Evaluation of MR-derived simulated CT-like images and simulated radiographs compared to conventional radiography in patients with shoulder pain: a proof-of-concept study

Abstract

Background To evaluate the diagnostic value of MR-derived CT-like images and simulated radiographs compared with conventional radiographs in patients with suspected shoulder pathology. Methods 3 T MRI of the shoulder including a 3D T1-weighted gradient echo sequence was performed in 25 patients (mean age 52.4 ± 18 years, 13 women) with suspected shoulder pathology. Subsequently a cone-beam forward projection algorithm was used to obtain intensity-inverted CT-like images and simulated radiographs. Two radiologists evaluated the simulated images separately and independently using the conventional radiographs as the standard of reference, including measurements of the image quality, acromiohumeral distance, critical shoulder angle, degenerative joint changes and the acromial type. Additionally, the CT-like MR images were evaluated for glenoid defects, subcortical cysts and calcifications. Agreement between the MR-derived simulated radiographs and conventional radiographs was calculated using Cohen’s Kappa. Results Measurements on simulated radiographs and conventional radiographs overall showed a substantial to almost perfect inter- and intra-rater agreement (κ = 0.69–1.00 and κ = 0.65–0.85, respectively). Image quality of the simulated radiographs was rated good to excellent (1.6 ± 0.7 and 1.8 ± 0.6, respectively) by the radiologists. A substantial agreement was found regarding diagnostically relevant features, assessed on Y- and anteroposterior projections (κ = 0.84 and κ = 0.69 for the measurement of the CSA; κ = 0.95 and κ = 0.60 for the measurement of the AHD; κ = 0.77 and κ = 0.77 for grading of the Samilson-Prieto classification; κ = 0.83 and κ = 0.67 for the grading of the Bigliani classification, respectively). Conclusion In this proof-of-concept study, clinically relevant features of the shoulder joint were assessed reliably using MR-derived CT-like images and simulated radiographs with an image quality equivalent to conventional radiographs. MR-derived CT-like images and simulated radiographs may provide useful diagnostic information while reducing the amount of radiation exposure.

Bone Tissue in Magnetic Resonance Imaging: Contribution of New Zero Echo Time Sequences

“…2,18 Another type of imaging, derived from postprocessing of 3D T1-weighted or ZTE acquisitions, can help diagnose calcifying tendinopathy: simulated radiography. Feuerriegel et al 19 reported its contribution on anteroposterior and Lamy's lateral views. Fine calcium deposits within the tendon are clearly seen on ZTE and simulated radiographs, whereas they may not be visible on conventional radiographs.…”

Editorial for “Comparing CT‐Like Images Based on Ultra‐Short Echo Time and Gradient Echo T1‐Weighted MRI Sequences for the Assessment of Vertebral Disorders Using Histology and True CT as the Reference Standard”

“…They can also gather information about the mineralization of the tumor matrix and soft tissue expansion. The role of CT‐like images has been demonstrated previously in the assessment of shoulder joint, 6 hands, 7 mandible, 8 vertebrae, 9 skull 4 and other issues like bony degenerative changes, 2 and bone neoplasm and metastasis 3 . However, these techniques are still new, and ex vivo evidence may contribute to a better understanding of the diagnostic value of CT‐like images in the assessment of vertebrae.…”

Imaging of traumatic mandibular fractures in young adults using CT-like MRI: a feasibility study

“…As a different approach, Deppe et al proposed the use of CT-like images based on susceptibility-weighted imaging (SWI) and were able to show comparable results to CT when assessing the sacroiliac joint [ 15 ]. More recently, the acquisition of CT-like images based on a three-dimensional (3D) T1-weighted spoiled gradient echo (T1 GRE) sequence has shown promising results when assessing osseous pathologies of the spine and shoulder [ 16 , 17 ]. Furthermore, CT-like imaging based on a 3D T1 GRE has been used to successfully assess periosteal growth pattern in malignant and benign bone tumors [ 18 ].…”