The differentiation between aneurysmal bone cyst and telangiectatic osteosarcoma: a clinical, radiographic and MRI study.

OBJECTIVES: Aneurysmal bone cyst (ABC) and telangiectatic osteosarcoma (TOS) share several clinical and imaging features, including young presentation, long bone involvement, lytic appearance on radiography and fluid-fluid levels on MRI. Therefore, they may be difficult to differentiate. The aim of this study is to identify clinical, radiological and MRI features which aid differentiation of the two lesions. MATERIALS AND METHODS: Retrospective review of all histologically confirmed ABC and TOS over an 11-year period. Data recorded include age at presentation, sex, skeletal location and various radiographic and MRI features. RESULTS: This retrospective study included 183 patients, 92 males and 91 females. Mean age at presentation of 18.4 years (range 1-70 years); 152 cases of ABC and 31 TOS. No significant difference between age and sex. TOS was significantly less likely to involve the axial skeleton; no difference related to location within the bone. Radiographic findings significantly favouring ABC included a less aggressive pattern of bone destruction, a purely lytic appearance, an expanded but intact cortex, no periosteal response and no soft tissue mass. MRI features significantly favouring ABC included smaller tumour size (maximum mean dimension 46 mm compared to 95 mm for TOS), absence of soft tissue mass, > 2/3 of the lesion filled with fluid levels and thin septal enhancement following contrast. CONCLUSIONS: Several radiographic and MRI features aid in the differentiation between ABC and TOS. Lesions with a geographic Type 1A or IB pattern of bone destruction which are completely filled with FFLs on MRI can confidently be diagnosed as ABC.

Conus infarction after non-guided transcoccygeal ganglion impar block using particulate steroid for chronic coccydynia.

Introduction: Ganglion impar block (GIB) is a well-recognised treatment for chronic coccydynia. Several side effects have previously been described with this procedure, including transient motor dysfunction, bowel, bladder, and sexual dysfunction, neuritis, rectal perforation, impingement of the sciatic nerve, cauda equina syndrome, and infection. Case presentation: We describe the first report of imaging-documented conus infarction after an unguided-GIB performed in theatre using particulate steroids for a 17-year-old patient with coccydynia. Immediately post-GIB, patient developed transient neurological deficits in her lower limbs of inability to mobilise her legs that lasted for 24 h. These include back and leg pain, decreased power and movement, increased tone, brisk reflexes, reduced light touch sensation and proprioception of legs up to the T10 level. Urgent MRI spine showed intramedullary hyperintense signal within the conus and mild restricted diffusion on the distal cord and conus, suggestive of an acute conus infarction. On follow-up, the GIB did not result in symptom improvement of coccydynia and there was persistent altered sensation of her legs. Discussion: Various approaches of ganglion impar block have been described and performed in the past with different imaging techniques and injectants. A few cases of unusual neurological complications have been reported with the use of epidural steroid injections and ganglion impar block. Clinicians should be aware of the possible neurological complications following ganglion impar blocks and the risk of inadvertent intravascular injection of particulate steroids can potentially to be minimised by using imaging guidance.

Acquired Chiari malformation following spinal cord injury-a case series.

Introduction: Chiari malformation is characterized by caudal descent of the cerebellar tonsils through the foramen magnum. Acquired Chiari malformations (ACM) have previously been described after a variety of pathologies including lumbar puncture, cerebrospinal fluid (CSF) drainage, lumboperitoneal shunts, and conditions causing craniocephalic disproportion. Case presentation: We present four cases of ACM following spinal cord injury (SCI), which has not previously been described in the literature. Discussion: ACM is rare and typically associated with abnormalities in CSF pressure or space-occupying lesions. This case series describes the potential association of SCI with ACM. We discuss the imaging findings and clinical management of these patients. Early recognition and intervention may be important to prevent progressive neurology in this vulnerable patient group.

Non-traumatic myelopathy associated with prolonged hyperextension during swimming: an unusual variation of Surfer's Myelopathy.

INTRODUCTION: Surfer's myelopathy (SM) is a rare cause on non-traumatic acute myelopathy. This has classically been described in novice surfers however has been reported in other scenarios. CASE PRESENTATION: We present a case of non-traumatic paraparesis associated with prolonged cervical hyperextension during swimming with imaging characteristics consistent with an unusual variation of SM in a swimmer. DISCUSSION: SM and its variants should be considered in the differential diagnosis of any patient presenting with an anterior spinal cord syndrome with a history of either sustained or repeated spinal hyperextension.

Intracranial Carotid Calcification on Cranial Computed Tomography: Visual Scoring Methods, Semiautomated Scores, and Volume Measurements in Patients With Stroke.

BACKGROUND AND PURPOSE: Intracranial internal carotid artery calcification is associated with cerebrovascular risk factors and stroke, but few quantification methods are available. We tested the reliability of visual scoring, semiautomated Agatston score, and calcium volume measurement in patients with recent stroke. METHODS: We used scans from a prospective hospital stroke registry and included patients with anterior circulation ischemic stroke or transient ischemic stroke whose noncontrast cranial computed tomographic scans were available electronically. Two raters measured semiautomatic quantitative Agatston score, and calcium volume, and performed qualitative visual scoring using the original 4-point Woodcock score and a modified Woodcock score, where each image on which the internal carotid arteries appeared was scored and the slice scores summed. RESULTS: Intra- and interobserver coefficient of variations were 8.8% and 16.5% for Agatston, 8.8% and 15.5% for calcium volume, and 5.7% and 5.4% for the modified Woodcock visual score, respectively. The modified Woodcock visual score correlated strongly with both Agatston and calcium volume quantitative measures (both R(2)=0.84; P<0.0001); calcium volume increased by 0.47-mm/point increase in modified Woodcock visual score. Intracranial internal carotid artery calcification increased with age by all measures (eg, visual score, Spearman ρ=0.4; P=0.005). CONCLUSIONS: Visual scores correlate highly with quantitative intracranial internal carotid artery calcification measures, with excellent observer agreements. Visual intracranial internal carotid artery scores could be a rapid and practical method for epidemiological studies.