Bone MRI Research Articles

Buccal bone thickness assessment for immediate anterior dental implant planning: A pilot study comparing cone-beam computed tomography and 3D double-echo steady-state MRI.

To evaluate image quality and diagnostic accuracy of buccal bone thickness assessment in maxillary and mandibular anterior region using cone-beam computed tomography (CBCT) and 3-dimensional double-echo steady-state (DESS) MRI for preoperative planning of immediate dental implants in healthy individuals. One hundred and twenty teeth in 10 volunteers were retrospectively evaluated for image quality and artifacts using Likert scale (4=excellent to 0=decreased). Buccal bone thickness was measured at three measurement points (M1=2 mm from the cementoenamel junction, M2=middle of the root, and M3=at the root apex) for each tooth in the maxillary (13-23) and the mandibular anterior region (33-43). Descriptive statistics and two-way ANOVA with Tukey's Post-hoc test were performed to evaluate the significant differences (α=0.05) between both imaging modalities. Image quality showed little to no artifacts and enabled confident diagnostic interpretation (CBCT (3.72 ± 0.46); MRI (3.65 ± 0.49)), with no significant differences between both imaging modalities (p > 0.05). Regarding the assessment of buccal bone thickness at M1-M3 for the teeth 13-23 and 33-43, no significant differences were noted (p > 0.05). MRI demonstrated slight, nonsignificant overestimation of thickness with the canines having mainly a thick buccal bone wall, where thin buccal wall was evident for the central incisors. Black bone MRI sequences, such as 3D-DESS MRI, for immediate implant planning provided confidential diagnostic accuracy in bone thickness assessment without significant disadvantages compared to CBCT. Thus, the implementation of no-dose protocols for dental rehabilitation using an immediate loading approach seems promising and could further improve the treatment strategy for dental rehabilitation.

Utility of apparent diffusion coefficient histogram analysis in differentiating benign and malignant palate lesions

ObjectivesTo explore the ability of conventional MRI and histogram analysis of apparent diffusion coefficient (ADC) for differentiating between malignant and benign palatal lesions. Materials and MethodsA retrospective analysis was performed on MRI images of 86 patients with palatal lesions confirmed by histopathology between January 2015 and December 2018. Each lesion was evaluated based on the conventional MRI characteristics, including size, location, morphology, inner texture, enhancement, capsule, bone destruction, and nerve invasion. ADC histogram analysis was fitted to a bimodal Gaussian distribution mixture curve. Nine histogram analysis parameters were extracted from ADC maps and were compared between malignant and benign palatal lesions. Statistical analysis was performed to assess the differential performance of each parameter individually and combined. ResultsOn conventional MRI, the capsule structure and nerve invasion were useful characteristics for the differential diagnosis of palatal lesions. Histogram analysis showed significant differences between the groups in terms of mean ADC values of the lower curve and overall curve of the bimodal histogram, as well as ADC10 and ADC50. The optimal diagnostic threshold of ADC value was ADC50 = 1.17 × 10−3 mm2/s (area under curve [AUC] = 0.934, sensitivity = 93.0 %, specificity = 86.2 %). The combination of conventional MRI and ADC values yielded the best predictive performance, with an AUC of 0.949, and an increase in sensitivity from 80.7 % to 96.5 % and specificity from 58.6 % to 82.8 %, compared to conventional MRI. ConclusionsHistogram analysis of DWI combined with conventional MRI allows accurate differentiation between benign and malignant palatal lesions.

Improvements in Prostate Cancer Management: Focus on Imaging and Treatment

Prostate cancer has traditionally been staged through the use of conventional imaging techniques such as bone scintigraphy, CT, and MRI. However, the introduction of more sensitive techniques, such as prostate-specific membrane antigen (PSMA) imaging, has allowed previously undetectable metastases to be identified, thereby enabling more accurate staging of the disease and greater refinement in management strategies. This article summarises a symposium delivered on 3rd July 2022 at the 37th European Association of Urology (EAU) Annual Congress in Amsterdam, the Netherlands, where speakers from three different specialties raised important questions in prostate cancer imaging. Stefano Fanti, Professor of Diagnostic Imaging/Director from S. Orsola Policlinic Hospital, Bologna, Italy, asked: “What is PSMA all about?”, and Jochen Walz, Professor of Urology and Head, Department of Urology at the Institut Paoli-Calmettes Cancer Centre, Marseille, France, wondered: “When does PSMA help me?” Alicia Morgans, Genitourinary Medical Oncologist/Medical Director at the Dana-Faber Cancer Institute, USA, then offered an overview of the future of prostate cancer management. The session concluded with the presentation of three cases of patients with different stages of prostate cancer, all of which illustrated the transformative benefit of PSMA imaging in accurately staging patients and directing subsequent treatment options.

Improvements in Prostate Cancer Management: Focus on Imaging and Treatment

Prostate cancer has traditionally been staged through the use of conventional imaging techniques such as bone scintigraphy, CT, and MRI. However, the introduction of more sensitive techniques, such as prostate-specific membrane antigen (PSMA) imaging, has allowed previously undetectable metastases to be identified, thereby enabling more accurate staging of the disease and greater refinement in management strategies. This article summarises a symposium delivered on 3rd July 2022 at the 37th European Association of Urology (EAU) Annual Congress in Amsterdam, the Netherlands, where speakers from three different specialties raised important questions in prostate cancer imaging. Stefano Fanti, Professor of Diagnostic Imaging/Director from S. Orsola Policlinic Hospital, Bologna, Italy, asked: “What is PSMA all about?”, and Jochen Walz, Professor of Urology and Head, Department of Urology at the Institut Paoli-Calmettes Cancer Centre, Marseille, France, wondered: “When does PSMA help me?” Alicia Morgans, Genitourinary Medical Oncologist/Medical Director at the Dana-Faber Cancer Institute, USA, then offered an overview of the future of prostate cancer management. The session concluded with the presentation of three cases of patients with different stages of prostate cancer, all of which illustrated the transformative benefit of PSMA imaging in accurately staging patients and directing subsequent treatment options.

Deep Learning for Synthetic CT from Bone MRI in the Head and Neck.

Bone MR imaging techniques enable visualization of cortical bone without the need for ionizing radiation. Automated conversion of bone MR imaging to synthetic CT is highly desirable for downstream image processing and eventual clinical adoption. Given the complex anatomy and pathology of the head and neck, deep learning models are ideally suited for learning such mapping. This was a retrospective study of 39 pediatric and adult patients with bone MR imaging and CT examinations of the head and neck. For each patient, MR imaging and CT data sets were spatially coregistered using multiple-point affine transformation. Paired MR imaging and CT slices were generated for model training, using 4-fold cross-validation. We trained 3 different encoder-decoder models: Light_U-Net (2 million parameters) and VGG-16 U-Net (29 million parameters) without and with transfer learning. Loss functions included mean absolute error, mean squared error, and a weighted average. Performance metrics included Pearson R, mean absolute error, mean squared error, bone precision, and bone recall. We investigated model generalizability by training and validating across different conditions. The Light_U-Net architecture quantitatively outperformed VGG-16 models. Mean absolute error loss resulted in higher bone precision, while mean squared error yielded higher bone recall. Performance metrics decreased when using training data captured only in a different environment but increased when local training data were augmented with those from different hospitals, vendors, or MR imaging techniques. We have optimized a robust deep learning model for conversion of bone MR imaging to synthetic CT, which shows good performance and generalizability when trained on different hospitals, vendors, and MR imaging techniques. This approach shows promise for facilitating downstream image processing and adoption into clinical practice.

The predictive value of a novel site-specific MRI-based bone quality assessment, endplate bone quality (EBQ), for severe cage subsidence among patients undergoing standalone lateral lumbar interbody fusion

BACKGROUND CONTEXTStudies have shown that site-specific bone density measurements had more predictive value for complications than standard whole-region measurements. Recently, MRI-based assessments of vertebral bone quality (VBQ) were introduced. However, there have been few studies that investigate the association between site-specific MRI bone assessment and osteoporosis-related complications in patients undergoing lumbar interbody fusion. In this work, we created a novel site-specific MRI-based assessment of the endplate bone quality (EBQ) and assessed its predictive value for severe cage subsidence following standalone lateral lumbar interbody fusion (SA-LLIF). PURPOSETo investigate the predictive value of a novel MRI-based bone assessment for severe cage subsidence after SA-LLIF. STUDY DESIGN/SETTINGRetrospective cohort study. PATIENT SAMPLEPatients who underwent SA-LLIF from 2008 to 2019 at a single, academic institution with available preoperative lumbar CT and T1-weighted MRIs. OUTCOME MEASURESAssociation between EBQ and severe subsidence after SA-LLIF. METHODSWe retrospectively reviewed the records of SA-LLIF patients treated between 2008 and 2019. EBQ was measured using preoperative non-contrast T1-weighted MRIs of the lumbar spine. EBQ was defined as the average value of signal intensity of both endplates divided by that of the cerebrospinal fluid space at the level of L3. Bivariate and multivariable analyses with generalized linear mixed models were performed and set binary severe subsidence as the outcome. RESULTSTwo hundred five levels in 89 patients were included. Fifty levels (24.4%) demonstrated severe subsidence. Bone mineral density measured by quantitative computed tomography was significantly lower in the subsidence group. Both VBQ and EBQ were significantly higher in the subsidence group. The EBQ plus Modic change (MC) model demonstrated that the effect of EBQ was independent of MC. In multivariate analyses adjusted with QCT-vBMD, EBQ showed a significant association with cage subsidence whereas VBQ only showed a marginal trend. The EBQ-based prediction model for severe subsidence showed better goodness of fit compared to the VBQ-based model. CONCLUSIONSHigh EBQ was an independent factor for severe cage subsidence after SA-LLIF and the EBQ-based model showed better goodness of fit compared to VBQ- or MC-based models. EBQ assessment before SA-LLIF may provide insight into a patient's risk for severe subsidence.

Differential diagnosis and management of hemangioma at geniculate ganglion

Objective: To investigate the clinical characteristics, differential diagnosis, treatments and prognosis of facial nerve hemangioma and schwannoma at genicular ganglion, so as to provide reference for clinical diagnosis and treatments of facial nerve tumor at genicular ganglion. Methods: Clinical data of 13 patients with facial nerve tumors at genicular ganglion confirmed by postoperative pathology in the Ninth People's Hospital affiliated to Shanghai Jiaotong University School of Medicine from March 2018 to April 2020 were retrospectively analyzed, including seven cases of hemangioma and six cases of schwannoma. There were eight males and five females. Their ages ranged from 20 to 65, with an average age of 40. The course of disease ranged from 3 to 118 months, with an average of 52 months. All the patients underwent preoperative HRCT of the temporal bone and facial nerve dynamic contrast-enhanced(DCE) MRI examinations. All the patients had detailed surgical procedures and at least one-year postoperative follow-up. Results: On HRCT of the temporal bone, (4/7) hemangioma at geniculate ganglion showed characteristic honeycomb appearance, while 6/6 schwannoma and 3/7 hemangiomas showed expansive bone changes. On DCE-MRI, geniculate ganglion hemangioma (7/7) showed characteristic "point-to-surface" enhancement, and schwannoma (6/6) showed characteristic "face-to-surface" enhancement. For five hemangioma-patients with HB-Ⅱ-Ⅳ before surgery, the facial nerve anatomy was completely preserved through transcanal endoscopic approach(TEA), and the facial nerve function improved one year after surgery (two cases of HB-I, two cases of HB-Ⅱ, and one case of HB-Ⅲ). For two patients, with preoperative facial nerve function HB-Ⅴ-Ⅵ, since their tumors was inseparable from the nerves, they were performed with facial nerve anastomosis during the surgery, and the facial nerve function was improved to HB-Ⅳ level one year after surgery. For six patients with meningioma whose facial nerve function was greater than or equal to HB-Ⅲ, based on the preoperative hearing level, the involved segments, and duration of facial paralysis, three of them were conducted surgeries through middle cranial fossa approach, one by translabyrinthine approach, and one via mastoid approach. Two patients among them with complete facial paralysis over three years preoperatively were not performed facial nerve anastomosis after total resections of the tumors, and there was no improvement in facial nerve function one year after surgery. Three patients underwent facial nerve anastomosis after total tumor resections, and their facial nerve function was HB-Ⅲ in one patient, HB-Ⅳ in two patients one year after surgery. One patient (preoperative HB-Ⅲ) had a normal hearing level preoperatively, and the tumor involved the labyrinth segment. To protect the hearing, partial tumor was resected through the middle cranial fossa approach, and facial nerve function improved to HB-Ⅱ one year after surgery. Conclusions: Temporal bone HRCT combined with DCE-MRI are useful for the differential diagnosis of hemangioma and schwannoma at geniculate ganglion and provide references for preoperative clinical decision makings. It is extremely necessary to select the appropriate surgical approach based on the patient's hearing and involved segments. For geniculate ganglion hemangioma, early surgery can improve the possibilities of anatomical integrity of facial nerve, thereby improving facial nerve function postoperatively.TEA is a kind of surgical method worth consideration, with the characteristics of minimally invasive, favorable postoperative features, and so on. For schwannoma, one-stage functional reconstruction of the facial nerve is recommended during the resection of the tumors because of the inevitable damage to the anatomical integrity of the facial nerve.

Region‐based two‐stage MRI bone tissue segmentation of the knee joint

Region‐based two‐stage MRI bone tissue segmentation of the knee joint

Knee Cartilage and Subchondral Bone Evaluations by Magnetic Resonance Imaging Correlate with Histological Biomarkers in an Osteoarthritis Rabbit Model.

ObjectiveTo evaluate pathological changes in cartilage and subchondral bone MRI biomarkers in a rabbit model of osteoarthritis (OA) and correlate these with histological variations.DesignTransection of the anterior cruciate ligament was performed on the right knee of eighteen 12-week-old New Zealand white rabbits to induce OA. 3-Tesla MR images were obtained from 18 healthy control knees (left) and 18 knees with OA (right). Imaging biomarkers included volume, thickness, T1 and T2* cartilage parametric maps, and several subchondral bone features: bone volume to total volume ratio, trabecular thickness, trabecular spacing, trabecular number (TbN), 2D and 3D fractal dimensions, and quality of trabecular score (QTS). Microscopic analysis of the lateral femoral condyles was set as the ground truth.ResultsWhen healthy and osteoarthritic knees were compared, significant differences were seen in the T1 and T2* values of the femur and tibia cartilage and in the subchondral bone volume to total volume, TbN, and QTS of both the lateral and medial aspects of the femur and tibia. Histological findings revealed significant osteoarthritic changes between healthy and osteoarthritic knees in stain, structure, chondrocyte density, total score, and subchondral bone biomarker levels. A positive correlation was found between histological staining, structure, chondrocyte density, and total score variables in T1 and T2* cartilage biomarkers. A negative correlation was observed between histological subchondral bone variables and magnetic resonance D2D and QTS biomarkers.ConclusionQuantification of several cartilage and subchondral bone imaging biomarkers in a rabbit model of OA allows the detection of significant changes, which are correlated with histological findings.

DISSEMINATED TB IN AN IMMUNOCOMPETENT PATIENT

TYPE: Case Report TOPIC: Chest Infections INTRODUCTION: Disseminated tuberculosis (TB) is a rare presentation, more common in patients with HIV, chronic liver disease or alcohol abuse and associated with high rates of treatment failure. CASE PRESENTATION: A 28 years-old male, with history of asthma, started complains of cough, sputum production and asthenia . Despite inhaled steroids, he continued to deteriorate. Skin ulcerations on the right wrist, elbow and leg appeared 4 months later. Fourteen months after the first symptoms, there was purulent drainage in the ulcers and a right knee edema which prevented the patient from walking. The patient presented to the hospital with extreme weight loss (20Kg). HIV screening was negative. CT scan with peri broncho-vascular opacities, tree-in-bud, cavitary lesions and pneumomediastinum. PCR for Mycobacterium tuberculosis was positive on sputum and knee pus. The patient started antibiotics (Clindamycin) and anti-TB drugs. A drain was placed on the right knee. Bone MRI revealed osteomyelitis in the knee, femur and cervical-dorsal spine, with need for surgical cleaning. DISCUSSION: A long evolution of symptoms was probably responsible for the exuberant presentation in this case of disseminated TB. The antibiotics and surgical strategies to treat the skin lesions were very challenging due to different microbiologic isolates and recurrence after drainage. The extension of lesions to the bone led to leg and arm movement impairment. Due to this, a multidisciplinary evaluation and decision to perform surgery were essential to prevent permanent disability. CONCLUSIONS: This case highlights the challenges in the management of thoracic complications of cavitary lesions, cutaneous ulceration and osteomyelitis due to TB. DISCLOSURE: Nothing to declare. KEYWORD: disseminated tuberculosis

Dental MRI of Oral Soft-Tissue Tumors-Optimized Use of Black Bone MRI Sequences and a 15-Channel Mandibular Coil.

Soft-tissue lesions in the oral cavity, one of the most common sites for tumors and tumor-like lesions, can be challenging to diagnose and treat due to the wide spectrum from benign indolent to invasive malignant lesions. We report an abnormally large, rapidly growing hyperplastic lesion originating from the buccal mucosa in a 28-year-old male patient. Clinical examination revealed a well-circumscribed, smooth-surfaced, pinkish nodular lesion measuring 2.3 × 2 cm, which suggested the differential diagnosis of irritation fibroma, pyogenic granuloma, oral lipoma, and other benign or malignant neoplasms such as hemangioma, non-Hodgkin’s lymphoma, or metastases to the oral cavity. Dental MRI using a 15-channel mandibular coil was performed to improve perioperative radiological and surgical management, avoiding adverse intraoperative events and misdiagnosis of vascular malformations, especially hemangiomas. Black bone MRI protocols such as STIR (short-tau inversion recovery) and DESS (double-echo steady-state) were used for high-resolution radiation-free imaging. Radiologic findings supported the suspected diagnosis of an irritation fibroma and ruled out any further head and neck lesions, therefore complete surgical resection was performed. Histology confirmed the tentative diagnosis. This article evaluates the use of this novel technique for MR diagnosis in the perioperative management of soft-tissue tumors in oral and maxillofacial surgery.

Pre-treatment GH levels and number of therapeutic interventions for acromegaly management are predictive of altered MRI bone shape and severity of arthropathy in acromegaly

Pre-treatment GH levels and number of therapeutic interventions for acromegaly management are predictive of altered MRI bone shape and severity of arthropathy in acromegaly

FC010: Multicentric Experience with RNA Interference Medication (OXLUMO®) in Patients with Primary Hyperoxaluria Type 1

Abstract BACKGROUND AND AIMS Primary hyperoxaluria type 1 (PH1) is a rare metabolic disorder of the glyoxylate metabolism in the liver inducing severe endogenous oxalate overproduction. Massive hyperoxaluria leads to recurrent urolithiasis and/or nephrocalcinosis and often early end-stage kidney failure. Current treatment options were scarce until the first RNA interference drug, Oxlumo® (Lumasiran, Alnylam Pharmaceuticals, USA) can now be prescribed. Oxlumo® targets the mRNA of glycolate oxidase and, thus, prevents its translation. This reduces production of glyoxylate (i.e. the precursor to oxalate) and thus oxalate production. However, glycolate production increases. METHOD We herein report our current clinical experience with s.c. administration of Oxlumo adhering to provide dosage recommendation. A total of 25 PH1 patients were included. Seven patients were on haemodialysis, 1 patient on peritoneal dialysis and 17 were on stable kidney function at start of Oxlumo medication (eGFR > 30 and <55 mL/min in 2 patients and >70 mL/min in all others). The male: female ratio was 15:10, and the age range was 1–62 years of age at start of treatment. In both groups plasma oxalate (Pox) and glycolate (Pglyc) were determined before the first and every next Oxlumo dosage. In non-dialysis patients, urinary oxalate (Uox) and urinary glycolate in 24 h urines were analysed at same interval plus monthly collection until month 6 of treatment and thereafter in 6 weeks’ intervals, if Uox did not reach near normalisation, or had increased again at end of dosing interval (3 monthly). Oxalate and glycolate were determined using ion chromatography/mass spectrometry in the same lab. RESULTS We now report data of those patients, who have received at least four dosages of Oxlumo (n = 15). Non-dialysis patients: Uox was normal (<0.5 mmol/1.73 m2/d) in two patients, in five patients it was near normal (1.5 times the upper limit, <0.75) and in three patients Uox was above 0.75 mmol/1.73 m2/d. Pox was normal in seven and above 7.4 µmol/L in three patients. In seven patients data were available at fifth to seventh dosage interval. Here, one patient had a normal Uox; in all other patients Uox was above 0.75 mmol/1.73 m2/d before next dosage. In the seven dialysis patients median Pox did not really decline over time (median of 45.1 at baseline, n = 7; and 39.9 post fourth dosage, n = 5), as was median Pglyc (86.05/71.1). Patient-specific follow-up differed and must also be related to co-medication with B6. For example, one dialysis patient remained stable with Pglyc below 2 µmol/L (under B6) and another patient experienced Pglyc > 1 mmol/L (without B6). CONCLUSION Oxlumo® has reduced Uox in 7/10 patients after the fourth dosage. However, adjustment of dosage intervals or dosage per se are necessary in the majority of patients to reach the goal of treatment, e.g. at least near normalisation of urinary oxalate excretion. In dialysis patients lack of reduction of Pox maybe because patients dissolve systemic oxalate deposits. However, specific imaging (bone MRI) in three of the dialysis patients did not show improvement of oxalate osteopathy over 6 and 9 months, respectively.

Comparison of a Novel MRI Technique that Produces Equivalent Bone Contrast with 2D-CT for the Assessment of Glenoid Bone Loss

Background:Advanced imaging in patients with shoulder instability can be variable. MRI offers visualization of soft tissue injuries including capsulolabral injuries, however may not be ideal to assess osseous injuries. CT examination may often be desired as the accepted standard for assessment of glenoid and humeral bone loss, the extent of which can dictate surgical management in the adolescent age group in which bone loss is common.Hypothesis/Purpose:Our hypothesis, MRI bone sequence/method (FRACTURE: FFE Resembling A CT Using Restricted Echo-spacing) can provide measurements comparable to standard CT for glenoid bone loss. The objective of this study was to validate this technique in a cadaveric glenoid bone loss model using 2D-CT as the reference standard.Methods:Glenoid fractures of varying sizes were arthroscopically created in 10 cadaveric shoulders. 2D-CT and MRI FRACTURE on 3T Philips Ingenia; Philips Healthcare, Best, Netherlands) were performed on all 10 shoulders. FRACTURE is a 3D-gradient echo pulse sequence with restricted echo-spacing combined with an automated post-processing is a technical innovation which provides superior cortical and trabecular bone contrast on MRI. The CT and MRI were presented in a blinded fashion to 2 experienced musculoskeletal radiologists for independent measurement of the glenoid fracture length, width, as well as % glenoid bone loss using the best-fit circle method. Paired t-tests were performed to compare the measurements obtained on CT with those obtained on the MR FRACTURE images. Intraclass correlation coefficient was used to measure interobserver reliability.Results:There was no statistically significant difference between CT and MRI in terms of the measured glenoid fracture length(P-value=0.54) or fracture width(P-value=0.86). The mean length measured on CT was 23.40 mm ± 6.87 and on MRI was 22.96 mm ± 7.38. The mean width on CT measured 7.96 mm ± 3.51 and on MRI measured 7.89 mm ± 3.18. There was also no statistically significant difference between CT and MRI in terms of measured glenoid bone loss (P-value=0.65). Intraclass correlation coefficients for interobserver reliability ranged from 0.95 to 0.99 for measurements performed on CT and MRI.Conclusion:Measurements of glenoid fracture and associated % bone loss on CT were comparable with measurements obtained using the MR FRACTURE technique. Inter-observer reproducibility for these measurements was excellent. MRI FRACTURE technique may obviate preoperative CT in patients with anterior shoulder instability.

Correlation of semi-quantitative findings of endolymphatic hydrops in MRI with the audiometric findings in patients with Meniere's disease

Purpose: To investigate the correlation between vestibular hydrops (VH), cochlearhydrops (CH), vestibular aqueduct non-visibility (VANV), and visually increased perilymphatic enhancement (VIPE) with the findings of pure-tone audiometry (PTA) in Meniere’s disease (MD) patients.Methods: In this cross-sectional study, 53 ears belonging to 48 patients were divided into two groups and evaluated. In group “MD patients,” there were 24 ears of 19 patients diagnosed with the definite MD (14 patients with unilateral and 5 patients withbilateral involvements). The “control group” consisted of 29 non-symptomatic ears belonging to patients diagnosed with unilateral sudden sensory-neural hearing loss or unilateral schwannoma. All the patients underwent 2 sessions of temporal bone MRI using the same 3T system: an unenhanced axial T1, T2, and 3D-FLAIR MRI, an intravenous gadolinium-enhanced axial T1 fat-sat, and 4 h after the injection, an axial 3D-T2 cube and 3D-FLAIR session. VH, CH, VANV, and VIPE were assessed. Subsequently, the correlation between EH indices and PTA findings (in three frequency domains of low, middle, and high) were evaluated, and the predictive value of MRI was calculated.Results: VH was significantly correlated with the hearing threshold in the low, middle, and high-frequency domains. CH was also correlated with the hearing threshold in the low and middle domains. Contrarily, VIPE was not associated with hearing thresholds, and VANV was only correlated with the hearing threshold in low frequencies.Conclusion: The grade of VH, CH, and VANV were significantly correlated with the hearing thresholds in PTA.

Application of SPECT combined with CT and MRI in malignant tumors Clinical value in the diagnosis of bone metastasis

Objective：To evaluate the value of single-photon emission computerized tomography (SPECT) combined with CT and MRI in the diagnosis of bone metastasis of malignant tumors. Method：Eighty patients with bone metastasis from malignant tumors who admitted to Affiliated Hospital of Chengde Medical College were selected from March 2019 to June 2021. SPECT bone imaging, CT and MRI were used to analyze the regional distribution of primary tumor bone metastasis and the efficacy of three detection methods in the diagnosis of bone metastasis. Results: A total of 464 lesions were detected by SPECT and CT in the same scanning field，with SPECT detection rate of 92. 5% ( 429 /464) and CT detection rate of 77. 8% ( 361 /464) ( P＜0. 05). In addition，143 lesions were detected by SPECT beyond the same scanning field. A total of 321 lesions were detected by SPECT and MＲI in the same scanning field，with SPECT detection rate of 95. 6% ( 307 /321) and MRI detection rate of 82. 6% ( 265 /321) ( P＜0. 05)，and other 286 lesions were detected by SPECT beyond the same scanning field. In all，259 lesions were detected by CT and MＲI scans in the wild same scanning field. The detection rate was 71. 4% ( 185 /259) for CT，and 95. 7% ( 248 /259) for MRI( P＜0. 05). The sensitivity，specificity and accuracy of SPECT imaging combined with CT and MＲI were higher than single SPECT imaging，CT and MＲI ( P＜0. 05). Conclusion: SPECT may be the preferred screening modality for suspected bone metastases and when combined with CT and MＲI，it can clarify the regional distribution of bone metastasis from malignant tumors and improve the sensitivity，specificity and accuracy of diagnosis with high clinical significance.

KELLGREN-LAWRENCE 2 AND 3 KNEES WITH A CARTILAGE-MENISCUS PHENOTYPE SHOW DIFFERENT PATTERNS OF STRUCTRAL PROGRESSION

Purpose: Imaging plays an important role in defining structural disease severity and potential suitability of patients recruited to disease-modifying osteoarthritis drug (DMOAD) trials. Three main structural phenotypes in knee OA have been proposed based on MRI, i.e., inflammation, cartilage-meniscus and subchondral bone. Recently, Rapid OsteoArthritis MRI Eligibility Score (ROAMES1) system has been introduced that allows structural phenotypic stratification based on abbreviated MRI assessment and thus, may potentially be applicable in screening efforts for inclusion into clinical DMOAD trials.

Safety and efficacy of salvage high-dose rate brachytherapy for prostate-bed recurrences following radical prostatectomy and external beam radiotherapy.

This retrospective study aims to evaluate the efficacy and safety of salvage HDR brachytherapy in second local recurrences of prostate cancer after applying radical prostatectomy (RP) and post-operative external beam radiotherapy (EBRT). Fifteen patients with locally recurrent prostate cancer after RP and EBRT were salvaged with HDR brachytherapy. Patients had no nodal or distant metastasis evidence on imaging findings, including whole body bone scan, CT scan, and MRI or PSMA PET scan. HDR brachytherapy was applied with 36Gy in four fractions, in two implantations with 1week apart. We followed the patients for a control visit every 3months for 2years, and every 6months thereafter. Fifteen patients with the mean age of 64years (ranged 51-79) underwent salvage HDR brachytherapy. The mean baseline level of PSA was calculated 2.26ng/ml (ranged from 0.21 to 9, SD = 2.33), which has been significantly decreased in all patients. Hence, two of our patients experienced a biochemical failure during the follow-up period. Our results showed that 86.6% (n = 13) of patients had never experienced a significant increment in PSA level after a median follow-up of 48months (ranging from 12 to 132months). Besides, salvage HDR brachytherapy did not induce any significant side effects such as acute or late rectal complications, despite causing urinary complication. HDR brachytherapy could be considered as a treatment in well-selected patients with the second recurrence in their prostatic bed after the former EBRT allowing for dose escalating to the second nodular recurrence.

Multimodal imaging of the distal interphalangeal-joint synovio-entheseal complex in psoriatic arthritis (MIDAS): a cross-sectional study on the diagnostic accuracy of different imaging modalities comparing psoriatic arthritis to psoriasis and osteoarthritis.

ObjectiveCan ultrasound (US), MRI and X-ray applied to the distal interphalangeal (DIP)-joint and synovio-entheseal complex (SEC) discriminate between patients with psoriatic arthritis (PsA), skin psoriasis (PsO) and hand osteoarthritis (OA)?MethodsIn this prospective, cross-sectional study, patients with DIP-joint PsA and nail involvement (n=50), PsO with nail involvement (n=12); and OA (n=13); were consecutively recruited. Risk ratios (RR) were calculated for US, MRI and X-ray findings of the DIP-joint and SEC between diagnoses.ResultsNew bone formation (NBF) in US and MRI was a hallmark of OA, reducing the risk of having PsA (RR 0.52 (95% CI 0.43 to 0.63) and 0.64 (95% CI 0.56 to 0.74). The OA group was different from PsA and PsO on all MRI and X-ray outcomes reflected in a lower RR of having PsA; RR ranging from 0.20 (95% CI 0.13 to 0.31) for MRI bone marrow oedema (BMO) to 0.85 (95% CI 0.80 to 0.90) in X-ray enthesitis. No outcome in US, MRI or X-ray was significantly associated with a higher risk of PsA versus PsO, although there was a trend to a higher degree of US erosions and NBF in PsA. 82% of PsA and 67% of PsO was treated with disease modifying antirheumatic drugs which commonly reflects the clinical setting.ConclusionHigh grade of US, MRI and X-ray NBF reduce the RR of having PsA compared with OA. In PsA versus PsO patients, there was a trend for US to demonstrate more structural changes in PsA although this did not reach significance.

Multimodal imaging analysis of the cyst like lesion of condyle in temporomandibular joint

Objective: To investigate the imaging features of condylar cystic degeneration of temporomandibular joint (TMJ) by cone-beam CT (CBCT), spiral CT, MRI and radionuclide bone imaging. Methods: From January 2018 to December 2020, thirty-two patients with cyst-like lesions of condylein temporomandibular joint were examined by CBCT, spiral CT, MRI and radionuclide bone imaging at the Department of Oral and Maxillofacial Surgery in General Hospital of Chinese PLA. There were 12 males and 20 females involved, aged from 16 to 65 years with an average age of (33.9±12.5) years. The characteristics of CBCT, spiral CT, MRI and radionuclide bone imaging were analyzed. Condylar cyst like lesions were classified as type A and type B based on the presence or absence of surface bone defects. Condylar cyst like lesions were classified as type Ⅰ(yes) and type Ⅱ(no) according to the accompanying bone marrow edema-like lesions of the condyles. The incidence of condylar bone marrow edema, disc displacement and abnormal bone metabolism were analyzed. Results: A total of 64 joint images of 32 patients were included, including 34 sides with TMJ cyst-like lesion and 6 sides with multiple cyst-like lesions,the total cyst-like lesions were 42. The largest diameter of cyst-like lesion ranged from 1.0 to 12.4 mm, with an average length of (3.7± 1.8) mm. There were 24 cases of type A TMJ cyst like lesion and 10 cases of type B cyst-like lesion. The detection rate of CBCT was 95.2% (40/42) and that of spiral CT was 100% (42/42), there was no significant difference (Calibration Chi-square=0.51, P=0.474). The detection rate of nuclear magnetic resonance was 80.1% (34/42), and the detection rate of cyst-like lesions less than 2 mm was 3/11. In the cyst like lesion side, there were 9 sides with anterior disc displacement with reduction, 20 sides with anterior disc displacement without reduction. In the non-cyst like lesion side, 10 sides with anterior disc displacement with reduction and 6 sides with anterior disc displacement without reduction. There was a significant difference in the displacement of the disc between cyst-like and non-cystic lesion side (χ²=7.80, P=0.005). MRI showed that 6 cases of cystic side[17.6% (6/34)] had bone marrow edema-like lesions (all type A), 1 case of non-cyst like lesions side [3.3% (1/30)] had bone marrow edema-like lesion, there was no significant difference between cystic and non-cystic lesions (Calibration Chi-square=2.04, P=0.153). There was a significant difference between type A and B cystic lesions (Fisher exact probability method, P=0.024). Radionuclide bone imaging showed abnormal bone metabolism in 26 patients in the cyst-like lesion side and 5 patients in the non-cyst like lesion side (χ²=22.82, P<0.001). Conclusions Multi-slice Spiral CT could detect the cyst-like lesion of TMJ condyle in the early stage, which is different from the large joint. And the formation mechanism may vary from the different classifications.