title: Single-portal-phase low-tube-voltage dual-energy CT for short-term follow-up of acute pancreatitis: evaluation of CT severity index, interobserver agreement and radiation dose.
abstract: OBJECTIVE
  To intra-individually compare single-portal-phase low-tube-voltage (100-kVp) computed tomography (CT) with 120-kVp images for short-term follow-up assessment of CT severity index (CTSI) of acute pancreatitis, interobserver agreement and radiation dose.
  
  
  METHODS
  We retrospectively analysed 66 patients with acute pancreatitis who underwent initial dual-contrast-phase CT (unenhanced, arterial, portal phase) at admission and short-term (mean interval 11.4 days) follow-up dual-contrast-phase dual-energy CT. The 100-kVp and linearly blended images representing 120-kVp acquisition follow-up CT images were independently evaluated by three radiologists using a modified CTSI assessing pancreatic inflammation, necrosis and extrapancreatic complications. Scores were compared with paired t test and interobserver agreement was evaluated using intraclass correlation coefficients (ICC).
  
  
  RESULTS
  Mean CTSI scores on unenhanced, portal- and dual-contrast-phase images were 4.9, 6.1 and 6.2 (120 kVp) and 5.0, 6.0 and 6.1 (100 kVp), respectively. Contrast-enhanced series showed a higher CTSI compared to unenhanced images (P < 0.05) but no significant differences between single- and dual-contrast-phase series (P > 0.7). CTSI scores were comparable for 100-kVp and 120-kVp images (P > 0.05). Interobserver agreement was substantial for all evaluated series and subcategories (ICC 0.67-0.93). DLP of single-portal-phase 100-kVp images was reduced by 41 % compared to 120-kVp images (363.8 versus 615.9 mGy cm).
  
  
  CONCLUSIONS
  Low-tube-voltage single-phase 100-kVp CT provides sufficient information for follow-up evaluation of acute pancreatitis and significantly reduces radiation exposure.
  
  
  CONCLUSIONS
  • Single-portal-phase CT provides sufficient evaluation for follow-up of acute pancreatitis. • Follow-up CT does not benefit from unenhanced or arterial-phase acquisition. • CT severity index scores are equal for dual-contrast-phase 100-/120-kVp acquisition (P > 0.05). • 100-kVp single-portal-phase follow-up CT of acute pancreatitis significantly reduces radiation exposure.
authors.affiliation: Department of Diagnostic and Interventional Radiology, University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt am Main, Germany, docwichmann@gmail.com.
authors.forename: Julian L
authors.initials: JL
authors.lastname: Wichmann
authors.forename: Pawel
authors.initials: P
authors.lastname: Majenka
authors.forename: Martin
authors.initials: M
authors.lastname: Beeres
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kromen
authors.forename: Boris
authors.initials: B
authors.lastname: Schulz
authors.forename: Stefan
authors.initials: S
authors.lastname: Wesarg
authors.forename: Ralf W
authors.initials: RW
authors.lastname: Bauer
authors.forename: J Matthias
authors.initials: JM
authors.lastname: Kerl
authors.forename: Tatjana
authors.initials: T
authors.lastname: Gruber-Rouh
authors.forename: Renate
authors.initials: R
authors.lastname: Hammerstingl
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Vogl
authors.forename: Thomas
authors.initials: T
authors.lastname: Lehnert
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D019283:Pancreatitis, Acute Necrotizing / Q000000981:diagnostic imaging*; D012372:ROC Curve; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult
chemical_list: D003287:Contrast Media