The role of imaging in osteoarthritis.

Osteoarthritis is a complex whole-organ disorder that involves molecular, anatomic, and physiologic derangement. Advances in imaging techniques have expanded the role of imaging in evaluating osteoarthritis and functional changes. Radiography, magnetic resonance imaging, computed tomography (CT), and ultrasonography are commonly used imaging modalities, each with advantages and limitations in evaluating osteoarthritis. Radiography comprehensively analyses alignment and osseous features, while MRI provides detailed information about cartilage damage, bone marrow edema, synovitis, and soft tissue abnormalities. Compositional imaging derives quantitative data for detecting cartilage and tendon degeneration before structural damage occurs. Ultrasonography permits real-time scanning and dynamic joint evaluation, whereas CT is useful for assessing final osseous detail. Imaging plays an essential role in the diagnosis, management, and research of osteoarthritis. The use of imaging can help differentiate osteoarthritis from other diseases with similar symptoms, and recent advances in deep learning have made the acquisition, management, and interpretation of imaging data more efficient and accurate. Imaging is useful in monitoring and predicting the prognosis of osteoarthritis, expanding our understanding of its pathophysiology. Ultimately, this enables early detection and personalized medicine for patients with osteoarthritis. This article reviews the current state of imaging in osteoarthritis, focusing on the strengths and limitations of various imaging modalities, and introduces advanced techniques, including deep learning, applied in clinical practice.

Quantitative CT Analysis Based on Smoking Habits and Chronic Obstructive Pulmonary Disease in Patients with Normal Chest CT.

Purpose: To assess normal CT scans with quantitative CT (QCT) analysis based on smoking habits and chronic obstructive pulmonary disease (COPD). Materials and Methods: From January 2013 to December 2014, 90 male patients with normal chest CT and quantification analysis results were enrolled in our study [non-COPD never-smokers (n = 38) and smokers (n = 45), COPD smokers (n = 7)]. In addition, an age-matched cohort study was performed for seven smokers with COPD. The square root of the wall area of a hypothetical bronchus of internal perimeter 10 mm (Pi10), skewness, kurtosis, mean lung attenuation (MLA), and percentage of low attenuation area (%LAA) were evaluated. Results: Among patients without COPD, the Pi10 of smokers (4.176 ± 0.282) was about 0.1 mm thicker than that of never-smokers (4.070 ± 0.191, p = 0.047), and skewness and kurtosis of smokers (2.628 ± 0.484 and 6.448 ± 3.427) were lower than never-smokers (2.884 ± 0.624, p = 0.038 and 8.594 ± 4.944, p = 0.02). The Pi10 of COPD smokers (4.429 ± 0.435, n = 7) was about 0.4 mm thicker than never-smokers without COPD (3.996 ± 0.115, n = 14, p = 0.005). There were no significant differences in MLA and %LAA between groups (p > 0.05). Conclusion: Even on normal CT scans, QCT showed that the airway walls of smokers are thicker than never-smokers regardless of COPD and it preceded lung parenchymal changes.

MRI in Acute Ankle Sprains: Should We Be More Aggressive with Indications?

Acute ankle sprains are common sports injuries. MRI is the most accurate test for assessing the integrity and severity of ligament injuries in acute ankle sprains. However, MRI may not detect syndesmotic and hindfoot instability, and many ankle sprains are treated conservatively, questioning the value of MRI. In our practice, MRI adds value in confirming the absence or presence of ankle sprain-associated hindfoot and midfoot injuries, especially when clinical examinations are challenging, radiographs are inconclusive, and subtle instability is suspected. This article reviews and illustrates the MRI appearances of the spectrum of ankle sprains and associated hindfoot and midfoot injuries.

Can Bone Erosion in Axial Spondyloarthropathy be Detected by Ultrashort Echo Time Imaging? A Comparison With Computed Tomography in the Sacroiliac Joint.

BACKGROUND: Structural lesion evaluation in axial spondyloarthropathy (SpA) can improve accuracy of diagnosis. However, structural lesions (bone erosions) are difficult to be assessed using conventional MRI compared to computed tomography (CT). PURPOSE: To evaluate the diagnostic performance of ultrashort echo time (UTE) for detecting bone erosion in axial SpA compared to T1WI and three-dimensional double-echo steady-state (3D DESS) imaging using CT as the reference standard. STUDY TYPE: Retrospective. POPULATION: Fourteen patients (eight females, 57.1%) and 14 healthy controls (seven females, 50.0%) who underwent sacroiliac (SI) joint MRI and CT. FIELD STRENGTH/SEQUENCE: 3 T; TSE T1WI, 3D DESS, 2D UTE. ASSESSMENT: The bilateral SI joints were assessed for bone erosion. Three observers scored bone erosion for all three sequences of MRI. CT was used as the gold standard. Diagnostic confidence in axial SpA was measured based on a four-point confidence score. STATISTICAL TESTS: Correlation of erosion scores between CT and MRI were evaluated using Spearman's correlation test. Sensitivity, specificity, and positive-negative predictive values were calculated. Confidence scores were compared using the Wilcoxon sum rank test. Statistical significance was set at P < 0.05. RESULTS: Compared with erosion scores of CT, the correlation coefficients for each MRI sequence showed significant low-to-high positive correlations (0.39-0.72). UTE imaging showed the highest correlation coefficients for all observers (0.70, 0.72, and 0.67, respectively). The specificity of UTE imaging was equal or higher than those of T1WI and 3D DESS for all observers (0.86 vs. 0.71 vs. 0.57; 0.93 vs. 0.71 vs. 0.57; 0.79 vs. 0.79 vs. 0.43). All observers had the highest confidence in interpreting UTE imaging for detecting bone erosion among the three sequences (3.5, 3.4, and 3.3 for UTE; 3.1, 3.0, and 2.6 for T1WI; and 3.2, 2.7, and 2.4 for DESS). DATA CONCLUSION: UTE imaging can detect bone erosions in patients with axial SpA and show higher specificity than conventional T1WI and 3D DESS. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 2.

Clumpy artifacts can be differentiated from tophi with DECT: comparison between gout-free and gouty patients.

OBJECTIVES: To accurately differentiate clumpy artifacts from tophi with foot and ankle DECT. METHODS AND MATERIALS: In session 1, 108 clumpy artifacts from 35 patients and 130 tophi images from 25 patients were analyzed. Reviewers classified green pixelation according to anatomic location, shape (linear, stippled, angular, oval), and height and width ratio. In session 2, green pixelation confined to the tendon was evaluated (shape, height and width ratio, occupied area in the tendon, accompanied peritendinous green pixelation). RESULTS: In session 1, while tophi were noted at various locations, almost all clumpy artifacts were located at the tendon (99%, p < 0.0001). Most clumpy artifacts were linear, stippled, and wide, while most tophi were angular and oval (p < 0.05). In session 2, the shape of green pixelation from clumpy artifacts and tophi was significantly different (p < 0.0001) and most clumpy artifacts occupied less than 50% of the tendon (p = 0.02), and most tophi were accompanied by peritendinous green pixelation (p < 0.0001). Univariant logistic regression showed that tophi were significantly correlated with peritendinous deposits, angular and oval shape, and more than 50% of the tendon (p < 0.05). CONCLUSION: Clumpy artifacts can be differentiated from tophi in DECT. Clumpy artifacts typically are located in the tendon with a linear or stippled shape, wide, and less than 50% of a tendon's cross-section. Tophi, on the other hand, typically are oval, larger than 50% of the tendon's cross-section, and associated with adjacent peritendinous green pixelation. ADVANCES IN KNOWLEDGE: Clumpy artifacts can be differentiated from tophi in image findings by their location and shape.

Unique Ultrasonographic Findings of Isolated IgG4-Related Lymphadenopathy.

IgG4-related disease is a rare immune-mediated disease that can involve many organs in the body. The lymph node is also where IgG4-related diseases occur, but its histological structure is different from that of other organs. For this reason, pathologists have difficulty diagnosing IgG4-related lymphadenopathy. If there were specific imaging findings of IgG4-related lymphadenopathy, it would be of great help to pathologists. A 64-year-old male visited our hospital with right ankle pain. On physical examination, the right lower extremity showed severe swelling with wound dehiscence, and infection was suspected. On CT (128-MDCT, Somatom Definition Flash, Siemens Healthcare) taken at the lower extremity, multiple enlarged lymph nodes were incidentally noted in the right inguinal area. On ultrasonography, a "starry night sign" resembling hyperechoic follicles was observed in the enlarged lymph node. A core needle biopsy was performed, and IgG4-related lymphadenopathy was diagnosed. Laboratory examination showed hypergammaglobulinemia with marked elevated serum IgG4, corresponding to IgG4-related disease. Chest and abdominal imaging were evaluated, but there was no extranodal IgG4-related disease. IgG4-related lymphadenopathy showed a very unique ultrasonography imaging finding. The cortex was filled with diffusely scattered hyperechoic foci and some bright foci gathered to form a follicle. This imaging finding may help diagnose IgG4-related lymphadenopathy.

Congenital dermoid sinus of the anterior chest region.

BACKGROUND: Congenital dermoid sinus of the anterior chest region (CDACR) is a rare developmental anomaly. Therefore, the aim of our study was to draw attention to this underrecognized lesion. METHODS: From 2011 to 2019, our study group included 11 patients who presented to our hospital with pits and masses of their anterior chest walls. All lesions were surgically excised with histologic confirmation of the diagnosis of CDACR. The medical records of these patients were reviewed for the following data: patient age, gender, clinical characteristics of the lesion and site of involvement, department first visited, diagnostic evaluation, management, postoperative complications, and histopathological findings. RESULTS: There was a clear left-sided predominance, with 10/11 cases occurring on the left and a female predominance of eight cases out of 11. Although the pits were present at birth, the mean age at presentation was 19.7 months. All patients showed clinical signs of infection at the time of presentation and were treated with antibiotics. Seven patients had a history of abscess formation treated with incision and drainage. Ultrasound was performed in eight patients. In all cases, the lesions, including pit and sinus, were completely excised. CONCLUSIONS: Congenital dermoid sinus of the anterior chest region is likely underrecognized. We encountered a high frequency of complications such as infections or abscesses prior to surgical excision. Complete excision of CDACR is not technically difficult. Therefore, surgical removal should be considered, even for asymptomatic lesions, to avoid future complications and for cosmesis.

Methotrexate use does not increase the prevalence of hepatic steatosis: a real-world retrospective nested case-control study.

OBJECTIVE: We aimed to determine whether methotrexate (MTX) treatment in patients with rheumatoid arthritis (RA) leads to the development of non-alcoholic fatty liver (NAFL). METHOD: Data were derived from records of all patients with RA who underwent abdominal ultrasonography at the Jeonbuk National University Hospital. Patients with ultrasound-proven NAFL were identified, and those without NAFL were matched by age and sex using the propensity score matching method at 1:3 ratio. We also analyzed the Health Insurance Review and Assessment Service-National Patient Samples, a nationwide cohort database, to determine the association between MTX use and NAFL in a large number of patients (n = 24,653). RESULTS: In the hospital cohort, 92 patients with NAFL did not show significant differences in the cumulative MTX dose when compared with the no-NAFL group (n = 276) (1908.5 ± 1757.5 vs. 1948.6 ± 2118.8 mg, p = 0.911). The prevalence of NAFL was not significantly different across strata of cumulative MTX dose. Multiple logistic analyses identified hypertriglyceridemia (OR, 4.88 [95% CI, 1.13-20.93]) and higher body mass index (OR, 1.22 [95% CI, 1.05-1.41]) as being associated with an increased risk of NAFL. In the nationwide cohort, the MTX exposure rate between the NAFL and no-NAFL groups was not significantly different. CONCLUSIONS: Collectively, no significant association between NAFL development and administration of MTX was detected in this study. Our results suggest that it is more efficient to adjust for individualized risk factors for NAFL prevention rather than discontinuation of MTX in patients with RA. Key Points • NAFLD has been highlighted with increasing prevalence worldwide and possible progression to end-stage liver disease. • Cumulative dose or exposure history of MTX does not show a significant association with NAFLD prevalence. • Modifying well-established risk factors is more efficient in NAFLD prevention rather than discontinuation of MTX.

Myositis ossificans of the thigh causing external compression of the superficial femoral artery and vein: A case report.

RATIONALE: Myositis ossificans (MO) is a benign condition characterized by heterotopic bone formation in the skeletal muscle of extremities. Marked variation can occur in the incidence and location of the bone formed as well as resulting complications. Femoral vessel obstruction caused by MO is an extremely rare but disabling complication. Arterial occlusion may aggravate ischemic conditions, resulting in necrosis in the lower extremity. PATIENT CONCERNS: We report a 41-year-old female with progressive pain and swelling of the right thigh region for 1 year. DIAGNOSES: We diagnosed it as obstruction of the superficial femoral artery and vein caused by external compression of the MO between the sartorius and vastus medialis of the thigh. INTERVENTIONS AND OUTCOMES: Adherent tissues and mass were excised with care without damaging the femoral artery or the vein. However, normal morphology did not recover due to loss of elasticity of femoral vessels. Therefore, after resection of the narrowed region of the femoral artery, a femoral-to-femoral graft interposition using the greater saphenous vein was performed. At 12 months after the surgery, vessel reconstruction computed tomography images confirmed normal continuous flow of the femoral artery. LESSONS: Vascular compression and peripheral inflammatory response due to MO can cause loss of normal vascular morphology. Surgical excision of the mass and the involved femoral artery segment followed by femoral arterial reconstruction should be considered for lesions that do not spontaneously regress to prevent functional impairment and secondary complications in extremities.

Early detection of ankylosing spondylitis using texture features and statistical machine learning, and deep learning, with some patient age analysis.

Ankylosing spondylitis (AS) is an arthritis with symptoms visible in medical imagery. This paper proposes, to the authors' best knowledge, the first use of statistical machine learning- and deep learning-based classifiers to detect erosion, an early AS symptom, via analysis of computed tomography (CT) imagery, giving some consideration to patient age in so doing. We used gray-level co-occurrence matrices and local binary patterns to generate input features to machine learning algorithms, specifically k-nearest neighbors (k-NN) and random forest. Deep learning solutions based on a modified InceptionV3 architecture were designed and tested, with one classifier produced by training with a cross-entropy loss function and another produced by additionally seeking to minimize validation loss. We found that the random forest classifiers outperform the k-NN classifiers and achieve an eightfold cross-validation average accuracy, recall, and area under receiver operator characteristic curve (ROC AUC) of 96.0%, 92.9%, and 0.97, respectively, for erosion vs. young control patients, and 82.4%, 80.6%, and 0.91, respectively, for erosion vs. old control patients. We found that the deep learning classifier trained without minimizing validation loss was best and achieves an eightfold cross-validation accuracy, recall, and ROC AUC of 99.0%, 97.5%, and 0.97, respectively, for erosion vs. all (combined young and old) control patients; this classifier outperforms a musculoskeletal radiologist with 9 years of experience in raw sensitivity and specificity by 8.4% and 9.5%, respectively. Despite the relatively small dataset on which we trained and cross-validated, our results indicate the potential of machine and deep learning to aid AS diagnosis, and further research using larger datasets should be conducted.

Early Diagnosed Hirayama Disease with Unusual Symptoms Improved by Steroid Pulse Therapy.

BACKGROUND: Hirayama disease (HD), or monomelic amyotrophy, is a benign neurologic disorder mostly affecting young Asian men. It usually presents with unilateral or bilateral muscular atrophy and weakening of the upper limbs. We treated a patient with HD with bilateral hand paresthesia and weakness in 1 hand and both legs. To our knowledge, this is the first HD case including lower extremity weakness and sensory abnormalities. We improved the patient's symptoms by administering steroids in parallel with conservative treatment. CASE DESCRIPTION: A 22-year-old man visited our clinic with bilateral hand paresthesia and weakness in the right hand and both legs. He had been affected 40 days. Results of blood and cerebrospinal fluid tests were normal. Evoked potential study and brain magnetic resonance imaging (MRI) were normal. In cervical MRI, however, a lesion with high signal intensity of the C6 level on T2-weighted images was confirmed, and gray and white matter were extensively invaded. We performed empirical steroid pulse therapy before the results of blood tests to differentiate spinal demyelinating disease. MRI with neck flexion showed HD-related findings, and autoantibody tests showed no specific findings. After steroid pulse therapy, his neurologic symptoms improved within 7 days, leaving only paresthesia of toes of both feet when discharged. CONCLUSIONS: HD occurs at a young age and therefore can damage quality of life. Although the patient had unusual symptoms, the condition was diagnosed quickly, and his symptoms improved with steroid therapy. If HD is suspected, additional tests such as MRI with neck flexion should be performed and early steroid treatment might be considered.

Not All Green Is Tophi: The Importance of Optimizing Minimum Attenuation and Using a Tin Filter to Minimize Clumpy Artifacts on Foot and Ankle Dual-Energy CT.

OBJECTIVE. The clumpy artifact has a high misdiagnosis rate, but the artifact has not been well studied. The aims of this study were to evaluate the frequency and location of clumpy artifacts, the rate of misdiagnosis of clumpy artifacts as gout, and the effects of raising the minimum attenuation value and using a selective photon shield in dual-energy CT (DECT). MATERIALS AND METHODS. Forty patients without gout who underwent foot and ankle DECT were enrolled in this study. Images in both sets were randomly assigned a minimum attenuation of 130 HU or 150 HU. Three radiologists independently checked all images for presence, volume, and location of green color-coded pixelation and graded their findings according to a 4-point confidence scale, frequency, and volume. Misdiagnosis rate and misdiagnosis score were compared using the Wilcoxon signed rank and McNemar tests. RESULTS. In set 1, the frequency of clumpy artifacts in DECT with the minimum attenuation set to 130 HU and 150 HU were 81% and 68%, respectively. For all three readers, the misdiagnosis rate and misdiagnosis score decreased when changing the minimum attenuation from 130 HU to 150 HU. In set 2, with the minimum attenuation set to 130 HU, the frequency of the clumpy artifact was 44%; with the minimum attenuation set to 150 HU, no clumpy artifacts were seen. CONCLUSION. Clumpy artifacts occurred frequently in DECT without a tin filter. Setting the minimum attenuation to the higher value of 150 HU reduced the frequency of clumpy artifacts, and adding a tin filter to DECT greatly reduced their occurrence.

Fracture of ankle: MRI using opposed-phase imaging obtained from turbo spin echo modified Dixon image shows improved sensitivity.

OBJECTIVE: To evaluate if opposed-phase (OP) imaging obtained from the turbo spin echo (TSE) modified Dixon (mDixon) technique can increase the sensitivity of MRI for diagnosing ankle fractures. METHODS: This study included 95 CT-confirmed ankle fractures with additional MRI of the ankle using a TSE modified Dixon (mDixon) technique. Two groups of images were analyzed independently: Group 1-imaging group without OP imaging; Group 2-imaging group with OP imaging. Readers assessed the images using a 4-point confidence score to detect fractures. During the first review session, the fracture site was blinded. For the second review session, the fracture site was provided. Sensitivity and positive-predictive value were calculated. RESULTS: In both sessions, the sensitivity for Group 2 was significantly greater than that for Group 1 (Session 1: 76.3% vs 62.6%, p < 0.0001; Session 2: 80.5% vs 65.3%, p < 0.0001). The positive-predictive value of Group 2 was significantly lower in both sessions 1 and 2 (Session 1: 85.8% vs 97.5%, p < 0.0001; Session 2: 90.5% vs 96.9%, p = 0.0068). Among the 28 false-negative fractures missed in Group 1 (Session 1), 12 (9 minimal displaced and 4 small diameter fractures) were identified in Group 2 (Session 1). While 8.9% showed lower movement, 33.6% showed upper movement in Group 2 compared with Group 1. Possible causes of false-positive lesions were subcutaneous fat, bone marrow edema, and intraosseous vessel mimic fractures. CONCLUSION: OP imaging obtained using the modified Dixon technique provided better sensitivity and improved descriptions of fractures, especially for minimal displaced fractures and small diameter fractures. However, caution is required when diagnosing fractures with OP imaging because pseudofractures can appear as a result of adjacent bone marrow edema, vascular structures, or subcutaneous fat lobules. Advances in knowledge: In MRI, minimal displaced or small chip bone fracture maybe missed, OP imaging obtained using the mDixon technique provided better sensitivity and improved descriptions of fractures using the black boundary artifact.

Association Between Breastfeeding and Childhood Breathing Patterns: A Systematic Review and Meta-Analysis.

OBJECTIVES: This systematic review aimed to evaluate the association between breastfeeding and breathing patterns in children. MATERIALS AND METHODS: We searched PubMed, EMBASE, Web of Science, CINAHL, and the Cochrane Central Register of Controlled Trials for publications from inception to October 1, 2017. The breastfeeding duration and period of exclusive breastfeeding were selected as primary outcomes. The odds ratio (OR) and 95% confidence interval (CI) were calculated. A meta-analysis was conducted to synthesize the evidence. The Newcastle-Ottawa Score was used for quality and comparability assessment. RESULTS: Of the 54 articles identified, three observational studies met the inclusion criteria for this meta-analysis, representing 1,046 participants. The results of the meta-analysis revealed that the prevalence rate of mouth breathing (OR = 2.04; 95% CI, 1.26-3.31; p = 0.004) was significantly higher in subjects who were breastfed for less than 6 months, but no significant difference was observed within the periods of exclusive breastfeeding (6 months or less) (OR = 1.27; 95% CI, 0.73-2.21; p = 0.40). CONCLUSION: We found only limited evidence about the association between breastfeeding and breathing patterns. However, the current evidence supports the association between breastfeeding and childhood breathing patterns. Based on this review, we found that the frequency of normal nasal respiration increases with the duration of breastfeeding. The methodological quality of the studies included was moderate. Thus, future studies should aim to correct the confounding factors related to breathing patterns, to use standardized diagnostic criteria of mouth breathing, and to conduct a prospective research to reduce the recall bias.

Evaluation of an automated breast volume scanner according to the fifth edition of BI-RADS for breast ultrasound compared with hand-held ultrasound.

OBJECTIVES: To investigate the automated breast volume scanner (ABVS) in comparison with hand-held ultrasound (HHUS) according to the fifth edition of BI-RADS ultrasound. MATERIAL AND METHODS: A total of 831 lesions in 786 patients who underwent both HHUS and ABVS were included. Three radiologists independently evaluated the sonographic features of each lesion according to the fifth BI-RADS edition. The kappa coefficient (κ) was calculated for each BI-RADS descriptor and final assessment category. The accuracy of malignancy prediction and diagnostic performance of the BI-RADS descriptors were assessed using multivariate logistic regression and area under the receiver operator characteristic curve (AUC), respectively. RESULTS: ABVS and HHUS showed moderate to good interobserver agreement (κ = 0.53-0.67 and 0.55-0.70, respectively) except in associated features (κ = 0.31 and 0.36, respectively) for BI-RADS lexicons. Irregular shape, a non-circumscribed margin, and posterior features (combined or shadowing) were independently associated with malignancy in both ABVS and HHUS. Calcification presence on ABVS (odds ratio [OR], 95% confidence interval [CI]: 2.09, 1.11-3.94) and non-parallel orientation on HHUS (OR, 95% CI: 2.04, 1.10-3.78) were independently associated with malignancy. There were no significant differences between ABVS and HHUS in sensitivity (84.2% vs. 84.2%), specificity (80.5% vs. 83.9%), or AUC (0.88 vs. 0.90). CONCLUSIONS: According to the fifth BI-RADS edition, ABVS is not statistically significantly different from HHUS with regard to interobserver variability and diagnostic performance.

Comparison of transient severe motion in gadoxetate disodium and gadopentetate dimeglumine-enhanced MRI: effect of modified breath-holding method.

OBJECTIVES: To compare the occurrence of transient severe motion (TSM) between gadoxetate disodium- and gadopentetate dimeglumine-enhanced MRI and between gadoxetate disodium-enhanced MRI scans obtained with and without the application of a modified breath-holding technique. METHODS: We reviewed 80 patients who underwent two magnetic resonance examinations (gadoxetate disodium-enhanced MRI and gadopentetate dimeglumine-enhanced MRI) with the application of a modified breath-holding technique (dual group). This group was compared with 100 patients who underwent gadoxetate disodium-enhanced MRI without the application of the modified breath-holding technique (single group). Patient risk factors and motion scores (1 [none] to 5 [non-diagnostic]) for each dynamic-phase imaging were analysed. RESULTS: In the dual group, mean motion scores did not differ significantly between gadoxetate disodium- and gadopentetate dimeglumine-enhanced MRI (p=0.096-0.807) in any phase. However, in all phases except the late dynamic phase, mean motion scores of the dual group were significantly lower than those in the single group. TSM incidence did not differ significantly between gadoxetate disodium- and gadopentetate dimeglumine-enhanced MRI in the dual group (3.8% vs. 1.3%, p=0.620). CONCLUSION: With proper application of the modified breath-holding technique, TSM occurrence with gadoxetate disodium-enhanced MRI was comparable to that associated with gadopentetate dimeglumine-enhanced MRI. KEY POINTS: • The modified breath-holding method significantly reduced the incidence of TSM. • Gadoxetate disodium and gadopentetate dimeglumine showed comparable motion scores. • TSM incidence was comparable between gadoxetate disodium- and gadopentetate dimeglumine-enhanced MRI.

Intra-articular osteochondroma of the posteroinferior femoral neck associated with hip joint osteochondromatosis: A case report.

Osteochondromas are usually extra-articular lesions originating from the metaphysis of long bones. Intra-articular osteochondromas may also occur, causing pain and discomfort and restricting the range of motion. Osteochondromas of the femoral neck are intra-articular lesions that are difficult to access for surgical resection, particularly when located posteriorly. We herein present a rare case of an intra-articular osteochondroma involving the posteroinferior aspect of the femoral neck associated with secondary synovial osteochondromatosis (SOC) of the hip joint in a 25-year-old woman. Determining the optimal treatment was difficult due to the high risk of avascular necrosis (AVN) following surgical excision. The patient was successfully treated with arthroscopic surgery and she remained in good condition at 2 years postoperatively, with a full range of motion of the hip joint, and without signs of limping, recurrence of the SOC, or AVN of the femoral head.

Transient severe motion in the arterial phase during gadoxetate disodium-enhanced MR imaging: evaluation of patients with multiple MR examinations.

PURPOSE: To determine whether patients undergoing multiple gadoxetate disodium-enhanced magnetic resonance (MR) examinations who experienced transient severe motion (TSM) in the arterial phase were affected by the TSM noted in the first examination. MATERIALS AND METHODS: 214 patients who underwent three or more repeated gadoxetate disodium-enhanced MR imaging were retrospectively analyzed. Three radiologists scored all of the examinations demonstrating a motion artifact using a five-point rating scale. Risk factor analysis and comparison of TSM recurrence rates were performed in the whole study population as well as in a subpopulation of patients with TSM. RESULTS: The overall incidence of TSM was 5.9% (54/922), which was observed in 40 patients. Thirty-two patients had one episode of TSM, and eight patients had recurrent TSM. Although TSM in the first examination increased the risk of recurrent TSM in the whole population (OR 24.45; P < 0.001), the incidence of recurrent TSM was low (2.4%, 22/922). On subpopulation analysis, TSM in the first examination did not influence recurrent TSM (OR 0.36; P = 0.250). CONCLUSION: Patients undergoing multiple gadoxetate disodium-enhanced MR examinations who experienced recurrent TSM were not affected by TSM in the first examination. Therefore, a single episode of TSM should not be considered a risk factor of recurrent TSM.

Successfully Managed Acute Transverse Myelitis Related to Scrub Typhus and Serial Image Findings.

Central nervous system involvement manifesting as meningitis or meningoencephalitis is a known complication of scrub typhus, but very few spinal cord lesions such as acute transverse myelitis (ATM) have been reported in association with this disease. Scrub typhus patients with a spinal lesion present with neurologic symptoms including dysuria, motor, and sensory weakness. Herein, we describe a rare case of ATM associated with scrub typhus. Clinical characteristics, cerebrospinal fluid cytology, Orientia tsutsugamushi serum antibody titer, and serial magnetic resonance imaging scans resulted in a diagnosis of ATM associated with scrub typhus.