Comparing the Accuracy of Transvaginal Ultrasound and MRI

In a recent article published in Clinical Radiology, researchers determined whether a transvaginal ultrasound (TVUS) or an MRI was more accurate in detecting endometrial cancer. According to the publication, endometrial cancer is the most common gynecological malignancy. Precise diagnostic measurements for endometrial cancer are essential to positive patient outcomes.

Investigators used data collected during the Preoperative Diagnostics of Endometrial Cancer study between January 2017 and June 2019. Overall, this investigation included 259 patients with low-grade endometrial cancer.

Researchers in the study concluded that “there was a statistically significant difference in specificity assessing deep myometrial invasion between MRI and TVUS (MRI 0.88, TVUS 0.68). There was no difference in sensitivity (MRI 0.73, TVUS 0.68). When assessing cervical stroma infiltration, MRI had higher specificity (MRI 0.96, TVUS 0.90), but there was no difference in sensitivity (MRI 0.41, TVUS 0.32).”

Overall, researchers stated that MRI was more accurate than TVUS at detecting deep myometrial and cervical stroma invasion. The publication's authors noted that using TVUS as a first line is sufficient as it is low-cost and easily accessible, preventing surgical delays. However, for patients with inconclusive TVUS imaging results, a referral for an MRI is necessary.

While these guidelines are helpful for clinicians and patient care, they pose a significant concern. MRIs have long been a tool for providers to detect problems such as myometrial invasions. Despite the benefits of MRI, the global helium shortage has threatened the use of MRIs.

Liquid helium is necessary to maintain the temperature required for superconductivity in MRI scanners. In addition to the 2,000 liters of liquid helium required for the average MRI machine to function, technicians must replenish any helium that boils off. According to an NBC article, an MRI machine uses 10,000 liters of helium over its lifespan of 12.8 years.

With these statistics and the lack of available helium, clinicians are becoming increasingly concerned about the growing shortage. The study published in Clinical Radiology — while not focused directly on the deficit — presents another area of healthcare that will be affected by these supply chain issues.