DOI: 10.1148/radiol.2271020313
Brain Fiber Tracking with Clinically Feasible Diffusion-Tensor MR Imaging: Initial Experience1
Kei Yamada, MD, PhD,
Osamu Kizu, MD, PhD,
Susumu Mori, PhD,
Hirotoshi Ito, MD,
Hisao Nakamura, MD,
Sachiko Yuen, MD,
Takao Kubota, MD,
Osamu Tanaka, MD,
Wataru Akada, MD,
Hiroyasu Sasajima, MD, PhD,
Katsuyoshi Mineura, MD, PhD and
Tsunehiko Nishimura, MD, PhD
1 From the Departments of Radiology (K.Y., O.K., H.I., H.N., S.Y., T.K., O.T., W.A., T.N.) and Neurosurgery (H.S., K.M.), Kyoto Prefectural University of Medicine, Kajii-cyo, Kawaramachi Hirokoji Sagaru, Kamigyo-ku, Kyoto City, Kyoto 602-8566, Japan; and Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, Md (S.M.). Received April 1, 2002; revision requested June 13; revision received June 20; accepted August 8. Address correspondence to K.Y. (e-mail: kyamada@koto.kpu-m.ac.jp).
View larger version (74K):
[in a new window]
|
Figure 1. ROIs for tracking the corticospinal tract (CST), corticopontine tract (CPT), and sensory tract. The first ROI (ROI-1) was placed at the superior level of the ventral pons. The second ROI (ROI-2) was placed at the level of the cerebral peduncle. The most medial and lateral ROIs correspond to corticopontine tracts. The medial corticopontine tract represents the frontopontine tract, and the lateral corticopontine tract represents the temporo-parieto-occipitopontine tract (TPOPT). The corticospinal tract is located between these tracts, and we arbitrarily divided it into two ROIs. The ROIs for the sensory tracts were chosen from the area that corresponded to the medial lemniscus and spinal lemniscus. All ROI placements were performed in transverse planes.
|
|
View larger version (146K):
[in a new window]
|
Figure 2. Patient 8. Bronchogenic large cell carcinoma in a 48-year-old man who presented with left arm weakness. Color-coded vector maps calculated from diffusion-tensor MR image (top left) and transverse conventional T2-weighted MR image (top right) reveal a mass in the right frontal lobe that is surrounded by vasogenic edema. Presurgical fiber-tracking results overlaid on the T2-weighted MR image depicted the locations of sensory (green), motor (red), and corticopontine (brown) tracts. Motor tracts on the right side were deviated slightly laterally compared with those on the contralateral side. Bottom left: Sagittal reconstruction image depicts termination of the tracts within the vasogenic edema. The patient underwent successful resection of the mass from a right frontal approach, with full recovery of motor function after surgery. Bottom right: Postoperative fiber-tracking image confirms the well-preserved fiber tracts. Motor tracts appear to have shifted back to a more medial position.
|
|
View larger version (44K):
[in a new window]
|
Figure 3. Patient 15. Seizures in a 57-year-old woman. Left: Transverse diffusion-weighted MR image that was the source image for fiber tracking shows a left frontal lesion with substantial mass effect. Hypointensity of the central cystic component ruled out the possibility of brain abscess. Middle: Fiber-tracking results superimposed on transverse T2-weighted MR image show the motor tract (red) on the lesion side to be deviated toward the dorsal aspect. Left sensory tract was not depicted, which was assumed to be a result of remote mass effect. Sensory (green), motor (red), and corticopontine (brown) tracts on the contralateral side are depicted in normal locations. The patient underwent subtotal resection of this mass, which revealed glioblastoma multiforme. Right: Follow-up fiber-tracking MR image shows shift of the fiber tracts toward the rostral aspect. Left sensory tract (green) is clearly depicted posteromedially to the motor tract (red).
|
|
View larger version (55K):
[in a new window]
|
Figure 4. Patient 16. Bronchogenic carcinoma in a 64-year-old man who presented with progressive motor aphasia and weakness in the right upper and lower extremities. Transverse contrast-enhanced T1-weighted (left) and T2-weighted (middle) MR images reveal a large mass in the left frontal lobe, with cystic degeneration and wall enhancement. Incidental meningioma is noted medial to this mass. Middle: Fiber-tracking MR image depicts the sensorimotor pathways, which deviated posteromedially to the mass. Since these tracts were in proximity to the mass, we suggested use of a careful approach to the posteromedial wall of the mass. Sensory (green), motor (red), and corticopontine (brown) tracts on the contralateral side are depicted in normal locations. Right: Follow-up fiber-tracking MR image obtained after subtotal resection of the tumor clearly depicts the well-preserved sensorimotor pathway dorsal to the surgical cavity. The patient experienced dramatic improvement in motor symptoms soon after surgery.
|
|
Copyright © 2003 by the Radiological Society of North America.
