Ultraschall Med 2013; 34 - WS_SL13_01
DOI: 10.1055/s-0033-1354880

Fusion Imaging (CEUS/CE-CT or CEUS/CE-MRI), a clinical investigation tool for comparing different contrast enhanced (CE) imaging procedures, is able to uncover investigation limitations and has influence on important clinical decisions

M Höpfner 1, J Neebe 1, N Timmesfeld 2, HP Weskott 3, C Löser 1
  • 1Rotes Kreuz Krankenhaus Kassel, Medizinische Klinik, Kassel, Germany
  • 2Philipps Universität Marburg, Institut für Med. Biometrie und Epidemiologie, Marburg, Germany
  • 3Klinikum Region Hannover Siloah, Medizinische Klinik II, Hannover, Germany

Purpose: Fusion imaging – a tool to visualize different imaging procedures simultaneously – is capable of comparing focal liver lesions. Evaluation of lesions and their localization were prospectively investigated.

Material and methods: 150 in- and out-patients with focal liver lesions were enrolled in an ethical approved prospective study, where fusion imaging was used to compare findings with CEUS and CE-CT or CE-MRI.

Equipment: LOGIQ E9 (GE Healthcare, Milwaukee, Il, USA) C1 – 5 or L9 probe; MRT (1.5 – 3T (Siemens) and CT (1 – 64 (Siemens/GE/Philips) slice scanners, most of them performed as 3 phase investigation, if no contraindications against contrast agents were present.

Results: In all patients fusion process was performed even when one of the image techniques suffered under its typical shortcomings or artifacts, e.g. steatosis/obesity or breathing problems. Mismatching results were investigated for the influence on clinical decisions using a descriptive statistical analysis.

Mismatching lesions were seen in 42.2%. Reducing these differences to clinical important decisions, patients with diagnostic findings like metastases or other malignant disorders were discordant in 24.5%. Reasons for misdiagnosing lesions in US were tiny lesions (4 – 12 mm) near or at liver surface or near ligaments in 3.9%. Lesions overseen on CT or MRI were 3 – 29 mm in size. Differences in applied CT scanners (1 – 64 slices) didn't seem to be a relevant reason to explain mismatching results.

Conclusion: Fusion-Imaging is able to show detailed differences in number and localization of focal liver lesions and has influence on important clinical decisions in 24% of the investigated patients.

Discussion: Explanations for these differences – physical and/or pathophysiological – are necessary to improve diagnostic decision-making in the future and further to decide about “gold-standard” of detection of liver lesions. Time of contrast phase and different latephase behavior of applied contrast agents are possible factors that may have influence on detection of metastases.