Methods: The algorithm for an IDR of 2.22 gI·s-1 was developed based on the relationship between VCE and contrast volume in 141 patients; test bolus parameters and characteristics in 75 patients; and, tube voltage in a phantom study. The algorithm was retrospectively tested in 45 patients who underwent retrospectively ECG-gated CCTA with a 100 kVp protocol. Image quality, TID and radiation dose exposure were compared with those produced using the 120 kVp and routine contrast protocols.

Results: Age, sex, body surface area (BSA) and peak contrast enhancement (PCE) were significant predictors for VCE (P<0.05). A strong linear correlation was observed between VCE and contrast volume (r=0.97, P<0.05). The 100-to-120 kVp contrast enhancement conversion factor (Ec) was calculated at 0.81. Optimal VCE (250 to 450 HU) and diagnostic image quality were obtained with significant reductions in TID (32.1%) and radiation dose (38.5%) when using 100 kVp and personalized contrast volume calculation algorithm compared with 120 kVp and routine contrast protocols (P<0.05).

Case presentation: We report a 10-year-old Dusun girl presenting with left hypochondrial pain and noted a left hypochondrial mass on examination. This report highlights the role of clinical imaging during the pre-operative and post-operative phases.

Clinical discussion: Ultrasound and CT imaging was useful in determining that the tumor originated from the tail of the pancreas. The presence of a definite capsule with internal solid-cystic components helped narrowed the differential diagnosis to solid pseudopapillary neoplasm (SPN) of the pancreas. MR liver was useful to rule out liver metastasis in this child.

Intervention and outcome: The patient was scheduled for laparotomy and tumour excision at a regional paediatric centre. Successful excision of the tumor en-mass was performed and the child's subsequent recovery was uneventful.

METHODS: A retrospective review of clinical records of all patients with CT scan evidence of tracheobronchial compression from January 2007 to December 2017 at National Heart Institute. Cardiovascular causes of tracheobronchial compression were divided into three groups; group I: vascular ring/pulmonary artery sling, II: abnormally enlarged or malposition cardiovascular structure due to CHD, III: post-CHD surgery.

RESULTS: Vascular tracheobronchial compression was found in 81 out of 810 (10%) patients who underwent CT scan. Group I lesions were the leading causes of vascular tracheobronchial compression (55.5%), followed by group II (34.6%) and group III (9.9%). The median age of diagnosis in groups I, II, and III were 16.8 months, 3 months, and 15.6 months, respectively. Half of group I patients are manifested with stridor and one-third with recurrent chest infections. Persistent respiratory symptoms, lung atelectasis, or prolonged respiratory support requirement were clues in groups II and III. Higher morbidity and mortality in younger infants with severe obstructive airway symptoms, associated airway abnormalities, and underlying complex cyanotic CHD.

CASE DESCRIPTION: The authors present a case of a 68-year-old elderly female with a large right fronto-parieto-temporal arachnoid cyst who has been suffering from mild left hemiparesis for the past 4 years and presented with sudden onset of seizures. The 3 Tesla MR system with diffusion tensor imaging (DTI) and MR tractography of the brain showed a large right fronto-parieto-temporal cystic lesion measuring 7 × 5 × 5 cm with a midline shift of 1 cm, suggestive of an arachnoid cyst with surrounding ipsilateral white matter projection pathways and inferior occipito-frontal fasciculus or inferior longitudinal white matter tracts. The cyst was successfully treated with neuronavigation-guided endoscopic and hodotopical approach to fenestrate the arachnoid cyst into the sylvian cistern, avoiding inadvertent injury to major white matter tracts portrayed by DTI. Postoperatively, a repeated computed tomography (CT) scan of the brain revealed a smaller arachnoid cyst with correction of the midline shift. The patient was weaned off from the ventilator and her hemiplegia improved gradually.

MATERIALS AND METHODS: We retrospectively assessed 107 cadavers that had undergone conventional autopsy and PMCT. We made 5 measurements from the PMCT that included cervical length (CL), thoracic length (TL), lumbosacral length (LS), total column length of the spine, excluding the sacrum and coccyx (TCL), and ellipse line measurement of the whole spine, excluding the sacrum and coccyx (EL). We compared these anthropometric PMCT measurements with AL and correlated them using linear regression analysis.

RESULTS: The results showed a significant linear relationship existed between TL and LS with AL, which was higher in comparison with the other parameters than the rest of the spine parameters. The linear regression formula derived was: 48.163 + 2.458 (TL) + 2.246 (LS).