Pulmonary perfusion imaging: Qualitative comparison of TCIR MRI and SPECT/CT in porcine lung.
OBJECTIVE
To validate the anatomical accuracy, homogeneity and sensitivity of two-compartment modeled inversion recovery (TCIR) magnetic resonance imaging (MRI) in a multimodal animal experiment as a non-invasive alternative to standard functional imaging techniques.


METHODS
Seven pigs were studied on a 1.5 T whole-body MR scanner and SPECT/CT. The specimens were intubated and maintained in general anesthesia throughout the experiment. TCIR maps of the fractional pulmonary blood volume were compared to dynamic contrast enhanced MRI and SPECT/CT via a region of interest (ROI) based reader study. A comprehensive statistical analysis was performed on the coefficient of variation to evaluate homogeneity properties. Sensitivity was assessed by detecting gravitation dependent perfusion variation and delineation of pathological areas.


RESULTS
The fPBV-maps of all examined specimens indicate a superior homogeneity in the computed values (p<1.3×10(-4)). The sensitivity of the TCIR maps to a gravitation effect on the blood distribution was verified and a similar anteroposterior signal and count dependency was observed in DCE MRI and SPECT. Bland-Altman analysis showed no significant intra- or inter-observer difference within the ROI reader study (p>0.06).


CONCLUSIONS
Superior information content, significantly higher homogeneity and similar sensitivity of TCIR when compared to DCE and SPECT/CT demonstrated the feasibility of TCIR MRI as an alternative contrast agent-free, non-invasive functional lung imaging approach.
Department of Clinical Radiology, University Hospital Munich, Ludwig-Maximilians-University Munich, Marchioninistr 15, 81377 Munich, Germany; Comprehensive Pneumology Center, German Center for Lung Research, Marchioninistr 15, 81377 Munich, Germany; German Cancer Research Center, Division of Medical Physics in Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. Electronic address: thomas.gaass@med.uni-muenchen.de.
Thomas
T
Gaass
German Cancer Research Center, Division of Medical Physics in Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Department of Radiology, Division of Radiological Physics, University Hospital Basel, Spitalstrasse 21, 4056 Basel, Switzerland.
Grzegorz
G
Bauman
University Medical Center Schleswig-Holstein, Campus Kiel, Department of Diagnostic Radiology, Arnold-Heller-Str. 3, 24105 Kiel, Germany.
Jürgen
J
Biederer
German Cancer Research Center, Division of Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; University Medical Center Schleswig-Holstein, Campus Kiel, Department of Diagnostic Radiology, Arnold-Heller-Str. 3, 24105 Kiel, Germany.
Christian
C
Hintze
Department of Clinical Radiology, University Hospital Munich, Ludwig-Maximilians-University Munich, Marchioninistr 15, 81377 Munich, Germany.
Moritz
M
Schneider
Department of Clinical Radiology, University Hospital Munich, Ludwig-Maximilians-University Munich, Marchioninistr 15, 81377 Munich, Germany; Comprehensive Pneumology Center, German Center for Lung Research, Marchioninistr 15, 81377 Munich, Germany; German Cancer Research Center, Division of Radiology, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
Julien
J
Dinkel
D000818:Animals; D005240:Feasibility Studies; D005260:Female; D008168:Lung / Q000098:blood supply* / Q000000981:diagnostic imaging; D008279:Magnetic Resonance Imaging / Q000379:methods*; D023421:Models, Animal; D064847:Multimodal Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*
Animal experimentation; Blood volume; Lung; Magnetic resonance imaging