Abdomen of female: Figures 462–470
Figure 462 Left lateral recumbent projection of abdomen. Beagle dog 2 years old, entire female (same dog as in all projections abdomen of female). (Approximately 60% of original size.)
Figure 463 Line drawing of photograph representing radiographic positioning for Figure 462.
Figure 464 Left lateral recumbent projection of abdomen.
1 Diaphragmatic shadow
1(a) Left ‘crus’
1(b) Right ‘crus’
1(c) Cupola
2 11th thoracic vertebra
3 Soft tissue shadows of nipples
4 Skin margin
5 Subcutaneous fat
6 M. rectus abdominis
7 Intraperitoneal fat
8 Mineralised costal cartilages
9 Soft tissue shadow of liver
9(a) Caudoventral margin of liver. (Normally seen just beyond cranioventral level of the costal arch forming an acute angle of 30 degrees or less.)
Note that in aged and obese animals this shadow often projects beyond the costal arch due to stretching of the ligaments supporting the liver. A right lateral recumbent projection shows the dorsal extent of the liver to be less in these cases when compared to younger non-obesed dogs.
The liver shadow is slightly more caudally positioned during inspiration but most adbominal radiography is performed during expiration.
The position of the liver is also influenced by the gastric shadow. There is variation in the normal appearance of the gastric shadow relative to the shape of the thorax and cranial abdomen (see below).
10 Spleen
10(a) Ventral extremity. (Normally seen at this position but varies depending on gastric distention.)
10(b) Dorsal extremity
11 Gas in gastric fundus. (In this radiograph there is an abnormally large volume of gas seen for left lateral recumbency.)
The fundus is dependant in this projection and is usually fluid filled. Normally most of the gastric gas will be found in the pyloric part, as this is uppermost in left lateral recumbency.
12 Gastric mucosa
13 Gastric body
14 Pyloric part, antrum and canal, of gastric shadow. (Some gas is present due to left lateral recumbency, see number 11.)
15 Position of pylorus (pylorus not seen in this film)
The term pylorus is often incorrectly used to mean pyloric antrum and canal.
16 Position of gastric cardia (cardia not seen in this film)
Contrast media normally required to demonstrate numbers 15 and 16.
Guidance for normal gastric size
Width of fundus and proximal body should be less than 3 intercostal spaces wide and approximately 2 times the width of the pyloric part. Gastric size best achieved in right lateral recumbency.
Variation of normal apperance of gastric shadow with breed of dog
Short, barrel chested breeds of dog have a wider fundus and body. The pyloric part is narrower.
Liver shadow in this breed of dog appears larger due to the caudoventral angle projecting more caudally into the costal arch.
Deep, narrow chested breeds of dog have a long, slender gastric shadow. The pyloric part is similar in width.
Liver shadow in this breed of dog appears smaller as the caudoventral angle may only just be visible at the costal arch.
17 Duodenal shadow (seen due to the presence of luminal gas contrast)
18 Jejunum and ileum (seen due to the presence of luminal gas contrast)
Loops of bowel are normally visible, their lumens filled with gas or fluid, or a mixture of both. The mixture of luminal gas and fluid can mimic wall ‘thickening’ when lateral recumbent projections are taken. This is caused by the fluid lining the lumen being in contact with the wall while gas is in the centre of the lumen. Fluid and soft tissue have the same radiographic opacity and hence can not be differentiated between in plain radiographs. A bowel fluid line, i.e. a gas and fluid interface, will only be seen in lateral standing projections of the abdomen.
In the dog radiographed for this film, very little abdominal intraperitoneal fat was present. This resulted in poor soft tissue contrast and has made the gas-filled gastrointestinal shadows most obvious.
The long jejunum is indistinguishable from the short ileum and generally the diameter of all the bowel is equal. It has been noted that the terminal ileum can be greater in diameter as it approaches the caecum. The terminal ileum is usually located in the central abdomen, just to the right of the midline.
Guidance on normal size of small bowel
Maximum width equal to the height of lumbar vertebral body or twice the rib width. No loop must be twice the width of surrounding loops and should be smaller than the large bowel width.
19 Caecal shadow (elongated comma shape is not clearly seen in this film)
20 Ascending colon
21 Transverse colon
22 Descending colon
Guidance on normal size of large bowel
Maximum width is 1.5 times the length of the 7th lumbar verebral body.
23 Rectum
24 Left kidney
The left kidney is more mobile than right. In obese dogs the craniocaudal axis often becomes more vertical than horizontal and fat opacity is present dorsally.
Kidney shape varies from bean to elliptical but outline is always smooth.
Guidance on normal size of kidney
Length of kidney is 2.5 to 3 times the length of the 2nd lumbar vertebral body. Maximum size has been reported to be as high as 3.5 times the length of the vertebral body. Both kidneys are similar in size. Kidney size best achieved in ventrodorsal projection.
Kidneys and ureters are retroperitoneal. Ureters are not visible in the normal dog in plain films.
25 Region of urinary bladder
Although not seen in this film, the urine filled bladder is usually clearly identifiable. It extends cranially in a ventral position.
The genital system of the non-pregnant normal female dog is not usually seen without contrast material.
26 Sublumbar muscles: m. psoas minor, m. iliopsoas and m. quadratus lumborum.
Also included in this shadow are ureters, lymph nodes plus aorta, caudal vena cava and other vessels.
The shadow gradually decreases in opacity caudal to the 4th lumbar vertebra as the m. iliopsoas diverge to insert on the proximal femora. The m. quadratus lumborum inserts on the wing of the ilium. The caudal vena cava forms from the iliac veins and aorta divides to form the left and right internal and external iliac arteries.
27 2nd lumbar vertebra
28 7th lumbar vertebra
29 Body of ilium
30 Iliopubic or iliopectineal eminence
31 Femoral bodies
32 Skin folds
Figure 465 Line drawing of photograph representing radiographic positioning for Figure 466.
Figure 466 Ventrodorsal projection of abdomen. Beagle dog 2 years old, entire female (same dog as in all projections abdomen of female). (Approximately 65% of original size.)
Figure 467 Ventrodorsal projection of abdomen.
1 Diaphragmatic shadow
1(a) Cupola
2 8th thoracic vertebra
3 8th rib
4 Skin folds
5 Skin margin
6 Subcutaneous fat (only just visible in this dog as a thin grey line between the outer skin and the first superficial muscle layer of the lateral abdominal wall)
7 M. obliquus externus abdominis
8 Very thin layer of fat overlying the superficial surface of the caudal ribs.
This layer usually serves to separate the m. obliquus externus abdominis from the m. obliquus internus abdominis and m. transversus abdominis. Unfortunately the fat layer is too thin to clearly distinguish between the two muscle layers in this female dog.
9 Intraperitoneal fat
10 Soft tissue shadow of liver
11 Dorsal extremity of spleen
12 Gastric fundus
13 Gastric mucosa
14 Gastric body. (Contains most of gas within the gastric structures due to the ventrodorsal positioning allowing gas to collect in the uppermost part of gastric shadow.)
14(a) Lesser curvature
14(b) Greater curvature
15 Pyloric part of gastric shadow; pyloric antrum and canal
16 Pylorus; pyloric sphincter muscle. The term pylorus is often misused to mean pyloric antrum and canal.
17 Ingesta within gastric lumen
18 Position of gastric cardia (cardia not visible in this film)
Variation of normal appearance of gastric shadow with breed of dog
Short, barrel chested breeds of dog have more convex caudal shadow. The pyloric part is more medial in position.
Deep, narrow chested breeds of dog have a more transverse cranial shadow. The pyloric part is more cranial in position.
19 Duodenal shadow (seen due to the presence of gas in the lumen)
20 Jejunum and ileum (seen due to the presence of gas in the lumen). Prolonged either left or right lateral recumbency will cause a displacement of a large degree of jejunal and ileal shadows to the dependant side.
See (18) in left lateral recumbent projection of abdomen of female, Figure 464, for additional information.
21 Caecal shadow. (Comma shape more obvious in this film than in the corresponding dorsoventral projection drawing, Figure 470.)
22 Ascending colon
23 Transverse colon (superimposed in part by gastric shadow)
24 Descending colon
25 Rectum
26 Left kidney (only just visible).
See (24) in left lateral recumbent projection of abdomen of female, Figure 464, for more information.
The right kidney is not visible in this film due to small amount of perirenal fat contrast.
27 Soft tissue shadows representing nipples
28 2nd lumbar vertebra
28(a) Transverse process
29 7th lumbar vertebra
29(a) Transverse process
30 Body of ilium
31 Sacrum
32 Femoral bodies
Figure 468 Line drawing of photograph representing radiographic positioning for Figure 469.
Figure 469 Dorsoventral projection of abdomen. Beagle dog 2 years old, entire female (same dog as in all projections abdomen of female). (Approximately 70% of original size.)
Figure 470 Dorsoventral projection of abdomen.
Although the dorsoventral projection is not routinely used as a standard abdominal projection, comparison of the ventrodorsal and dorsoventral projections, in the same female dog, highlights how free gas within the gastrointestinal tract changes position. In addition structures further away from the filmed cassette e.g. kidneys (in the dorsoventral projection) are less well defined. Also note the shape of the pelvis in the dorsoventral projection, as opposed to the usual appearance in the ventrodorsal projection.
1 Diaphragmatic shadow
1(a) Cupola
2 9th thoracic vertebra
3 9th rib
4 Skin folds
5 Skin margin
6 Subcutaneous fat
7 M. obliquus externus abdominis
8 Very thin fat layer
See (8) in ventrodorsal projection of abdomen of female, Figure 467, for additional details.
9 Soft tissue shadow of liver
10 Lucent gas shadows of caudal lung lobes superimposed over soft tissue shadow of liver
11 Dorsal extremity of spleen (most of the triangular shadow lines are only just visible)
12 Gastric fundus. (Contains most of the gas in the stomach due to positioning causing gas to rise to the uppermost part of the stomach. i.e. fundus in dorsoventral projection.)
13 Gastric mucosa
14 Gastric body
14(a) Lesser curvature
14(b) Angular notch
14(c) Greater curvature
15 Pyloric part of gastric shadow; pyloric antrum and canal
16 Pylorus; pyloric part of the stomach containing the pyloric sphincter muscle. Term pylorus is often misused to mean pyloric antrum and canal.
17 Position of gastric cardia (cardia not visible in film)
18 Ingesta within gastric lumen
19 Duodenum. (Shadow seen due to the presence of gas in lumen and can be seen more extensively than in the corresponding ventrodorsal projection, Figure 467.)
20 Jejunum and ileum. See (18) in left lateral recumbent abdominal projection of female, Figure 464, for additional information.
20(a) Terminal portion of ileum. (Apart from this bowel shadow jejunum and ileum can not be differentiated in plain radiographs.)
21 Caecal shadow
22 Ascending colon
23 Transverse colon (superimposition less in this film as compared to the corresponding ventrodorsal projection, Figure 467)
24 Descending colon
25 Rectum
26 Left kidney (only the craniolateral pole is visible with the aid of colonic gas contrast)
See (24) in left lateral recumbent projection of abdomen of female, Figure 464, for additional information.
The right kidney is not visible in this film due to insufficient perirenal fat contrast and radiographic projection.
27 Soft tissue shadows representing nipples
28 2nd lumbar vertebra
28(a) transverse process
29 7th lumbar vertebra
29(a) Transverse process
30 Body of ilium
31 Sacrum
32 Femoral bodies
Left lateral recumbent, ventrodorsal and dorsoventral projections
Guidance information on size of liver, gastric, intestinal, kidney and variation of normal gastric shadow with breed: Figure 464
Guidance information on variation of normal gastric shadow with breed: Figure 467
Abdomen of male: Figures 471–498
Figure 471 Line drawing of photograph representing radiographic positioning for Figure 472.
Figure 472 Left lateral recumbent projection of abdomen. Cranially centred. Beagle dog 7 years old, entire male (same dog as in all projections abdomen of male). (Approximately 60% of original size.)
Figure 473 Left lateral recumbent projection of abdomen. Cranially centred.
1 Diaphragmatic shadow
1(a) Left ‘crus’
1(b) Right ‘crus’
1(c) Cupola
2 Caudal vena cava entering the central tendon just right of the midline
3 11th thoracic vertebra
4 Skin margin
5 Subcutaneous fat
6 M. rectus abdominis
7 Fat in falciform ligament of the liver
8 Skin folds
9 Mineralised costal cartilages
9(a) Costal arch (formed by costal cartilages 10, 11 and 12)
10 Soft tissue shadow of liver. See (9) in left lateral recumbent projection abdomen of female, Figure 464, for more details.
10(a) Caudoventral margin (acute angle not clearly seen due to superimposition of fluid-filled intestinal shadow)
11 Ventral extremity of spleen
12 Pyloric part, antrum and canal, of gastric shadow. (Large volume of gas present due to left lateral recumbency resulting in gas entering the uppermost part of the gastric shadow. No other part of the gastric shadow is seen in this film.)
13 Position of pylorus; sphincter at entrance of duodenum. (Not seen as a separate structure in this film.)
The term pylorus is often incorrectly used to mean the pyloric antrum and canal.
14 Jejunum and ileum (seen as fluid-filled viscera with a few gas pockets in lumens)
See (18) in Left lateral recumbent projection abdomen of female, Figure 464, for more details.
15 Caecal shadow. (Contrast of gas in the lumen makes the comma shape of the caecum distinguishable from the surrounding intestinal shadows.)
16 Ascending colon
17 Transverse colon
18 Descending colon
19 Right kidney. Please see (24) in left lateral recumbent projection of abdomen of female, Figure 464, for additional kidney information.
20 Position of left kidney. (Shadow cannot be seen as it is obscured by caecal and colonic shadows.)
See ventrodorsal and dorsoventral projections drawings, Figures 484–489 and 490–495, for left kidney in this dog.
21 Sublumbar muscles. For more details see (26) left lateral recumbent projection of abdomen of female, Figure 464.
22 2nd lumbar vertebra
23 7th lumbar vertebra. (A degenerative bony change, spondylosis, is present on ventral aspect of cranial endplate. See ‘Normality’ in the Introduction.)
24 Ilia
25 Os penis
26 Preputial shadow
Figure 474 Left lateral recumbent projection of abdomen. Caudally centred. Beagle dog 7 years old, entire male (same dog as in all projections abdomen of male). (Approximately 60% of original size.)
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