Anterior talofibular ligament footprint dimension measured using three-dimensional magnetic resonance imaging.

OBJECTIVE: Knowledge of footprint anatomy is essential for ankle anterior talofibular ligament repair and reconstruction. We aimed to determine the intra- and inter-rater measurement reliability of the anterior talofibular ligament footprint dimension using three-dimensional MRI. METHODS: MRI images of 20 ankles with intact ligaments, including 11 with a single bundle and nine with double-bundle ligaments, were analyzed. Imaging was performed using a 3.0-Tesla MRI. Isotropic three-dimensional proton density-weighted images with a voxel size of 0.6 mm were obtained. The fibular and talar footprints were manually segmented using image processing software to create three-dimensional ligament footprints. The lengths, widths, and areas of each sample were measured. A certified orthopedic surgeon and a senior orthopedic fellow performed the measurements twice at 6-week intervals. The intra- and inter-rater differences in the measurements were calculated. RESULTS: The length, width, and area of the single-bundle fibular footprint were 8.7 mm, 5.4 mm, and 37.4 mm2, respectively. Those of the talar footprint were 8.4 mm, 4.3 mm, and 30.1 mm2, respectively. The inferior bundle of the double-bundle ligament was significantly smaller than the single and superior bundles (p < 0.001). No differences were observed between intra-rater measurements by either rater, with maximum differences of 0.7 mm, 0.5, and 1.7 mm2, in length, width, and area, respectively. The maximum inter-rater measurement differences were 1.9 mm, 0.5, and 2.4 mm2, respectively. CONCLUSION: Measurements of the anterior talofibular ligament dimensions using three-dimensional MRI were sufficiently reliable. This measurement method provides in vivo quantitative data on ligament footprint anatomy.

Intra- and interrater measurement reliability of lateral ankle ligament attachment locations using three-dimensional magnetic resonance imaging.

BACKGROUND: We aimed to evaluate the intra- and interrater measurement reliability of the lateral ankle ligament attachment locations using three-dimensional magnetic resonance imaging. METHODS: We analysed 54 participants with a mean age of 43 years who underwent three-dimensional ankle magnetic resonance imaging and had normal lateral ligaments. Bony landmarks of the distal fibula, talus, and calcaneus were identified in the reconstructed images. The centers of the anterior talofibular ligament and calcaneofibular ligament attachments were also identified. The distances between the landmarks and attachments were measured. Two raters performed the measurements twice, and intra- and interrater intraclass correlation coefficients were calculated. RESULTS: The intrarater intraclass correlation coefficient values were between 0.71 and 0.96 for the anterior talofibular ligament attachment measurements and between 0.77 and 0.95 for the calcaneofibular ligament attachments. The interrater intraclass correlation coefficient was higher than 0.7, except for the distance between the anterior talofibular ligament superior bundle and fibular obscure tubercle. The fibular attachment of a single-bundle anterior talofibular ligament was located 13.3 mm from the inferior tip and 43% along the anterior edge of the distal fibula. The superior and inferior bundles of the double-bundle ligament were located at 43% and 23%, respectively. The calcaneofibular ligament fibular attachment was 5.5 mm from the inferior tip, at 16% along the anterior edge of the distal fibula. CONCLUSION: The measurements of anterior talofibular ligament and calcaneofibular ligament attachment locations identified on three-dimensional magnetic resonance imaging were sufficiently reliable. This measurement method provides in vivo anatomical data on the lateral ankle ligament anatomy.

Clinical evaluation of 3D high-resolution isotropic knee MRI using Multi-Interleaved X-prepared TSE with inTUitive RElaxometry (MIXTURE) for simultaneous morphology and T2 mapping.

PURPOSE: Quantitative MRI techniques such as T2 mapping are useful in comprehensive evaluation of various pathologies of the knee joint yet require separate scans to conventional morphological measurements and long acquisition times. The recently introduced 3D MIXTURE (Multi-Interleaved X-prepared Turbo-Spin Echo with Intuitive Relaxometry) technique can obtain simultaneous morphologic and quantitative information of the knee joint. To compare MIXTURE with conventional methods and to identify differences in morphological and quantitative information. METHODS: Phantom studies were conducted, and in vivo human scans were performed (20 patients) presented with knee arthralgia. MIXTURE is based on 3D TSE without and with T2 preparation modules in an interleaved manner for both morphology with PDW and fat suppressed T2W imaging as well as quantitative T2 mapping within one single scan. Image quality and lesion depiction were visually assessed and compared between MIXTURE and conventional 2D TSE by two experienced radiologists. Contrast-to-noise ratio was used to assess the adjacent tissue contrast in a quantitative way for both obtained PDW and fat suppressed T2W images. Quantitative T2 values were measured in phantom and from in vivo knee cartilage. RESULTS: The overall diagnostic confidence and contrast-to-noise ratio were deemed comparable between MIXTURE and 2D TSE. While the chosen T2 preparation modules for MIXTURE rendered consistent T2 values comparing to the current standard, measured cartilage T2 values ranged from 26.1 to 50.7 ms, with significant difference between the lesion and normal areas (p < 0.05). CONCLUSIONS: MIXTURE can help to provide high-resolution information for both anatomical and pathological assessment.

AOZORA: long-term safety and joint health in paediatric persons with haemophilia A without factor VIII inhibitors receiving emicizumab - protocol for a multicentre, open-label, phase IV clinical study.

INTRODUCTION: Persons with haemophilia A (PwHA) commonly experience regular bleeding into joints, which may result in joint damage and complications such as degenerative arthritis. Emicizumab has previously demonstrated efficacy in reducing the occurrence of joint bleeds and target joints, along with having a favourable safety profile; however, data on the long-term effects on joint health are lacking. The AOZORA study will evaluate the long-term safety and joint health of paediatric PwHA without factor (F)VIII inhibitors taking emicizumab; here, we report the details of the study protocol and baseline data. METHODS AND ANALYSIS: AOZORA is a multicentre, open-label, phase IV clinical study in Japan that aims to enrol approximately 30 PwHA aged <12 years without FVIII inhibitors. The primary endpoints include a long-term safety evaluation of adverse events, laboratory test abnormalities and FVIII inhibitor development; and a long-term joint health assessment using MRI and the Hemophilia Joint Health Score. Exploratory endpoints include characterising participants' physical activities and the number of activity-related bleeds requiring coagulation factor treatment. Currently, 30 participants have been enrolled, including 20 emicizumab-naïve participants and 10 who transferred from HOHOEMI, a previous study in paediatric PwHA. ETHICS AND DISSEMINATION: The AOZORA study was approved by the Institutional Review Boards of Nara Medical University and the St Marianna University Group. The study will be conducted in compliance with the Declaration of Helsinki, the standards stipulated in paragraph 3 of Article 14 and Article 80-2 of the Pharmaceuticals, Medical Devices and Other Therapeutic Products Act, the Ministerial Ordinance on Good Clinical Practice and the Ministerial Ordinance on Good Post-marketing Study Practice. Data will be published in peer-reviewed journals and presented at Global congresses. TRIAL REGISTRATION NUMBER: JapicCTI-194701.

The Diagnostic Accuracy of MRI to Evaluate Acute Lisfranc Joint Injuries: Comparison With Direct Operative Observations.

BACKGROUND: Early diagnosis is important in patients with Lisfranc joint injury to avoid subsequent complications. As the ligaments in the Lisfranc joint are relatively small and course obliquely, isotropic 3-dimensional (3D) magnetic resonance imaging (MRI) can be beneficial to evaluate ligament injury. The purpose of this study was to investigate the diagnostic accuracy of MRI, including isotropic 3D MRI for acute injury of the Lisfranc joint, especially of the interosseous C1-M2 ligament (Lisfranc ligament), the dorsal C1-M2 ligament (dorsal ligament), and the interosseous C1-C2 ligament, compared with direct operative observations. METHODS: This retrospective review identified 27 patients who had undergone MR examination for acute Lisfranc joint injury followed by surgery. We reviewed the operative reports that described the Lisfranc, dorsal, and interosseous C1-C2 ligaments. All patients underwent an MRI, including a 2D oblique plane image parallel to the Lisfranc ligament and an isotropic 3D MRI. An image analysis of the integrity of the 3 ligaments and other associated injuries was performed. The diagnostic accuracy of MRI was analyzed using operative findings as a reference standard. RESULTS: Lisfranc and dorsal ligament injuries were identified on MRI in all patients. MRI depicted disruption of the interosseous C1-C2 ligament in 12 patients. MRI diagnostic accuracy for detection of Lisfranc, dorsal, and interosseous C1-C2 ligaments was 100% (95% CI 0.82-1.0), 74% (95% CI 0.54-0.89), and 70% (95% CI 0.50-0.86), respectively. CONCLUSION: MRI with oblique planes parallel to the Lisfranc ligament and isotropic 3D MRI was reliable for detecting Lisfranc ligament injury, whereas MRI findings of the dorsal and interosseous C1-C2 ligaments were less consistent with operative observations. LEVEL OF EVIDENCE: Level IV, case series.

Combination of compressed sensing and parallel imaging for T2-weighted imaging of the oral cavity in healthy volunteers: comparison with parallel imaging.

OBJECTIVE: Compressed sensing (CS) and parallel imaging (PI) are magnetic resonance (MR) imaging acceleration techniques. Image quality of two-dimensional fast spin echo imaging of the oral cavity using CS or combined CS and PI has not been evaluated. The aim of this study was to compare the acquisition time and image quality between T2-weighted imaging (T2WI) with CS and PI (CSPI-T2WI) and T2WI with PI (PI-T2WI) of the oral cavity. MATERIALS AND METHODS: Twenty healthy volunteers who underwent CSPI-T2WI and PI-T2WI of the oral cavity on a 3 T MR scanner were enrolled in the study. Contrast ratios of fat/muscle and bone/muscle on CSPI-T2WI and PI-T2WI were measured. Overall image quality, 4 kinds of artifacts, and visualization of 18 anatomical structures were independently evaluated by two radiologists with grading scales. The quantitative and qualitative measurements were compared between CSPI-T2WI and PI-T2WI by using the Wilcoxon signed-rank test. RESULTS: Mean acquisition time of CSPI-T2WI and PI-T2WI was 72 s and 136 s, respectively (p < .001). CSPI-T2WI showed a significantly higher contrast ratio of fat/muscle than PI-T2WI (p < .01). There were no significant differences in the overall image quality, artifacts, and visualization of anatomical structures between CSPI-T2WI and PI-T2WI. CONCLUSIONS: CSPI-T2WI of the oral cavity in healthy volunteers can provide a reduction in acquisition time without impaired image quality compared to PI-T2WI. KEY POINTS: • The acquisition time of T2WI with the combined CS and PI provided a 47% reduction in acquisition time compared with T2WI with PI. • T2WI with the combined CS and PI did not show impaired image quality compared with T2WI with PI. • Combined CS and PI can be a useful technology to evaluate the oral cavity with high-speed acquisition.

Venous malformation of the foot: Spontaneous regression postpartum on MRI.

Venous malformations (VMs) are present at birth, grow proportionally during childhood, and usually do not regress. We report the imaging appearance of a VM of the foot found during pregnancy, which regressed spontaneously postpartum. A 35-year-old, 8-month-pregnant woman presented with a 6-month history of painful swelling of the left foot. MRI demonstrated a well-defined, intricate-shaped mass measuring 38 × 36 × 28 mm between the muscles and tendons of the third, fourth, and fifth toes with subcutaneous extension. Dynamic CT taken a month after delivery revealed gradual enhancement of the lesion. Gray-scale ultrasonography (US) showed a heterogenic hypoechoic mass containing thrombi with venous waveforms on Doppler US. A second MRI obtained 15 months after delivery showed a remarkable reduction of the lesion size (16 × 20 × 15 mm). Symptomatic VMs found during pregnancy can be observed conservatively without treatment.

MRI findings of spring ligament injury: association with surgical findings and flatfoot deformity.

BACKGROUND: Spring ligament injury is an important cause for flatfoot deformity; however, reliability of magnetic resonance imaging (MRI) findings of spring ligament injury is still ambiguous. PURPOSE: To investigate the reliability of MRI findings for the diagnosis of spring ligament injury. MATERIAL AND METHODS: Forty-three cases with spring ligament injury proven by surgery and 29 control cases were enrolled. The spring ligament complex was demonstrated on proton density-weighted images reconstructed from 3D-isotropic MRI data. The presence of waviness, discontinuity, and abnormally high signal intensity of the spring ligament complex was evaluated by two radiologists in cooperation. Also, injury of the posterior tibial tendon (PTT) on MRI and the lateral talo-1st metatarsal angles on weight-bearing X-rays were evaluated. RESULTS: Discontinuity and abnormally high signal intensity of the superomedial calcaneonavicular ligament (SmCNL) on MRI were more frequently observed in patients with spring ligament injury than in controls (p < 0.001). Discontinuity and abnormally high signal intensity of the SmCNL were found more often in the PTT injury group than in those without (p < 0.001). The talo-1st metatarsal angle was greater in patients with discontinuity and abnormally high signal intensity of the SmCNL on MRI than in patients without these findings (p < 0.001). CONCLUSION: Discontinuity and abnormally high signal intensity are reliable MRI findings for spring ligament injury and related disorders, such as flatfoot deformity and PTT injury.

MRI findings and demographics of elastofibroma dorsi: assessment of diffusion-weighted imaging and contrast enhancement patterns.

Background Elastofibroma dorsi is a rare pseudotumoral lesion. Thus, there is no report of magnetic resonance imaging (MRI) findings that investigates multiple patients particularly with respect to diffusion-weighted imaging (DWI) findings and contrast enhancement patterns. Purpose To describe the imaging findings of elastofibroma on MRI, particularly DWI findings and contrast enhancement patterns, and to further investigate patient demographics. Material and Methods Forty-four patients with elastofibroma that underwent MRI were enrolled in this retrospective study. All images were evaluated by two radiologists to visually assess the signal intensity for each sequence. Enhanced elastofibromas were classified into four categories to assess the enhancement pattern. Differences in gender and laterality were also assessed statistically. Results An equal number of men and women were included (n = 22 each). There was no significant difference in laterality ( P = 0.783). All lesions (73 lesions) had low signal intensity on both T1-weighted (T1W) and T2-weighted (T2W) images: heterogeneous in 56, homogeneous in 17. None of the 41 lesions with DWI had true abnormal diffusion restriction. The average ADC value was 1.36 × 10-3 ± 0.29 mm2/s. All 31 lesions that had contrast-enhanced MRI were classified according to enhancement pattern: homogeneous (three lesions, 9.7%); heterogeneous (15 lesions, 48.4%); streak-like (three lesions, 9.7%); and rim-like (ten lesions, 32.2%). Conclusion There were no statistically significant differences in gender or laterality. Elastofibroma showed homogeneous to heterogeneous low signal intensity on T1W and T2W images. No lesion showed abnormal diffusion restriction, and all lesions demonstrated enhancement on MRI.

A cohort study of the usefulness of primary prophylaxis in patients with severe haemophilia A.

Primary prophylaxis is a method of haemostatic management to prevent bleeding and arthropathy in patients with severe haemophilia. The aim of this study was to evaluate the usefulness of primary prophylaxis in patients with severe haemophilia A. This study included 15 patients with haemophilia A who received primary prophylaxis at our institution for a minimum of 5 years. We evaluated the annualized bleeding ratio of joints or other sites, current joint function, and X-ray images and MRI scans taken when patients were 6 years old. The range of patients' ages at the end of the study was 6.2-16.8 years, and at the start of primary prophylaxis it was 0.8-2.4 years. Factor VIII concentrates (25-40 units kg(-1) dose(-1)) were administered 3 times/week or every other day, according to the Swedish protocol. Mean joint and non-joint annualized bleeding ratios were 0.49 ± 0.5 and 1.54 ± 1.69, respectively. At the final evaluation, all patients displayed a normal range of motion for both elbows, knees, and ankles. The radiography and MRI findings at the age of 6 were unremarkable in all patients. Overall, primary prophylaxis for patients with severe haemophilia A was performed safely, reduced the number of bleeding events, and prevented progression to arthropathy.

MR Imaging Evaluation of the Lisfranc Ligament in Cadaveric Feet and Patients With Acute to Chronic Lisfranc Injury.

BACKGROUND: Magnetic resonance (MR) imaging is known to be useful to demonstrate Lisfranc ligament injury. There are few studies that report differences in MR imaging findings of acute or chronic Lisfranc ligament injuries. We applied oblique MR imaging planes parallel to the Lisfranc ligament for better visualization of the entire course of the ligament and assessed the detailed MR imaging appearances of the Lisfranc ligament in cadavers and patients with presumed Lisfranc injuries. METHODS: Twelve preserved cadaveric feet were examined using a small-diameter surface coil. Long axis, oblique sagittal, and oblique short axis cross sections parallel to the Lisfranc ligament, dorsal ligament, and plantar ligament were obtained. Twenty-six MR examinations from 23 patients with suspected Lisfranc joint injuries were evaluated. RESULTS: In the cadaveric study, the Lisfranc ligament was satisfactorily visible along its entire course in a single slice on long axis and oblique sagittal MR images. The dorsal ligament and the plantar ligament were visible separately from the Lisfranc ligament in oblique sagittal and oblique short axis planes. In the patient study, 11 MR examinations led to diagnoses of complete tears of the Lisfranc ligament that were acute injuries (3-21 days after trauma) mostly associated with disruption of the dorsal and plantar ligaments. Nine studies led to diagnoses of incomplete tears of the Lisfranc ligament that were chronic injuries (2-14 months after trauma). Recovery of the continuity of the disrupted ligament was observed in 3 patients. CONCLUSION: MR imaging demonstrated the integrity of the ligaments and was useful for diagnosing an acute Lisfranc injury. Fibrous healing of the torn ligament was observed in a chronic injury.

(18)F-2-fluoro-2-deoxyglucose uptake in or adjacent to blood vessel walls.

Incidental (18)F-2-fluoro-2-deoxyglucose (FDG) uptake in blood vessel walls is sometimes demonstrated during routine oncologic imaging with positron emission tomography/computed tomography (PET/CT). FDG uptake in vessel walls can also be seen under some non-physiological conditions such as vasculitis and arteriosclerosis. Radiologists need to be aware of the diseases which can exhibit FDG uptake in the vessel wall for proper interpretation.