Imaging of articular cartilage.

We tried to review the role of magnetic resonance imaging (MRI) in understanding microscopic and morphologic structure of the articular cartilage. The optimal protocols and available spin-echo sequences in present day practice are reviewed in context of common pathologies of articular cartilage. The future trends of articular cartilage imaging have been discussed with their appropriateness. In diarthrodial joints of the body, articular cartilage is functionally very important. It is frequently exposed to trauma, degeneration, and repetitive wear and tear. MRI has played a vital role in evaluation of articular cartilage. With the availability of advanced repair surgeries for cartilage lesions, there has been an increased demand for improved cartilage imaging techniques. Recent advances in imaging strategies for native and postoperative articular cartilage open up an entirely new approach in management of cartilage-related pathologies.

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.

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.

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.

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.

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.

Testicular hamartomas and epididymal tumor in a cowden disease: a case report.

Testicular hamartomas (TH) is a benign condition. An association of TH with Cowden disease (CD) is known. Ultrasound features of hamartomas are often diagnostic. We present a case of Cowden disease with TH and an epididymal tumor. Imaging features of TH and its differentials has been discussed. Although, association of Cowden disease with many malignancies have been documented, epididymal tumor has not been described. To our knowledge, this paper is the first to describe epididymal tumor in association with Cowden disease.

Ultrasound features of deep-seated lipomas.

PURPOSE: The objective of this study was to describe the sonographic features of deep-seated lipomas. METHODS: A retrospective review of the sonographic features of 64 deep seated lipomas in 64 patients (43 females, 21 males, mean age 46.5, range 16-77 years) seen over an 8-year period (1998-2006) was undertaken. RESULTS: Features evaluated were location, size, shape, marginal definition, internal echogenicity, including the presence of intermingled muscle fibres and linear internal echoes, acoustic transmission and vascularity. Confirmation was histological in 37 (58%) cases and by typical magnetic resonance imaging (MRI) appearance in 27 (42%) cases. CONCLUSION: The results show that although the features of deep-seated lipoma are more variable than those reported for subcutaneous lipomas, the presence of thin internal echoes in conjunction with other less specific features should enable a correct diagnosis.

Migrating biliary stent with final destination at the ileocecal junction causing intestinal obstruction and obstructive biliopathy.

Endoscopic plastic biliary stent insertion is a minimally invasive, well-established procedure for the management of benign biliary pathology. We report a case of a migrating stent for over two days, which finally got impacted at the ileocecal junction, leading to intestinal obstruction and obstructive biliopathy. Radiological findings depicted the exact site of the dislodged biliary stent and its related complications, both of which were successfully treated in a nonoperative stepwise manner.

MRI findings in patients with severe trismus following radiotherapy for nasopharyngeal carcinoma.

The aim of the study was to document MRI findings in masticator structures in patients with trismus developing after radiotherapy for nasopharyngeal carcinoma (NPC). MRI neck examinations were reviewed in 35 patients with marked trismus, defined as an interincisal gap of 25 mm or less, post-radiotherapy for NPC. Patients with trismus before treatment, infiltration of masticator structures at the time of trismus, or previous surgery involving the masticator structures were excluded. Sixteen patients had no significant abnormality in their masticator structures (46%). Nineteen patients (54%) had abnormalities comprising radiotherapy-induced masticator muscle fibrosis (n = 19), denervation atrophy of the masticator muscles secondary to mandibular nerve damage (n = 1), mandibular ramus signal abnormalities (n = 5), mandibular condyle sclerosis with or without capsular thickening (n = 5), perimasticator fibrosis extending into the masticator space (n = 3) and inflammation secondary to severe sinusitis extending into the masticator space (n = 2). Nine patients (26%) had more than one type of abnormality. Twenty-two patients (63%) had concomitant skull base osteoradionecrosis which extended into the pterygoid bases in 16 patients (45%). The presence of several MRI abnormalities in the masticator structures of patients with trismus after radiotherapy suggests that trismus is multifactorial. This study advances the understanding of mechanisms behind this debilitating side effect of radiotherapy.