E1436. Don’t Have Tunnel Vision: Important Incidental Findings on Routine Musculoskeletal and Spine Magnetic Resonance Imaging
Authors
Andrew Gallo;
Brooke Army Medical Center
Douglas Byerly;
Brooke Army Medical Center
MIchael Tall;
University of Texas San Antonio
Background
In the United States, roughly 40 million magnetic resonance imaging (MRI) examinations are performed yearly. Many of these examinations relate to musculoskeletal (MSK) and spine imaging. Incidental findings on MRI have been reported in the ranges of 4-9% and up to 26% on spine MRI; therefore, the likelihood a radiologist will encounter incidental findings is high. In fact, the increasing likelihood of detecting incidental findings led to a recommendation by a US Presidential Commission to counsel patients about the possibility of incidental findings prior to obtaining imaging.
Educational Goals / Teaching Points
MRI examinations often include anatomic details outside the direct region of interest which may be related or unrelated to the reason for imaging, but nonetheless are important to examine to accurately identify and communicate findings which may need further imaging or work-up. Although many incidental findings are benign, the radiologist may be the first healthcare provider to detect critical or life-threatening diagnoses that can result in significant morbidity or mortality if untreated). This educational presentation will demonstrate examples of incidental findings found on MSK and spine MRI such as malignancy, benign tumors, vascular abnormalities, and congenital abnormalities with examples of follow-up imaging and pathology confirmation.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Scout images are an essential component of MRI examinations and often include structures which are not seen on standard imaging sequences. Pathology seen only on the scout images of an examination has been reported in up to 25% of cases in a study of 122 patients, although larger studies report a rate closer to 1%. Literature suggests scout images are often not reviewed by the radiologist. Field of view (FOV) may vary between imaging sequences, involving different planes (coronal, sagittal, axial) and different techniques (T2, T1, postcontrast). Therefore, anatomic structures, incidental findings, and pathology may only be imaged on a subset of sequences. Each type of MRI examination has potential areas of concern that will be covered. Additionally, radiologists should not dismiss sequences that have been repeated due to artifact such as motion. If the radiologist fails to review redundant images a significant finding may be missed.
Conclusion
Radiologists will increasingly encounter incidental findings as the use of advanced imaging continues to progress. Scout images should be carefully reviewed to ensure there are no abnormalities excluded from standard sequences. Care should be taken to assess the various FOV as anatomic structures and/or pathology may only be appreciated on a single sequence. Each modality commonly includes images of anatomic structures unrelated to the patient presentation but still require assessment. Proper attention to these potential pitfalls and a dedicated search pattern will decrease the likelihood of missing potentially significant findings.
