Proton magnetic resonance (MR) spectroscopy (MRS) of the mammary gland region has customarily been used in basic research but is now commonly performed in clinical practice as MR techniques have improved. To debate its usefulness in a variety of fields and ultimately grade the timing of its use, a symposium entitled “Clinical Application and the Latest Technology of MRS—Timing of the Addition of MRS” was presented in 2009 at the 37th Annual Meeting of the Japanese Society for Magnetic Resonance in Medicine (JSMRM). MRS timing was classified into 3 grades according to when its addition: is always better, Grade 1; will sometimes be effective, Grade 2; and can provide only supplemental information, Grade 3. We describe the content of the meeting session on “Timing of the Addition of MRS in the Breast Cancer Field,” explain the reasons for the timing classifications, and review previous papers.

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Purpose: We assessed the signal of the globus pallidus (GP) in cases of hepatic insufficiency, especially to evaluate the degree of discrepancy in paramagnetic effects on shortening of T₁ and T₂* using susceptibility-weighted images (SWI).
Materials and Methods: Seven patients with hepatic insufficiency underwent magnetic resonance (MR) examinations that included T₁-weighted images (T₁WI), T₂-weighted images (T₂WI), and SWI on a 1.5-tesla MR imager, and we compared their results to those of controls. On T₁WI and T₂WI, we measured signal intensity in the GP and posterior segment of the putamen (Put) to obtain a signal ratio (GP/Put ratio), and on SWI, we classified signal intensity into 4 grades: A, higher than the cortex; B, lower than the cortex and higher than the cerebrospinal fluid (CSF); C, lower than the CSF and higher than the red nucleus; and D, lower than the red nucleus.
Results: In the 7 patients with hepatic insufficiency, the mean GP/Put ratio was significantly higher on T₁WI and T₂WI than those values in controls. On SWI, we classified 2 cases each as Grade A, Grade B, and Grade C, and one as Grade D. Although the signal of the GP was elevated on T₁WI, there was no decrease in signal on T₂WI. On SWI, we obtained no low signal intensity.
Conclusion: In patients with hepatic insufficiency, the globus pallidus did not show low signal intensity on either T₂WI or SWI. Hyperintensity of the GP on T₁WI without hypointensity on T₂WI, or even SWI, suggests a discrepancy between paramagnetic effect on T₁ and T₂ shortening that reflects the accumulation of manganese and the presence of hepatic insufficiency.

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Measuring exercise-induced muscle activity is essential in sports medicine. Previous studies proposed measuring transverse relaxation time (T₂) using muscle functional magnetic resonance imaging (mfMRI) to map muscle activity. However, mfMRI uses a spin-echo (SE) sequence that requires several minutes for acquisition. We evaluated the feasibility of T₂ mapping of muscle activity using ultrafast imaging, called fast-acquired mfMRI (fast-mfMRI), to reduce image acquisition time. The current method uses 2 pulse sequences, spin-echo echo-planar imaging (SE-EPI) and true fast imaging with steady precession (TrueFISP). SE-EPI images are used to calculate T₂, and TrueFISP images are used to obtain morphological information. The functional image is produced by subtracting the image of muscle activity obtained using T₂ at rest from that produced after exercise. Final fast-mfMRI images are produced by fusing the functional images with the morphologic images. Ten subjects repeated ankle plantar flexion 200 times. In the fused images, the areas of activated muscle in the fast-mfMRI and SE-EPI images were identical. The geometric location of the fast-mfMRI did not differ between the morphologic and functional images. Morphological and functional information from fast-mfMRI can be applied to the human trunk, which requires limited scan duration. The difference obtained by subtracting T₂ at rest from T₂ after exercise can be used as a functional image of muscle activity.

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Purpose: The blood flow patterns of chronic thoracic aortic dissection are complicated, and their clinical significance remains unknown. We evaluated the technical and clinical potentials of time-resolved 3-dimensional (3D) magnetic resonance (MR) velocity mapping for assessing these patterns.
Methods: We used data collected from time-resolved 3D phase-contrast MR imaging of 16 patients with chronic thoracic aortic dissection to generate time-resolved 3D MR velocity mapping that included 3D streamline and path line. We investigated blood flow patterns of this disease in the mapping and compared them with the morphological changes of the patent false lumen.
Results: Time-resolved 3D MR velocity mapping visualized rapid flow at the entry and in the true lumen immediately distal to the entry. We observed slower helical or laminar flow in the patent false lumen. In patients with disease progression, slower helical flow following rapid entry jet collided with the outer wall of the false lumen and was also observed in a growing ulcer-like projection.
Conclusion: We showed the potential of time-resolved 3D MR velocity mapping for visualizing pathologic flow patterns related to chronic thoracic aortic dissection.

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Purpose: Endolymphatic hydrops of Ménière's disease has been visualized after intratympanic injection of gadopentetate dimeglumine (Gd-DTPA) using a 3-dimensional (3D) inversion-recovery sequence with real reconstruction (3D real IR). This technique enables differentiation of bone and endo- and perilymph space on a single image but requires 15 min of scan time. Therefore, we compared it with 2D real IR, which is faster.
Materials and Methods: We investigated 10 ears in 9 patients with suspected Ménière's disease. Twenty-four hours after intratympanic administration of 8-fold diluted Gd-DTPA, we obtained 3D and 2D real IR images as well as magnetic resonance (MR) cisternography at 3 tesla. Three radiologists independently graded the degree of endolymphatic hydrops according to previously proposed criteria. Contrast-to-noise ratio (CNR) between peri- and endolymph was measured.
Results: We could evaluate the degree of endolymphatic hydrops in 9 cochleas and 10 vestibules but not in a tenth cochlea, which was too faintly enhanced on both 2D and 3D real IR. Grading of all evaluated cochleas and vestibules agreed completely among the 3 radiologists. Evaluation on 2D real IR and 3D real IR also agreed completely. Mean CNR was significantly higher on 3D than 2D real IR (P<0.05), and CNR on both correlated significantly (r = 0.872).
Conclusion: Endolymphatic hydrops in Ménière's disease can be evaluated with 2D as well as 3D real IR and in a shorter scan time.

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Purpose: We investigated the effect of verapamil on the transport of manganese in the olfactory connections of rat brains in vivo using statistical parametric mapping and manganese-enhanced magnetic resonance (MR) imaging.
Methods: We divided 12 7-week-old male Sprague-Dawley rats into 2 groups of six and injected 10 μL of saline into the right nasal cavities of the first group and 10 μL of verapamil (2.5 mg/mL) into the other group. Twenty minutes after the initial injection, we injected 10 μL of MnCl₂ (1 mol/L) into the right nasal cavities of both groups. We obtained serial T₁-weighted MR images before administering the verapamil or saline and at 0.5, one, 24, 48, and 72 hours and 7 days after administering the MnCl₂, spatially normalized the MR images on the rat brain atlas, and analyzed the data using voxel-based statistical comparison.
Results: Statistical parametric maps demonstrated the transport of manganese. Manganese ions created significant enhancement (t-score = 36.6) 24 hours after MnCl₂ administration in the group administered saline but not at the same time point in the group receiving verapamil. The extent of significantly enhanced regions peaked at 72 hours in both groups and both sides of the brain. The peak of extent in the right side brain in the group injected with saline was 70.2 mm³ and in the group with verapamil, 92.4 mm³. The extents in the left side were 64.0 mm³ for the group with saline and 53.2 mm³ for the group with verapamil.
Conclusion: We applied statistical parametric mapping using manganese-enhanced MR imaging to demonstrate in vivo the transport of manganese in the olfactory connections of rat brains with and without verapamil and found that verapamil did affect this transport.

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Diffusion tensor imaging (DTI) is a magnetic resonance (MR) imaging technique that has attracted attention in recent years for applications such as nerve fiber tracking, neurography, and tumor detection. In DTI measurements, 2 motion-probing gradient (MPG) pulses are applied to evaluate water diffusion. In DTI for nerve fiber tracking, acquisition parameters, such as strength, duration, and separation of MPGs, influence the MR signal.
In this study, we set acquisition parameters in DTI to emphasize fractional anisotropy to clarify the direction of nerve fibers. We performed Monte Carlo simulations of restricted diffusion in a cylinder model and phantom measurements with capillary plates to examine the relationship between the acquisition parameters in DTI and the size of restricted structures, particularly their diameter and length, which we will refer to as “compartment size.”
We confirmed that normalized signal intensities in DTI measurements depend on diffusion time, which, in turn, depends on the separation and duration of the MPG, and they decrease with increase in compartment size. Furthermore, our simulation and phantom results suggest that use of a longer diffusion time effectively emphasizes fractional anisotropy to clarify the direction of nerve fibers.

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We report magnetic resonance (MR) imaging findings of ductal carcinoma in situ (DCIS) within a fibroadenoma in a 42-year-old woman. Dynamic MR imaging revealed the mass to have 2 components with different kinetics. A nodular area within the mass showed faster initial enhancement followed by earlier washout and was histologically proven to be DCIS. Dynamic MR imaging reflected differences in vascularity between the fibroadenoma and DCIS, and parameter color maps generated from the dynamic data clearly demonstrated the extent of the DCIS.

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We correlate findings from magnetic resonance (MR) imaging and pathology in a 55-year-old woman with spindle cell carcinoma of the breast. Pathological examination showed a fibrous capsule at the margins and abundant fibromyxoid stroma within the mass. Spindle cell carcinoma may be included in the differential diagnosis of expanding round masses with internal components that demonstrate rapid initial enhancement with high signal intensity on T₂-weighted images in postmenopausal women.

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We explored the feasibility of using carbon-13 (¹³C) magnetic resonance imaging (¹³C-MRI) to depict ¹³C-labeled methionine-enriched gliomas at 4.7 tesla. We transplanted 2 types of glioma cells separately to 2 subcutaneous tissue sites on the backs of mice weighing 15 to 20 g. After confirming tumor growth, we used ¹³C-MRI and ¹H-MRI to scan 4 mice that had been administered ¹³C-labeled methionine and 2 control mice. ¹³C-MRI of all 4 transplanted mice administered with ¹³C-labeled methionine revealed 2 areas of hyperintensity that corresponded to the tumor sites on ¹H-MR images, but no such areas were visualized in transplanted controls. Our data suggest that ¹³C-MRI can show the accumulation of ¹³C-labeled tracer by gliomas.

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