MR imaging of scaphoid fractures. Fat-saturated T2-weighted and Short tau inversion recovery images.

Louise Meincke,Carsten Ammitzbøl Lauridsen,Rie Eriksen,Ivanov Radev Dimitar

doi:10.7577/radopen.2150

Louise Meincke, Carsten Ammitzbøl Lauridsen + Show 2 more

Open Access

https://doi.org/10.7577/radopen.2150

Copy DOI

Abstract

Objective: Traumatic injuries of os scaphoideum are serious, and might lead to two main grades of consequences (i.e. osteoarthrosis or avascular necrosis), if a fracture remains undiagnosed. Bone bruise may be the only pathological sign of pain which can last for week or month. Articles describe the importance of early MRI and hereby predict bone bruise with the help of fat suppression sequence; however, only a limited selection articles compares various fat suppression techniques. The purpose of this prospective study was to compare the short tau inversion recovery (STIR) and T2 fat saturation (FAT SAT) sequences, sectional directed along the scaphoid bone axis. In relation to background fat intensity suppression, this study sought the sequence that best evaluated posttraumatic bone marrow edema (bone bruise) on scaphoid injury musculoskeletal magnetic resonance imaging (MRI, 1.5 T extremity scanner).Materials and methods: Two hundred and fifty-one patients with relevant trauma and positive clinical test for scaphoid bone fractures, exceeding no more than 14 days, underwent MRI examinations. A fast STIR and T2 FAT SAT fast spin echo sequence (FSE) were obtained using a comparable parameter setting (scan time ca. 3 minutes). Three experienced readers (one radiographer and two radiologists) carried out the evaluation blinded to each other’s, based on a quantitative assessment of size (area) and image quality (image contrast, IC and contrast-to-noise ratio, CNR). The study period lasted March 2014-April 2015. Sixty patients met the inclusion criteria and were enrolled. This prospective study was ethically approved by the institutional review board.Results: There were no significant difference between the bone bruise areas (P=0.45, P=0.44 and P=0.83) or CNR (P=0.31, P=0.38 and P=0.17). However, image contrast showed significant difference in favour of T2 FAT SAT in all three readers’ reports (P<0.05, P<0.05 and P<0.05).Conclusions: The two sequences appear almost identical. An interchangeable usage of the two sequences was found being acceptable for the diagnosis if the protocol is composed appropriately (1.5T). However, the T2 FAT SAT provided a higher image contrast by specific settings (e.g. short TI = 125 ms) compared to STIR.

Highlights

Fat suppression, an essential technique in MR imaging is used to improve depiction of bone marrow edema, determining the lipid content by suppressing the bright fat signal on T2 weighted fast spin echo images, improving the contrast resolution for resolving the bright fluid signal of bone marrow edema,[1,2,3,4] hereby bone marrow edema appears as a hyper intense area on proton density and T2 weighted sequences.Bone bruise is a term for a bone marrow edema, caused by a traumatic injury sustained from a forceful impact during sports, accidents or a direct hit
There were no significant difference between the bone bruise areas (P=0.45, P=0.44 and P=0.83) or contrast-to-noise ratio (CNR) (P=0.31, P=0.38 and P=0.17)
There was no significant difference between bone bruise area and the CNR (P=0.31, P=0.38 and P=0.17) on short tau inversion recovery (STIR) and T2 fat saturation (FAT SAT) in the areas drawn by the image readers (Figure 4)

Summary

Introduction

An essential technique in MR imaging is used to improve depiction of bone marrow edema, determining the lipid content by suppressing the bright fat signal on T2 weighted fast spin echo images, improving the contrast resolution for resolving the bright fluid signal of bone marrow edema,[1,2,3,4] hereby bone marrow edema appears as a hyper intense area on proton density and T2 weighted sequences.Bone bruise is a term for a bone marrow edema, caused by a traumatic injury (micro-trabecular fractures) sustained from a forceful impact during sports, accidents or a direct hit. The best way to help healing is to rest, support, and protect the bone or joint involved, and to apply conventional treatments for trauma.[1,2,3, 5,6,7,8,9,10,11,12,13,14] Identifying and locating the bone bruise are important for many reasons, knowing that a bone bruise on a T2 fat saturated image in conjunction with a fracture line on a T1 weighted image will set the diagnose for a fracture (a fat saturated sequence cannot stand alone for the diagnosis of a fracture).[3,6] Pseudoarthrosis, osteoarthrosis, avascular necrosis and chronic wrist pain, are potential consequences of undiagnosed fractures.[2,3,4,5,6,8] a standardized method for diagnostic and treatment purposes is important. The location and radiation pattern may indicate the point from which the trauma arises.[1,2,3,5,6,7,8,9,10,11,12,13,14]

Methods

Results

Conclusion