Abdomen problem solving & positioning errors

Situation: The ER physician suspects that a patient has a kidney stone. The patient is sent to the radiology department to confirm the diagnosis. What specific positioning routine would be used to rule out the presence of a kidney stone?

A KUB would be performed with the correct exposure factors to visualize the possible stone.

Situation: A patient in intensive care may have developed intra-abdominal bleeding. The patient is in critical condition and cannot go to the radiology department. The physician has ordered a portable study of the abdomen. Which specific position or projection can be used to determine the extent of the bleeding?

A bedside portable left lateral decubitus projection could be performed to demonstrate any fluid levels in the abdomen.

Situation: A KUB radiograph shows that the gonadal shielding is superior to the upper margin of the symphysis pubis. The female patient has a history of kidney stones. What is the next step the technologist should take?

Because the patient may have renal calculi in the distal ureters and urinary bladder, gonadal shielding cannot be used.

Situation: A patient comes from the ER with a large distended abdomen caused by an ileus. The physician suspects that the distention is caused by a large amount of bowel gas that is trapped in the small intestine. The analog technique for a KUB on an average, healthy adult is 76 kV, 30 mAs. Should the technologist change any of these exposure factors for this patient? (AEC is not being used.)

Decrease the mAs. Because trapped air is easier to penetrate than soft tissue with x-rays, reducing the mAs will prevent overexposing the radiograph.

Situation: A child goes to radiology for an abdomen study. It is possible that he swallowed a coin. The ER physician believes it may be in the upper GI tract. Which of the following routines would best identify the location of the coin?

KUB and lateral abdomen. With any foreign body study, two projections 90 degrees opposite are recommended to pinpoint the location of the foreign body.

A KUB radiograph shows that the symphysis pubis was cut off along the bottom of the image. Is this an acceptable radiograph? If it is not, how can this problem be prevented during the repeat exposure?

No. A KUB must include the symphysis pubis on the radiograph to ensure that the bladder is seen. The positioning error involves centering of the central ray to the iliac crest. The technologist should also palpate the symphysis pubis (if permitted by institutional policy) or greater trochanter to ensure that it is above the bottom of the cassette.

A radiograph of an AP abdomen shows the left iliac wing is more narrowed than the right. What specific positioning error caused this?

Patient was rotated into a slight right posterior oblique (RPO) position. (The downside ilium will appear wider.)

Situation: An obese patient comes to the radiology department for a KUB. The radiograph shows that the symphysis pubis is included on the image, but the upper abdomen, including the kidneys, is cut off. What is the next step the technologist should take?

Repeat the exposure using two 35 × 43 cm image receptors placed in landscape orientation. The obese patient often requires this type of IR placement for abdomen studies.

A radiographic image of an AP projection of the abdomen demonstrates motion. The following analog exposure factors were selected: 78 kV, 200 mA, 2/10 second, grid, and 40-inch (102-cm) SID. The technologist is sure that the patient did not breathe or move during the exposure. What may have caused this blurriness? What can be done to correct this problem on the repeat exposure?

The blurriness may be caused by involuntary motion. To control this motion, the technologist needs to increase the milliamperage and decrease the exposure time (e.g., 400 mA at 1/10 second).

Situation: A patient with a history of ascites comes to the radiology department. Which of the following positions best demonstrates this condition?

The erect AP abdomen position best demonstrates air-fluid levels. Ascites produces free fluid in the intraperitoneal cavity.

A radiograph of an AP projection of an average-size adult abdomen was produced using the following exposure factors: 100 kV, 400 mA, 1/10 second, grid, and 40-inch (102-cm) SID using a film/screen (analog) imaging system. The overall density of the radiograph was acceptable, but the soft tissue structures, such as the psoas muscles and kidneys, were not visible. Which adjustment to the technical considerations enhances the visibility of these structures on the repeat exposure?

The selected kilovoltage (100 kV) was too high. The technologist needs to lower the kilovoltage to between 70 and 80 kV (analog) or 80 +/− 5 kV (digital systems). The milliamperage and exposure time can be altered to maintain the density.

Situation: A patient with a possible dynamic ileus enters the emergency room. The patient is able to stand. The physician has ordered an acute abdominal series. What specific positioning routine should be used?

The three-way acute abdominal series, including the anteroposterior (AP) supine and erect abdomen and posteroanterior (PA) erect chest projections.

Situation: A patient with a possible perforated duodenal ulcer enters the emergency room. The ER physician is concerned about the presence of free air in the abdomen. The patient is in severe pain and cannot stand. What positioning routine should be used to diagnose this condition?

The two-way acute abdomen series: AP supine abdomen and left lateral decubitus