• Ultrasonography (USG) - USG is the most applicable modality in the pediatric age group as it is easily available, fast to perform & it does not require the use of ionizing radiation. It is mainly used to visualize the abdomen & urinary tract. It is also utilized to see the intracranical contents (in infants, when the anterior fontanelle is open). Testis, Thyroid and also the eye can be evaluated. It is also used for assessment of congenital dislocation of hip, examination of the vertebral canal, septic Arthritis etc.
  
  It is a simple & rapid method of guiding a wide variety of invasive procedures (both diagnostic & therapeutic) requiring needle puncture.
  
  For pelvis examination, ideally, the patient should be starving. The patient should also have a full urinary bladder.
  
  Air is a poor conductor for sound & aerophagia may hamper the yield of USG examination.
  
  The child may have to be sedated for Doppler as it is a long procedure.
  
  
• Computed tomography - The machine consists of a circular array of detectors and the computer output is displayed on a monitor with the image being presented as a matrix of varying degrees of attenuation of the x-ray beam.
  
  The common indications of a CT Scan are:
  
  

  • CNS (Tumor/Infection/Congenital abnormality/Trauma)
  • Chest (Mediastinal mass)
  • Abdomen (Tumor etc.)
  • Evaluation of musculoskeletal syste.

Water-soluble, iodine containing, contrast medium is usually given for CECT. CT scan gives excellent cross sectional details. However, its disadvantages include high radiation dose & need for sedation/anesthesia.