E1052. Dual Energy CT of Pediatric Genitourinary Disorders
  1. Helen Kim; Seattle Children's Hospital; University of Washington
  2. Sakura Noda; Seattle Children's Hospital; University of Washington
  3. Erin Romberg; Seattle Children's Hospital; University of Washington
  4. Luana Stanescu; Seattle Children's Hospital; University of Washington
  5. Shawn Kamps; Seattle Children's Hospital; University of Washington
  6. Sarah Long; Seattle Children's Hospital; University of Washington
  7. Grace Phillips; Seattle Children's Hospital; University of Washington
Dual energy CT (DECT) offers powerful tools for diagnostic imaging. However, much of the recent DECT literature has focused on its use in adults. Our goal is to illustrate the various DECT techniques in the assessment of pediatric genitourinary conditions.

Educational Goals / Teaching Points
Describe dual energy CT (DECT) protocols that facilitate the imaging evaluation of the pediatric genitourinary system, illustrate various clinical scenarios in which DECT is useful for diagnosing pediatric GU pathologies, and highlight common DECT artifacts that may confound image evaluation.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Ultrasound is generally favored over CT in the assessment of the pediatric genitourinary system. However, CT may be used when ultrasound findings are equivocal, or in specific clinical settings such as trauma. DECT allows for material separation, such that normal structures and pathological processes can be better characterized on the basis of their tissue composition. For example, the generation of virtual unenhanced images can be used to differentiate calcifications from contrast enhancement on a contrast-enhanced CT examination, and may reduce radiation exposure if used in place of a true unenhanced series. Although ultrasound is the modality of choice in children with suspected urinary tract calculi, DECT is useful in the setting of high clinical suspicion for calculi despite a negative sonogram. Additionally, DECT can aid in discriminating types of renal calculi using the principle of material separation. Color-coded iodine overlay imaging (CCI) can improve the conspicuity of enhancement. CCI therefore has utility in the diagnosis of infectious and inflammatory conditions, such as cystitis and abscess. In the setting of a genitourinary neoplasm, CCI can help to differentiate acute hemorrhage from enhancement. Virtual monoenergetic images (VMI) can be used to improve contrast resolution when generated at energies that are closer to the K-edge of iodine and can therefore, in part, mitigate a suboptimal intravenous contrast bolus. VMI at higher energies help reduce metallic artifact. However, there are also known artifacts and pitfalls that must be taken into account with DECT imaging. Recognition of artifacts and pitfalls is essential for avoiding misdiagnosis.

DECT is valuable in the radiological workup of the pediatric genitourinary conditions and is complementary to other modalities such as sonography and fluoroscopy. Employing the available DECT techniques can assist in accurate diagnosis in this clinical setting.