Imaging pregnant patients: 3 key takeaways from a recent survey

Is there a general consensus among U.S. specialists when it comes to abdominal and pelvic imaging of pregnant or potentially pregnant patients? Puneet Bhargava, MD, associate professor at the University of Washington School of Medicine in Seattle, and colleagues conducted a survey to find out, publishing their findings in Current Problems in Diagnostic Radiology.

“Choosing the most appropriate imaging technique(s) for pregnant or potentially pregnant patients with acute abdominal and pelvic conditions can be challenging,” the authors wrote. “Ultrasound is the preferred modality for the initial imaging of the abdomen and pelvis of a pregnant patient in most clinical scenarios, because it is rapid and poses no risk to the fetus from ionizing radiation. However, ultrasound is often nondiagnostic because of poor resolution owing to the patient’s large body habitus during pregnancy, anatomical changes that occur during pregnancy, and other intrinsic limitations of the technology. In these cases, other imaging modalities must be considered.”

The researchers surveyed members of the Association of University Radiologists, the Association of Program Directors in Radiology and the Society of Radiologists in Ultrasound in 2014 about their policies for acute abdominal and pelvic imaging of patients who are pregnant. They received a total of 225 responses.

These are three key takeaways from the survey:

1. Imaging organizations agree on many policies

Based on 225 responses, the data showed that organization members agreed on a number of topics. Seventy-nine percent of members have a written policy on imaging pregnant patients, for example, while 74 percent agree on avoiding gadolinium contrast during MR scans of pregnant patients.

Bhargava et al. also noted that there are several “areas of emerging consensus.” For instance, the use of serum or urine testing to confirm pregnancy increased from 14 percent in 2007 to more than 59 percent in 2014. Also, the use of MRI after an inconclusive ultrasound for pregnant patients who may have appendicitis is now much more common. In 2007, 46 percent of respondents agree with MRI in the first trimester and 29 percent agreed with MRI in the third trimester, but those numbers increased to 73 percent in the first trimester and 67 percent in the third trimester.

2. Practices are working more toward reducing radiation dose for pregnant patients

This point shouldn't surprise too many specialists in the industry.

In the 2007 survey, 78 percent of respondents answered that they “always” or “sometimes” lower radiation dose for pregnant patients, with 22 percent saying they “never” alter the dose. Fast forward to 2014, and more than 86 percent of respondents “always” or “sometimes” lower the dose for pregnant patients. Just 4 percent said they “never” do this, a significant change from 22 percent just seven years prior.

3. Respondents choose CT for trauma patients after an inconclusive ultrasound

One scenario in the survey involved a patient who had sustained “blunt abdominal trauma” in a motor vehicle collision. After an inconclusive initial ultrasound, the survey asked, where do you turn next?

For a patient who is eight weeks pregnant, 83 percent of respondents went with CT. For a patient 30 weeks pregnant, that number was 88 percent. Bhargava and colleagues noted that more than half of the respondents choosing CT chose to use IV iodinated contrast.

“The [American Congress of Obstetricians and Gynecologists] and [ American College of Radiology] guidelines emphasize the need for prompt diagnostic imaging in high-risk situations without excessive delay owing to concern about potential effects of radiation on the fetus,” the authors wrote.

The study did have limitations, according to its authors. For example, it was an online survey sent to self-selected individuals, meaning it may not represent the true feelings of the country’s entire population. Also, the response rate was just 11 percent.