Claudia M. Martinez Rios Arellano MD, Abstract Co-Author: Research Grant, Koninklijke Philips NV

Rong Rong MD, Abstract Co-Author: Institutional Grant support, Koninklijke Philips NV

Robert C. Gilkeson MD, Abstract Co-Author: Research Consultant, Riverain Technologies, LLC Research support, Koninklijke Philips NV Research support, Siemens AG

Luis Alberto Landeras MD, Abstract Co-Author: Institutional Grant support, Koninklijke Philips NV

Prabhakar Rajiah MD, FRCR, Presenter: Institutional Research Grant, Koninklijke Philips NV

To evaluate the incremental benefit and clinical significance of the availability and utility of spectral reconstruction data with spectral detector CT technology.

Seventy-eight adult patients (34 female, 44 male) were prospectively scanned at the Spectral Detector-based CT (SDCT Philips Healthcare) scanner  technology. Clinical indication was noted and two radiologists made unanimous decision if a dual energy acquisition would have been requested in advance of the scan. The CT images with spectral reconstructions were evaluated for clinical findings, artifacts and image quality. Readers selected which cases would benefit from spectral reconstructions and the type of reconstruction was indicated. Clinical significance of the spectral reconstructions was graded as 0- no significant; 1- low; 2- intermediate, 3-moderate; and 4-highly significant.

8 CT of chest, 29 abdomen, 9 chest, abdomen, pelvis, 31 angiograms and 1 spine were included. A dual energy mode would have been prospectively clinically indicated in 15 patients (19%). However, readers requested retrospective spectral reconstructions in 67 patients (84.6 %). A total of 183 additional reconstructions with high monoenergy (monoE) images in 72 instances [(39.34%), 51 cases, 65.3%]; low monoE in 35 instances [(19.13%), 35 patients, 44.8%]; iodine-only images in 44 instances [(39.34%), 42 patients, 53.8%]; virtual non contrast in 17 instances [(9.29%), 17patients, 21.8%]; effective-z in 15 instances [(8.19%), 15 patients,19.2 %] were required. Additional spectral reconstructions were required on average 2.3 instances per patient. High monoE images were clinically useful in 56.94% for artifact reduction; low monoE in 44.8% for vascular contrast boost; iodine-only images in 15.9% for cystic and solid lesions evaluation 61.36%; and effective z for stone analysis in 33.3%. Clinical significance was rated as 0 in 10.38%, 1 in 36.1%, 2 in 29.51%, 3 in 20.21% and 4 in 3.82%.

Additional retrospective CT data reconstructed from SDCT scanner improves the diagnostic capabilities mainly for eliminating artifacts, improving contrast in vascular structures and characterizing lesions.

Spectral detector-CT allows retrospective reconstruction and improved diagnostic capabilities even in patients who would not have been preselected for a DECT technique. 

Martinez Rios Arellano, C, Rong, R, Gilkeson, R, Landeras, L, Rajiah, P, Incremental Benefit and Clinical Significance of Retrospectively Obtained Spectral Data in a Novel Spectral Detector CT Technology- Initial Experiences and Results.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14019367.html