Glenoid morphology variation between patients with hypermobile shoulder joints and controls: Identification of hyperlaxity-related morphologic bone changes.

Objective: Our study aims to quantitatively determine the concavity of the glenoid articular surface in patients with hypermobile shoulders compared to those without. Method: We examined medical records of shoulder CTs from 2017 to 2022, selecting 50 patients with clinical signs of joint hypermobility for our case group and 54 for our control group. Two blinded readers independently assessed the glenoid morphology, calculating the glenoid concavity angle (GCA) and evaluating the articular surface shape as concave, flat, or convex. They also recorded the presence and severity of glenoid dysplasia. We compared these assessments between groups. Results: The mean GCA was significantly lower in the hypermobile group (2.3 ± 3.7° and 2.3 ± 3.8°) versus controls (6.6 ± 3.3° and 5.3 ± 3.8°) (P < 0.05). Interobserver reproducibility was high (ICC=0.76). A stark difference in glenoid morphology was noted between groups (P < 0.001), with a majority of hypermobile patients having a flat or convex glenoid. GCAs decreased with increasing shoulder laxity and dysplasia. GCA showed 77-81 % sensitivity and 55-82 % specificity for detecting shoulder hyperlaxity with a 4° cutoff. Conclusion: There is a significant association between GCA and shoulder hyperlaxity, demonstrating diagnostic efficacy and substantial interobserver agreement. Clinical Relevance: GCA values lower than 4° warrant further clinical investigation for shoulder hyperlaxity and associated conditions, which is crucial for patient treatment planning.

Clinical, radiological and dynamic CT results of scapholunate intercarpal ligamentoplasty for scapholunate dissociation.

A clinical, radiological and four-dimensional computed tomography (4DCT) assessment of the outcomes of scapholunate intercarpal ligamentoplasty (SLICL) was done with a minimum follow-up of 2 years. Twenty-nine patients (23 men and 6 women) with a mean age of 40 years (22-57) who had chronic scapholunate dissociation were treated with the SLICL procedure. There were 18 cases of dynamic instability and 11 of static instability. The patients were evaluated with a mean follow-up of 61 months (24-94). SLICL significantly reduced pain and increased grip strength and wrist function. On radiographs, the mean static and dynamic scapholunate gaps as well as the scapholunate and radiolunate angles improved significantly. The dorsal scaphoid displacement was always corrected. 4DCT after surgery provided a more precise analysis of the SLICL's effectiveness at restoring intracarpal alignment. Correction of the DISI deformity and dorsal scaphoid displacement was confirmed. SLICL restored a normal variation in the scapholunate gap (range value) during radioulnar deviation movement without systematically reducing the distance between the bones (mean and maximum values) which remained pathological in wrists with static instability but not in those with dynamic instability. At the final follow-up, no patients had signs of osteoarthritis due to ScaphoLunate Advanced Collapse. LEVEL OF EVIDENCE: III.

Effect of Matrix Size and Acquisition Mode on Image Quality and Radiation Dose of Ultra-High-Resolution CT of the Temporal Bone: An Anatomical Study.

Purpose: To compare image quality and radiation exposure between super- and ultra-high-resolution helical and super-high-resolution volumetric CT of the temporal bone. Methods: Six cadaveric temporal bone specimens were used to evaluate key temporal bone structures using the following CT reconstruction and acquisition modes: helical and single-volume acquisition modes in super-high resolution (0.25-mm slice thickness, 10242 matrix), and helical mode in ultra-high resolution (0.25-mm slice thickness, 20482 matrix). Two observers performed 5 previously described preoperative measurements, measured noise and signal-to-noise ratios for air, and noise for bone, and rated the visualization of 5 anatomical structures on a 4-point scale, for each reconstruction mode. Radiation dose exposure was recorded for each examination. Results: There was no significant difference between any of the quantitative or qualitative measurements in any of the reconstruction and acquisition modes. There was a slight increase in noise and a decrease in signal-to-noise ratio in the air using the single-volume mode (115 ± 13.1 HU and 8.37 ± 0.91, respectively) compared to the helicoidal super-high-resolution (92.4 ± 11.8 HU and 10.8 ± 1.26, respectively) and helicoidal ultra-high-resolution (91.1 ± 10.7 HU and 10.9 ± 1.39, respectively) modes (P < .002). The volumic CT dose index was 50.9 mGy with helical acquisition and 29.8 mGy with single-volume acquisition mode (P < .0001). Conclusion: The single-volume super-high-resolution acquisition mode allows a reduction in radiation dose exposure without compromising image quality compared to helical scanning, but with a slightly lower signal-to-noise ratio in air with the single-volume mode, while there was no difference in image quality between the helical super- and ultra-high-resolution modes.

Radiation dose reduction and image quality improvement with ultra-high resolution temporal bone CT using deep learning-based reconstruction: An anatomical study.

PURPOSE: The purpose of this study was to evaluate the achievable radiation dose reduction of an ultra-high resolution computed tomography (UHR-CT) scanner using deep learning reconstruction (DLR) while maintaining temporal bone image quality equal to or better than high-resolution CT (HR-CT). MATERIALS AND METHODS: UHR-CT acquisitions were performed with variable tube voltages and currents at eight different dose levels (volumic CT dose index [CTDIvol] range: 4.6-79 mGy), 10242 matrix, and 0.25 mm slice thickness and reconstructed using DLR and hybrid iterative reconstruction (HIR) algorithms. HR-CT images were acquired using a standard protocol (120 kV/220 mAs; CTDI vol, 54.2 mGy, 5122 matrix, and 0.5 mm slice thickness). Two radiologists rated the image quality of seven structures using a five point confidence scale on six cadaveric temporal bone CTs. A global image quality score was obtained for each CT protocol by summing the image quality scores of all structures. RESULTS: With DLR, UHR-CT at 120 kV/220 mAs (CTDIvol, 50.9 mGy) and 140 kV/220 mAs (CTDIvol, 79 mGy) received the highest global image quality scores (4.88 ± 0.32 [standard deviation (SD)] [range: 4-5] and 4.85 ± 0.35 [range: 4-5], respectively; P = 0.31), while HR-CT at 120 kV/220 mAs and UHR-CT at 120 kV/20 mAs received the lowest (i.e., 3.14 ± 0.75 [SD] [range: 2-5] and 2.97 ± 0.86 [SD] [range: 1-5], respectively; P = 0.14). All the DLR protocols had better image quality scores than HR-CT with HIR. CONCLUSION: UHR-CT with DLR can be performed with up to a tenfold reduction in radiation dose compared to HR-CT with HIR while maintaining or improving image quality.

Measurement of stapes footplate thickness using ultra-high-resolution computed tomography: stapes axial plane correlates better with otosclerosis than lateral semicircular canal plane.

BACKGROUND, AIMS: Stapes footplate thickness measurement using ultra-high-resolution CT has been described only in the lateral semicircular canal plane. The purpose of this study was to compare stapes footplate thickness between the lateral semicircular canal and stapes axial planes in patients with otosclerosis compared to controls. MATERIAL AND METHODS: We performed a retrospective single-center study of patients undergoing high-resolution temporal bone CT. Two radiologists measured stapes footplate thickness in both the lateral semicircular canal and stapes axial planes. RESULTS: Between February 2020 and October 2022, we collected 81 ears from 49 patients (75% of women; mean age 51.22 ± 16.6 years, 17 otosclerosis, and 64 controls). In the stapes axial plane, there was a significant anterior thickening in otosclerosis patients (Reader 1: 0.52 ± 0.12 [0.3-0.7] vs. 0.41 ± 0.08 [0.3-0.6], p = 0.001; Reader 2: 0.54 ± 0.06 [0.5-0.7] vs. 0.39 ± 0.08 [0.2-0.6], P < 0.001) compared to controls. These differences were not significant using the lateral semicircular canal plane. CONCLUSION: The stapes footplate was thickened at its AC in otosclerosis patients using only the stapes axial plane. SIGNIFICANCE: We propose to use the stapes axial plane instead of the lateral semicircular canal plane when analyzing the stapes.

Evaluation of the Prognostic Value of Pretherapeutic Magnetic Resonance Imaging in Predicting Soft Tissue Sarcoma Radiation Response: A Retrospective Study from a Large Institutional Sarcoma Imaging Database.

Background: RT-induced hyalinization/fibrosis was recently evidenced as a significant independent predictor for complete response to neoadjuvant radiotherapy (RT) and survival in patients with soft tissue sarcoma (STS). Purpose: Non-invasive predictive markers of histologic response after neoadjuvant RT of STS are expected. Materials and Methods: From May 2010 to April 2017, patients with a diagnosis of STS who underwent neoadjuvant RT for limb STS were retrieved from a single center prospective clinical imaging database. Tumor Apparent Diffusion Coefficients (ADC) and areas under the time-intensity perfusion curve (AUC) were compared with the histologic necrosis ratio, fibrosis, and cellularity in post-surgical specimens. Results: We retrieved 29 patients. The median ADC value was 134.3 × 10-3 mm2/s. ADC values positively correlated with the post-treatment tumor necrosis ratio (p = 0.013). Median ADC values were lower in patients with less than 50% necrosis and higher in those with more than 50% (120.3 × 10-3 mm2/s and 202.0 × 10-3 mm2/s, respectively (p = 0.020). ADC values higher than 161 × 10-3 mm2/s presented a 95% sensitivity and a 55% specificity for the identification of tumors with more than 50% tumor necrosis ratio. Tumor-to-muscle AUC ratios were associated with histologic fibrosis (p = 0.036). Conclusions: ADC and perfusion AUC correlated, respectively, with radiation-induced tumor necrosis and fibrosis.

Olfactory cleft stenosis and obstruction on paranasal sinus CT scan in pre-septo-rhinoplasty patients: normal variants or pathologic findings?

OBJECTIVE(S): To determine the frequency of olfactory cleft (OC) stenosis and obstruction on paranasal sinus CT scans in pre-septorhinoplasty of patients who had septal deviation, septopyramidal deformation or nasal obstruction without other sinonasal conditions. METHODS: This retrospective study included patients referred to our institution between December 2013 and December 2021 for septorhinoplasty due to nasal obstruction without other sinonasal or neurological conditions. All patients underwent preoperative paranasal sinus CT scan and olfactory testing. OC stenosis was quoted as none, partial, or total (less than 1/3 contact between nasal septum and ethmoid turbinates, 1/3-2/3, more than 2/3, respectively), as well as OC obstruction as none, partial, or complete (obstruction of less than 1/3 of OC, 1/3-2/3, more than 2/3, respectively). Radiologic evaluation was validated by near perfect interobserver agreement. RESULTS: A total of 75 patients (32 women, 43 men) with a mean age of 44.2 ± 15.64 (23-74) years were included, of which 36 were normosmic and 39 hyposmic. OC stenosis was partial in 58.7% (n = 44) of the patients, absent in 28% (n = 21), and total in 13.3% (n = 10), without difference between normosmic and hyposmic patients (p = .66). OC obstruction was absent in 52% (n = 39) and partial in 46.7% (n = 35), without difference between normosmic and hyposmic patients (p = .51). Only one normosmic patient had complete OC obstruction. CONCLUSION: OC partial stenosis and partial obstruction were frequent findings in pre-septorhinoplasty patients without respiratory mucosa disease and did not influence their olfactory status. Total stenosis and complete obstruction were rarer and require further investigation. CLINICAL RELEVANCE STATEMENT: Isolated partial olfactory cleft stenosis and obstruction should be considered normal variants, whereas the impact of complete olfactory cleft stenosis and obstruction on patient's olfactory status remains to be determined. KEY POINTS: • The incidence of olfactory cleft stenosis and obstruction in asymptomatic patients remains unknown, even though it is encountered in clinical practice. • Partial and total olfactory cleft stenosis occurred in 58.7% and 13.3% of the patients; partial obstruction occurred in half of the cases, but complete obstruction was extremely rare. • There are frequent findings of partial olfactory cleft obstruction and stenosis, but complete obstruction and total stenosis should be further investigated.

Reconstruction of the ulnar artery in Guyon's canal with an arterial graft: Anatomical study.

Ulnar artery thrombosis in Guyon's canal can lead to vascular insufficiency in the fingers. The recommended treatment is resection and reconstruction of the pathological area. A bypass may be necessary, which may be venous or arterial. Arterial bypasses have better long-term patency; however, they are a source of donor-site complications. We carried out an anatomical study on 11 upper limbs and 7 lower limbs from cadavers to identify a technically accessible arterial graft, of a diameter suitable for bypassing the ulnar artery in Guyon's canal and with acceptable scar sequelae (few predicted postoperative complications, discreet size and/or location of scar). Three grafts were considered: anterior interosseous artery, radial recurrent artery and descending genicular artery. The various grafts were dissected and harvested from cadaver specimens, then their lengths and diameters were measured. The diameter of the candidate grafts was compared to the diameter of the distal ulnar artery. The diameter of the descending genicular artery matched the ulnar artery better than the radial recurrent artery or the anterior interosseous artery (103% vs 44% and 67%, respectively). Mean graft length was 6.6 cm. The anatomical configuration of the descending genicular artery allowed Y-shaped bypasses to be performed. Harvesting this artery appears to cause little damage and allows bypasses up to 6 cm to be performed. Despite its smaller diameter making it necessary to perform a microvascular size adjustment, the anterior interosseous artery is a candidate graft because it is long enough (119 mm) and located near the surgical site. LEVEL OF EVIDENCE: V.

Prevalence of abnormalities seen on orthopantomograms performed for forensic age estimation in unaccompanied minor asylum seekers.

OBJECTIVES: Evaluate the prevalence of radiological anomalies on orthopantomograms (OPT) performed as part of forensic age estimation in unaccompanied minors. METHODS: This is a retrospective study conducted on 208 OPT examinations requested by a magistrate. These OPTs were interpreted independently by two readers to establish the number of missing teeth (MT), presence of dental fillings (DF), and dental anomalies (DA). The presence of radiolucent (RL), radiopaque, and mixed lesions was also assessed. RESULTS: Most radiologic anomalies were RL, detected on 41% and 39% of the subjects evaluated for R1 and R2, respectively, with a mean of 1.3 ± 2.4 (1-16) and 1.1 ± 2 (1-13) RL lesions per subject. Among the RL identified, the majority were dental (70% for R1 and 65% for R2), all of which had a suspected infectious origin. Among readers, 43% and 41% of the subjects evaluated presented MT, 21% and 15% presented DF, and 22% and 20% presented DA for R1 and R2, respectively. The inter- and intra-observer reproducibility for OPT classification was considered excellent (Kappa = 0.84, 95% CI 0.78-0.90, and Kappa = 0, 95, 95% CI 0.86-0.99). DISCUSSION: There was a non-negligible prevalence of radiological anomalies in OPT studies performed for forensic age estimation. Most of these lesions were suspected to be infectious in origin, potentially requiring medical care. This constitutes an ethical dilemma inherent in the judicial expertise injunction requiring a limited specific response. CLINICAL RELEVANCE STATEMENT: This study highlights a non-negligible prevalence of supposedly infectious radiological abnormalities. The restricted possibility for the legal expert to declare these abnormalities raises ethical and medical questions. KEY POINTS: • Orthopantomograms can be performed as part of forensic age estimation. • Results indicate the majority of radiological anomalies detected on OPTs were of suspected infectious origin. • These findings give rise to ethical and medical questions about the way in which these forensic examinations are carried out.

Assessment of Scapholunate Instability on 4D CT Scans in Patients with Inconclusive Conventional Images.

Background Initial imaging work-up using radiography and CT arthrography sometimes can be insufficient to identify a scapholunate (SL) instability (SLI) in patients suspected of having SL ligament tears. Purpose To determine the diagnostic performance of four-dimensional (4D) CT in the identification of SLI and apply the findings to patients suspected of having SLI and with inconclusive findings on radiographs and CT arthrograms. Materials and Methods This prospective single-center study enrolled participants suspected of having SLI (recent trauma, dorsal pain, positive Watson test results, decreased grip strength) between March 2015 and March 2020. Participants with wrist fractures, substantial joint stiffness, or history of wrist surgery were excluded. Each participant underwent radiography, CT arthrography, and 4D CT on the same day. Participants were divided into three groups: those with no SLI, those with SLI, and those with inconclusive results. SL gap and radioscaphoid and lunocapitate angle were measured using semiautomatic quantitative analysis of 4D CT images by two independent readers. Receiver operating characteristic curves were used to evaluate the diagnostic performance of 4D CT. Thresholds were determined with the Youden index and were applied to the inconclusive group. Results Of the 150 included participants (mean age, 41 years ± 14 [SD]; 102 male, 48 female), there were 63 with no SLI, 48 with SLI, and 39 with inconclusive results. The maximum value and range of SL gap measurements on 4D CT scans showed high sensitivity (83% [40 of 48] and 90% [43 of 48], respectively) and high specificity (95% [59 of 62] and 81% [50 of 62], respectively) in the identification of SLI. At least one of these parameters was abnormal on 4D CT scans in 17 of 39 (44%) participants in the inconclusive group, and 10 of 17 (59%) participants had confirmed SLI. In the 22 participants in the inconclusive group with no indication of SLI at 4D CT, follow-up showed no evidence of SLI in 10 (45%) and enabled confirmation of SLI via arthroscopy in three (14%). Conclusion Scapholunate gap measurements on kinematic 4D CT scans enabled correct identification of SLI in 59% of participants with inconclusive results on conventional images. ClinicalTrials.gov registration no. NCT02401568 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Demehri and Ibad in this issue.

Initial Evaluation of Focal Bone Lesions: How Do We Do It?

Focal bone lesions are frequent, and management greatly depends on the characteristics of their images. After briefly discussing the required work-up, we analyze the most relevant imaging signs for assessing potential aggressiveness. We also describe the imaging aspects of the various types of lesion matrices and their clinical implications.

The effect of intercarpal arthrodeses on wrist kinematics during radial and ulnar deviation: a cadaveric study using four-dimensional CT.

In this cadaveric study, we report quantitative dynamic four-dimensional CT evaluation of the effect on wrist kinematics of three intercarpal arthrodeses during radial and ulnar deviation. In five wrists, we successively performed scaphocapitate, four-corner and two-corner fusions. Four-dimensional CT examinations were performed prior to dissection and after each arthrodesis. The lunocapitate gap, posterior lunocapitate angle, radiolunate radial gap, radiolunate ulnar gap and radiolunate angle were assessed. After scaphocapitate arthrodesis, in radial deviation, we noted midcarpal diastasis and dorsal displacement of the capitate. In ulnar deviation, there was correction of that incongruence. After four-corner and two-corner fusions, in radial deviation, we noted radial radiolunate impingement and ulnar radiolunate incongruence. In ulnar deviation, after two-corner fusion, ulnar radiolunate impingement and radial radiolunate incongruence were present contrary to four-corner fusion. Our findings confirm that the constant radiocarpal and midcarpal congruence during radioulnar deviation in normal wrists is no longer possible with intercarpal kinematic modifications after these arthrodeses.

Association between opportunistic vertebral bone density measurements and new vertebral fractures after percutaneous vertebral cementoplasty: a case-control study.

OBJECTIVES: To study the relationship between opportunistic CT bone density measurements and the occurrence of new vertebral fractures after percutaneous vertebral cementoplasty (PVC) of osteoporotic vertebral compression fractures (OVCF). METHODS: A prospective analysis of retrospective data of 275 patients with OVCF treated by PVC between 2014 and 2019 with a clinico-radiological follow-up one year after treatment was conducted. Opportunistic bone density measurements were obtained at the trabecular bone of the L1 or an adjacent vertebra in Hounsfield units performed on the preoperative CT study. These density measurements values ​​were then compared between patients with and without new OCVF and in various population subgroups. RESULTS: There were 275 patients included, with 53 (19%) presenting a new OCVF and 24 (9%) developing a fracture cascade. The median opportunistic density measurements ​​in patients with recurrent OCVF were lower than those without (median 52[40.5]) HU and 77[49] HU)(p < 0.00001). Among the patients with new OVCF the median opportunistic density measurements in patients with fracture cascades were also lower than those without (44 HU and 62 HU, respectively) (p < 0.0096). Patients with density measurements under 61 HU were 3.6 times more likely to present recurrent fractures and those with density under 54 HU were 9.8 times more likely to develop a fracture cascade. The 36 HU threshold yielded a high specificity (90-91%) for the prediction of recurrent fractures and fracture cascade but with low sensitivity (respectively 26% and 37%). CONCLUSION: Low opportunistic vertebral density measurements are associated with a higher risk of OVCF and fracture cascades after PVC. KEY POINTS: • Low opportunistic density measurements are associated with a higher risk of OVCF and fracture cascades after PVC. • Measuring bone density before performing a PVC could help predict the risk of new vertebral fracture after treatment • Patient management could be adapted according to bone density.

Correlation Between Dynamic 4-Dimensional Computed Tomography Data and Arthroscopic Testing of Scapholunate Instability: A Preliminary Study.

PURPOSE: The aim of this study was to test the validity and reliability of the assessments of scapholunate (SL) instability status on 4-dimensional (4D) computed tomography (CT) using wrist arthroscopy as a reference standard. METHODS: Thirty-three patients (16 men, 17 women; mean age, 48 ± 13 years) with suspected SL instability were evaluated prospectively with 4D-CT and wrist arthroscopy. Based on the arthroscopic testing of SL joint, 2 groups were defined: group 1 (n = 8) consisted of patients who had no, or slight, SL malalignment in the midcarpal space and group 2 (n = 25) consisted of patients who had moderate or severe SL malalignment. Two independent readers, who did not know the arthroscopic findings, used 4D-CT to evaluate the SL gap, lunocapitate angle (LCA), and radioscaphoid angle (mean and range values) during radioulnar deviation. RESULTS: The interobserver reliability was deemed good or excellent for most of the 4D-CT variables, except for the LCA range (moderate) and SL gap range (poor). For both readers, the SL gap mean, maximum, and minimum values were significantly higher (+67%, +78%, and +39%, respectively) and the LCA mean was significantly lower (-17%) in group 2 than in group 1. The radioscaphoid angle range values were lower (-34%) and the radioscaphoid angle mean values slightly higher (+4%) in group 2, but there was no significant difference between the 2 groups. The SL gap range values were also higher (+86% for R1 and +40% for R2) and the LCA range values also lower (-50% for R1 and -31% for R2) in group 2. CONCLUSIONS: Quantitative 4D-CT data corresponded well with the arthroscopic dynamic analysis of the SL joint in patients with suspected chronic SL instability. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Initial Characterization of Focal Bone Lesions with Conventional Radiographs or Computed Tomography: Diagnostic Performance and Interobserver Agreement Assessment.

Objectives: To ascertain the role of CT and conventional radiographs for the initial characterization of focal bone lesions.Methods: Images from 184 patients with confirmed bone tumors included in an ethics committee-approved study were retrospectively evaluated. The reference for benign-malignant distribution was based on histological analysis and long-term follow-up. Radiographs and CT features were analyzed by 2 independent musculoskeletal radiologists blinded to the final diagnosis. Lesion margins, periosteal reaction, cortical lysis, endosteal scalloping, presence of pathologic fracture, and lesion mineralization were evaluated. Results: The benign-malignant distribution in the study population was 68.5-31.5% (126 benign and 58 malignant). In the lesions that could be seen in both radiographs and CT, the performance of these methods for the benign-malignant differentiation was similar (accuracy varying from 72.8% to 76.5%). The interobserver agreement for the overall evaluation of lesion aggressiveness was considerably increased on CT compared to radiographs (Kappa of .63 vs .22). With conventional radiographs, 18 (9.7%) and 20 (10.8%) of the lesions evaluated were not seen respectively by readers 1 and 2. Among these unseen lesions, 50%-61.1% were located in the axial skeleton. Compared to radiographs, the number of lesions with cortical lysis and endosteal scalloping was 26-34% higher with CT. Conclusion: Although radiographs remain the primary imaging tool for lesions in the peripheral skeleton, CT should be performed for axial lesions. CT imaging can assess the extent of perilesional bone lysis more precisely than radiographs with a better evaluation of lesion fracture risk.

Quantitative dynamic contrast-enhanced MRI of bone marrow perfusion at the proximal femur: influence of femoral head osteonecrosis risk factor and overt osteonecrosis.

OBJECTIVE: To evaluate the MRI perfusion changes in patients with risk factors for osteonecrosis and normally appearing femoral heads prior to overt femoral head osteonecrosis. METHODS: Fifty-eight patients (105 hips) were prospectively included in this ethics committee-approved study. There were 46 hips with no image anomalies and no risk factors for osteonecrosis of the femoral head (ONFH) risk factors, 38 with ONFH risk factors and no image abnormalities, and 21 with overt ONFH. All patients underwent DCE-MRI. Semi-quantitative (peak enhancement [PE], area under the curve [AUC], time to maximum enhancement [TME]) and quantitative perfusion parameters (volume plasma, KTRANS, and KEP) were calculated. Excessive alcohol consumption, corticosteroid use, and trauma were considered major risk factors for osteonecrosis of the femoral head. RESULTS: Measured at the femoral neck and compared to the healthy hips without OFNH risk factors, PE was significantly lower in the hips of patients with OFNH risk factors. Moreover, the difference was greater in females with risk factors, who presented significantly lower PE values (p = 0.0096). A PE threshold of 1.4% yielded a 92% sensitivity and 54% specificity for the presence of associated ONFH risk factors. The hips with overt OFNH compared to those with normally appearing showed an increase of PE of 45% in the neck (p < 0.014). Various epiphyseal femoral head perfusion parameters (PE, TME, AUC, and Ktrans) presented statistically significant differences in hips with ONFH and those without (p < 0.0001). CONCLUSION: DCE-MRI can identify perfusion marrow changes related to the presence of ONFH risk factors and adjacent to osteonecrosis areas. KEY POINTS: • Bone marrow perfusion changes may occur prior to overt ONFH and extend beyond the osteonecrosis area to the entire femoral head and neck. • Peak enhancement values were significantly reduced in patients with ONFH risk factors, compared to those without. • The presence of ONFH led to a significant increase in marrow perfusion adjacent to the osteonecrosis area.

Imaging in Hip Arthroplasty Management-Part 1: Templating: Past, Present and Future.

Hip arthroplasty is a frequently used procedure with high success rates. Its main indications are primary or secondary advanced osteoarthritis, due to acute fracture, osteonecrosis of the femoral head, and hip dysplasia. The goals of HA are to reduce pain and restore normal hip biomechanics, allowing a return to the patient's normal activities. To reach those goals, the size of implants must suit, and their positioning must meet, quality criteria, which can be determined by preoperative imaging. Moreover, mechanical complications can be influenced by implant size and position, and could be avoided by precise preoperative templating. Templating used to rely on standard radiographs, but recently the use of EOS® imaging and CT has been growing, given the 3D approach provided by these methods. However, there is no consensus on the optimal imaging work-up, which may have an impact on the outcomes of the procedure. This article reviews the current principles of templating, the various imaging techniques used for it, as well as their advantages and drawbacks, and their expected results.

Imaging in Hip Arthroplasty Management Part 2: Postoperative Diagnostic Imaging Strategy.

Hip arthroplasty (HA) is a frequently used procedure with high success rates, but 7% to 27% of the patients complain of persistent postsurgical pain 1 to 4 years post-operation. HA complications depend on the post-operative delay, the type of material used, the patient's characteristics, and the surgical approach. Radiographs are still the first imaging modality used for routine follow-up, in asymptomatic and painful cases. CT and MRI used to suffer from metallic artifacts but are nowadays central in HA complications diagnosis, both having their advantages and drawbacks. Additionally, there is no consensus on the optimal imaging workup for HA complication diagnosis, which may have an impact on patient management. After a brief reminder about the different types of prostheses, this article reviews their normal and pathologic appearance, according to each imaging modality, keeping in mind that few abnormalities might be present, not anyone requiring treatment, depending on the clinical scenario. A diagnostic imaging workup is also discussed, to aid the therapist in his imaging studies prescription and the radiologist in their practical aspects.

Kinematic 4D CT case-control study of wrist in dart throwing motion "in vivo": comparison with other maneuvers.

OBJECTIVES: To compare the diagnostic performance of scapholunate gap (SLG) measurements acquired with dart throwing (DT), radio-ulnar deviation (RUD), and clenching fist (CF) maneuvers on 4D CT for the identification of scapholunate instability. METHODS: In this prospective study, 47 patients with suspected scapholunate interosseous ligament (SLIL) tears were evaluated from March 2015 to March 2020 with semiautomatic quantitative analysis on 4D CT. Five parameters (median, maximal value, range, and coefficient of variation) for SLG, lunocapitate angle (LCA), and radioscaphoid angle (RSA) obtained during DT maneuver were evaluated in patients with and without SLIL tears. CT arthrography was used as the gold standard for the SLIL status. The SLG values obtained were also compared with those obtained during CF and RUD maneuvers. RESULTS: Significant differences in all SLG- and LCA-derived parameters are found between patients with and without SLIL tears with DT (p < 0.003). The best diagnostic performance for the diagnosis of SLIL tears was obtained with median and maximal SLG values (sensitivity and specificity of 86-89% and 95%) and with maximal and range LCA values (sensitivity and specificity of 86% and 74%). No significant differences were observed for RSA values (p > 0.275). The SLG range obtained with DT maneuver was the only dynamic parameter statistically different between patients with partial and complete torn SLIL (p = 0.037). CONCLUSION: 4D CT of the wrist during DT showed a similar performance than RUD and a better performance than CF for the differentiation between patients with and without SLIL tears. KEY POINTS: • Four-dimensional computed tomography can dynamically assess scapholunate instability. • The best results for differentiating between patients with and without SLIL tears were obtained with SLG median and maximal values. • The dart throwing and radio-ulnar deviation maneuvers yielded the best results for the dynamic evaluation of scapholunate instability.