Volume 3, Case 19
Loren G. Yamamoto, MD, MPH
Kapiolani Medical Center For Women And Children
University of Hawaiʻi John A. Burns School of Medicine
This is a 4-year old female with a history of abdominal pain for 3 days. She was seen by her private physician in the morning and then referred to the emergency department for further evaluation because of tenderness in the right lower quadrant.
Exam: VS T37.0 (oral), P122, R24, BP 108/73, oxygen saturation 99% in room air. Alert, cooperative, uncomfortable, but no acute distress. Oral mucosa sticky. Neck supple. Heart regular without murmurs. Lungs clear. Abdomen flat. Guarding on the right. She points to the epigastrium as the site of her pain. However, most of the tenderness is elicited in the right lower quadrant. Bowel sounds are hypoactive. Color and perfusion are good.
An abdominal series is ordered.
View abdominal series: Flat (supine) view.
Abdominal series: Upright view.
The following laboratory results are obtained:
Her abdominal series shows diffuse gaseous distention of the colon and small bowel compatible with an ileus or an early obstruction. The distribution of gas is good. No free air is visible under the diaphragm. No appendicolith is visible.
Compare the radiographic appearance of the left lower quadrant with the right lower quadrant. Can you appreciate any differences? Look at the peritoneal fat stripe on the left and on the right. The bowel should generally lie very close to this fat stripe. This is true on the patient's left (right on image), but note that this is not the case on the patient's right (left on image). In the right lower quadrant, the bowel is about 1 cm from the peritoneal fat stripe. In the left lower quadrant, the bowel is about 1-2 mm from the fat stripe. This can be best visualized in the magnified focused view of the lower abdomen.
View close-up of lower abdomen.
Look at the peritoneal fat stripes on both sides just above the iliac crests (white arrows). Note that on the patient's left, there is a very narrow space between the fat stripe and the bowel. However, on the patient's right, the bowel is farther away from the fat stripe suggesting that there is fluid, a mass, or thickened tissue pushing the bowel aside.
The black arrow points to a small gas pocket that does not appear to be within bowel. These findings together are highly suggestive of a ruptured appendix.
The patient is taken to surgery where a ruptured appendix is found. There is exudate extending from the right paracolic gutter to the liver and diaphragm. She recovers and is discharged in good condition on the sixth post-operative day.
The radiographic findings in appendicitis are infrequent and diverse. Radiographic findings highly suggestive of an acute appendicitis include an appendicolith, free air, RLQ sentinal loops (dilated bowel loop(s) in the RLQ in an otherwise nearly gasless abdomen), and absence or indistinctness of the right psoas margin. Free air may not always be present under the diaphragm since it may be loculated. Less specific findings include diminished intestinal gas, a scoliosis to the left (concavity to the right, due to splinting), or a bowel obstruction.
References
Swischuk LE. Emergency Radiology of the Acutely Ill or Injured Child, second edition. Baltimore, Williams and Wilkins, 1986, pp 191-209.