Purpose: As stereotactic radiotherapy (SRT) becomes widespread, precise information including number, location, and margin of lesions is required when magnetic resonance (MR) imaging of brain metastasis is performed. We compare methods using 2 separate injections and a single injection for the administration of a double dose of contrast medium for contrastenhanced MR imaging.
Materials and Methods: We divided 40 patients with brain metastasis into 2 groups of 20 patients. Group A received 2 separate injections (0.2 + 0.2 mL/kg) of contrast medium (gadoteridol); Group B received a single injection of the same total dose (0.4 mL/kg). Group A underwent spin echo (SE) T₁-weighted imaging (T₁WI) and magnetization prepared rapid acquisition with gradient echo sequence (MPRAGE) after each injection, and Group B underwent the same MR studies at the same timing as Group A. We evaluated the number, signal-to-noise ratio (SNR), diameter, margin delineation, and volume of lesions and compared them between early and delayed studies by the 2 methods.
Results: The number of detected lesions was largest in delayed studies of MPRAGE in both groups. The SNR of the lesions was statistically lower in early studies of Group A than other studies. Delayed studies of Group B showed statistically better margin delineation than other studies on both SE-T₁WI and MPRAGE studies. Diameter and enhanced volume were statistically significantly larger on delayed phase than early phase in both groups.
Conclusion: Use of a single injection of double-dose contrast medium and longer delay time may improve margin delineation of lesions for the study of brain metastasis. Enhanced volume was larger on delayed phase, and it may influence selection of therapeutic strategy.

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Objective: We qualitatively evaluated the differences among susceptibility-weighted (SWI), magnitude (MAG), and high pass filtered phase (PHA) images in depicting interlobar differences in the appearance of the signal of the corticomedullary junction (CMJ). We conducted quantitative evaluation to validate the qualitative results.
Materials and Methods: We obtained SWI images from 25 preoperative brain tumor patients (12 men, 13 women, aged 19 to 82 years, mean, 52 years). Two trained neuroradiologists evaluated MAG, PHA, and SWI images. Qualitative evaluation of the CMJ signal and quantitative calculation of the relative signal ratio (RSR) percentages between the CMJ and deep white matter (WM) were conducted at 3 different slice levels of the brain independently for 4 different lobes (frontal, parietal, temporal, and occipital) and compared among MAG, PHA, and SWI. The extent of the area of the CMJ signal was graded on a 4-point scale (Grade 3, >75%; Grade 2, 50 to 75%; Grade 1, 25 to 50%; Grade 0, <25%). Data were statistically analyzed using a nonparametric Friedman test.
Results: The Kappa coefficients between the qualitative and quantitative grades were 0.002 for MAG, 0.0047 for PHA, and 0.050 for SWI. Qualitatively, on the PHA images and SWI, grades of the occipital lobes were significantly higher than those of the other lobes (P < 0.005). Quantitatively, PHA images showed statistically significant interlobar differences in RSR percentage values of the CMJ (P = 0.025).
Conclusion: Qualitatively, the appearance of the CMJ differed significantly among the different lobes of the brain on SWI and underlying PHA images but not on MAG images. Quantitatively, only PHA images showed significant interlobar differences in the RSR. PHA images are most sensitive to the CMJ signal contrast due to local paramagnetic iron content.

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Purpose: We compared the regional cerebral blood flow (rCBF) obtained by pulsed continuous arterial spin labeling (pCASL) and iodine-123-N-isopropyl-p-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) using 3-dimensional stereotactic region-of-interest (ROI) software for automated definition of ROIs in anatomic regions of the brain.
Methods: Thirteen patients with cerebrovascular occlusive disease and three with transient ischemic attacks underwent pCASL and IMP SPECT imaging. We compared rCBF values of each anatomic region and calculated the correlation coefficients between pCASL and IMP SPECT. We also calculated the asymmetry index (AI) using ROIs in contralateral regions of the hemispheres.
Results: The rCBF values calculated from pCASL and IMP SPECT were comparable in most segments, but rCBF in the thalamus (P < 0.0001) and hippocampus (P = 0.0006) was significantly higher measured by pCASL than IMP SPECT. The correlation of rCBF between pCASL and IMP SPECT in the affected hemisphere (r = 0.50) tended to be lower than that in the normal hemisphere (r = 0.59), but not significantly different (P = 0.25). Moreover, there was a fixed bias for underestimation of rCBF by pCASL (P = 0.0047) in the affected hemisphere. The calculated AI showed a significant relationship between methods (r = 0.79, P < 0.0001).
Conclusion: The rCBF obtained by pCASL had positive relationships with IMP SPECT. However, it should be considered that pCASL tends to have a weak relationship with IMP SPECT in some normal regions and regions affected by cerebrovascular occlusive disease.

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Purpose: We evaluated the rim patterns of intracranial meningiomas on nonenhanced (NE) and contrast-enhanced (CE) 3-dimensional fluid-attenuated inversion recovery (3D FLAIR) imaging on 3-tesla magnetic resonance (MR) imaging to clarify the associated imaging and pathological findings and the value of the rims in predicting tumor cleavability.
Methods: Thirty-two patients with meningioma underwent tumor excision. We classified the rim patterns on 3D FLAIR, subdivided into “rim-NE,” a rim with relatively low signal intensity on NE 3D FLAIR and “rim-CE,” a rim with relatively high signal intensity on CE 3D FLAIR, into 4 grades by their extent from 0 (no rim visible) to 3 (rim visible over most of the tumor-brain interface) and correlated them with tumor size, grade of peritumoral brain edema, presence/absence of pial supply, grade of tumor-brain adhesion, and histological findings.
Results: On NE 3D FLAIR, “rim-NE” was graded 0 in 5 patients, one in 5, 2 in 6, and 3 in 16. On CE 3D FLAIR, “rim-CE” was graded 0 in one patient, one in 13, 2 in 4, and 3 in 14. The grade of “rim-NE” correlated negatively with the grade of brain edema (P = 0.023) and positively with surgical tumor-brain cleavability (P < 0.001). It also correlated with the amount of connective tissue at the tumor-brain interface histologically (P = 0.041). Furthermore, a lower grade of “rim-NE” was more often seen in atypical than benign meningioma (P = 0.003). Although “rim-CE” was more prominent in tumors with pial supply on digital subtraction angiography (DSA) (P = 0.002), it was not useful in predicting tumor-brain adhesion or histological tumor grading.
Conclusion: The rim pattern of meningioma on NE 3D FLAIR can predict surgical cleavability and histological tumor grading. A higher grade of rim pattern on CE 3D FLAIR suggests prominent pial supply to the tumor but has no added value in predicting tumor-brain adhesion and histological tumor grading.

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Purpose: We measured T₂ relaxation time of the intervertebral discs (IVD) and facet joints (FJ) in patients with degenerative spondylolisthesis (DS) and no spondylolisthesis (NS) and investigated the characteristics of these parts in DS.
Methods: In 40 patients with DS and 40 patients with NS, we measured T₂ relaxation time of the IVD and FJ and compared them between groups. In the group with DS, we also examined the relationship between the degree of slippage using Meyerding grade and T₂ relaxation of each part in the IVD and FJ.
Results: T₂ relaxation time of the IVD tended to be lower in the DS than NS group and differed significantly (P < 0.01) within the anterior annulus fibrosus. T₂ relaxation time in the FJ was significantly higher in the DS than NS group. T₂ relaxation time in the FJ was significantly higher for those assessed Meyerding Grade II than Grade I, although we observed no significant differences in T₂ relaxation time in any area of the IVD.
Conclusion: T₂ relaxation time decreased in the anterior annulus fibrosus of the IVD and increased in the FJ in patients with DS, suggesting an association of IVD and FJ degeneration with the development of lumbar DS.

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Villoglandular papillary adenocarcinoma (VGPA) is a rare subtype of cervical adenocarcinoma that generally affects young women and has a favorable prognosis. Its preoperative diagnosis is important to avoid excessive surgery. We report the magnetic resonance (MR) findings of a case in which the cervical tumor showed a fern-leaf-like appearance on high resolution T₂-weighted images obtained at 3 tesla. MR imaging clearly showed this pathological feature that may suggest this disease.

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We report the time course of magnetic resonance imaging and spectroscopy of a case with lesions of the splenium and white matter with transiently reduced diffusion in clinically reversible encephalopathy. Initially normal spectroscopy showed slightly elevated choline. Signal abnormality in T₂-weighted and fluid-attenuated inversion recovery images persisted for 90 days. Lesions of the splenium and white matter with transiently reduced diffusion in clinically reversible encephalopathy are not always reversible and may reflect heightened glial cell-membrane turnover without neuronal damage.

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We introduced and optimized a novel sequence of fast (about 4 min), volumetric, high resolution, simultaneous bright- and black-blood imaging with sufficient T₁ contrast between enhanced metastasis and surrounding brain parenchyma for their differentiation. This proposed sequence can be used for 3-dimensional volumetric T₁-weighted bright- and black-blood imaging in contrast-enhanced studies and may be promising for detecting small brain metastases by improving differentiation between blood vessels and small brain metastases.

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We critically evaluated analog and digital transceivers for magnetic resonance (MR) imaging systems under identical experimental conditions to identify and compare their advantages and disadvantages. MR imaging experiments were performed using a 4.74-tesla vertical-bore superconducting magnet and a high sensitivity gradient coil probe. We acquired 3-dimensional spin echo images of a kumquat with and without using a gain-stepping scan technique to extend the dynamic range of the receiver systems. The acquired MR images clearly demonstrated nearly identical image quality for both transceiver systems, but DC and ghosting artifacts were obtained for the analog transceiver system. We therefore concluded that digital transceivers have several advantages over the analog transceivers.

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Purpose: We evaluated the usefulness of an automatic slice-alignment method to simplify planning of cardiac magnetic resonance (MR) scans with a 3-tesla scanner.
Methods: We obtained 2-dimensional (2D) axial multislice images using steady-state free precession (SSFP) sequences covering the whole heart at the end-diastole phase with electrocardiography (ECG) gating in 38 patients. We detected several anatomical feature points of the heart and calculated all planes required for cardiac imaging based on those points. We visually evaluated the acceptability of an acquired imaging plane and measured the angular differences of each view between the results obtained by this method and by a conventional manual pointing approach.
Results: The average visual scores were 3.4 ± 1.0 for short-axis images, 3.2 ± 0.9 for 4-chamber images, 3.2 ± 0.8 for 2-chamber images, and 3.3 ± 0.8 for 3-chamber images; average angular differences were 5.8 ± 5.1 (short axis), 7.7 ± 5.7 (4-chamber), 11.5 ± 6.7 (2-chamber), and 9.1 ± 4.6 degrees (3-chamber). Processing time was within 1.8 s in all subjects.
Conclusion: The proposed method can provide planes within the clinically acceptable range and within a short time in cardiac imaging of patients with various cardiac shapes and diseases without the need for high level operator proficiency in performing the examination and interpreting results.

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