Paediatric intra-axial posterior fossa tumours: pictorial review.

Paediatric brain tumours commonly arise in the posterior cranial fossa. Early diagnosis is often challenging due to initial non-specific clinical symptoms, especially in very young children. The typical MR features of tumours in this region including medulloblastoma, ependymoma, juvenile pilocytic subtype of cerebellar astrocytoma, brain stem glioma and atypical teratoid-rhabdoid tumour are illustrated. Diffusion-weighted imaging and apparent diffusion coefficient values combined with signal characteristics on conventional MR sequences can usually differentiate low-grade from high-grade tumours. Prompt diagnosis is crucial as total surgical resection, which is only possible in localised disease, improves prognosis. A practical MR flow chart is introduced for differentiating different types of posterior cranial fossa tumours, which might be useful in clinical practice.

US assessment of medial arterial calcification: a sensitive marker of diabetes-related microvascular and macrovascular complications.

PURPOSE: To examine the sensitivity of ultrasonography (US) compared with conventional radiography in detection of lower limb (thigh) medial arterial calcification (MAC) in type 2 diabetic patients and evaluate its association with diabetes-related complications. MATERIALS AND METHODS: The study was approved by the local research ethics committee, and informed written consent was obtained. US was performed in 289 patients with type 2 diabetes mellitus, and MAC severity was assigned a score from 0 to 8. Among the patients, 263 underwent radiographic examinations. All subjects underwent clinical evaluation to detect the presence of diabetes-related complications. RESULTS: US helped detect MAC in more subjects compared with radiography (65.8% vs 12.2%). US helped detect MAC from mild (scores 1-4) to severe (scores 5-8) degrees, while mild degree of MAC was poorly demonstrated with radiography. The incidence of nephropathy, retinopathy, sensory neuropathy, and macrovascular complications increased with the severity of MAC (based on US scoring). With univariate analysis, the presence of MAC was associated with nephropathy (P<.001), retinopathy (P<.001), sensory neuropathy (P=.004), and macrovascular complications (P<.001). After adjustment for potential confounders, the presence of severe MAC was associated with nephropathy, retinopathy, and macrovascular complications, with the odds ratios of 3.4 (95% confidence interval [CI]: 1.53, 7.43; P=.003), 2.6 (95% CI: 1.22, 5.32; P=.013), and 3.8 (95% CI: 1.37, 10.6; P=.01), respectively. CONCLUSION: In type 2 diabetic Chinese patients, US was more sensitive than conventional radiography in the detection of MAC, particularly when the MAC was mild. The presence of severe MAC was associated with diabetic nephropathy, retinopathy, and macrovascular complications. US detection of MAC was a potential early marker to identify diabetes-related complications.

Primary spinal cord desmoplastic astrocytoma in an adolescent: a rare tumour at rare site and rare age.

We report a case of a non-infantile primary intramedullary spinal cord desmoplastic astrocytoma in an 18-year-old girl who presented with spastic paraparesis. The patient had been unable to run for 1 year. Magnetic resonance imaging of her spine showed an intramedullary solid and cystic heterogeneously enhancing lesion located at T7-T8 level. Partial excision was performed. Histology revealed a desmoplastic astrocytoma. To the best of our knowledge, there is no report on primary desmoplastic astrocytoma of the spinal cord in literature. Nor has such a symptomatic tumour manifesting at the age of 18 years been documented.

Imaging in children presenting with acute neurological deficit: stroke.

Neurological deficits in the paediatric age group are much rarer than in adults; however, it is an urgent condition that relies heavily on imaging for a prompt accurate diagnosis. Neurological deficits caused by cerebrovascular diseases are defined as stroke, whereas conditions manifesting with neurological deficits without underlying cerebrovascular diseases are referred to as stroke mimics. To the best of the authors' knowledge, there is a lack of systematic pictorial review that collectively describes the imaging of neurological deficit in children. The purpose of the present series is to discuss the causes and imaging appearance of neurological deficits in childhood, based on the experience of a tertiary paediatric referral centre These are broadly categorised into stroke, infection, inflammation, metabolic disorder, cerebral neoplasms and drug poisoning. Different entities of stroke and their respective imaging findings are discussed. Paediatric stroke can further be divided into arterial ischaemic stroke, sino-venous stroke, haemorrhagic stroke and hypoxic-ischaemic encephalopathy.

Imaging in children presenting with acute neurological deficit: paediatric stroke mimics.

Stroke mimics refer to conditions manifesting with neurologic deficits without underlying cerebrovascular diseases. Major causes in the paediatric population under this category include infections, inflammation, demyelination, neoplasm, drug related, phacomatosis, and miscellaneous disorders. These conditions and their respective imaging findings are briefly discussed here.

Radiographic study of the hip joint to determine anthropometric parameters for Indian population.

Hip replacement surgeries are on the rise in India. However, for these surgeries, most of the implants used are imported and manufactured entirely to suit the geometrical considerations of the western population. Studies in the past have shown that there are anatomical variations in the hip joint for different ethnic backgrounds and geographical locations. There is paucity of anthropometric hip joint data related to Indian population and anthropometric variations in skeletal geometry between Asian and Western counterparts have not yet been thoroughly reviewed and considered for implant manufacturing. The purpose of this anthropometric study is to determine any anatomical variations in the normal hip joint among the Indian population and to statistically compare the mean values with the existing data on western population. 422 Hip radiographs of 211 individuals (141 males and 70 females) with normal and healthy hip joints were evaluated to obtain the horizontal offset, vertical offset and neck shaft angle. For males, mean neck shaft angle was 127.68° (SD = 3.94), horizontal offset was 34.60mm (SD=6.55) and vertical offset was 39.17 mm (SD = 5.86). For females, mean neck shaft angle was 125.92° (SD = 4.75), horizontal offset was 32.96 mm (SD = 7.04) and vertical offset was 36.38 mm (SD = 6.28). When these parameters were compared to the data available from western world, there were significant anatomical variations and it was evident that there is a need to evaluate existing implants in relation to this data and possibly design the implants suited and relevant to Indian population.

Primary pleomorphic liposarcoma of bone in an adolescent: imaging features of a rare entity.

We report a rare case of a primary osseous pleomorphic liposarcoma of the distal femur in a 13-year-old boy. Primary liposarcoma of bone is a very rare malignant tumour originating from primitive mesenchymal cells rather than mature adipose tissue. Pleomorphic liposarcoma is the least common of the eight known histological subtypes in the WHO classification. The entity is not previously reported in children. This is the third reported case of pleomorphic liposarcoma of the bone, and the first reported case presenting in adolescence. We describe the computed tomography and magnetic resonance imaging features of this rare bony tumour.

Malignant pigmented clear cell epithelioid cell tumor (PEComa) in an adolescent boy with widespread metastases: a rare entity in this age group.

Malignant pigmented clear cell epithelioid cell tumor of the kidney is a rare variant of perivascular epithelioid cells tumors (PEComa) or epithelioid angiomyolipoma (AML). PEComa is characteristically composed purely of epitheloid cells. The fat cells and the blood vessels that are typical of classic AML are absent. Most epithelioid AML cases are benign; however, malignant epithelioid AML of the kidney has been occasionally reported in adults in association with tuberous sclerosis. We report the radiological-pathological features of a malignant pigmented clear cell epithelioid renal tumor in a 15-year-old boy presenting with extensive metastases but without clinical evidence of tuberous sclerosis.

Intravascular papillary endothelial hyperplasia: report of two cases.

Intravascular papillary endothelial hyperplasia is a rare benign vascular proliferative process as a result of papillary proliferation of the endothelial cells within the vascular lumen. We report two cases of intravascular papillary endothelial hyperplasia affecting the extremities. The characteristic sonological and MR imaging features are discussed, with updated review of literature. Imaging features are helpful in achieving a definitive diagnosis of the intravascular papillary endothelial hyperplasia.

Use of rapid prototyping and three-dimensional reconstruction modeling in the management of complex fractures.

BACKGROUND: The production of a copy of the fracture or a deformity in a bone with a complex geometry can be one of the important applications of the integration between two modern computer-based technologies, reverse engineering (RE) and rapid prototyping (RP). METHODS: This article reviews recent development in this field and present a case series about the use of medical CT/MRI scanning, three-dimensional reconstruction, anatomical modeling, computer-aided design, RP and computer-aided implantation in treating a complex fracture of acetabulums, calcaneum, and medial condyle of femur (Hoffa's fracture). CONCLUSION: The use of RP technology helped us to understand the fracture configuration and to achieve near anatomical reduction. With this we believe, this technology will reduce the surgical time as was observed in our cases. This consequently, will lower the requirement of an anesthetic dosage and decrease the intraoperative blood loss.In summary, the merging of computational analysis, modeling, designing, and fabrication will serve as important means to treat conditions and fractures around joints, spine, acetabulum, and craniofacial region. LEVEL OF EVIDENCE: Level 4, case series.

Pulmonary metastases in children with osteosarcoma: characteristics and impact on patient survival.

BACKGROUND: Approximately 15-20% of patients with osteosarcoma present with detectable metastatic disease and the majority of whom (85%) have pulmonary lesions as the sole site of metastasis. Previous studies have shown that the overall survival rate among patients with localized osteosarcoma without metastatic disease is approximately 60-70% whereas survival rate reduces to 10-30% in patients with metastatic disease. OBJECTIVE: To determine the incidence and characteristic features of pulmonary metastases in a group of osteosarcoma patients and correlate the findings with the prognostic outcome/survival. MATERIALS AND METHODS: Seventy-seven cases of histologically confirmed osteosarcoma were reviewed (47 male, 30 female, mean age 10.9). The site and size of the primary tumour and degrees of chemonecrosis were recorded. Lung metastases were analyzed according to their size, number, distribution and interval from diagnosis. The Kaplan-Meier method was used to analyze the survival probability curve. Significant differences (P < 0.05) were evaluated with the log-rank test for univariate analyses. RESULTS: Seventeen patients had synchronous and 11 had metachronous lung metastases. Sixteen (57%) underwent pulmonary metastasectomy. Nine of sixteen (56%) patients with metastasectomy and 10/12 (83%) patients without metastasectomy died. Poor chemonecrosis was associated with a worse outcome. Number, distribution and timing of lung metastases, but not the size of lung metastases, were of prognostic value for survival. CONCLUSION: Radiological detection of lung metastases is clinically important as it indicates a worse prognosis.

Asynchronous neuro-osseous growth in adolescent idiopathic scoliosis--MRI-based research.

Adolescent idiopathic scoliosis (AIS) is a common worldwide problem and has been treated for many decades; however, there still remain uncertain areas about this disorder. Its involvement and impact on different parts of the human body remain underestimated due to lack of technology in imaging for objective assessment in the past. The advances in imaging technique and image analysis technology have provided a novel approach for the understanding of the phenotypic presentation of neuro-osseous changes in AIS patients as compared with normal controls. This review is the summary of morphological assessment of the skeletal and nervous systems in girls with AIS based on MRI. Girls with AIS are found to have morphological differences in multiple areas including the vertebral column, spinal cord, skull and brain when compared with age- and sex-matched normal controls. Taken together, the abnormalities in the skeletal system and nervous system of AIS are likely to be inter-related and reflect a systemic process of asynchronous neuro-osseous growth. The current knowledge about the anatomical changes in AIS has important implications with respect to the understanding of fundamental pathomechanical processes involved in the evolution of the scoliotic deformity.

Intra-abdominal testicular seminoma in a woman with testicular feminization syndrome.

We report a case of intra-abdominal testicular tumor in a 36-year-old married lady presenting with chief complaints of primary amenorrhea. The patient was later diagnosed with testicular feminization syndrome, a form of male pseudohermaphroditism. This testicular tumor was histologically proven as seminoma. Due to rarity, imaging findings in patients with testicular feminization syndrome and intraabdominal testicular tumor have been poorly documented. So far, only one case report had described the combined role of CT and MR imaging in intraabdominal testicular sex-cord stromal tumor. To our knowledge, this case is first to document USG and MR imaging in addition to MR spectroscopy features in intraabdominal testicular seminoma.

An institutional review of paediatric haemangiomas: prevalence, imaging features, and outcomes.

OBJECTIVE: To review the demographic data, imaging features, and outcomes of paediatric haemangiomas. DESIGN: Retrospective study. SETTING: University teaching hospital, Hong Kong. PATIENTS: A total of 58 children diagnosed with haemangioma between 1998 and 2007. MAIN OUTCOME MEASURES: Demographic data, imaging features, type of treatment received, and outcomes. RESULTS: In all, 19 (33%) of these patients were males and 39 (67%) were females. Most of the lesions (64%) were in the head and neck region. Three (5%) of the patients were complicated by the Kasabach-Merritt syndrome; 21 underwent no imaging, and 37 had ultrasound and/or magnetic resonance imaging. In the majority (85%), ultrasound of the lesions revealed mixed echogenicity and/or phleboliths with variable colour Doppler patterns. On magnetic resonance imaging, most (87%) of the lesions were T1 iso- to hypo-intense and T2 hyperintense with slight heterogeneous signalling and revealed presence of central flow voids (vascular channels) or low-signal areas (fibrous tissue or calcification). In all, 85% appeared homogeneous while 15% showed heterogeneous enhancement. Of 58 patients, 39 (67%) patients received conservative treatment; the lesions resolved spontaneously in 34 (87%) patients, enlarged in 2 (5%), and remained static in 3 (8%). Interventions were directed at the lesions in 19 patients. These entailed surgical excision (n=7), argon laser therapy (n=3), and medical treatment (n=9). Of the latter patients, treatment included: systemic steroids (n=5), interferon (n=1), steroids and interferon (n=1), vincristine (n=1), and sclerotherapy (n=1). Partial or complete resolution of the lesions ensued in 15 (79%) of the patients, while their size remained static in four (21%). CONCLUSION: Though ultrasound and magnetic resonance imaging features varied, the diagnosis of most haemangiomas could be confidently made by imaging. About 33% of haemangiomas underwent surgical/medical interventions, for which imaging was useful to monitor post-treatment progress.

Real-time qualitative ultrasound elastography of cervical lymph nodes in routine clinical practice: interobserver agreement and correlation with malignancy.

To evaluate real-time qualitative ultrasound (US) elastography for cervical lymphadenopathy in routine clinical practice, 74 nodes (37 malignant, 37 benign) in 74 patients undergoing sonography underwent US elastography prior to fine needle aspiration for cytology. Dynamic cine loops of elasticity imaging displayed using a chromatic-scale were qualitatively scored by three independent observers for the proportion of stiff areas from ES1-4 (soft to stiff). There was fair to good interobserver agreement as indicated by weighted kappa (κ) statistic from 0.374 to 0.738. Median ES for benign and malignant nodes were 2 and 3 respectively. ES was higher in malignant nodes (p = 0.0003-0.0049, Mann Whitney U tests) although areas under receiver operating characteristic curves (0.68-0.74) indicated suboptimal discrimination. The optimal discriminatory cut-off, ES > 2, achieved only 62.2% sensitivity, 83.8% specificity and 73% accuracy for malignancy. Improvements in reliability and accuracy of real-time qualitative ultrasound elastography are required for it to be adopted into routine clinical practice.

Real-time qualitative ultrasound elastography of miscellaneous non-nodal neck masses: applications and limitations.

To evaluate real-time qualitative ultrasound elastography as an adjunct to conventional sonography for evaluation of non-nodal neck masses identified in routine clinical practice, 52 consecutive masses in 49 patients underwent both techniques. Lesion stiffness was graded visually on chromatic-scale elastograms from ES0-3 (low to high). Diagnosis was based on (cyto)pathology (11), corroborative cross-sectional imaging (18) or characteristic conventional sonography (23). There were 16 lipomas, 15 lymphatic/venous vascular malformations (LVVMs), six neurogenic tumours/neuromas, five thyroglossal duct cysts (TGCs), five (epi)dermoids, three abscesses, one second-arch branchial cleft cyst (BCC), and one soft-tissue metastasis. In general terms, lesion stiffness was high (ES2-3) for neurogenic tumours/neuromas, (epi)dermoids and metastasis, and low (ES0-1) for lipomas, LVVM, TGCs and BCC. Abscesses displayed variable stiffness according to fluid content. Technical limitations and artefacts of elastograms were identified. Data from real-time qualitative ultrasound elastography may be a useful adjunct to sonography for diagnosis of non-nodal neck masses.