title: The role of late-phase pulse inversion harmonic imaging in the detection of occult hepatic metastases.
abstract: OBJECTIVE
  The purpose of this study was to investigate the efficacy of late-phase pulse inversion harmonic imaging (PIHI) in detecting occult metastases and to compare the results with helical computed tomography (CT) in a group of patients whose fundamental liver sonographic results were normal.
  
  
  METHODS
  Thirty-two patients (21 women and 11 men; age range, 20-87 years) with a known primary malignancy were enrolled in the study. The patients were evaluated with conventional sonography, unenhanced PIHI, and PIHI 3 minutes after the injection of Levovist (SH U 508A; Schering AG, Berlin, Germany). All patients also underwent triphasic helical CT within 1 week after sonography. In 1 patient, mangafodipir-enhanced magnetic resonance imaging was performed as part of the clinical workup.
  
  
  RESULTS
  After Levovist injection, in 4 (12.5%) of 32 patients, at least 1 hypoechoic lesion was detected by PIHI; multiple lesions were shown in 1 patient. The mean diameter of newly detected lesions was 12 mm. Triphasic helical CT also showed all of the lesions that were detected by PIHI. The diagnoses were confirmed by biopsy and CT findings in 2 patients and by the typical CT and magnetic resonance imaging findings in 1 patient. For the fourth patient, the diagnosis was confirmed by follow-up and CT. Conclusions. Late-phase PIHI is comparable to helical CT for detecting occult hepatic metastases, but it protects patients from the potentially hazardous effects of radiation and iodinated contrast agents. Further series involving a larger number of patients are needed to determine its place in the evaluation of cancer staging and treatment planning.
authors.affiliation: Gazi Universitesi Tip Fakültesi, Radyoloji Anabilim Dali, 06510 Besevler-Ankara, Turkey. serapgultekin@gazi.edu.tr
authors.forename: Serap
authors.initials: S
authors.lastname: Gültekin
authors.forename: Cem
authors.initials: C
authors.lastname: Yücel
authors.forename: Hakan
authors.initials: H
authors.lastname: Ozdemir
authors.forename: Halil
authors.initials: H
authors.lastname: Celik
authors.forename: Suna Ozhan
authors.initials: SO
authors.lastname: Oktar
authors.forename: Mehmet
authors.initials: M
authors.lastname: Araç
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011134:Polysaccharides; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed; D014463:Ultrasonography
chemical_list: D003287:Contrast Media; D011134:Polysaccharides; C059891:SHU 508