Clubfoot: Congenital Talipes Equinovarus.

Congenital talipes equinovarus (CTEV), also known as clubfoot, is a common musculoskeletal entity that affects one to two per 1000 live births worldwide. Imaging modalities including radiography, US, and MRI have emerged as valuable tools for the diagnosis, treatment, and monitoring of CTEV. The deformity is characterized by midfoot cavus, forefoot adductus, and hindfoot varus and equinus. The Ponseti method of manipulation and serial casting is the standard treatment of CTEV. Radiography shows the anatomy, position, and relationships of the different bones of the foot. US allows accurate assessment of cartilaginous and bony structures, in addition to its inherent advantages such as absence of ionizing radiation exposure. One of the indications for US is to monitor the response to Ponseti method treatment. MRI enables visualization of bones, cartilage, and soft tissues and allows multiplanar evaluation of deformities, providing a comprehensive imaging analysis of CTEV. An integrated approach that combines clinical examination and imaging findings is essential for effective management of CTEV. The authors provide a comprehensive overview of CTEV with a review of imaging modalities to help evaluate CTEV, focusing on radiography, US, and MRI. Using this article as a guide, radiologists involved in the assessment and treatment of CTEV can contribute to the management of the condition. ©RSNA, 2024 Supplemental material is available for this article.

Magnetic Resonance Imaging Features of Plantar Vein Thrombosis.

Plantar vein thrombosis (PVT) is an underdiagnosed condition affecting the deep plantar veins, with challenging clinical diagnosis, often presenting with non-specific symptoms that mimic other foot pathologies. This study assessed the magnetic resonance imaging (MRI) features of patients diagnosed with PVT to contribute to the understanding of this condition. We performed the comprehensive analysis of a substantial dataset, including 112 patients, with a total of 130 positive MRI scans (86 of the forefoot and 44 of the ankle) presenting with PVT. Upon evaluating all the veins of the feet, we observed a higher frequency of involvement of the lateral plantar veins (53.1%) when compared to the medial veins (3.8%). The most affected vascular segments in the forefeet were the plantar metatarsal veins (45.4%), the plantar venous arch (38.5%), and the plantar communicating veins (25.4%). The characteristic findings on MRI were perivascular edema (100%), muscular edema (86.2%), venous ectasia (100%), perivascular enhancement (100%), and intravenous filling defects (97.7%). Our study provides valuable insights into the imaging evaluation of PVT and shows that MRI is a reliable resource for such diagnosis.

Imaging Features of Plantar Vein Thrombosis: An Easily Overlooked Condition in the Differential Diagnosis of Foot Pain.

Plantar vein thrombosis is a venous disorder affecting deep plantar veins that can manifest with non-specific localized pain, plantar foot pain, swelling, and sensation of fullness. Plantar veins are not routinely assessed during sonographic scans for deep venous thrombosis, which makes plantar venous thrombosis a commonly missed diagnosis. This paper provides a comprehensive review of the venous anatomy of the foot and imaging findings of plantar venous thrombosis as well as discusses the current literature on the topic and its differential diagnoses.

3D isotropic MRI of ankle: review of literature with comparison to 2D MRI.

The ankle joint has complex anatomy with different tissue structures and is commonly involved in traumatic injuries. Magnetic resonance imaging (MRI) is the primary imaging modality used to assess the soft tissue structures around the ankle joint including the ligaments, tendons, and articular cartilage. Two-dimensional (2D) fast spin echo/turbo spin echo (FSE/TSE) sequences are routinely used for ankle joint imaging. While the 2D sequences provide a good signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) with high spatial resolution, there are some limitations to their use owing to the thick slices, interslice gaps leading to partial volume effects, limited fluid contrast, and the need to acquire separate images in different orthogonal planes. The 3D MR imaging can overcome these limitations and recent advances have led to technical improvements that enable its widespread clinical use in acceptable time periods. The volume imaging renders the advantage of reconstructing into thin continuous slices with isotropic voxels enabling multiplanar reconstructions that helps in visualizing complex anatomy of the structure of interest throughout their course with improved sharpness, definition of anatomic variants, and fluid conspicuity of lesions and injuries. Recent advances have also reduced the acquisition time of the 3D datasets making it more efficient than 2D sequences. This article reviews the recent technical developments in the domain 3D MRI, compares imaging with 3D versus 2D sequences, and demonstrates the use-case scenarios with interesting cases, and benefits of 3D MRI in evaluating various ankle joint components and their lesions.

Upper extremity infection: imaging features with focus on magnetic resonance imaging.

Upper extremity infections are frequently seen, especially in individuals with weakened immune system, posttraumatic events, and after surgery procedures. If not properly treated, such conditions can lead to serious consequences, such as movement impairment, amputation, and even mortality. These infections have the potential to spread extensively from their initial site of entry, traversing interconnected spaces either intra or extra-compartmental. Understanding the relevant anatomy is crucial to assess location and stage of infection, since surgical intervention and intravenous antibiotics are usually required. In this article, the authors provide a comprehensive review of the imaging findings of upper extremity infection, focusing on magnetic resonance imaging (MRI). Furthermore, this article sheds light on the pivotal role of radiology in managing hand, elbow, and shoulder infections offering an overview of available treatment options. KEY FINDINGS: Various types of infections affecting the upper extremity will be discussed, including infectious tenosynovitis, deep space infections, septic arthritis, and osteomyelitis. Authors also highlight anatomical spaces, common pathogens, spread routes, and key radiological features of these conditions.

Identification and structural characterization of a pathogenic ARSA missense variant in two consanguineous families from Jammu and Kashmir (India) with late infantile metachromatic leukodystrophy.

BACKGROUND: Metachromatic leukodystrophy (MLD) is a rare lysosomal storage disorder caused by a deficiency of Arylsulfatase A (ARSA) enzyme activity. Its clinical manifestations include progressive motor and cognitive decline. ARSA gene mutations are frequent in MLD. METHODS AND RESULTS: In the present study, whole exome sequencing (WES) was employed to decipher the genetic cause of motor and cognitive decline in proband's of two consanguineous families from J&K (India). Clinical investigations using radiological and biochemical analysis revealed MLD-like features. WES confirmed a pathogenic variant in the ARSA gene. Molecular simulation dynamics was applied for structural characterization of the variant. CONCLUSION: We report the identification of a pathogenic missense variant (c.1174 C > T; p.Arg390Trp) in the ARSA gene in two cases of late infantile MLD from consanguineous families in Jammu and Kashmir, India. Our study utilized genetic analysis and molecular dynamics simulations to identify and investigate the structural consequences of this mutation. The molecular dynamics simulations revealed significant alterations in the structural dynamics, residue interactions, and stability of the ARSA protein harbouring the p.Arg390Trp mutation. These findings provide valuable insights into the molecular mechanisms underlying the pathogenicity of this variant in MLD.

Acute ankle injuries: association between sprain severity and ancillary findings.

Miranda et al. reported a correlation between the significance of injuries to osseous, chondral, tendon, and ligamentous tissues in participants with low-grade versus high-grade acute ankle sprains. They demonstrated that participants with high-grade ankle sprains presented with shorter calcaneonavicular distances and increased rates of structural abnormalities compared to those with low-grade sprains. Special attention should be paid to acute ankle sprains in emergency settings to avoid failure in detecting severe injuries that could lead to chronic pain, impairment, or instability. Participants presenting acute ankle sprains (<15 days) were divided into low-grade versus high-grade sprain,according to the presence of a complete tear in at least one component of lateral ligament complex. High-grade ankle sprains group presented increased rates of medial malleolus bone bruise, deltoid ligament tears,extensor retinaculum lesions, and articular effusion. The calcaneonavicular distance was statistically shorter in patients with high-grade sprains (median, 3.0mm) when compared to those with low-grade sprains (median, 4.0mm) Objective: To correlate the significance of osseous, chondral, tendon, and ligamentous injuries with anatomical variations in low-grade versus high-grade acute ankle sprains. METHODS: We retrospectively identified the magnetic resonance imaging findings of acute ankle sprains (<15 days). Participants with a history of previous sprains, arthritis, tumors, infections, or inflammatory conditions were excluded. Images were independently evaluated by two musculoskeletal radiologists and assessed for osseous, chondral, tendon, and ligamentous injuries and anatomical variations. Participants were divided into low-grade versus high-grade sprain groups, according to the presence of a complete tear in at least one component of the lateral ligament complex. RESULTS: The final study group comprised 100 magnetic resonance images (mean age, 36 years), the majority of males (54%), the right ankle (52%), and a mean sprain duration of 5 days. Participants with high-grade sprains presented with increased rates of medial malleolus edema (p<0.001), moderate and large articular effusions (p=0.041), and shorter calcaneonavicular distance (p=0.008). Complete tears of the anterior talofibular ligament and calcaneofibular ligaments were observed in 100% and 51.2% of the participants in the High-Grade Group, respectively. The deltoid ligament complex was partially torn in this group (55.8% versus 8.8%, p<0.001). Extensor tendon retinaculum lesions occurred significantly more frequently in this group (41.9%) compared to the overall study population (23%) (p<0.001). CONCLUSION: Participants with high-grade ankle sprains presented with shorter calcaneonavicular distances and increased rates of medial malleolus edema, deltoid complex partial tears, extensor retinaculum lesions, and articular effusion.

2-Dimensional and 3-Dimensional MR Imaging-Aid to Knee Preservation Surgery: Focus on Meniscus and Articular Cartilage.

With an increasing life expectancy of global human population, there is a growing demand for preservation of native articular meniscus and cartilage to delay joint arthroplasties, especially in younger and active patients. Since damage to the meniscus and hyaline cartilage of the knee have limited intrinsic capacity to heal, such lesions lead to premature and/or accelerated osteoarthritis. However, knee surgical treatments have evolved and may allow restoration of the natural anatomy, delay the progression of damage, and alter the biology of the meniscus and articular cartilage. The knee preservation surgery is aided by timely detection of such injuries and high-resolution illustration and characterization of the pathology using two-dimensional and three-dimensional magnetic resonance imaging (MRI), made possible due to better MR scanner technology and related software improvements. This article reviews the current literature and authors' experience with imaging concepts and high-resolution MR imaging techniques as they relate to management and planning for such restorative procedures. Relevant arthroscopy correlations have been illustrated.

Neuropathy Score Reporting and Data System (NS-RADS): A Practical Review of MRI-Based Peripheral Neuropathy Assessment.

The Neuropathy Score Reporting and Data System (NS-RADS) is a newly developed MR imaging-based classification that standardizes reporting and multidisciplinary communication for MR imaging diagnosis and follow-up of peripheral neuropathies. NS-RADS classification has shown to be accurate and reliable across different centers, readers' experience levels, and degrees of peripheral neuropathies, which include nerve injury, entrapment, neoplasm, diffuse neuropathy, post-interventional status, and temporal changes in muscle denervation. This article brings a practical review of NS-RADS classification, representative MR cases, and a step-by-step tutorial on how to approach this staging system. Readers can gain knowledge and apply it in their practice, aiming to standardize the communications between specialties and improve patient management.

Imaging features of the postoperative spine: a guide to basic understanding of spine surgical procedures.

Spinal surgical procedures are becoming more common over the years, and imaging studies can be requested in the postoperative setting, such as a baseline study when implants are used, or when there is a new postoperative issue reported by the patient or even as routine surveillance. Therefore, it helps the surgeon in the appropriate management of cases. In this context, there is increasing importance of the radiologist in the adequate interpretation of postoperative images, as well as in the choice of the most appropriate modality for each case, especially among radiographs, computed tomography, magnetic resonance imaging and nuclear medicine. It is essential to be familiar with the main types of surgical techniques and imaging characteristics of each one, including the type and correct positioning of hardware involved, to differentiate normal and abnormal postoperative appearances. The purpose of this pictorial essay is to illustrate and discuss the more frequently used spine surgical interventions and their imaging characteristics, with an emphasis on classical decompression and fusion/stabilization procedures. KEY POINTS: Plain radiographs remain the main modality for baseline, dynamic evaluation, and follow-ups. CT is the method of choice for assessing bone fusion, hardware integrity and loosening. MRI should be used to evaluate bone marrow and soft tissue complications. Radiologists should be familiar with most performed spinal procedures in order to differentiate normal and abnormal. CRITICAL RELEVANCE STATEMENT: This article discusses the main surgical procedures involved in the spine, which can be didactically divided into decompression, stabilization-fusion, and miscellaneous, as well as the role of diagnostic imaging methods and their main findings in this context.

Advanced Imaging in the Chronic Lateral Ankle Instability: An Algorithmic Approach.

Imaging examinations are a fundamental part of assessing chronic lateral ankle instability (CLAI). Plain radiographs are used in the initial examination, whereas stress radiographs can be requested to actively search for instability. Ultrasonography (US) and Magnetic Resonance Imaging (MRI) allow direct visualization of ligamentous structures, with the advantage of dynamic evaluation for US, and assessment of associated lesions and intra-articular abnormalities for MRI, which plays an essential role in surgical planning. This article reviews imaging methods to diagnose and follow up on CLAI, along with illustrative cases and an algorithmic approach.

Acute ankle injuries: association between sprain severity and ancillary findings

ABSTRACT Objective To correlate the significance of osseous, chondral, tendon, and ligamentous injuries with anatomical variations in low-grade versus high-grade acute ankle sprains. Methods We retrospectively identified the magnetic resonance imaging findings of acute ankle sprains (<15 days). Participants with a history of previous sprains, arthritis, tumors, infections, or inflammatory conditions were excluded. Images were independently evaluated by two musculoskeletal radiologists and assessed for osseous, chondral, tendon, and ligamentous injuries and anatomical variations. Participants were divided into low-grade versus high-grade sprain groups, according to the presence of a complete tear in at least one component of the lateral ligament complex. Results The final study group comprised 100 magnetic resonance images (mean age, 36 years), the majority of males (54%), the right ankle (52%), and a mean sprain duration of 5 days. Participants with high-grade sprains presented with increased rates of medial malleolus edema (p<0.001), moderate and large articular effusions (p=0.041), and shorter calcaneonavicular distance (p=0.008). Complete tears of the anterior talofibular ligament and calcaneofibular ligaments were observed in 100% and 51.2% of the participants in the High-Grade Group, respectively. The deltoid ligament complex was partially torn in this group (55.8% versus 8.8%, p<0.001). Extensor tendon retinaculum lesions occurred significantly more frequently in this group (41.9%) compared to the overall study population (23%) (p<0.001). Conclusion Participants with high-grade ankle sprains presented with shorter calcaneonavicular distances and increased rates of medial malleolus edema, deltoid complex partial tears, extensor retinaculum lesions, and articular effusion.

Incidence of adhesive capsulitis of the shoulder during the beginning of the COVID-19 pandemic.

OBJECTIVE: Adhesive capsulitis is an inflammatory disease of the joint capsule, clinically manifested as pain, stiffness, and dysfunction of the shoulder. We subjectively observed an increased incidence of adhesive capsulitis, and raised the hypothesis that adhesive capsulitis was more frequent in magnetic resonance imaging examinations performed during the COVID-19 pandemic as compared with examinations prior to this period. METHODS: Data from medical records and magnetic resonance imaging of the shoulder presenting typical imaging findings of adhesive capsulitis, performed in our organization from March to June 2020, were evaluated and compared with data and imaging from the same period of the previous year. To this end, an organizational business intelligence tool called "search reports" was used, searching for the term "adhesive capsulitis" in the radiological report, results were tabulated, and corresponding magnetic resonance imaging exams were analyzed. RESULTS: Our search found a total of 240 and 1,373 cases of adhesive capsulitis in the 2020 and 2019 periods, respectively. The mean age of patients was 53.9 years in the 2020 group and 49.9 years in 2019 (p<0.001). Magnetic resonance imaging findings were positive for adhesive capsulitis in 40 out of 240 shoulders (16.7%) in the 2020 group versus 127 out of 1,373 shoulders (9.2%) in the 2019 group. This difference was statistically significant (p=0.001). CONCLUSION: Our study findings suggest a relative increase in the proportion of magnetic resonance imaging findings suggestive of adhesive capsulitis cases during COVID-19 pandemics based on data from our organization.

PELVIC INCIDENCE AND OSTEITIS PUBIS IN PROFESSIONAL SOCCER PLAYERS.

INTRODUCTION: Osteitis pubis is a common inflammatory disease of the pubic symphysis, defined as a chronic pain syndrome caused by repetitive microtrauma. Since adaptative changes are necessary in the pelvis to adjust the equilibrium of the myotendinous structures, the aim of this study was to evaluate the correlation between pelvic incidence and osteitis pubis among professional soccer players. MATERIALS AND METHODS: An observational, cross-sectional study was performed with professional soccer players from five teams during pre-season. Athletes with previous congenital pelvic abnormalities or a history of surgery were excluded. Radiographs of the pelvis were analyzed by two radiologists and assessed for findings consistent with osteitis pubis, and the following parameters were measured: pelvic incidence (PI), sacral inclination (SI), and pelvic version (PV). RESULTS: A total of 107 subjects were included in the study, with a mean age of 25.6 ± 3.1 years. Findings compatible with osteitis pubis were present in 74.8% of the subjects (80/107). There was no statistical correlation between osteitis pubis and PI (52.3°±12.7° vs. 48.4°±10.8°; p=0.156), SI (43.1°±9.8° vs. 39.9°±10.1°; p=0.146), or PV (9.2°± 6.3° vs 8.6°± 7.5°; p=0.649). Agreement between readers was excellent (p<0.0001). CONCLUSION: There was no significant correlation between pelvic parameters and radiographic diagnosis of osteitis pubis. Leve of Evidence II; Diagnostic study.

Introdução. A osteíte púbica é uma doença inflamatória comum da sínfise púbica, definida como síndrome de dor crônica causada por microtraumas de repetição. Uma vez que são necessárias mudanças adaptativas na pelve para adequar o equilíbrio das estruturas miotendíneas, o objetivo deste estudo foi avaliar a correlação entre e a incidência pélvica e a osteíte púbica em jogadores profissionais de futebol. Materiais e Métodos. Estudo transversal, observacional, conduzido com jogadores profissionais de futebol de cinco times profissionais durante a pré-temporada. Foram excluídos do estudo atletas com anormalidades congênitas prévias ou com história de cirurgia. As radiografias de pelve foram avaliadas por dois médicos radiologistas quanto aos achados compatíveis com osteíte púbica, e os seguintes parâmetros foram medidos: incidência pélvica (PI), inclinação sacral (SI) e versão pélvica (PV). Resultados. Foram incluídos 107 participantes, com média de idade de 25,6 ± 3,1 anos. Achados compatíveis com osteíte púbica estavam presentes em 74,8% dos indivíduos (80/107). Não houve correlação estatística entre osteíte púbica e PI (52,3°± 12,7° vs. 48,4° ± 10,8°; p = 0,156), SI (43,1° ± 9,8° vs. 39,9° ± 10,1°; p = 0,146) ou PV (9,2° ± 6,3° vs. 8,6° ± 7,5°; p = 0,649). A concordância entre os médicos radiologistas foi excelente (p < 0,0001). Conclusões. Não houve correlação significativa entre os parâmetros pélvicos e o diagnóstico radiográfico de osteíte púbica. Nível de Evidência II; Estudo diagnóstico.

Incidence of adhesive capsulitis of the shoulder during the beginning of the COVID-19 pandemic

ABSTRACT Objective Adhesive capsulitis is an inflammatory disease of the joint capsule, clinically manifested as pain, stiffness, and dysfunction of the shoulder. We subjectively observed an increased incidence of adhesive capsulitis, and raised the hypothesis that adhesive capsulitis was more frequent in magnetic resonance imaging examinations performed during the COVID-19 pandemic as compared with examinations prior to this period. Methods Data from medical records and magnetic resonance imaging of the shoulder presenting typical imaging findings of adhesive capsulitis, performed in our organization from March to June 2020, were evaluated and compared with data and imaging from the same period of the previous year. To this end, an organizational business intelligence tool called "search reports" was used, searching for the term "adhesive capsulitis" in the radiological report, results were tabulated, and corresponding magnetic resonance imaging exams were analyzed. Results Our search found a total of 240 and 1,373 cases of adhesive capsulitis in the 2020 and 2019 periods, respectively. The mean age of patients was 53.9 years in the 2020 group and 49.9 years in 2019 (p<0.001). Magnetic resonance imaging findings were positive for adhesive capsulitis in 40 out of 240 shoulders (16.7%) in the 2020 group versus 127 out of 1,373 shoulders (9.2%) in the 2019 group. This difference was statistically significant (p=0.001). Conclusion Our study findings suggest a relative increase in the proportion of magnetic resonance imaging findings suggestive of adhesive capsulitis cases during COVID-19 pandemics based on data from our organization.

Pelvic incidence and osteitis pubis in professional soccer players / Incidência pélvica e osteíte púbica em jogadores profissionais de futebol

ABSTRACT Introduction. Osteitis pubis is a common inflammatory disease of the pubic symphysis, defined as a chronic pain syndrome caused by repetitive microtrauma. Since adaptative changes are necessary in the pelvis to adjust the equilibrium of the myotendinous structures, the aim of this study was to evaluate the correlation between pelvic incidence and osteitis pubis among professional soccer players. Materials and Methods. An observational, cross-sectional study was performed with professional soccer players from five teams during pre-season. Athletes with previous congenital pelvic abnormalities or a history of surgery were excluded. Radiographs of the pelvis were analyzed by two radiologists and assessed for findings consistent with osteitis pubis, and the following parameters were measured: pelvic incidence (PI), sacral inclination (SI), and pelvic version (PV). Results. A total of 107 subjects were included in the study, with a mean age of 25.6 ± 3.1 years. Findings compatible with osteitis pubis were present in 74.8% of the subjects (80/107). There was no statistical correlation between osteitis pubis and PI (52.3°±12.7° vs. 48.4°±10.8°; p=0.156), SI (43.1°±9.8° vs. 39.9°±10.1°; p=0.146), or PV (9.2°± 6.3° vs 8.6°± 7.5°; p=0.649). Agreement between readers was excellent (p<0.0001). Conclusion. There was no significant correlation between pelvic parameters and radiographic diagnosis of osteitis pubis. Leve of Evidence II; Diagnostic study.

RESUMO Introdução. A osteíte púbica é uma doença inflamatória comum da sínfise púbica, definida como síndrome de dor crônica causada por microtraumas de repetição. Uma vez que são necessárias mudanças adaptativas na pelve para adequar o equilíbrio das estruturas miotendíneas, o objetivo deste estudo foi avaliar a correlação entre e a incidência pélvica e a osteíte púbica em jogadores profissionais de futebol. Materiais e Métodos. Estudo transversal, observacional, conduzido com jogadores profissionais de futebol de cinco times profissionais durante a pré-temporada. Foram excluídos do estudo atletas com anormalidades congênitas prévias ou com história de cirurgia. As radiografias de pelve foram avaliadas por dois médicos radiologistas quanto aos achados compatíveis com osteíte púbica, e os seguintes parâmetros foram medidos: incidência pélvica (PI), inclinação sacral (SI) e versão pélvica (PV). Resultados. Foram incluídos 107 participantes, com média de idade de 25,6 ± 3,1 anos. Achados compatíveis com osteíte púbica estavam presentes em 74,8% dos indivíduos (80/107). Não houve correlação estatística entre osteíte púbica e PI (52,3°± 12,7° vs. 48,4° ± 10,8°; p = 0,156), SI (43,1° ± 9,8° vs. 39,9° ± 10,1°; p = 0,146) ou PV (9,2° ± 6,3° vs. 8,6° ± 7,5°; p = 0,649). A concordância entre os médicos radiologistas foi excelente (p < 0,0001). Conclusões. Não houve correlação significativa entre os parâmetros pélvicos e o diagnóstico radiográfico de osteíte púbica. Nível de Evidência II; Estudo diagnóstico.

Meniscal ramp lesions: an illustrated review.

The purpose of this review is to describe the anatomy and lesions affecting the peripheral portion of posterior horn of medial menisci (ramp lesions), along with illustrations and MRI cases. We will correlate imaging features with arthroscopic classification of ramp lesions. Also, postoperative and chronic changes related to meniscocapsular tears will be presented, as well as biomechanical consequences and treatment approach.

Giant axonal neuropathy with novel GAN pathogenic variant in a patient of consanguineous origin from Poonch Jammu and Kashmir-India.

Giant axonal neuropathy (GAN) is a severe and rare autosomal recessive neurodegenerative disorder of childhood affecting both the peripheral and central nervous systems (CNS). It is caused by mutations in the GAN (gigaxonin) gene linked to chromosome 16q24. Here, we present a 15-year-old male patient with GAN from a consanguineous family of Poonch, Jammu and Kashmir (J&K)-India. Whole-exome sequencing (WES) was employed to unravel the genetic cause of GAN in the proband. Pathogenic variant identified with WES was confirmed in other affected sibling using Sanger sequencing. Magnetic resonance imaging (MRI) and detailed clinical investigation was also carried out on proband. WES revealed a novel homozygous stopgain GAN mutation (NM_022041, c.C1028G, p.S343X) in the patient. MRI of brain displayed bilateral symmetrical confluent areas of deep white matter signal changes affecting periventricular regions (with sparing of subcortical U-fibers), posterior limbs of internal capsules, thalami, external capsules, and semioval centers. The patient was initially suspected to be a case of metachromatic leukodystrophy. However, WES analysis revealed a pathogenic variant in GAN gene as causative. No other pathogenic variant relevant to any other type of dystrophy was reported in WES. Our findings extend the geographical distribution of GAN to even a very remote region in India, extend the mutational and imaging spectrum of GAN and substantiate the need for introducing genetic testing and counselling in primary referral centers/district hospitals in India.

Differential Diagnosis of Facet Joint Disorders.

Spinal pain due to facet joint disease is difficult to diagnose since the clinical history and physical examination findings are usually nonspecific. Facet joint disorders have a wide range of causes and, because of the potential for chronic back pain and disability, an accurate diagnosis is essential. The most frequent cause of pain in facet joints is osteoarthritis, which can be assessed at radiography, CT, or MRI. Ganglion and synovial cysts of the facet joints can cause compressive symptoms of adjacent structures, especially radiculopathy, lower back pain, and sensory or motor deficits. In ankylosing spondylitis, imaging findings of the facet joints are useful not only for diagnosis but also for monitoring structural changes. In septic arthritis of the facet joints, an early diagnosis at MRI is essential. Gout and metabolic diseases are best evaluated at dual-energy CT, which allows the depiction of crystals. Traumatic dislocations of facet joints are usually unstable injuries that require internal reduction, fixation, and fusion and can be well assessed at CT with three-dimensional reconstructions. Facet joint neoplasms like osteoid osteoma, plasmacytoma, tenosynovial giant cell tumor, and osteochondroma are best evaluated at CT or MRI. The authors provide an overview of key imaging features of the most common facet joint disorders along with anatomic tips and illustrative cases. Acknowledging key imaging findings for the differential diagnosis of facet joint disorders plays a crucial role in the diagnostic accuracy and proper treatment approach for such entities. Online supplemental material is available for this article. ©RSNA, 2021.