ABSTRACT
Objective To study the developmental process of the region of basal nuclei of postmortem fetuses by 3.0 T and 7.0 T MRI.Methods One hundred and thirty-one postmortem fetuses of 14 to 40 weeks of gestational age(GA)were scanned by 3.0 T MR,of which 11 fetuses of 14-27 weeks of GA were chosen and scanned by 7.0 T MR. The time when the structures in the region of basal nuclei could be detected and the changes of MR signal intensity were analyzed for MRI of different Tesla.Results On 3.0 T MRI.the dorsal thalamus could be delineated as early as 14 weeks of GA. The germinal matrix, caudate nucleus,and putamen could be visualized as early as 15 weeks of GA. The globus pallidus could be described as early as 18 weeks of GA.and the internal capsule and external capsule could be shown as early as 20 weeks of GA. The signal of the caudate nucleus during 15-30 weeks of GA was relatively hypointense on T1WI and hyperintense on T2WI.but during 31-40 weeks of GA, it was relatively hyperintense on T1WI and hypointense on T2WI. The putamen had a relatively high signal intensity on T1WI and low signal intemity on T1WI during 15-17 weeks of GA, and it appeared patchy during 18-25 weeks of GA,then it had a relatively low signal intensity on T1WI and high signal intensity on T2WI during 26-30 weeks of GA, and during 31-40 weeks of GA,its signal intensity was relatively high on T1WI and low on T2WI.The globus pallidus had a relatively high signal intensity on T1WI and low signal intensity on T2WI during 20-40 weeks of GA Compared to the 3.0 T MRI,the T2 images of 7.0 T MRl were more clear,and most structures in the region of basal nuclei could be clearly displayed as early as 16 weeks of GA.such as the germinal matrix,caudate nucleus,dorsal thalamus,putamen,globus pallidus,internal capsule,and external capsule.The claustrum could be delineated as early as 18 weeks of GA on 7.0 T MRI. Conclusions 3.0 T MRI could show the developmental process of the region of basal nuclei well,but the T2 images of 7.0 TMRl were comparatively better.
ABSTRACT
Objective To study the capability of high field MRI in demonstrating the post-mortem fetal brains at different gestational age(GA).Methods One hundred and eight post-mortem fetal brains of 14-40 weeks GA were evaluated by 3.0 T MRI. Eleven brains of 14 to 27 weeks GA with good 3.0 T MRI images were chosen and scanned by 7.0 T MRI. The developing sulci, layered structures of fetal cerebral cortex and basal nuclei were evaluated on MRI of different Tesla(3.0 T and 7.0 T)and their results analyzed. Results On T_1 WI of 3.0 T MRI, the layered structures of fetal cerebral cortex were present at 14 weeks GA, the sulci were more accurately identified after 16 weeks GA. The basal nuclei were clearly distinguishable after 20 weeks GA. and these structures were better visualized as the GA increased. On T_2WI of 7.0 T MRI, the sulei, layered structures of fetal cerebral cortex and basal nuclei were shown more clearly at the same GA when compared to 3.0 T, especially the sulci at the early developmental stages. Conclusions T_1 WI of 3.0 T MRI could show the developing structures of post-mortem fetal brain well, but the T_2 WI of 7.0 T MRI were comparatively better.
ABSTRACT
Objective To investigate the diagnostic value of 1H magnetic resonance spectroscopy (1H-MRS) in mammary tumors and to discuss the technique factors which influence the detection rate.Methods The 1H-MRS features of 47 mammary tumors, of which 24 malignant tumors and 23 benign tumors confirmed by pathology were analyzed. All of the tumors were detected before Gd-DTPA enhancement. Results Eleven of 24 malignant tumors showed increased choline resonance peak at 3.24 ppm while 4 of 23 benign ones at 3.24 ppm .The positive value were 45.8% and 17.4% respectively. The sensitivity and specificity were 45.8% and 82.6% respectively by using 1H-MRS to discriminate benign from malignant tumors. The main factors influencing the detection rate were low suppressed lipid, low suppressed water and low single-noise rate.Conclusion Choline is not special features of malignant tumors. Choline can be obtained despite the nature of tumor if they grow rapidly. The low sensitivity of choline to be detected mainly dues to technique factors.
ABSTRACT
Objective To evaluate neurovascular anatomical relationship in patients with trigeminal neuralgia.Methods 49 patients with neuralgia were examined by MRI 3D-CISS in combination with 3D-TOF and MPR technique.The MRI findings were compared to the partial operative results.Results 13 patients who underwent surgery were considered as a responsible compression of vessel on 3D-CISS and 3D-TOF imaging,the compression caused by artery and vein was seen in operation in 10 cases and 3 cases respectively.18 (90%) of 20 patients with the symptom of maxillary division had neurovascular compression at the medial site of the root of trigeminal nervus,while 15(79%) of 19 patients with the symptom of mandibular division had compression at the lateral site.Conclusion 3D-CISS MR imaging is useful in the detection of neurovascular relationship and correlation between the region of neuralgic manifestation and the site of trigeminal nerve compression.