Magnetic resonance colonography and virtual magnetic resonance colonoscopy with the 1.0-T system: a feasibility study.
OBJECTIVE
An ex vivo study and a clinical, prospective, patient study were undertaken to evaluate the feasibility of magnetic resonance (MR) colonography with a 1.0-T system.


METHODS
An ex vivo colon model was scanned. A cleaned pig colon was prepared with six simulated sessile polyps (diameters of 4-12 mm) and one simulated pedunculated polyp (diameter of 5 mm). Subsequently, five patients (aged 39-81 years; four women, one man) were examined with MR colonography, immediately followed by endoscopic colonoscopy. After preparation for colonoscopy, the colon was filled with a Gd-DTPA/water solution (1:100). A breath-hold 3D gradient-echo sequence was acquired in both the prone and supine positions and after intravenous Gd-DTPA administration. Images were analyzed interactively by using multiplanar projections, maximum-intensity projection, and a virtual endoscopic view. The MR results were compared with the findings of the fiberoptic endoscopy.


RESULTS
All seven simulated lesions of the colon model could be detected by MR imaging. In one patient, an advanced colon cancer as well as an additional small polyp was depicted. In the other four patients, single polyps with a diameter of 1 to 2.5 cm and a large adenoma were visualized by MR colonography. Contrast enhancement of the polyps was noted only after subtraction.


CONCLUSIONS
The 1.0-T system is feasible for MR colonography. Reduced requirements for hardware could contribute to establish the novel technique as a screening method for colorectal polyps.
Saar
B
B
Department of Radiology, University Hospital Rechts der Isar, Technische Universitaet of Munich, Germany. bsaar@roe.med.tumuenchen.de
Heverhagen
J T
JT
Obst
T
T
Berthold
L D
LD
Kopp
I
I
Klose
K J
KJ
Wagner
H J
HJ
D000236:Adenoma / Q000175:diagnosis*; D018253:Adenoma, Villous / Q000175:diagnosis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000818:Animals; D002277:Carcinoma / Q000175:diagnosis*; D003110:Colonic Neoplasms / Q000175:diagnosis*; D003111:Colonic Polyps / Q000175:diagnosis*; D003113:Colonoscopy / Q000379:methods*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012811:Sigmoid Neoplasms / Q000175:diagnosis
D003287:Contrast Media; D019786:Gadolinium DTPA