Head and neck CT

Computed tomography (CT) plays a major role in neuroradiology due to: Excellent spatial resolution Good contrast Easy detection of intracranial abnormalities Low price (compared to MRI) Less contraindication (compared to MRI) Widely available Easily reported by radiologists.

Clinical indication of head CT: Truma Inflammatory diseases Congenital problems Endocrine diseases Tumors

Head truma: CT can provide information about: Contusions (bruises) Hemtomas (blood clots) of the brain Hematomas outside the brain (epidural or subdural hematoma)

Inflammatory diseases: CT confirmation of lack of hydrocephalus or mass, CSF analysis can be performed safely on meningitis cases. In case of herpes simplex cephalitis CT can detect any abscess or inflammation.

Congenital abnormalities: CT plays a major role in detecting congenital abnormalities in new born, toddlers and older children. Endocrine disease: CT can detect any abnormality of the pituitary gland.

Tumors: CT can detect intra cerebral and extra cerebral cranial tumors. This provides great information for diagnoses of the tumor location, grade, follow up and treatment planning.

Indication for CT neck and face: Development of abnormalities Inflammations or infections Trauma Tumors

Indications for CT spine: Suspected disk herniation Suspected spine stenosis Suspected intraspinal tumors Spinal truma

Patient preparation: The technologist should introduce him/her self to the patient and explain the procedure. The patient should not eat a a large meal before the scan All metallic objects should be removed from the area to be studied. The patient should be instructed to empty the bladder shortly before the scan done. IV line should be started and the reason for contrast media should be explained. Technologist must be comfortable on the table.

Patient positioning: The anatomy of question should be positioned in the center of the gantry horizontally and vertically. The scan field (FOV) of view should encircle the entire anatomy. Any coverings or clothes should be firmly removed from the scanned area.

Scanning parameters: To improve signal-to-noise ratio and contrast resolution mA, kV or scan time should be increased. Thinner slice improve spatial resolution but reduces signal-to-noise ratio, therefore it is compensated by increasing Kv, mA or scan time.

Reconstruction algorithms: The standard algorithm Bone algoriyhm Detail algorithm