Darshana D. Rasalkar

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 (Hoffas 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.

Evaluation of real-time qualitative sonoelastography of focal lesions in the parotid and submandibular glands: applications and limitations

ObjectiveTo evaluate qualitative ultrasound elastography for focal salivary gland masses identified during routine clinical practice.MethodsSixty-five parotid or submandibular masses in 61 patients underwent real-time qualitative ultrasound elastography and were scored on colour-scaled elastograms in terms of their stiffness relative to adjacent normal salivary parenchyma from ES 1 (soft) to ES 4 (stiff). This was correlated with diagnosis from aspiration cytology or histology.ResultsThere were 29 Warthin’s tumours (WTs), 23 pleomorphic adenomas (PAs), 2 adenoid cystic carcinomas, 1 adenosquamous carcinoma, 1 nodal metastasis from nasopharyngeal carcinoma, 1 lymphoma (2 deposits), 3 Kuttner tumours and 4 cases of Kimura’s disease. ES scores showed clustering according to pathological condition. In this respect, PAs were firmer than WTs (P < 0.004, Fisher’s exact test). Nine, 19, 14 and 17 of the benign masses and 0, 1, 2 and 3 of the malignant masses were ES 1, 2, 3 and 4 respectively. All three primary salivary malignancies were ES 4 compared with 1/29 WTs and 16/23 PAs.ConclusionThese preliminary findings suggest that qualitative real-time ultrasound elastography, although an ancillary technique to conventional ultrasound in the salivary glands, is likely to have a poor ability to discriminate benign lesions (particularly PAs) from malignant disease.

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.

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

BackgroundApproximately 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.ObjectiveTo 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 methodsSeventy-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.ResultsSeventeen 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.ConclusionRadiological detection of lung metastases is clinically important as it indicates a worse prognosis.

Pictorial review of mucopolysaccharidosis with emphasis on MRI features of brain and spine

Mucopolysaccharidosis (MPS) is an inherited metabolic disorder of childhood, characterised by progressive multisystem involvement predominantly affecting the skeletal system leading to skeletal dysplasia. Mental retardation, neuropathy and cardiomyopathy may occur in the most severely affected patients, leading to progressive disability and death in their early third to fourth decades. The purpose of this paper is to illustrate the typical imaging features of different types of MPS, in particular the MR features of the brain and spine in MPS, which are expected to be encountered by radiologists more frequently in their clinical practice as a result of prolonged life expectancy for those with MPS with recent advances in therapeutic interventions. The treatment options and outcomes for MPS patients are also briefly discussed.

Neurocognitive dysfunction and grey matter density deficit in children with obstructive sleep apnoea

BACKGROUND Cerebral structural changes related to obstructive sleep apnoea (OSA) have been reported in adult OSA patients; however, similar data and their associations with neurocognitive dysfunction are scarce in childhood OSA. OBJECTIVE To compare neurocognitive function, regional grey matter density and cerebral volume in children with and without OSA. METHODS Fifty OSA cases and 27 normal controls underwent a panel of neurocognitive tests. High resolution 3-dimensional magnetic resonance images of the brain were obtained from 23 OSA cases and 15 gender and age matched controls. Total cerebral volume and regional grey matter density were analyzed using voxel-based morphometry technique and compared between the two groups. Individuals with an obstructive apnoea hypopnoea index (OAHI) > 5 were defined as having moderate-to-severe OSA. RESULTS Children with OSA showed significantly reduced attention and visual-fine motor coordination scores compared with controls. Grey matter volume deficit was observed in prefrontal and temporal regions of cases with moderate-to-severe OSA only. Significant negative correlations were found between the visual-fine motor coordination score and the ratio of grey matter volume over total brain volume. CONCLUSION Children with OSA had impaired attention and visual-fine motor coordination. Regional grey matter reduction was evident in children with more severe OSA.

Atypical location of germinoma in basal ganglia in adolescents: radiological features and treatment outcomes

The objective of this work is to describe the imaging findings, clinical profile and treatment response in four Chinese adolescent patients presenting with ectopic germinoma arising from basal ganglia. The clinical presentation, treatment regimens and the imaging findings at presentation and after treatment were described upon retrospective review of four Chinese adolescent patients. CT of the brain showed mixed solid cystic mass lesions in three patients. In one patient, only ill-defined hyperdensity was noted in the affected basal ganglia. Correlative MRI brain studies showed similar findings of large solid cystic masses in three patients, whereas the fourth patient showed small hyperintensities on T2 weighted and fluid-attenuated inversion-recovery sequences. All lesions were confirmed to be germinomas on biopsy. Chemotherapy followed by radiotherapy was given to three patients. There was a dramatic response, with complete resolution of tumour bulk in two patients and >80% reduction in tumour bulk in one patient. Debulking surgery was performed in one subject who had received cranial radiotherapy; the last follow-up MRI showed no evidence of residual disease.

Radiological appearance of inflammatory myofibroblastic tumour

Inflammatory myofibroblastic tumour (IMFT) is a distinct entity with variable clinical presentation and therapeutic options. We present three paediatric cases of IMFT, originated from the lung, bladder and ovary respectively. All lesions were heterogeneous, with mixed solid/cystic components and infiltrative pattern, and were interpreted as aggressive malignant neoplasms initially due to their bizarre imaging appearance. The definitive diagnosis was derived from characteristic histopathological features. Pediatr Blood Cancer 2010;54:1029–1031

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.