Motor neuron damage and cortical spinal tract (CST) degeneration are pathological features of amyotrophic lateral sclerosis (ALS). We combined whole-brain diffusion tensor imaging (DTI) and three-dimensional magnetic resonance spectroscopic imaging (MRSI) to study the CST at different locations. Eight ALS patients were compared with normal controls. Fractional anisotropy (FA) and mean diffusivity (MD), and the ratio of N-acetyl-aspartate (NAA) to creatine (Cr) were measured at various locations in the CST, including the subcortical white matter (SWM), centrum semiovale (CS), periventricular white matter (PV), posterior limb of the internal capsule (PIC) and cerebral peduncle (CP). Patients showed significantly lower FA than controls in the CST, including the SWM, CS, PV and PIC. Although there was a trend towards elevated MD in ALS patients, this did not reach statistical significance. NAA/Cr ratios were also decreased in ALS patients compared with normal controls, with significant differences in the SWM and PV but not in PIC. Combined whole-brain DTI and MRSI can detect axonal degeneration in ALS. Measurements of FA obtained in the SWM, CS, PV and PIC, and NAA/Cr ratios in the SWM and PV yield the most robust results.

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In this study, we have aimed to evaluate the relationship between the shape and location of superficial calcification and the presence of fibrous cap rupture and intraplaque hemorrhage in atherosclerotic carotid plaque. Sixty-three patients with carotid stenosis underwent contrast-enhanced high resolution MR examinations with a 3-T MR scanner and 226 slices with superficial calcification were evaluated in the study. The shape of superficial calcification was categorized as the irregular type (dotted/arcuated) and patchy type and the location of superficial calcification was categorized as the marginal type and central type. Intraplaque hemorrhage and fibrous cap rupture depicted on the same slice as superficial calcification were identified. The chi-squared test was used for statistical analysis. A total of 149 slices (65.9%) with intraplaque hemorrhage and 107 slices(47.3%)with fibrous cap rupture were detected. There were 191 slices with irregular type (dotted/arcuated) calcification and 166 slices with marginal type calcification. Irregular superficial calcification was found more frequently accompanied with intraplaque hemorrhage as compared to the patchy type (73.8 vs. 22.9%, P < 0.0001); there was a significant difference between the marginal type and the central type for the accompaniment of intraplaque hemorrhage (72.9 vs. 46.7%, P < 0.05). However, there was no significant difference between different shapes and locations of superficial calcification that accompanied with fibrous cap rupture (P > 0.05). This study showed that superficial calcification is an important factor for determination of instability of atherosclerotic carotid plaque. The shape and location of superficial calcification are important features associated with the occurrence of intraplaque hemorrhage.

Cerebral blood flow (CBF) in the human primary visual cortex is correlated with the loss of visual function in neuro-ophthalmological diseases. Advanced three-dimensional pseudo-continuous arterial spin labeling (3D pCASL), as a non-invasive method to access the CBF, can be a novel measurement to detect the visual cortex. The objective of the study was to assess the intra- and inter-scanner reliability of 3D pCASL of the visual cortex in healthy adults and suggest the selection of different post-labeling delay times (PLDs). For this reason, 3D pCASL was conducted in two 3.0T MR three times with twelve healthy volunteers at an interval of 10–15 days. The 1st and 3rd tests were performed on scanner-1, and the 2nd test was performed on scanner-2. The value of the CBF was abstracted from the visual cortex with two PLDs. The intra- and inter-scanner reliability and reproducibility were evaluated with the intraclass correlation coefficient (ICC) and Bland-Altman plots. By estimating the mean value of the CBF in the visual cortex, the intra-scanner results demonstrated the higher reliability (ICC for PLD = 1.5 second presented at 0.743 compared with 0.829 for PLD = 2.5 seconds), and the Bland-Altman plots showed the reproducibility at a longer PLD. We conclude that the calibrated 3D pCASL approach provides a highly reproducible measurement of the CBF of the visual cortex that can serve as a useful quantitative probe for research conducted at multiple centers and for the long-term observation of the clinical effects of neuro-opthalmological diseases.

Purpose: To determine if contrast-enhanced (CE) MRI of intracranial lesions benefits from time-resolved MR angiography (MRA) during contrast agent injection. Materials and Methods:For 126 patients with suspected intracranial lesions undergoing routine CE MRI at 3.0T (N ϭ 88) or 1.5T (N ϭ 38), time-resolved CE MRA (threedimensional [3D] time-resolved imaging of contrast kinetics [TRICKS]) was performed during injection of the routine gadolinium (Gd) dose of 0.1 mmol/kg. Time to peak (TTP) enhancement of lesions as well as time to internal carotid artery (ICA), middle cerebral artery (MCA), superior sagittal sinus (SSS), and jugular vein enhancement were measured. Source and maximum intensity projection (MIP) images were reviewed to delineate the spatial relationship of lesions and the vasculature. Results:In 61 patients (48%), additional important findings were detected on time-resolved MRA that were not seen on the routine CE protocol, including aneurysms (N ϭ 6), arteriovenous malformations (N ϭ 7), ICA stenoses (N ϭ 2), vascular anomalies (N ϭ 18), and relationships between lesions and vessels (N ϭ 28). In addition, tumor TTP correlated with glioma grade (r ϭ 0.87) and discriminated epithelial from nonepithelial meningiomas (P ϭ 2.6 ϫ 10 -5 ). MRA added eight minutes to the total exam time.Conclusion: Time-resolved MRA performed during contrast agent injection adds information to the routine brain CE MRI examination of intracranial lesions with only a small time penalty and no additional risk to the patient. PREOPERATIVE NEUROSURGICAL planning may require assessing the feeding arteries, neovascularity, and venous drainage of tumors and other lesions. This may be performed using catheter angiography with high anatomical and temporal resolution. However, Xray digital subtraction angiography (DSA) is invasive, requiring arterial catheterization, ionizing radiation, and a nephrotoxic iodinated contrast agent. Since intracranial lesions are typically evaluated by MRI both pre-and postinjection of gadolinium (Gd) contrast agent, it could be simpler and safer for the patient if contrast-enhanced (CE) angiography and dynamic lesion enhancement could be assessed by MR during the Gd injection.Several groups have developed innovative three-dimensional (3D) time-resolved MR sequences that provide dynamic information about normal and abnormal vasculature. These 3D data are acquired during the injection of the contrast agent (1-9) and do not interfere with routine postcontrast imaging when the standard Gd dose is utilized. The only extra cost above and beyond routine CE brain MRI is a few extra minutes for starting an intravenous line and imaging during the injection. If the intravenous line is started while the patient is waiting for the MRI scan there is virtually no inconvenience to the patient.To evaluate the potential for time-resolved MR angiography (MRA) to contribute useful information, we offered dynamic 3D-time-resolved imaging of contrast kinetics (TRICKS) during contrast agent injection to selected patients unde...