title: Incidentally detected splenic lesions in ultrasound: does contrast-enhanced ultrasonography improve the differentiation of benign hemangioma/hamartoma from malignant lesions?
abstract: OBJECTIVE
  The aim of the study was to identify and validate enhancing features for differentiating benign vascular neoplasms of the hemangioma/hamartoma type from malignant splenic lesions on contrast-enhanced ultrasonography (CEUS).
  
  
  METHODS
  136 splenic lesions (58 benign vascular neoplasms, 78 malignant) in 136 patients underwent baseline US and pulse-inversion CEUS after sulfur hexafluoride-filled microbubble injection. Two on-site readers assessed lesion enhancement features during arterial and parenchymal phase in consensus. Best predicting CEUS features for lesion diagnosis were identified through univariate and multivariate analyses. Two blinded off-site readers independently issued a confidence rating for lesion diagnosis in baseline US and CEUS using extracted diagnostic CEUS features. Diagnostic performance, receiver operating curves (Az-value), and interreader agreement were calculated. The reference standards were histopathology or CT and/or MR imaging with clinical follow-up.
  
  
  RESULTS
  Multivariate analysis outlined arterial hyperenhancement or isoenhancement to be an independent CEUS predictor of benign vascular neoplasms (odds ratio, 3.558; p < 0.0017). Within the subgroup of isoechoic or hypoechoic lesions, arterial hyperenhancement was virtually diagnostic for benign vascular neoplasm (odds ratio, 21.333; p < 0.001). The diagnostic accuracy and confidence (Az-value) of the two readers was 63.2 % and 70.6 % (0.785 and 0.818) for baseline US, which improved significantly to 87.5 % and 88.2 % (0.915 and 0.908) for CEUS (p < 0.001). Interreader agreement also increased with CEUS (қ = 0.88) compared to baseline US (қ = 0.52).
  
  
  CONCLUSIONS
  Sulfur hexafluoride-enhanced CEUS improves differentiation between benign vascular and malignant splenic tumors and may be especially useful in clinical scenarios in which the incidental hypoechoic splenic lesion is unclear on conventional US.
authors.affiliation: Department of Hematology, Oncology, and Palliative Care, Asklepios Hospital Barmbek, Hamburg, Germany. a.stang@asklepios.com
authors.forename: A
authors.initials: A
authors.lastname: Stang
authors.forename: H
authors.initials: H
authors.lastname: Keles
authors.forename: S
authors.initials: S
authors.lastname: Hentschke
authors.forename: C-U
authors.initials: CU
authors.lastname: von Seydewitz
authors.forename: J
authors.initials: J
authors.lastname: Dahlke
authors.forename: C
authors.initials: C
authors.lastname: Habermann
authors.forename: J
authors.initials: J
authors.lastname: Wessling
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D005260:Female; D006222:Hamartoma / Q000000981:diagnostic imaging*; D006391:Hemangioma / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D033162:Incidental Findings; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D015588:Observer Variation; D012680:Sensitivity and Specificity; D013154:Spleen / Q000000981:diagnostic imaging; D013158:Splenic Diseases / Q000000981:diagnostic imaging*; D013160:Splenic Neoplasms / Q000000981:diagnostic imaging*; D013459:Sulfur Hexafluoride; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D003287:Contrast Media; D013459:Sulfur Hexafluoride