Fast field echo resembling a CT using restricted echo-spacing (FRACTURE): a novel MRI technique with superior bone contrast

Usefulness of Fast Field Echo Resembling a CT Using Restricted Echo-Spacing (FRACTURE) in Pediatric Lumbar Spondylolysis: A Case Report

Multiple computed tomography (CT) scans are required to diagnose lumbar spondylolysis stage and confirm fusion degree. However, multiple CT scans should be avoided because of radiation exposure. There are no case reports of complete diagnosis and treatment of pediatric lumbar spondylolysis without the use of CT. Fast field echo resembling a CT using restricted echo-spacing (FRACTURE) is a magnetic resonance imaging (MRI) sequence used to evaluate bone lesions. Here we report the case of a pediatric patient with lumbar spondylolysis who was able to return to sports after diagnosis, treatment, and bone union confirmation using MRI and FRACTURE.

Evaluation of fracture lines in adolescent lumbar spondylolysis using MR bone imaging as an alternative to computed tomography

PURPOSE

The diagnosis of adolescent lumbar spondylolysis typically requires computed tomography (CT) imaging; however, concerns regarding medical radiation exposure have emerged. With recent advancements in magnetic resonance imaging (MRI), it has become possible to acquire CT-like images using an MR bone imaging approach. This study aimed to investigate whether MR bone imaging can be utilised as a substitute for CT in evaluating the fracture line in patients with adolescent spondylolysis.

METHODS

We included 24 patients (28 levels) diagnosed with adolescent lumbar spondylolysis between June and August 2023. In addition to the usual MRI, MR bone imaging and CT scans of the affected area were performed. Two raters evaluated the fracture lines on sagittal images and determined their presence or absence. For statistical analysis, we calculated the sensitivity, specificity, and accuracy of MR bone imaging using CT as the reference standard. Furthermore, we assessed intra- and inter-observer agreement using Cohen's Kappa coefficient.

RESULTS

This study included 42 fractured pars and 14 non-fractured pars interarticularis controls. The sensitivity, specificity, and accuracy of MR bone imaging were 0.846, 1.00, and 0.893, respectively, for rater A and 0.789, 1.00, and 0.857, respectively, for rater B. The intra-observer agreement rates were 0.841 and 0.769 for raters A and B, respectively. Inter-observer agreement rates were 1.00 for CT and 0.875 for MR bone imaging.

CONCLUSION

Our results show that MR bone imaging can detect fracture lines in adolescent lumbar spondylosis at a level comparable to that of CT in clinical settings.

Mineralized tissue visualization with MRI: Practical insights and recommendations for optimized clinical applications

Magnetic resonance imaging (MRI) techniques that enhance the visualization of mineralized tissues (hereafter referred to as MT-MRI) are increasingly being incorporated into clinical practice, particularly in musculoskeletal imaging. These techniques aim to mimic the contrast provided by computed tomography (CT), while taking advantage of MRI's superior soft tissue contrast and lack of ionizing radiation. However, the variety of MT-MRI techniques, including three-dimensional gradient-echo, ultra-short and zero-echo time, susceptibility-weighted imaging, and artificial intelligence-generated synthetic CT, each offer different technical characteristics, advantages, and limitations. Understanding these differences is critical to optimizing clinical application. This review provides a comprehensive overview of the most commonly used MT-MRI techniques, categorizing them based on their technical principles and clinical utility. The advantages and disadvantages of each approach, including their performance in bone morphology assessment, fracture detection, arthropathy-related findings, and soft tissue calcification evaluation are discussed. Additionally, technical limitations and artifacts that may affect image quality and diagnostic accuracy, such as susceptibility effects, signal-to-noise ratio issues, and motion artifacts are addressed. Despite promising developments, MT-MRI remains inferior to conventional CT for evaluating subtle bone abnormalities and soft tissue calcification due to spatial resolution limitations. However, advances in deep learning and hardware innovations, such as artificial intelligence-generated synthetic CT and ultrahigh-field MRI, may bridge this gap in the future.

Recent topics in musculoskeletal imaging focused on clinical applications of AI: How should radiologists approach and use AI?

The advances in artificial intelligence (AI) technology in recent years have been remarkable, and the field of radiology is at the forefront of applying and implementing these technologies in daily clinical practice. Radiologists must keep up with this trend and continually update their knowledge. This narrative review discusses the application of artificial intelligence in the field of musculoskeletal imaging. For image generation, we focused on the clinical application of deep learning reconstruction and the recently emerging MRI-based cortical bone imaging. For automated diagnostic support, we provided an overview of qualitative diagnosis, including classifications essential for daily practice, and quantitative diagnosis, which can serve as imaging biomarkers for treatment decision making and prognosis prediction. Finally, we discussed current issues in the use of AI, the application of AI in the diagnosis of rare diseases, and the role of AI-based diagnostic imaging in preventive medicine as part of our outlook for the future.

Detecting soft-tissue interposition in proximal tibial physeal injury based on fast field echo resembling a computed tomography using restricted echo-spacing (FRACTURE): a case report

Fast field echo resembling a computed tomography using restricted echo-spacing (FRACTURE) is a method of magnetic resonance bone imaging that provides computed tomography-like image contrast based on a high-resolution three-dimensional gradient sequence. This is the first report on the application of FRACTURE in the detection of soft-tissue interposition. We present a case of Ogden type IV proximal tibial physeal injury in an 11-year-old boy. FRACTURE revealed soft-tissue interposition into the displaced physis as high signal. Intraoperatively, the ruptured periosteum was entrapped into the displaced physis. In addition to the benefit of radiation-free imaging, FRACTURE is useful for assisting in the detection of interposition for many radiologists and orthopedic surgeons, and it may be useful in determining the treatment strategy for proximal tibial physeal injury.

Prevalence of abnormal ultrasonography findings in the posterosuperior humeral head of asymptomatic collegiate baseball pitchers

BACKGROUND

The posterosuperior humeral head contacts the glenoid during pitching. While magnetic resonance imaging often detects abnormalities in the posterosuperior humeral head of baseball pitchers, ultrasonography may also be effective in identifying these abnormalities. However, studies on such abnormalities in asymptomatic players are limited. Thus, this study aimed to determine the prevalence of abnormal findings in the humeral head using ultrasonography in asymptomatic collegiate baseball pitchers.

METHODS

We utilized ultrasonography to assess abnormal findings in the humeral head, defined as a break in continuity or an irregular surface around the infraspinatus insertion, in 33 college baseball pitchers (pitcher group) and 30 college students without experience in overhead sports (control group). For 11 of the 33 pitchers, computed tomography-like images were used to locate the abnormalities. The location was quantitatively identified in the axial plane using a clock system, with the bicipital groove designated as 12 o'clock, and qualitatively assessed in the sagittal plane. Shoulder internal and external rotation ranges of motion (IR and ER ROMs) and humeral retroversion were measured using an inclinometer. The prevalence of abnormalities among the 4 subgroups (throwing and nonthrowing shoulders of the pitcher group and dominant and nondominant shoulders of the control group) was compared using the Fisher's exact test. A paired t-test was also performed to compare the IR and ER ROMs, as well as the humeral retroversion between each group's throwing (dominant) and nonthrowing (nondominant) sides.

RESULTS

The prevalence of abnormalities was significantly higher (76%) in the throwing shoulder of the pitcher group than in the other shoulder groups (<.001). The mean position of the humeral head abnormalities in the axial plane was 8:32 ± 0:21 in the clock system, with all abnormalities located at the infraspinatus insertion on the greater tuberosity in the sagittal plane according to CT-like image analysis. While ER ROM and humeral retroversion were greater in the throwing shoulder, IR ROM was less than that in the non-throwing shoulder in the pitcher group (<.001).

CONCLUSION

Ultrasonographic assessments revealed a higher prevalence of abnormalities in humeral head for asymptomatic collegiate baseball pitchers. Repetitive throwing motions may lead not only to adaptations in the ROM of the shoulder joint but also to abnormalities in the humeral head. Thus, ultrasonography may help identify asymptomatic baseball players with physiological internal impingement.

Zero Echo Time and Similar Techniques for Structural Changes in the Sacroiliac Joints

Spondyloarthritis (SpA) encompasses inflammatory disorders affecting the axial skeleton, with sacroiliitis as a hallmark feature of axial SpA (axSpA). Imaging plays a vital role in early diagnosis and disease monitoring. Magnetic resonance imaging (MRI) is the preferred modality for detecting early inflammatory changes in axSpA, whereas structural lesions are better visualized using computed tomography (CT). However, synthetic computed tomography (sCT), a technique that generates CT-like images from MRI data, including deep learning methods, zero echo time, ultrashort echo time, and gradient-recalled echo sequences, has emerged as an innovative tool. It offers detailed anatomical resolution without ionizing radiation and combines the advantages of both, MRI and CT, by enabling the simultaneous evaluation of inflammatory and structural lesions. This review explores the potential role of MRI-based sCT in assessing structural changes in the sacroiliac joints, particularly in the context of axSpA, discussing conventional imaging and highlighting the potential of sCT to enhance early detection and monitoring of sacroiliitis.

Patterns of ankle injury in soccer: MRI clues to traumatic mechanism

Understanding the traumatic mechanisms of ankle injuries in soccer is crucial for an accurate and complete MRI diagnosis. Many ankle injuries share universal mechanisms seen in other athletic activities, but certain patterns are found to be more specific and relatively unique to soccer. Ankle impingement syndromes encountered in soccer encompass a spectrum of disorders that include anterior and posterior impingement categories, with anterior impingement representing pathology relatively specific to soccer. Lateral ligamentous sprains are one of the most common injuries; however, there is a higher rate of injuries to the medial structures in soccer as compared to other sports. Ankle fractures are uncommon in soccer while bone contusions and chondral and osteochondral injuries frequently accompany ligamentous sprains. Tendon abnormalities in soccer most commonly result from overuse injuries and typically affect peroneal tendons, posterior and anterior tibialis tendons, and Achilles tendon. Acute Achilles tendon ruptures occur in both recreational players and elite soccer athletes. Tibialis anterior friction syndrome may mimic tibial stress fractures. Long-term sequelae of acute traumatic and chronic overuse ankle injuries in professional soccer players manifest as ankle osteoarthritis that is more prevalent compared to not only the general population, but also to former elite athletes from other sports. This article examines the most common and specific injuries in soccer in order of their frequency.

Pearls and pitfalls in imaging of axial spondyloarthritis for rheumatologists

This review provides key insights into sacroiliitis imaging, covering anatomy, imaging techniques, and interpretation. It focuses on normal physiological changes in young to middle-aged women, children, and the elderly that can resemble sacroiliitis. We emphasize the importance of distinguishing between active and structural lesions, as highlighted in the recent ASAS-SPARTAN standardized magnetic resonance imaging protocol. Physicians should be aware that bone marrow oedema signals on magnetic resonance imaging, a hallmark of active inflammation in axial spondyloarthritis, can also be observed in young to middle-aged women, especially postpartum, even without spondyloarthritis. Paediatric sacroiliac joints may show changes mimicking inflammation due to ongoing bone growth. Furthermore, degenerative changes in the sacroiliac joint are common with advancing age and can be mistaken for sacroiliitis or interpreted as structural changes. The presence of accessory sacroiliac joints, prone to degeneration, further complicates diagnosis. Accurate interpretation requires considering these normal variations to avoid misdiagnosing spondyloarthritis. Collaboration between clinicians and radiologists is crucial, especially when encountering atypical or clinically inconsistent findings.

Assessment of proximal tibial fractures with 3D FRACTURE (fast field echo resembling a CT using restricted echo-spacing) MRI-intra-individual comparison with CT

OBJECTIVES

To evaluate the feasibility and diagnostic performance of a 3D FRACTURE (fast field echo resembling a CT using restricted echo-spacing) MRI sequence for the detection and classification of proximal tibial fractures compared with CT.

METHODS

We retrospectively included 126 patients (85 male; 39.6 ± 14.5 years) from two centers following acute knee injury. Patients underwent knee MRI at 3 T including FRACTURE-MRI. Additional CT was performed in patients with tibial fractures (32.5%; n = 41) as the reference standard for fracture classification. Two radiologists independently evaluated FRACTURE-MRI for the presence of fractures and classified them according to AO/OTA, Schatzker, and the 10-segment classification. Diagnostic performance of FRACTURE-MRI was assessed using crosstabulations. Inter-reader agreement was estimated using Krippendorff's alpha. Image quality was graded on a five-point scale (5 = excellent; 1 = inadequate definition of fracture lines and fracture displacement) and assessed using estimated marginal means.

RESULTS

Fractures were detected by FRACTURE-MRI with a sensitivity of 91.5% (83.2-96.5%) and a specificity of 97.1% (93.3-99.0%). Regarding fracture classification, diagnostic performances were slightly lower, with the 10-segment classification yielding the best sensitivity of 85.7% (81.4-89.3%) and specificity of 97.4% (96.6-98.0%), and the Schatzker classification yielding the lowest sensitivity of 78.2% (67.4-86.8%) and specificity of 97.7% (94.1-99.4%). Inter-reader agreement across the whole cohort was excellent (Krippendorff's alpha 0.89-0.96) and when considering only patients with fractures, good to acceptable (0.48-0.91). Image quality was rated good (estimated marginal mean 4.3 (4.1-4.4)).

CONCLUSION

FRACTURE-MRI is feasible at 3 T enabling accurate delineation of fracture lines for precise diagnosis and classification of proximal tibial fractures.

KEY POINTS

Question CT-like MRI is increasingly being evaluated for its advantages in bone imaging but is not yet established in routine practice. Findings The 3D FRACTURE (fast field echo resembling a CT using restricted echo-spacing) MRI sequence is feasible at 3 T, allowing for diagnosis and classification of proximal tibial fractures. Clinical relevance FRACTURE-MRI might be a helpful alternative to computed tomography in an acute trauma setting by reducing costs and radiation exposure in patients requiring a preoperative MRI anyway.

CT-like MR images to assess changes after radiotherapy for bone metastasis: a case report

Setting the echo time to zero allows for the acquisition of bone images that were otherwise difficult to obtain with conventional MRI and clear visualization of CT-like MR images. This technique is mainly useful for detecting compression fractures; however, studies examining bone tumours have been lacking. Furthermore, no reports to date have investigated the usefulness of MRI for evaluating images before and after radiotherapy (RT) for bone tumours. Therefore, plain CT and MRI (T1/T2-weighted image and CT-like MRI) were performed under the same conditions before and after radiation therapy (RT) and examined the obtained images. An 86-year-old man received RT (30 Gy/3 fraction) for painful lumbar metastasis from prostate cancer. At 2 months after RT, no changes in T2-weighted images and plain CT scans were noted, but CT-like MRI showed an increase in the signal inside the bone metastasis. Examining how the images change over time is imperative given the difficulty of predicting the duration of the pain relief effects of RT for bone metastases. Therefore, the current case report explored whether combining various modalities, such as CT and MRI, could predict prognosis. We highlight the importance of investigating whether signal changes are correlated with pain symptoms and whether MRI can be a predictor.

Characteristics of ulnohumeral joint alignment in distal ulnar collateral ligament tears compared to proximal tears in baseball and softball players

BACKGROUND

Dysfunctional features of distal ulnar collateral ligament (UCL) tears remain unclear. We aimed to clarify the characteristics of valgus and rotational alignment of the ulnohumeral joint at rest in distal UCL tears compared with those in proximal tears.

METHODS

The participants were baseball and softball players diagnosed with UCL tears, classified as proximal, middle, or distal. Valgus and rotation alignment of ulnohumeral joint were measured using computed tomography-like images and a 3-dimensional image analysis system. For valgus alignment, the medial joint space was measured as the distance between the medial epicondyle and the ulnar coronoid processes. For rotational alignment, the medial distance (MD) and lateral distance (LD) of the ulnohumeral joint were measured in the reconstructed axial views at the medial epicondyle and trochlear levels. MD was measured as the distance between the medial edges of the olecranon fossa and trochlear notch, whereas LD was measured as the distance between the lateral edges of the olecranon fossa and trochlear notch.

RESULTS

Of the 20 included cases, 6 (30%) were distal and 14 (70%) were proximal UCL tears. The medial joint space results showed no significant difference between the 2 groups. The MD was significantly higher in the distal tear than the proximal tear only at the trochlea level. The LD showed no significant difference at either level.

CONCLUSION

Distal tears did not show hypervalgus malalignment compared to proximal tears using conventional measurements. In contrast, distal tears showed hyperinternal rotation malalignment of the ulnohumeral joint only at the distal side of the joint compared to proximal tears.

Evaluation of temporomandibular joint osteoarthritis using a new FRACTURE sequence of 3.0T MRI

OBJECTIVES

The purpose of this study was to determine the usefulness of a new MRI sequence, CT-like fast field echo with limited echo-spacing (FRACTURE), in diagnosing temporomandibular joint (TMJ) osteoarthritis compared with routine MRI TMJ sequences.

METHODS

The study sample comprised 76 patients (152 joints) who underwent MRI and CT examinations to diagnose TMJ disorders. Two specialists in oral and maxillofacial radiology assessed the bony changes of the TMJ on FRACTURE, proton density-weighted (PDw), and fat-suppression T2-weighted (T2wFS) sequences. Receiver operating characteristic curves were plotted for each sequence, and the accuracy, sensitivity, specificity, and area under the curve (AUC) were calculated. Additionally, the interobserver agreement (Cohen's kappa value) and sensitivity in assessing each osteoarthritis finding were calculated for each sequence.

RESULTS

The FRACTURE sequence had the highest diagnostic performance, with an accuracy of 0.85, sensitivity of 0.85, specificity of 0.84, and AUC of 0.84. These values were 0.84, 0.72, 0.91, and 0.80, respectively, for the PDw sequence, and 0.83, 0.72, 0.91, and 0.79, respectively, for the T2wFS sequence. The AUC did not significantly differ between the FRACTURE and PDw sequences (Delong test, P > .05), but did significantly differ between the FRACTURE and T2wFS sequences (P < .05). For all osteoarthritis findings, the FRACTURE sequence had the highest kappa values and the highest sensitivity.

CONCLUSIONS

FRACTURE sequencing may be a promising tool for the diagnosis of TMJ osteoarthritis compared with other conventional sequences.

mFFE CT-like MRI Sequences for the Assessment of Vertebral Fractures

OBJECTIVES

The aim of this study was to evaluate the diagnostic performance, image quality, and inter- and intra-observer agreement of the 3D T1 multi-echo fast field echo (mFFE) sequence in cervico-thoraco-lumbar vertebral fractures compared with conventional computed tomography (CT) as the gold standard.

METHODS

We conducted a prospective single-centre study including 29 patients who underwent spinal magnetic resonance imaging (MRI) at the surgeon's request, in addition to CT for vertebral fracture assessment and classification. A 3D T1 mFFE sequence was added to the standard MRI protocol. Consecutively, two readers analyzed the 3D mFFE sequence alone, the 3D mFFE sequence with the entire MRI protocol, including the STIR and T1 sequences, and, finally, the CT images in random order and 1 month apart. A standardized assessment was performed to determine the presence or absence of a fracture, its location, its classification according to the Genant and AO classifications for traumatic and osteoporotic fractures, respectively, the loss of height of the anterior and posterior walls of the vertebral body, and the presence of concomitant disco-ligamentous lesions. Contingency tables, intraclass correlation coefficients, and Cohen's kappa tests were used for statistical analysis.

RESULTS

A total of 25 fractures were recorded (48% cervical, 20% thoracic, and 32% lumbar), of which 52% were classified A, according to the AO classification system. The quality of the 3D mFFE image was good or excellent in 72% of cases. Inter-observer agreement was near perfect (0.81-1) for vertebral body height and for AO and Genant classifications for all modalities. Intra-observer agreement was strong-to-near perfect between CT and the 3D mFFE sequence. Regarding the diagnostic performance of the 3D mFFE sequence, the sensitivity was 0.9200 and 0.9600, the specificity was 0.9843 and 0.9895, and the accuracy was 0.9861 and 0.9769 for Readers 1 and 2, respectively. In addition, up to 40% of intervertebral disc lesions and 33% of ligamentous lesions were detected by the 3D mFFE sequence compared to CT, allowing four AO type A fractures to be reclassified as type B.

CONCLUSIONS

The 3D mFFE sequence allows accurate diagnosis of vertebral fractures, with superiority over CT in detecting disco-ligamentous lesions and a more precise classification of fractures, which can prompt clinicians to adapt their management despite an image quality that still requires improvement in some cases.

KEY POINTS

Vertebral fractures and disco-ligamentous lesions can be assessed using CT-like MRI sequences, with 3D T1 mFFE being superior to CT for the detection of disco-ligamentous lesions. CT-like images using the 3D T1 mFFE sequence improve the diagnostic accuracy of bone structures in MRI.

Super-resolution deep learning reconstruction approach for enhanced visualization in lumbar spine MR bone imaging

OBJECTIVES

This study aims to assess the effectiveness of super-resolution deep-learning-based reconstruction (SR-DLR), which leverages k-space data, on the image quality of lumbar spine magnetic resonance (MR) bone imaging using a 3D multi-echo in-phase sequence.

MATERIALS AND METHODS

In this retrospective study, 29 patients who underwent lumbar spine MRI, including an MR bone imaging sequence between January and April 2023, were analyzed. Images were reconstructed with and without SR-DLR (Matrix sizes: 960 × 960 and 320 × 320, respectively). The signal-to-noise ratio (SNR) of the vertebral body and spinal canal and the contrast and contrast-to-noise ratio (CNR) between the vertebral body and spinal canal were quantitatively evaluated. Furthermore, the slope at half-peak points of the profile curve drawn across the posterior border of the vertebral body was calculated. Two radiologists independently assessed image noise, contrast, artifacts, sharpness, and overall image quality of both image types using a 4-point scale. Interobserver agreement was evaluated using weighted kappa coefficients, and quantitative and qualitative scores were compared via the Wilcoxon signed-rank test.

RESULTS

SNRs of the vertebral body and spinal canal were notably improved in images with SR-DLR (p < 0.001). Contrast and CNR were significantly enhanced with SR-DLR compared to those without SR-DLR (p = 0.023 and p = 0.022, respectively). The slope of the profile curve at half-peak points across the posterior border of the vertebral body and spinal canal was markedly higher with SR-DLR (p < 0.001). Qualitative scores (noise: p < 0.001, contrast: p < 0.001, artifact p = 0.042, sharpness: p < 0.001, overall image quality: p < 0.001) were superior in images with SR-DLR compared to those without. Kappa analysis indicated moderate to good agreement (noise: κ = 0.56, contrast: κ = 0.51, artifact: κ = 0.46, sharpness: κ = 0.76, overall image quality: κ = 0.44).

CONCLUSION

SR-DLR, which is based on k-space data, has the potential to enhance the image quality of lumbar spine MR bone imaging utilizing a 3D gradient echo in-phase sequence.

CLINICAL RELEVANCE STATEMENT

The application of SR-DLR can lead to improvements in lumbar spine MR bone imaging quality.

Bone Imaging of the Knee Using Short-Interval Delta Ultrashort Echo Time and Field Echo Imaging

Background: Computed tomography (CT) is the preferred imaging modality for bone evaluation of the knee, while MRI of the bone is actively being developed. We present three techniques using short-interval delta ultrashort echo time (δUTE), field echo (FE), and FE with high resolution-deep learning reconstruction (HR-DLR) for direct bone MRI. Methods: Knees of healthy volunteers (n = 5, 3 females, 38 ± 17.2 years old) were imaged. CT-like images were generated by averaging images from multiple echoes and inverting. The bone signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined. Results: The δUTE depicted a cortical bone with high signal intensity but could not resolve trabeculae. In contrast, both the FE and FE HR-DLR images depicted cortical and trabecular bone with high signal. Quantitatively, while δUTE had a good bone SNR of ~100 and CNR of ~40 for the cortical bone, the SNR for the FE HR-DLR was significantly higher (p < 0.05), at over 400, and CNR at over 200. Conclusions: For 3D rendering of the bone surfaces, the δUTE provided better image contrast and separation of bone from ligaments and tendons than the FE sequences. While there still is no MRI technique that provides a perfect CT-like contrast, continued advancement of MRI techniques may provide benefits for specific use cases.

Bone injury imaging in knee and ankle joints using fast-field-echo resembling a CT using restricted echo-spacing MRI: a feasibility study

Purpose

To explore the consistency of FRACTURE (Fast-field-echo Resembling A CT Using Restricted Echo-spacing) MRI and X-Ray/computerized tomography (CT) in the evaluation of bone injuries in knee and ankle joints.

Methods

From Nov. 2020 to Jul. 2023, 42 patients with knee joint or ankle joint injuries who underwent FRACTURE MRI examinations were retrospectively collected. 11 patients were examined by both X-Ray and FRACTURE examinations. 31 patients were examined by both CT and FRACTURE examinations. The fracture, osteophyte, and bone destruction of the joints were evaluated by two radiologists using X-Ray/CT and FRACTURE images, respectively. Kappa test was used for consistency analysis.

Results

The evaluation consistency of fracture, osteophyte and bone destruction via X-Ray and FRACTURE images by radiologist 1 were 0.879, 0.867 and 0.847 respectively, and for radiologist 2 were 0.899, 0.930, and 0.879, respectively. The evaluation consistency of fracture, osteophyte and bone destruction via CT and FRACTURE images by radiologist 1 were 0.938, 0.937 and 0.868 respectively, and for radiologist 2 were 0.961, 0.930, and 0.818, respectively.

Conclusion

For fracture, osteophyte, and bone destruction of knee and ankle joints. FRACTURE MRI showed a high consistency with X-Ray/CT examinations.

A Novel Evaluation for Vertebral Artery Course Using 3D Magnetic Resonance Imaging with Computed Tomography -like Bone Contrast and Magnetic Resonance Angiography: A Proof of Concept Study

OBJECTIVE

Vertebral artery (VA) injury poses a significant risk in cervical spine surgery, necessitating accurate preoperative assessment. This study aims to introduce and validate a novel approach that combines the Fast field echo that resembles a computed tomography using restricted echo spacing (FRACTURE) sequence with Time of Flight (TOF) Magnetic Resonance Angiography (MRA) for comprehensive evaluation of VA courses in the cervical spine.

MATERIALS AND METHODS

A total of eight healthy volunteers and two patients participated in this study. The FRACTURE sequence provided high-resolution bone images of the cervical spine, while TOF MRA offered non-invasive vascular imaging. Fusion images were created by merging FRACTURE and MRA modalities to simultaneously visualize cervical spine structures and VA courses. Board-certified orthopedic spine surgeons independently evaluated images to assess the visibility of anatomical characteristics of the VA course by Likert-scale.

RESULTS

The FRACTURE-MRA fusion images effectively depicted the extraosseous course of the VA at the craniovertebral junction, the intraosseous course of the VA at the craniovertebral junction, the VA entrance level to the transverse foramen, and the side-to-side asymmetry of bilateral VAs. Additionally, clinical cases demonstrated the utility of the proposed technique in identifying anomalies and guiding surgical interventions.

CONCLUSIONS

The integration of the FRACTURE sequence and TOF MRA presents a promising methodology for the precise evaluation of VA courses in the cervical spine. This approach improves preoperative planning for cervical spine surgery with detailed anatomy and is a valuable alternative to conventional methods without contrast agents.

Editorial Commentary: Both 3-Dimensional Magnetic Resonance Imaging and Computed Tomography Are Valuable for Determination of Glenoid and Humeral Bone Loss in Patients With On- and Off-Track Shoulder Instability

Improving the modalities for advanced glenohumeral joint imaging has been an important area to address in the field of orthopaedic surgery. The current gold standard for imaging glenoid and humeral bone loss in patients with shoulder instability, 3-dimensional (3D) computed tomography (CT), provides high-quality 3D images of bones but comes with a cost of extra time, additional imaging because of the need for an additional magnetic resonance imaging (MRI) scan, and exposure to radiation. Three-dimensional MRI is a promising solution that can produce high-contrast images depicting both bony structures and soft tissues. Multiple 3D MRI sequences have been studied, with the FRACTURE (fast field echo resembling a CT using restricted echo-spacing) sequence showing high comparability of bony measurements to 3D CT scans, as well as the ability for widespread clinical use. Recent research has shown minimal differences in 3D CT and 3D MRI and has confirmed that 3D imaging does provide clinically relevant data for determination of on- and off-track instability. Finally, the gold standard for determination of bone loss is the measurement of deficiencies in the surface area of the glenoid using the best-fit circle with a diameter line measurement. This is most practical for day-to-day clinical use.

Three-Dimensional Magnetic Resonance Imaging Fast Field Echo Resembling a Computed Tomography Using Restricted Echo-Spacing Sequence Is Equivalent to 3-Dimensional Computed Tomography in Quantifying Bone Loss and Measuring Shoulder Morphology in Patients With Shoulder Dislocation

PURPOSE

To evaluate the equivalence of 3-dimensional (3D) magnetic resonance imaging (MRI) (FRACTURE [Fast field echo Resembling A CT Using Restricted Echo-spacing]) and 3D computed tomography (CT) in quantifying bone loss in patients with shoulder dislocation and measuring morphologic parameters of the shoulder.

METHODS

From July 2022 to June 2023, patients with anterior shoulder dislocation who were aged 18 years or older and underwent both MRI and CT within 1 week were included in the study. The MRI protocol included an additional FRACTURE sequence. Three-dimensional reconstructions of MRI (FRACTURE) and CT were completed by 2 independent observers using Mimics software (version 21.0) through simple threshold-based segmentation. For bone defect cases, 2 independent observers evaluated glenoid defect, percentage of glenoid defect, glenoid track, Hill-Sachs interval, and on-track/off-track. For all cases, glenoid width, glenoid height, humeral head-fitting sphere radius, critical shoulder angle, glenoid version, vault depth, and post-processing time were assessed. The paired t test was used to assess the differences between 3D CT and 3D MRI (FRACTURE). Bland-Altman plots were constructed to evaluate the consistency between 3D CT and 3D MRI (FRACTURE). Interobserver and intraobserver agreement was evaluated with the interclass correlation coefficient. The paired χ2 test and Cohen κ statistic were used for binary variables (on-track/off-track).

RESULTS

A total of 56 patients (16 with bipolar bone defect, 5 with only Hill-Sachs lesion, and 35 without bone defect) were ultimately enrolled in the study. The measurements of 21 bone defect cases showed no statistically significant differences between 3D CT and 3D MRI: glenoid defect, 4.05 ± 1.44 mm with 3D CT versus 4.16 ± 1.39 mm with 3D MRI (P = .208); percentage of glenoid defect, 16.21% ± 5.95% versus 16.61% ± 5.66% (P = .199); glenoid track, 18.02 ± 2.97 mm versus 18.08 ± 2.98 mm (P = .659); and Hill-Sachs interval, 14.29 ± 1.93 mm versus 14.35 ± 2.07 mm (P = .668). No significant difference was found between 3D CT and 3D MRI in the diagnosis of on-track/off-track (P > .999), and diagnostic agreement was perfect (κ = 1.00, P < .001). There were no statistically significant differences between the 2 examination methods in the measurements of all 56 cases, except that the post-processing time of 3D MRI was significantly longer than that of 3D CT: glenoid height, 34.56 ± 1.98 mm with 3D CT versus 34.67 ± 2.01 mm with 3D MRI (P = .139); glenoid width, 25.32 ± 1.48 mm versus 25.45 ± 1.47 mm (P = .113); humeral head-fitting sphere radius, 22.91 ± 1.70 mm versus 23.00 ± 1.76 mm (P = .211); critical shoulder angle, 33.49° ± 2.55° versus 33.57° ± 2.51° (P = .328); glenoid version, -3.25° ± 2.57° versus -3.18° ± 2.57° (P = .322); vault depth, 37.43 ± 1.68 mm versus 37.58 ± 1.75 mm (P = .164); and post-processing time, 89.66 ± 10.20 seconds versus 360.93 ± 26.76 seconds (P < .001). For all assessments, the Bland-Altman plots showed excellent consistency between the 2 examination methods, and the interclass correlation coefficients revealed excellent interobserver and intraobserver agreement.

CONCLUSIONS

Three-dimensional MRI (FRACTURE) is equivalent to 3D CT in quantifying bone loss in patients with shoulder dislocation and measuring shoulder morphologic parameters.

LEVEL OF EVIDENCE

Level II, development of diagnostic criteria (consecutive patients with consistently applied reference standard and blinding).

Is 3T MR nerve-bone fusion imaging a viable alternative to MRI-CBCT to identify the relationship between the inferior alveolar nerve and mandibular third molar

OBJECTIVES

To investigate the feasibility of MRI nerve-bone fusion imaging in assessing the relationship between inferior alveolar nerve (IAN) / mandibular canal (MC) and mandibular third molar (MTM) compared with MRI-CBCT fusion.

MATERIALS AND METHODS

The MRI nerve-bone fusion and MRI-CBCT fusion imaging were performed in 20 subjects with 37 MTMs. The Hausdorff distance (HD) value and dice similarity coefficient (DSC) was calculated. The relationship between IAN/MC and MTM roots, inflammatory, and fusion patterns were compared between these two fused images. The reliability was assessed using a weighted κ statistic.

RESULTS

The mean HD and DSC ranged from 0.62 ~ 1.35 and 0.83 ~ 0.88 for MRI nerve-bone fusion, 0.98 ~ 1.50 and 0.76 ~ 0.83 for MRI-CBCT fusion. MR nerve-bone fusion had considerable reproducibility compared to MRI-CBCT fusion in relation classification (MR nerve-bone fusion κ = 0.694, MRI-CBCT fusion κ = 0.644), direct contact (MR nerve-bone fusion κ = 0.729, MRI-CBCT fusion κ = 0.720), and moderate to good agreement for inflammation detection (MR nerve-bone fusion κ = 0.603, MRI-CBCT fusion κ = 0.532, average). The MR nerve-bone fusion imaging showed a lower ratio of larger pattern compared to MR-CBCT fusion (16.2% VS 27.3% in the molar region, and 2.7% VS 5.4% in the retromolar region). And the average time spent on MR nerve-bone fusion and MRI-CBCT fusion was 1 min and 3 min, respectively.

CONCLUSIONS

Both MR nerve-bone fusion and MRI-CBCT fusion exhibited good consistency in evaluating the spatial relationship between IAN/MC and MTM, fusion effect, and inflammation detection.

CLINICAL RELEVANCE

MR nerve-bone fusion imaging can be a preoperative one-stop radiation-free examination for patients at high risk for MTM surgery.

Fast field echo resembling CT using restricted echo-spacing (FRACTURE) MR sequence can provide craniocervical region images comparable to a CT in dogs

Magnetic resonance imaging (MRI) is essential for evaluating cerebellar compression in patients with craniocervical junction abnormalities (CJA). However, it is limited in depicting cortical bone because of its short T2 relaxation times, low proton density, and organized structure. Fast field echo resembling a computed tomography (CT) scan using restricted echo-spacing (FRACTURE) MRI, is a new technique that offers CT-like bone contrast without radiation. This study aimed to assess the feasibility of using FRACTURE MRI for craniocervical junction (CCJ) assessment compared with CT and conventional MRI, potentially reducing the need for multiple scans and radiation exposure, and simplifying procedures in veterinary medicine. CT and MRI of the CCJ were obtained from five healthy beagles. MRI was performed using three-dimensional (3D) T1-weighted, T2-weighted, proton density-weighted (PDW), single echo-FRACTURE (sFRACTURE), and multiple echo-FRACTURE (mFRACTURE) sequences. For qualitative assessment, cortical delineation, trabecular bone visibility, joint space visibility, vertebral canal definition, overall quality, and artifacts were evaluated for each sequence. The geometrical accuracy, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were quantified. Both sFRACTURE and CT images provided significantly higher scores for cortical delineation and trabecular bone visibility than conventional MRI. Joint space visibility and vertebral canal definition were similar to those observed on CT images, regardless of the MR sequence. In the quantitative assessment, the distances measured on T2-weighted images differed significantly from those measured on CT. There were no significant differences between the distances taken using T1-weighted, PD-weighted, sFRACTURE, mFRACTURE and those taken using CT. T1-weighted and sFRACTURE had a higher SNR for trabecular bone than CT. The CNR between the cortical bone and muscle was high on CT and FRACTURE images. However, the CNR between the cortical and trabecular bones was low in mFRACTURE. Similar to CT, FRACTURE sequences showed higher cortical delineation and trabecular bone visibility than T2-weighted, T1-weighted, and PDW CCJ sequences. In particular, sFRACTURE provided a high signal-to-noise ratio (SNR) of the trabecular bone and a high CNR between the cortical bone and muscle and between the cortical and trabecular bones. FRACTURE sequences can complement conventional MR sequences for bone assessment of the CCJ in dogs.

Fast field echo resembling a CT using restricted echo-spacing (FRACTURE) sequence for shoulder joint in normal dogs

Shoulder disease is a common cause of forelimb lameness in dogs. Determining the precise underlying cause of shoulder lameness can be challenging, especially in veterinary practice. Computerized tomography (CT) is often the preferred imaging modality for bone evaluation; however, it uses ionizing radiation and provides limited soft tissue contrast. Conversely, magnetic resonance imaging (MRI) offers excellent soft tissue contrast but has limitations in bone imaging. This study aimed to introduce a new technical innovation that enhances cortical and trabecular bone contrast on MRI, which we refer to as Fast Field Echo Resembling a CT Using Restricted Echo-Spacing (FRACTURE). In this prospective pilot study, we aimed to evaluate the use of FRACTURE, CT, and conventional MRI sequences in assessing the normal canine shoulder using a 3.0 Tesla MRI scanner. Five research beagle dogs were included, and the following pulse sequences were acquired for each dog (1): three-dimensional (3D) FRACTURE, (2) T2-weighted (T2W) images using 3D turbo spin echo (TSE), (3) T1-weighted (T1W) images using 3D TSE, (4) PD-weighted (PDW) images using 3D TSE, and (5) CT. Various parameters, including the delineation of cortical bone (intertubercular groove, greater tubercle, and lesser tubercle), conspicuity of the trabecular bone, shoulder joint visualization, and image quality, were measured for each dog and sequence. In all sequences, the shoulder joint was successfully visualized in all planes with mild motion artifacts. The intertubercular groove was best visualized on CT and FRACTURE. Both the greater and lesser tubercles were easily identified on the CT, FRACTURE, and PDW images. The trabecular pattern scored significantly higher in the CT and FRACTURE images compared to the T1W, T2W, and PDW images. Overall, the visualization of the shoulder joint was excellent in all sequences except for T1W. The use of FRACTURE in combination with conventional MRI sequences holds promise for facilitating not only soft tissue evaluation but also cortical and trabecular bone assessment. The findings from this study in normal dogs can serve as a foundation for further FRACTURE studies in dogs with shoulder diseases.

Assessment of glenoid bone loss and other osseous shoulder pathologies comparing MR-based CT-like images with conventional CT

OBJECTIVES

To evaluate and compare the diagnostic performance of CT-like images based on a 3D T1-weighted spoiled gradient-echo sequence (T1 GRE), an ultra-short echo time sequence (UTE), and a 3D T1-weighted spoiled multi-echo gradient-echo sequence (FRACTURE) with conventional CT in patients with suspected osseous shoulder pathologies.

MATERIALS AND METHODS

Patients with suspected traumatic dislocation of the shoulder (n = 46, mean age 40 ± 14.5 years, 19 women) were prospectively recruited and received 3-T MR imaging including 3D T1 GRE, UTE, and 3D FRACTURE sequences. CT was performed in patients with acute fractures and served as standard of reference (n = 25). Agreement of morphological features between the modalities was analyzed including the glenoid bone loss, Hill-Sachs interval, glenoid track, and the anterior straight-line length. Agreement between the modalities was assessed using Bland-Altman plots, Student's t-test, and Pearson's correlation coefficient. Inter- and intrareader assessment was evaluated with weighted Cohen's κ and intraclass correlation coefficient.

RESULTS

All osseous pathologies were detected accurately on all three CT-like sequences (n = 25, κ = 1.00). No significant difference in the percentage of glenoid bone loss was found between CT (mean ± standard deviation, 20.3% ± 8.0) and CT-like MR images (FRACTURE 20.6% ± 7.9, T1 GRE 20.4% ± 7.6, UTE 20.3% ± 7.7, p > 0.05). When comparing the different measurements on CT-like images, measurements performed using the UTE images correlated best with CT.

CONCLUSION

Assessment of bony Bankart lesions and other osseous pathologies was feasible and accurate using CT-like images based on 3-T MRI compared with conventional CT. Compared to the T1 GRE and FRACTURE sequence, the UTE measurements correlated best with CT.

CLINICAL RELEVANCE STATEMENT

In an acute trauma setting, CT-like images based on a T1 GRE, UTE, or FRACTURE sequence might be a useful alternative to conventional CT scan sparing associated costs as well as radiation exposure.

KEY POINTS

• No significant differences were found for the assessment of the glenoid bone loss when comparing measurements of CT-like MR images with measurements of conventional CT images. • Compared to the T1 GRE and FRACTURE sequence, the UTE measurements correlated best with CT whereas the FRACTURE sequence appeared to be the most robust regarding motion artifacts. • The T1 GRE sequence had the highest resolution with high bone contrast and detailed delineation of even small fractures but was more susceptible to motion artifacts.

Magnetic resonance bone imaging: applications to vertebral lesions

MR bone imaging is a recently introduced technique, that allows visualization of bony structures in good contrast against adjacent structures, like CT. Although CT has long been considered the modality of choice for bone imaging, MR bone imaging allows visualization of the bone without radiation exposure while simultaneously allowing conventional MR images to be obtained. Accordingly, MR bone imaging is expected as a new imaging technique for the diagnosis of miscellaneous spinal diseases. This review presents several sequences used in MR bone imaging including black bone imaging, ultrashort/zero echo time (UTE/ZTE) sequences, and T1-weighted 3D gradient-echo sequence. We also illustrate clinical cases in which spinal lesions could be effectively demonstrated on MR bone imaging, performed in most cases using a 3D gradient-echo sequence at our institution. The lesions presented herein include degenerative diseases, tumors and similar diseases, fractures, infectious diseases, and hemangioma. Finally, we discuss the differences between MR bone imaging and previously reported techniques, and the limitations and future perspectives of MR bone imaging.

Preoperative Novel Magnetic Resonance Fusion Imaging for Carotid Endarterectomy Patients with Contrast Contraindications: A Pilot Study

OBJECTIVE

For carotid endarterectomy (CEA) patients with renal dysfunction and allergies to contrast media, we developed a preoperative novel method of noncontrast 3-dimensional magnetic resonance fusion imaging (NC-3DMRFI) which could describe well blood vessels, plaques, and bony structures even in surgical position. In this study, we examined the usefulness of this method.

METHODS

We extracted noncontrast magnetic resonance images of bones, blood vessels, and plaques to create a 3-dimensionalusion image. An image acquired in the normal position and another in the surgical position during CEA were used to create a fusion image. We compared the fusion imaging results with the intraoperative findings of 6 patients with contrast contraindications received CEA.

RESULTS

Preoperative NC-3DMRFI could clearly show the positions of the carotid bifurcation, the distal end of plaque, and the bony structure in 5 of the 6 cases. Intraoperative findings and preoperative fusion imaging results were comparable in all cases where fusion images could be created. The fusion imaging in the surgical position during CEA was useful for preoperative examination, and the surgical space could be secured in the case of a high cervical location.

CONCLUSIONS

This pilot study showed our novel NC-3DMRFI method is useful for preoperative simulation in CEA, especially in patients with renal dysfunction and allergies to contrast media.

Diagnostic Utility of Double-Echo Steady-State (DESS) MRI for Fracture and Bone Marrow Edema Detection in Adolescent Lumbar Spondylolysis

To evaluate the ability of double-echo steady-state (DESS) MRI to detect pars interarticularis fracture and bone marrow edema (BME) in spondylolysis, 500 lumber pars interarticularis from 50 consecutive patients (38 males and 12 females, mean age 14.2 ± 3.28 years) with spondylolysis who underwent both MRI and CT within 1 week were evaluated. All participants were young athletes who complained of lower back pain. Fractures were classified into four grades and CT was used as a reference; BME was evaluated in a binary manner and STIR was used as a reference. The diagnostic performance of fractures on DESS and T1WI, and BME on DESS was assessed by two radiologists independently. For fracture detection, DESS showed high diagnostic performance at a sensitivity of 94%, specificity of 99.5%, and accuracy of 98.8%, whereas T1WI showed lower sensitivity (70.1%). Fracture grading performed by DESS showed excellent agreement with CT grading (Kappa = 0.9). For BME, the sensitivity, specificity, and accuracy of DESS were 96.5%, 100%, and 99.6%, respectively. The inter-rater agreement of DESS for fracture and BME was 0.8 and 0.85, respectively. However, the inter-rater agreement for fracture on T1WI was 0.52. DESS had high diagnostic performance for fracture and BME in pars interarticularis. In conclusion, DESS had potential to detect all critical imaging findings in spondylolysis and may replace the role of CT.

Added value of ultra-short echo time and fast field echo using restricted echo-spacing MR imaging in the assessment of the osseous cervical spine

PURPOSE

To evaluate the added value of ultra-short echo time (UTE) and fast field echo resembling a CT using restricted echo-spacing (FRACTURE) MR sequences in the assessment of the osseous cervical spine using CT as reference.

MATERIALS AND METHODS

Twenty-seven subjects underwent postmortem CT and MRI within 48 h. Datasets were anonymized and analyzed retrospectively by two radiologists. Morphological cervical spine alterations were rated on CT, UTE and FRACTURE images. Afterward, neural foraminal stenosis was graded on standard MR and again after viewing additional UTE/FRACTURE sequences. To evaluate interreader and intermodality reliability, intra-class correlation coefficients (ICC) and for stenosis grading Wilcoxon-matched-pairs testing with multiple comparison correction were calculated.

RESULTS

Moderate interreader reliability (ICC = 0.48-0.71) was observed concerning morphological findings on all modalities. Intermodality reliability was good between modalities regarding degenerative vertebral and joint alterations (ICC = 0.69-0.91). Compared to CT neural stenosis grades were more often considered as nonsignificant on all analyzed MR sequences. Neural stenosis grading scores differed also significantly between specific bone imaging sequences, UTE and FRACTURE, to standard MR sequences. However, no significant difference was observed between UTE and FRACTURE sequences.

CONCLUSION

Compared to CT as reference, UTE or FRACTURE sequence added to standard MR sequences can deliver comparable information on osseous cervical spine status. Both led to changes in clinically significant stenosis gradings when added to standard MR, mainly reducing the severity of neural foramina stenosis.

Synthetic CT in Musculoskeletal Disorders: A Systematic Review

ABSTRACT

Repeated computed tomography (CT) examinations increase patients' ionizing radiation exposure and health costs, making an alternative method desirable. Cortical and trabecular bone, however, have short T2 relaxation times, causing low signal intensity on conventional magnetic resonance (MR) sequences. Different techniques are available to create a "CT-like" contrast of bone, such as ultrashort echo time, zero echo time, gradient-echo, and susceptibility-weighted image MR sequences, and artificial intelligence. This systematic review summarizes the essential technical background and developments of ultrashort echo time, zero echo time, gradient-echo, susceptibility-weighted image MR imaging sequences and artificial intelligence; presents studies on research and clinical applications of "CT-like" MR imaging; and describes their main advantages and limitations. We also discuss future opportunities in research, which patients would benefit the most, the most appropriate situations for using the technique, and the potential to replace CT in the clinical workflow.

Evaluation of ultrashort echo-time (UTE) and fast-field-echo (FRACTURE) sequences for skull bone visualization and fracture detection - A postmortem study

BACKGROUND AND PURPOSE

CT is considered the modality of choice in the assessment of the skull due to the fast and accurate depiction of bone structures. Nevertheless, MRI has evolved into a possible alternative due to optimal soft tissue contrast and recent advances with the ability to visualize tissues with shortest T2 times, such as osseous structures. In this study we compare skull bone visualization and fracture detection across two MRI sequences to CT as reference standard.

MATERIAL AND METHODS

Twenty subjects underwent CT and MRI with less than 72 h between examination. The MRI protocol included a 2D ultrashort echo time (UTE) and a 3D multi-echo in-phase fast-field-echo (FRACTURE) sequence. Independent raters evaluated qualitative characteristics and fracture detectability in different skull subregions (skull vault, skull base and viscerocranium). Interrater and intermodality agreement was evaluated by calculating intraclass coefficients (ICC).

RESULTS

FRACTURE ICC indicated a good agreement in all subregions (ICC = 0.83 - 0.88), whereas UTE had excellent results calculated in the skull vault and viscerocranium (ICC = 0.91 - 0.94). At the skull vault, both MRI sequences received an overall good rating (UTE: 2.63 ± 0.42 FRACTURE. 2.81 ± 0.32). Fracture detection using MRI sequences for the skull vault, was highest compared to other subregions.

CONCLUSIONS

Both MRI sequences may provide an alternative e.g. for surgical planning or follow up exams of the osseous neurocranium; although, at the skull base and viscerocranium bone visualization with MRI bone imaging sequences perform inferior to CT standard imaging.

3D MRI with CT-like bone contrast - An overview of current approaches and practical clinical implementation

CT is the imaging modality of choice for assessment of 3D bony morphology but incurs the penalty of ionizing radiation. Improving the ability of 3D MRI to provide high-resolution images of cortical bone with CT-like bone contrast has been a focus of recent research. The ability of 3D MRI to deliver cortical bone information with similar diagnostic performance to CT would complement assessment of soft tissues and medullary bone from a single MRI examination, simplifying evaluation and obviating radiation exposure from additional CT. This article presents an overview of current 3D MRI approaches for imaging cortical bone with CT-like bone contrast including ultrashort echo time, zero echo time, T1-weighted gradient recalled echo, susceptibility-weighted imaging and deep learning techniques. We also discuss clinical implementation of an optimized stack-of-stars 3D gradient recalled echo pulse sequence (3D-Bone) on commercially available MRI scanners for rendering 3D MRI with CT-like bone contrast in our institutional practice.