Azian Abd. Aziz

Clinical Evaluation of Watermarked Medical Images

Digital watermarking medical images provides security to the images. The purpose of this study was to see whether digitally watermarked images changed clinical diagnoses when assessed by radiologists. We embedded 256 bits watermark to various medical images in the region of non-interest (RONI) and 480K bits in both region of interest (ROI) and RONI. Our results showed that watermarking medical images did not alter clinical diagnoses. In addition, there was no difference in image quality when visually assessed by the medical radiologists. We therefore concluded that digital watermarking medical images were safe in terms of preserving image quality for clinical purposes

Diffuse choroid plexus hyperplasia : an under-diagnosed cause of hydrocephalus in children?

Hydrocephalus is a common neurological disorder in children and the result of a variety of causes. However, with the advancement of imaging modalities, particularly MRI, previously reported rarer causes of hydrocephalus in children are now being more readily appreciated. We report an 11-year-old boy with diffuse villous hyperplasia of the choroid plexus. He had a ventriculo-peritoneal (VP) shunt in-situ and a prior diagnosis from infancy of congenital aqueduct stenosis as the cause of his hydrocephalus. His current presentation was with further shunt dysfunction. CT and MRI demonstrated enlarged choroid plexuses but did not confirm aqueduct stenosis. CSF overproduction was demonstrated from the externalized ventricular drain. The enlarged choroid plexuses were surgically resected and histology confirmed choroid plexus hyperplasia. Identification of choroid plexus hyperplasia is important since the neurosurgical management of hydrocephalus is not VP shunt insertion, but resection of the hyperplastic choroid plexus.

Isolation of Proteus mirabilis from severe neonatal sepsis and central nervous system infection with extensive pneumocephalus

A fatal case of pure Proteus mirabilis meningitis complicated by extensive pneumocephalus demonstrated on brain CT is reported. We suggest that early institution of third generation cephalosporin combined with an aminoglycoside and a brain CT scan are warranted in neonates with neurological sepsis caused by this organism. In neonates and infants, Proteus mirabilis is encountered world-wide as an uncommon aetiological agent in sepsis and infections of the central nervous system (CNS), often as a mixed infection. A 5-day-old term baby girl was admitted to our neonatal intensive care unit with a 1-day history of jaundice and 3-day history of poor feeding and lethargy. There was no history of injury. Her mother was a 28-year-old hepatitis B carrier primigravida who was otherwise well. Antenatal, intrapartum and immediate postnatal periods were uneventful. On admission, the baby was poorly hydrated, jaundiced, lethargic and hypotonic. Her sucking reflex was poor. Her anterior fontanelle was soft and normotensive. A full septic screen was done and she was commenced on intravenous penicillin and gentamicin. She was put on nasal continous positive airway pressure which was later changed to ventilation when she became apnoiec and desaturated. Immediate investigations showed unconjugated hyperbilirubinaemia and hypoglycaemia (<1.0 mmol/l) but otherwise normal full blood count and serum electrolytes. Cerebrospinal fluid (CSF) microscopy showed a white cell count of >200 (70% polymorphs, 30% leukocytes), a CSF glucose of <1.0 mmol/l, and a CSF protein of 6.8 g/l, globulin positive but a latex test (for Neisseria meningitidis, Streptococcus pneumoniae, Escherichia coli, Streptococcus group B andHaemophilus influenzae type B) was negative. Penicillin was discontinued and cefotaxime was added to her antibiotic regime when she deteriorated on ventilator. The next day, she became hypotensive needing inotropic support and developed generalised convulsions which responded to phenobarbitone. A brain ultrasound scan revealed multiple areas of echogenicity with cerebral oedema. A brain CT scan was deferred at this stage due to her unstable condition. Later that day, the CSF culture was reported to grow a gram-negative bacillus. On day 3 of admission, she developed generalised hypertonia, hyper-reflexia and a tense anterior fontanelle. Her pupils were dilated and sluggish. Both CSF and blood cultures grew Proteus mirabilis and this was the only organism isolated from both samples. The organism was sensitive to both gentamicin and cefotaxime. Later that day, she had a further convulsion and went into renal failure. Her coagulation profiles were deranged and both platelets and haemoglobin were low. She was transfused with platelets, packed cells, fresh frozen plasma and cryoprecipitate. Her condition remained unchanged the next day. A brain CT scan performed on day 5 of admission showed extensive pneumocephalus replacing the substance of the frontal and temporal lobes. Air density was also present in the subdural space along the falx and in pockets within the cerebral hemispheres. Her parents were informed of the severe brain damage and of the poor prognosis. She died 2 days later following irreversible multi-organ failure and disseminated intravascular coagulation. Proteus mirabilis was responsible for 4% of 98 cases of gram-negative enteric bacterial meningitis seen in one American centre over a 21-year period [6]. It was the infective agent in 7.1% of 85 cases of neonatal bacterial Eur J Pediatr (2003) 162: 644–645 DOI 10.1007/s00431-003-1240-9

Three dimensional anthropometric measurements of the distal femur and proximal tibia for the Malay population

Current available implant for total knee arthroplasty normally based on the western population knee. Asian knee were different from the European knee. A prospective morphometric study of the knee joint was carried out. One hundred (100) participants consisting of 50 males and 50 females were scanned using computed tomography equipment. The age of the participants vary from 19 to 38 years old, with height variation from 141cm to 182cm, and weight from 39kg to 110kg. The knee joints were reconstructed in three dimensions from the CT datasets and measurements were done using computational method. The anterior-posterior (AP) length and the medial-lateral (ML) width of the distal femur and proximal tibia were measured. For the distal femur, the average dimension for the anterior-posterior (fAP) is 60.7±4.7mm and for the medial-lateral (fML) is 69.7±6.1mm. For proximal tibia, the average dimension for the anterior-posterior (tAP) is 48.1±4.7mm and for the medial-lateral (tML) is 72.6±6.8mm. These data provide the basis for the development of femoral components for high flexion total or partial knee replacement for Malaysian population.