? Specific for intestinal obstruction

1.Which is true regarding normal appearance of  abdomen on plain x –ray

a.relatively small  amount of gas is  present in colon

b.more than two fluid levels in dilated small bowel are said to be abnormal

c.Valvulae conniventes are usually identified in normal individual

d.gastric rugae rarely identified on supine x-ray

e.small bowel fluid levels are specific for obstruction

ANS.---b

Relatively large amounts of gas are normally present in the stomach and colon but only a small amount is usually seen in the small bowel.
The presence of bowel gas is useful in assessing the diameter and position of the bowel.
It is usual to be able to identify the gastric rugae on a supine radiograph.
There is rarely sufficient gas present in the small bowel to outline more than a short length, and although the mucosal pattern may be seen, the thin bands of the valvulae conniventes are seldom identified in a normal patient.
Air and fluid are normal contents of the small bowel, and short fluid levels are not abnormal on an erect radiograph, should one be obtained.
The following statements about fluid levels on an erect radiograph also apply to CT performed in the supine position--------
 A.----Fluid levels are common in normal people, and they usually lie in the colon. Three to five fluid levels less than 2.5 cm in length may be seen, particularly in the right lower quadrant, without any evidence of intestinal obstruction or paralytic ileus.
B.--- More than two fluid levels in dilated small bowel (calibre greater than 2.5 cm) are said to be abnormal, and usually indicate paralytic ileus or intestinal obstruction.
 C.---Fluid levels at different heights in the same loop of small bowel do not help differentiate obstruction from paralytic ileus and may occur in normal people.
D.---Small-bowel fluid levels are by no means specific for obstruction.