Imaging of brain metastases of bronchial carcinomas with 7 T MRI - initial results.
OBJECTIVE
To compare the depiction of brain metastases of bronchial carcinomas on susceptibility-weighted and contrast-enhanced images with 7 T and at 1.5 T MRI.


METHODS
Twelve patients with brain metastases of bronchial carcinomas underwent 7 T and 1.5 T MRI. Minimum intensity projections (MinIP) of a 1.5 T SWI sequence (voxel size = 0.9 x 0.9 x 2.0 mm(3)) were compared to 7 T SWI MinIPs (voxel size = 0.4 x 0.4 x 1.5 mm(3)). A T 1-w 3D MPRAGE at 1.5 T (voxel size = 1 x 1 x 1 mm(3) after double-dose (DD) gadoterate meglumine, Gd-DOTA) was compared to a 7 T MPRAGE sequence (voxel size = 0.7 x 0.7 x x 0.7 mm(3), single dose (SD) Gd-DOTA) in all patients, and to DD Gd-DOTA in 6 patients after a 10 minute delay. The number of intracranial microhemorrhages in SWI MinIPs and the number of contrast-enhancing metastases in MPRAGE images were compared in each patient grouped into three size ranges (< or = 2 mm, > 2 mm and < 6 mm, > or = 6 mm) by two radiologists in consensus.


RESULTS
In all 12 patients the 7 T SWI with spatially higher resolution allowed the identification of 87 versus 67 cerebral microhemorrhages at 1.5 T. 7 T T 1-w images after SD Gd-DOTA depicted 198 brain metastases versus 238 at 1.5 T after DD Gd-DOTA. After doubling the contrast dose in six patients, 4 additional brain metastases were identified at 7 T.


CONCLUSIONS
Our preliminary results indicate that despite the higher spatial resolution the detection of brain metastases on 7 T MPRAGE images is almost equal to 1.5 T MPRAGE images. The 7 T SWI sequence with spatially higher resolution allowed the detection of 20 % more microhemorrhages in brain metastases compared to the 1.5 T SWI sequence.
Mönninghoff
C
C
Institut für diagnostische und interventionelle Radiologie und Neuroradiologie, Universitätsklinikum Essen. christoph.moenninghoff@uk-essen.de
Maderwald
S
S
Theysohn
J M
JM
Schütt
P
P
Gauler
T
T
Kraff
O
O
Ladd
M E
ME
Ladd
S C
SC
Wanke
I
I
D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology; D001932:Brain Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D002283:Carcinoma, Bronchogenic / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000473:pathology / Q000556:secondary*; D003287:Contrast Media / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006571:Heterocyclic Compounds; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted; D007262:Infusions, Intravenous; D020300:Intracranial Hemorrhages / Q000175:diagnosis; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009942:Organometallic Compounds; D011446:Prospective Studies; D012680:Sensitivity and Specificity
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate