose tissue Female Images 1 & 2 Rt. ilium Rectum Posterior wall of acetabulum* Rt. & Lt. gracilis muscle (482, 487)(500, 505) Greater trochanter of Lt. femur Lesser trochanter of Lt. femur Intertrochanteric crest of Lt. femur (470, 471)(488,489) 9. Posterior elements of lumbar spine 10. Sigmoid colon 11. Rt. femoral head** 12. Rt. internal iliac vein*** (373)(392) 13. Lt. internal iliac artery**** * Superior part is composed of ilium, inferior part is ischium ** Most posterior aspect *** Artery is immediately below it ****Vein is immediately above it. See Netter’s plate 373 to appreciate why the internal vein is superior to the internal artery in these coronal sections. Images 1-4 Reference 1. 2. 3. 4. 5. Rt. & Lt. sacroiliac joints Neck of the Rt. femur Vertebral canal Shaft of the right femur* Sacral plateau 1 Images 3 & 4 * On image 3 & 4 the proximal shaft of the femur is seen to be anterior to the distal shaft: muscle tissue is covering the distal shaft on image 3. For this reason it is evident that as the distal portion of the shaft appears it will be cortical bone that first comes into the imaged plane. That is why the distal shaft is dark. Cortical bone is dense and contains little hydrogen, so no signal is returned. 3 2 4 5 Reference 1 2 3 1. 2. 3. 4. Rt. pedicle of the 4th lumbar vertebra Body of the 5th lumbar vertebra Images 5 & 6 Branches of the Lt. internal iliac artery* Posterior wall of the vagina 5. Fundus of the uterus** (352)(365) 6. L4-L5 intervertebral disk material (space) 4 * See Netter’s plate 383 (403) to appreciate the appearance of this streak in this coronal plane **First seen in image 5 6 5 Images 5-8 Reference 1. 2. 3. 4. Uterus Urinary Bladder* Lt. common iliac vein (381-383)(401-403) Images 7 & 8 Lt. internal iliac artery 3 1 2 4 5. Lt. external iliac vein** 6. Rt. iliopsoas muscle (478)(496) 7. Small bowel * Depending on the position of the uterus (see plate 358) (374), the amount of urine in the bladder, and the angle of the cut plane of the scan, when the bladder appears it may be superior or inferior to the uterus. The images seen here are similar to illustration B. A B 7 6 **In image 7 #3, the Lt. common iliac vein appears. The dark spot, #4, is the internal iliac artery which is unchanged from its first appearance in image #2. Where the internal iliac artery crosses the vein marks the spot where the common iliac vein becomes the external iliac vein. See plate 381 (401). 3 4 5 Images 9 & 10 Reference 4 5 1. 2. 3. 4. 5. 6. 7. 7 6 3 1 2 Urinary bladder Neck of bladder and internal urethral orifice (353)(366) Uterus Rt. psoas muscle Rt. iliacus muscle Rt. iliopsoas muscle Rt. internal iliac artery* 8. Rt. external iliac vein 9. Inferior vena cava** 10. Vestibule of the vagina (359)(377) * Just the darker spot 9 ** Most proximal part, at the anastomosis of the Rt. & Lt. common iliac veins. 7 8 10 Images 9-12 2 Reference 1. 2. 3. 4. 5. Rt. & Lt. common iliac arteries Inferior vena cava (381)(401) Cecum of the colon Lt. ovary (354-356)(369-371) Lt. fallopian tube (oviduct) 3 1 Images 11 & 12 4 5 6. Rt. & Lt. external iliac artery 7. Rt. & Lt. femoral artery (superficial femoral)* 8. Abdominal aorta 9. Pubic symphysis 10. Labia majora (labium=singular) 2 * On this image we see the origin of the deep femoral (profunda) 8 where the various branches of the circumflex feed the proximal femur. Compare the right side to plate 494 (512). 3 1 6 9 10 7