MR imaging of the pelvis: a guide to incidental musculoskeletal findings for abdominal radiologists

Beyond the abdominal and pelvic cavity: abdominal wall and spinal "Aunt Minnies"

Abdominal wall and spinal soft tissue findings are frequently encountered on CT or MR imaging of the abdomen and pelvis. Many of these entities have specific imaging findings, for which a definitive diagnosis can be made without the need for further work up. These abdominal wall and spinal findings may be diagnostically challenging for sub-specialized abdominal radiologists who are unfamiliar with their appearance and appropriate management. This review article describes and illustrates pathognomonic or characteristic abdominal wall and spinal pathologies, which reside outside the abdominopelvic cavity. The cases selected all have findings that allow a confident diagnosis without further imaging or intervention. The cases presented include myonecrosis, intramuscular abscess, myositis, iliopsoas bursitis, Morel-Lavallée lesion, hydrocele of canal of Nuck, Klippel Trenaunay Weber syndrome, neurofibroma with target sign, perineural cysts, filum terminale lipoma, calvarial bone flap, transverse rectus abdominis muscle (TRAM) flap, liposuction, and hidradenitis suppurativa, among others. Although not all-encompassing, this paper will help abdominal radiologists to accurately diagnose a variety of abdominal and pelvic extra-cavitary soft tissue pathologies by identifying key radiologic findings.

Analysis of critical report notification from musculoskeletal radiology in a tertiary academic medical institution with a regional trauma center

Purpose

We aimed to analyze the prevalence, causes, and clinical settings of 4-year critical radiologic reports (CRRs) notified from the musculoskeletal section of the radiology department. Then, we investigated the communication outcomes.

Methods

This study was approved by our institutional review board. We retrospectively included 175 musculoskeletal CRRs from our database between January 2017 and December 2020. The CRRs were analyzed by two musculoskeletal radiologists, who categorized the CRRs by clinical setting (emergency department(ED) patient, outpatient, and inpatient), body part, type of image modality, reason for CRR, incidental lesion, and clinical outcome. The clinical outcome was retrieved from the electronic medical records.

Results

The 175 musculoskeletal CRRs accounted for 5.4% of the CRRs (n = 3217) available in the study period. Most CRRs (94.9%, 166/175) corresponded to the musculoskeletal system, while the remaining ones (5.1%, 9/175) corresponded to the non-musculoskeletal system. In addition, the spine, extremities, and thoracic cage accounted for 52.6%, 40.6%, and 1.7% of the musculoskeletal CRRs, respectively. Moreover, most patients presented to the ED (50.3%, 88/175), followed by inpatients (30.9%, 54/175), and outpatients (18.9%, 33/175). The CRR reasons included missed fracture (54.3%), suspected malignancy (16%), clinical emergency (10.3%), unexpected infection/inflammation (11.4%), and others (8%). Furthermore, 11 (6.3%) incidental lesions were not related to the primary imaging purpose. Referring clinicians actively acknowledged 80% of the CRRs. The loss to follow-up action was the highest in the ED patients (35.2%, 31/88; p < 0.001), being significantly higher than that in outpatients (6.1%, 2/33) and inpatients (3.7%, 2/54).

Conclusion

Missed fractures were the most common cause of musculoskeletal CRRs. ED showed prevalence in musculoskeletal CRRs and reflected the highest loss to follow-up action. ED physicians should pay more attention to CRRs to enhance patient care.

Prevalence and Clinical Significance of Incidental Vertebral Marrow Signal Abnormality in Thoracolumbar Spine MRI

STUDY DESIGN

A cross-sectional study.

OBJECTIVE

This study investigates the prevalence of incidental vertebral marrow signal abnormality (VMSA) in thoracolumbar spine magnetic resonance imaging (MRI) ordered for the evaluation of back and/or leg pain and assess the clinical work-up for VMSAs.

SUMMARY OF BACKGROUND DATA

Patients presenting with back pain are often referred for spine MRI for diagnostic evaluation. VMSA is most frequently found in the lumbar spine and is of clinical concern because it can represent malignancy. Standardized procedures for reporting and managing VMSAs do not exist.

METHODS

The radiology database at the Oregon Health & Science University health system was queried to identify patients with thoracolumbar spine MRI scans performed between January 2014 and June 2016. Patients 16 years or older with MRIs ordered by providers at a multidisciplinary spine specialty clinic for the diagnostic evaluation of back and/or leg pain were included. Radiology reports were searched for keywords pertaining to VMSAs, such as "malignancy." Medical records of these patients were further reviewed for the clinical work-up and final diagnoses pertaining to the VMSA.

RESULTS

The study sample included 1503 individual patients, of whom 65 (4%) had MRI radiology reports that described a VMSA. Thirty-one (48%) of the 65 patients with VMSAs had further evaluation recommended by radiology. Ten (32%) of these 31 patients were followed clinically without further diagnostic testing for the VMSA. Of the 65 patients with VMSAs, only one was diagnosed with malignancy (multiple myeloma).

CONCLUSION

While VMSAs are not frequently found on thoracolumbar MRIs ordered to evaluate back and/or leg pain, there is a large amount of heterogeneity in how these abnormalities are documented and managed. This may indicate the need for clinical guidelines for the reporting and management of VMSAs detected on spine MRI and for improvement in communication between radiologists and ordering providers.

LEVEL OF EVIDENCE

3.

Incidental signal changes in the extensor carpi ulnaris on MRI

BACKGROUND

Magnetic resonance imaging (MRI) commonly finds musculoskeletal abnormalities incidental to the reason for ordering the test. The purpose of this study was to determine if the prevalence of extensor carpi ulnaris (ECU) signal changes on MRI varies between patients undergoing upper extremity MRI for assessment of clinically suspected ECU tendinopathy and those undergoing upper extremity MRI for other indications. Our secondary null hypotheses were that the prevalence of ECU signal changes on MRI does not vary based on patient age or sex and that the prevalence of ECU signal changes on MRI does not vary among other indications for MRI.

METHODS

We searched MRI reports of all patients undergoing MRI of the hand, wrist, or arm at our institution between 2001 and 2014 for signal changes in the ECU. The medical record was reviewed to determine the indication for the MRI and the presence of clinically suspected ECU tendinopathy.

RESULTS

ECU signal changes (overall prevalence of 13 %) were more common in patients undergoing MRI for a working clinical diagnosis of ECU tendinopathy or ulnar-sided wrist pain compared to patients evaluated for nonspecific pain and other indications. Age was independently associated with ECU signal changes on MRI. MRI signal changes are uncommonly associated with symptomatic tendinopathy (low positive predictive value).

CONCLUSIONS

ECU signal changes on MRI are common and often asymptomatic.

Incidence and evaluation of incidental abnormal bone marrow signal on magnetic resonance imaging

Purpose. The increased use of magnetic resonance imaging (MRI) has resulted in reports of incidental abnormal bone marrow (BM) signal. Our goal was to determine the evaluation of an incidental abnormal BM signal on MRI and the prevalence of a subsequent oncologic diagnosis. Methods. We conducted a retrospective cohort study of patients over age 18 undergoing MRI between May 2005 and October 2010 at Tufts Medical Center (TMC) with follow-up through November 2013. The electronic medical record was queried to determine imaging site, reason for scan, evaluation following radiology report, and final diagnosis. Results. 49,678 MRIs were done with 110 patients meeting inclusion criteria. Twenty two percent underwent some evaluation, most commonly a complete blood count, serum protein electrophoresis, or bone scan. With median follow-up of 41 months, 6% of patients were diagnosed with malignancies including multiple myeloma, non-Hodgkins lymphoma, metastatic non-small cell lung cancer, and metastatic adenocarcinoma. One patient who had not undergone evaluation developed breast cancer 24 months after the MRI. Conclusions. Incidentally noted abnormal or heterogeneous bone marrow signal on MRI was not inconsequential and should prompt further evaluation.