Medical THz imaging: an investigation of histo-pathological samples.
We present a THz investigation of histo-pathological samples including the larynx of a pig and a human liver with metastasis. Our measurements show that different types of tissue can be clearly distinguished in THz transmission images, either within a single image or by a comparison of images obtained for different frequency windows. This leads to the problem that images obtained for different frequencies inherently have a different spatial resolution. An image obtained from two such images by a simple mathematical operation may contain artefacts. We discuss measures to deal with this problem. Furthermore, we investigate the possibility of improving the spatial resolution of THz images. Finally, we present a cw THz imaging system based on a photomixer and an external cavity semiconductor laser that allows for simultaneous two-mode operation. The cw system is less expensive and more compact than conventional time-domain imaging systems.
Knobloch
P
P
Institut für Hochfrequenztechnik, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
Schildknecht
C
C
Kleine-Ostmann
T
T
Koch
M
M
Hoffmann
S
S
Hofmann
M
M
Rehberg
E
E
Sperling
M
M
Donhuijsen
K
K
Hein
G
G
Pierz
K
K
D000465:Algorithms; D000818:Animals; D016477:Artifacts; D003238:Connective Tissue / Q000033:anatomy & histology; D003952:Diagnostic Imaging / Q000295:instrumentation / Q000379:methods; D055590:Electromagnetic Phenomena / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007817:Laryngeal Cartilages / Q000033:anatomy & histology; D007830:Larynx / Q000033:anatomy & histology*; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008872:Microwaves; D019047:Phantoms, Imaging; D011237:Predictive Value of Tests; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D013552:Swine