Proton MR Spectroscopy in the Diagnostic Evaluation of Suspected Mitochondrial Disease
Doris D. M. Lina,
Thomas O. Crawfordb and
Peter B. Barkera
a Russel H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD
b Department of Neurology and Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD

View larger version (66K):
[in a new window]
|
FIG 1. Images from the case of a 31-year-old man with MELAS syndrome, which was documented by a point mutation in the mitochondrial tRNA (Leu). T2-weighted MR image (T2 MRI) (2600/80/1) shows a large focal hyperintensity in the left parietal region, predominantly affecting the gray matter. This area corresponds to elevated choline (Cho), decreased N-acetylaspartate (NAA), and markedly elevated lactate (Lac) on the multisection spectroscopic imaging metabolic maps. In addition, multisection spectroscopic images show globally elevated lactate, which is greatest in the left parietal strokelike lesion, next highest in the remaining gray matter (G.M.) and CSF, and lowest in the white matter. R., right; L., left.
| |

View larger version (65K):
[in a new window]
|
FIG 2. Images from the case of a 3-year-old male patient with MELAS-MERRF overlapping syndrome, which was documented by a point mutation. Initial multisection spectroscopic images show no definitive lactate signal intensity. Voxels placed in the right corona radiata (area 1), CSF (area 2), and periventricular white matter (areas 3 and 4) show no clear evidence of lactate doublet. Lipid contamination (*) in this region (1.11.4 ppm) may, however, obscure a small lactate peak. R., right; L., left; Cho, choline; Cr, creatine; NAA, N-acetylaspartate; W.M., white matter; T1 MRI, T1-weighted MR image; Lac, lactate.
| |

View larger version (62K):
[in a new window]
|
FIG 3. Images from the same case of MELAS-MERRF overlapping syndrome shown Figure 2, obtained 1 year later during a subsequent study. MR spectroscopic images show a lactate doublet in the CSF (lateral ventricles, areas 2 and 3) and periventricular white matter (areas 5 and 6), bilaterally. R., right; L., left; Cho, choline; Cr, creatine; NAA, N-acetylaspartate; W.M., white matter; T1 MRI, T1-weighted MR image; Lac, lactate.
| |

View larger version (75K):
[in a new window]
|
FIG 4. Images from the case of an 8-year-old female patient with complex I mitochondrial disease, which was diagnosed when the patient was older than 3 years. MR image shows extensive T1-hypointense and T2-hyperintense signal abnormalities in the periventricular regions, particularly in the frontal white matter, in addition to T2 hyperintensity involving the genu of the corpus callosum. MR spectroscopic images show a large lactate peak in the CSF (left lateral ventricle, area 2). A small lactate peak may occur in the frontal white matter lesion (area 1), although spectra are also partially contaminated by lipids (*).W. M., white matter; Lac, lactate; Cho, choline; Cr, creatine; NAA, N-acetylaspartate; G. M., gray matter; T1 MRI, T1-weighted MR image; FLAIR, fluid-attenuated inversion recovery.
| |