The Diagnostic Value of Abnormal Bone Marrow Signal Changes on Magnetic Resonance Imaging: Is Bone Marrow Biopsy Essential?

BACKGROUND

It is essential to determine whether bone marrow signal changes on magnetic resonance imaging (MRI) represent a physiological response or pathology; at present, the clinical significance of these signal changes is unclear. It is unknown whether a bone marrow biopsy is required when bone marrow signal changes are detected incidentally in individuals without suspected malignancy.

OBJECTIVE

The primary purpose of this study was to determine whether incidentally detected bone marrow signal changes on MRI performed for various reasons (at the time of admission or during follow-up) are clinically significant.

METHODS

We retrospectively evaluated the bone marrow biopsy clinical and laboratory findings of 42 patients with incidental bone marrow signal changes on MRI between September 2016 and January 2020. We also determined whether the patients were diagnosed with malignancy during admission or follow-up.

RESULTS

Of the 42 patients, three (7%) were diagnosed with hematological malignancies during admission, while two were diagnosed with multiple myeloma and one with B-cell acute lymphoblastic leukemia. Of the 42 patients, 35 had a mean follow-up of 40.6 ± 5.3 months. One patient was diagnosed with monoclonal gammopathy of undetermined significance four months after their first admission.

CONCLUSIONS

In addition to MRI, detailed clinical and laboratory evaluations should be performed to inform the decision for bone marrow biopsy and exclude hematological malignancy. If there is any doubt, a bone marrow biopsy should be performed. Moreover, since bone marrow signal changes may be a preliminary finding, follow-up of these patients is essential.

Acute phase supra-aortic intraluminal thrombus signal changes on magnetic resonance angiography: A case series: Intraluminal thrombus signal changes on MRA

BACKGROUND AND OBJECTIVES

Intraluminal thrombus (ILT) is a relatively rare cause of stroke. MRI/MRA is increasingly used for stroke patients eligible for acute treatment. Radiological ILT characteristics have never been studied systematically on MRA. We aimed to analyse signal changes and other radiological characteristics of ILT in the acute phase on MRA in a case series of ILT patients.

MATERIALS AND METHODS

Consecutive stroke patients registered in our stroke database between January 2013 and September 2022 were screened for supra-aortic ILT on MRA, in whom MRA was the first supra-aortic vessel imaging performed. Twelve patients were included for analysis. Radiological analysis on MRA included ILT localisation, diameter of the free-floating ILT component, total ITL length, degree of stenosis caused by ILT, and ILT signal intensity.

RESULTS

Median age was 65 years and 92% were men. Median time interval between stroke onset and MRA was 0.5 days. Atherosclerosis was the underlying ILT aetiology in half of the patients. The most frequent ILT localisation was the internal carotid artery, always involving the C1 segment. Median ILT diameter was 4.35 mm, median length 20.9 mm, median stenosis 65%, and with a homogeneous hypointensity of the ILT in 67% and a mixed hypo-hyperintensity in 33% (with ILT showing central hyperintensity surrounded by peripheral hypointensity).

DISCUSSION

When observed on MRA, ILT showed a homogeneous hypointensity in two-thirds and a mixed hypo-hyperintensity in one third of patients. In future studies, follow-up MRA scans should be performed to analyse whether these signal changes are time-related or influenced by antithrombotic treatment for ILT.

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.