16. ⢠Radiodensity on CT, Range from -1000 to
+1000.
⢠By definition water (CSF) = 0.
17. ⢠Air is -1000 because it is the least dense
structure.
⢠Bone is the most dense and measures
+1000.
18. ⢠Fat is less dense than water and therefore
measures -100.
⢠Brain parenchyma is more dense than water and
ranges from +20 to +40.
⢠White matter is less dense than gray matter due
to the fat within the myelin within the white
matter.
19. ⢠Acute blood is bright on CT and measures +
55 to +75 HU. C
⢠Calcification is more dense than blood and
will measure in the low 100's.
22. ⢠Reductions in intensity of x-ray beam as
it traverses matter either by absorption
or deflection.
23. ⢠High attenuation
â Absorption of x-ray photon
â Presented as white on image
⢠Low attenuation
â Free passage of photon
â Presented as black on image
28. ⢠Different âWindows" can be created to
highlight specific structures.
⢠Adjustments in gray scale/shade according to
the specific attenuation properties of tissue
34. ⢠Iodinated intravenous contrast
â Increases the density of blood vessels and
organs
â Lymph nodes distinguished from blood
vessels
â Abnormal lesions in solid organs become
easier to distinguish from normal
surrounding parenchyma
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46. ⢠Iodinated oral contrast
â During abdominal CT
â Opacify the small bowel
â This makes it easier to distinguish normal
bowel from pathological lymph nodes or
other mesenteric masses
59. ⢠Always begin cranial and gradually
move caudally.
⢠Assess structures from superficial to
deep, first analyze tissues of abdominal
wall and then progress to internal
structures
60. ⢠Begin by following one organ
⢠Track it through entire sequence.
⢠With experience, follow organs that lie
in same transverse plane.
67. This is an excellent image of the right, middle and left hepatic veins draining into the
Inferior Vena Cava. Donât confuse this structure with the IVC, this is the esophagus at
the level of the Lower esophageal sphincter, page up and down to confirm this.
68. The outline of the Inferior Vena Cava is more
distinct in this image.
78. You can see the Celiac artery starting to branch from the Aorta. You can follow
this down in the next four images Proper Hepatic Artery is labeled in the upper
right The splenic vein and artery are in the lower left
79. Proper Hepatic Artery and Splenic Artery (the splenic
artery is the circle). Splenic Vein
80. Here the Splenic Vein is emptying into the portal vein.
Follow this up and down.
Pancreas
81.
82. This is the Superior Mesenteric Artery
Branching off the Aorta.
84. Renal Veins emptying into the IVC.
We also see the right renal artery branching off the Aorta,
follow it down till you see it enter the right kidney.
The Superior Mesenteric Vein is outlined on the top of this image.
If you follow the SMV up, you will see it empty into the Portal Vein.
85. Here we see the right and left renal vein entering into the Inferior Vena Cava. We
Also see the left renal artery branching off the aorta and heading toward the left
kidney. Page up and down to trace these vessels.
223. ⢠1, duodenal- descending,
horizontal, ascending
part.
⢠2, spleen and splenic vein.
⢠3, fundus of stomach.
⢠4, tail of pancreas.
⢠5, left colic and right colic
vein.
⢠6, ascending and
descending colon.
⢠7, right and left external
iliac vein
⢠8, inferior mesentric vein.
⢠9,IVC
224. ⢠1, caudate lobe of
liver
⢠IVC and left renal
vein.
⢠2, abdominal aorta
and right common
iliac aretry.
⢠3, splenic vein.
⢠4,celiac trunk and
superior mesentric
artery.
⢠5,inferior mesentric
vein.
⢠6, right colic vein
225. ⢠1,.abdominal aorta and
renal artery
⢠2, IVC.
⢠3, Spleen
⢠4,Right and Left kidney.
⢠5, Gluteus medius and
minimus muscle.
⢠6, Iliac and psoas
muscle.
⢠8, Asc. and Desc. colon.
⢠9, UB.
226. ⢠Right and left crus
of diaphragm.
⢠Both kidneys
⢠Right lobe of liver
⢠Spleen
⢠Psoas and iliac
muscle.
⢠Right and left
common iliac artery
and vein.
234. ⢠Transverse colon
⢠Body of stomach
⢠Jejunal loops
⢠Left kidney
⢠Erector spinae and
quadratus
lumborum.
⢠Iliac and psoas
muscle.
⢠Gluteus medius
⢠Gluteus maximus
235. ⢠Splenic vessel
posterior to the tail
of pancreas.
⢠Left lobe of liver.
⢠Pyloric antrum
⢠Jejunal loop.
⢠Left common iliac
artery ,
⢠Left external iliac
artery
⢠Left common iliac
vein
⢠Left external iliac vein
236. ⢠Abdominal aorta
⢠Celiac trunk
⢠SMA
⢠Pyloric antrum
⢠Body of pancreas
with splenic artery
and vein behind it.
⢠Duodenum
237. ⢠IVC
⢠Head of pancreas
⢠Horizontal part of
duodenum
⢠Portal vein
⢠Left lobe of liver
⢠Jejunal loop
⢠Transverse colon
⢠Sigmoid colon
⢠Rectum
⢠UB