Pilot Study of Model Based Iterative Reconstruction Using 64-Slice

Inclusion Criteria: * Men or Women 30 years of age or older voluntarily willing to sign an informed consent. * Patients indicated for one of the following: CNS: Known or suspected pathology in the posterior fossa Thorax: Patients referred for staging of a known or suspected lung cancer Abdomen: Patients with acute flank pain and suspected urolithiasis or Abdomen: Patients with a known or suspected focal liver lesion Exclusion Criteria: * Subjects less than 30 years of age * Pregnant women as confirmed by urine test or current accepted institution standard * If IV contrast is required: * Severe or uncontrolled allergy to iodinated contrast media * Serum creatinine \> 1.7 mg/dl or estimated glomerular filtration rate \[eGFR\] of \<60 mg/min as recorded in medical file or by current accepted institution standard * Unable or unwilling to provide written informed consent by self or legal guardian at the time of study enrollment * Unstable physical condition as identified by physician