Medical Devices: What to Look for in Abdominal X-rays

As technology has advanced, the appearance of medical devices on abdominal X-rays has become more and more common. Knowing what to look for – and recognizing what might be wrong – can play a big role in augmenting a patient’s care.

In a presentation during the 2021 European Congress of Radiology (ECR) annual meeting, D.C. Carvalho, a radiology resident at Centro Hospital Universitário de São João in Portugal, outlined several devices that appear on these images and what you should look out for.

For additional ECR 2021 coverage, click here.

“Failure to recognize [these devices], as well as correct placement or complications can compromised the efficacy of diagnosis,” he said. “The evaluation of abdominal and pelvic devices, as well as their related complications should be an integral part of the study of abdominal X-rays.”

Consequently, when you are reading abdominal X-rays, Carvalho recommended you keep these things in mind:

Nasogastric tube: The most common complication is misplacement. The ideal position is distal to the gastric cardia, 10 cm caudal to the gastroesophageal junction, he said.

Gastrostomy/Jejunostomy tubes: The most common complication is misplacement that can result in an abnormal peritoneum, such as a perforation.

Gastric band: This device has three parts: the adjustable gastric band, connector tube, and subcutaneous port. The proper phi angle should be between 4° and 58°. Calculate the angle by drawing a vertical line along the spinal column and a line along the long axis of the band.

Foley catheter: The balloon should be located inside the bladder. If it is visualized below the bladder in the urethra or ureter, it is mispositioned, he said.

Suprapubic cystostomy: The most common complications are the inadvertent catheterization of the urethra, retained catheter, or encrustation.

Peritoneal dialysis catheter: The tip should be in the lower pelvis. An X-ray can be useful in detecting non-infectious complications, such as catheter misplacement, migration, or kinking.

Ureteric stent/nephrostomy tube: The tip should be in the renal pelvis, and in the case of the ureteric stent, the other end should be in the bladder. Common complications include migration, encrustation, and stent fracture.

Intrauterine contraceptive devices (IUD)/tubal sterilization devices: For an IUD, look for perforation, migration, and fragments. In addition, there are many types of tubal devices, and they are generally horizontal. The distance between the two proximal markers should be less than 4 cm, he said.

Vaginal pessary: Used to prevent pelvic organ collapse, this device will appear as a large thick ring of uniform density. It should be perpendicular to the plane of the vagina.

Penile prostheses: Look for prosthetic fracture, migration, or kinking.

Inferior vena cava filters: Keep an eye out for filter tilt – an angle of the filter more than 15° in relation to the device’s long axis – mispositioning, fracture, and migration – the movement of 2 cm or more from its original position.

Endoprosthetic stent: Look for pneumoperitoneum, stent fracture, migration, misplacement, or collapse.

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