Radiography Exam Case Studies & Practical Application 2 — Questions and Answers
Question 1: A patient arrives for a chest X-ray but is unable to stand or sit upright due to injury. Which projection is most appropriate?
- PA erect
- AP supine (Correct answer)
- Lateral decubitus
- Oblique standing
Correct answer: AP supine
An AP supine projection is performed when the patient cannot stand or sit upright, allowing imaging while lying flat. Image quality is somewhat reduced compared to PA erect but is the safest option for this patient.
When a patient cannot assume an erect position, an AP supine chest radiograph is taken. The X-ray tube is positioned above the patient with the IR beneath the table. Magnification is greater than a PA erect view because the heart-to-IR distance is increased. SID should be maximized (72 inches) when possible to reduce magnification. The AP supine projection is a common adaptation in portable/bedside radiography.
Question 2: During a barium enema procedure, the patient complains of sudden severe abdominal pain and the radiograph shows free air under the diaphragm. What is the most likely complication?
- Bowel obstruction
- Perforation of the colon (Correct answer)
- Allergic reaction to barium
- Vasovagal response
Correct answer: Perforation of the colon
Free air (pneumoperitoneum) under the diaphragm following a barium enema indicates perforation of the colon, a serious emergency requiring immediate cessation of the procedure and physician notification.
Colonic perforation is a rare but serious complication of barium enema. Signs include sudden severe pain, free intraperitoneal air on radiograph, and patient distress. If perforation occurs with barium sulfate (not water-soluble contrast), peritonitis risk is high because barium is not absorbable. The radiographer must stop the exam immediately, notify the radiologist/physician, and prepare for emergency intervention. Documentation is critical.
Question 3: A pediatric patient is brought in for a femur X-ray. Multiple healed fractures in various stages of healing are noted on the image. The radiographer should:
- Proceed with the exam and say nothing
- Inform the radiologist of the findings immediately (Correct answer)
- Repeat the images for better quality
- Discharge the patient and family
Correct answer: Inform the radiologist of the findings immediately
Multiple fractures in various stages of healing in a pediatric patient are a classic radiographic sign of non-accidental trauma (child abuse). The radiographer has an ethical and legal duty to report this finding immediately to the radiologist and follow institutional protocol.
Radiographers are mandated reporters in most jurisdictions. Multiple fractures in different stages of healing — particularly metaphyseal corner fractures, posterior rib fractures, or fractures inconsistent with the stated mechanism of injury — are classic indicators of non-accidental trauma. The radiographer must immediately alert the radiologist, document objectively, and follow facility protocol for suspected child abuse. Never confront the caregiver directly.
Question 4: A patient scheduled for an IVU (intravenous urogram) reports a previous allergic reaction to iodinated contrast media. The radiographer should:
- Proceed with the exam as ordered
- Notify the radiologist before proceeding (Correct answer)
- Substitute barium sulfate for the contrast
- Cancel the exam without consulting anyone
Correct answer: Notify the radiologist before proceeding
A history of contrast allergy requires notification of the radiologist before proceeding. The radiologist will decide whether premedication, alternative contrast, or a different imaging modality is appropriate for patient safety.
Patients with prior reactions to iodinated contrast are at increased risk for repeat reactions. The radiographer must document the allergy history and notify the radiologist or ordering physician immediately. Options include premedication protocols (corticosteroids and antihistamines), use of low-osmolar or iso-osmolar contrast agents, or substituting with non-contrast CT, ultrasound, or MRI. The decision rests with the radiologist — never proceed without clearance.
Question 5: Which positioning aid is most useful when performing a lateral hip radiograph on a patient with a suspected hip fracture?
- Compression band
- Sandbag on the unaffected side (Correct answer)
- Angled sponge under the pelvis
- No aids — patient remains supine with frog-leg position
Correct answer: Sandbag on the unaffected side
For a suspected hip fracture, a frog-leg lateral is contraindicated. The cross-table lateral (Danelius-Miller) is performed with the patient supine; a sandbag or support stabilizes the unaffected leg elevated while the IR is placed vertically alongside the injured hip.
The Danelius-Miller (cross-table lateral) projection is the preferred method when hip fracture is suspected. The patient remains supine and the unaffected leg is elevated and abducted; the IR is placed vertically at the lateral aspect of the injured hip. The central ray is directed horizontally through the femoral neck. This avoids painful or dangerous internal/external rotation of the injured limb. Sandbags help stabilize the elevated leg.
Question 6: An image of the lumbar spine shows the vertebral endplates are not parallel and the disc spaces appear wedge-shaped. What adjustment should be made?
- Increase kVp by 15%
- Angle the central ray cephalad (Correct answer)
- Rotate the patient obliquely
- Increase SID by 6 inches
Correct answer: Angle the central ray cephalad
When the intervertebral disc spaces appear wedge-shaped on an AP lumbar spine, the vertebral endplates are not parallel to the IR. Angling the central ray cephalad (typically 5-8 degrees) opens the disc spaces and projects them as parallel lines.
The lumbar spine has a natural lordotic curve. To project the disc spaces open (parallel to the IR), the central ray is angled cephalad 5-8 degrees for the AP lumbar spine. This compensates for the angle created by the lordosis, ensuring the beam passes through the disc spaces rather than being obstructed by the vertebral bodies' inferior and superior endplates. Proper angulation reduces repeat exposures and diagnostic errors.
Radiography Exam Case Studies & Practical Application 2
A patient arrives for a chest X-ray but is unable to stand or sit upright due to injury.
Which projection is most appropriate?