MR imaging and MR spectroscopy in rhizomelic chondrodysplasia punctata

Abstract

A case of rhizomelic chondrodysplasia punctata was investigated with MR imaging of the brain and hydrogen-1 MR spectroscopy of the brain and blood. Areas with abnormal signal hyperintensity on T2-weighted images or hypointensity on T1-weighted images were detected in the subcortical white matter. MR spectroscopy of the brain showed that normal-appearing white matter was characterized by increased levels of mobile lipids and myo-inositol, reduced levels of choline, and the presence of acetate. The importance of these metabolic anomalies is correlated to the deficiency in plasmalogen biosynthesis.

Fig 1.

MR images. A, Axial T1-weighted image of the basal ganglia shows small delivery-related hemorrhage over the temporal convexity and bilateral areas (arrows) of low signal intensity in the white matter of the most anterior portion of the superior frontal gyrus. Hypointense areas are more pronounced on the left. Note the encysted cavum septi pellucidi. B, Coronal T2-weighted image shows bilateral areas (arrows) of high signal intensity in the superior parietal lobules. Hyperintense areas are more pronounced on the left.

Fig 2.

¹H MR spectrum obtained at with the STEAM sequence (TE, 20 milliseconds) in the occipitoparietal white matter. The dominant feature of the spectrum is the high lipid and Ins-Gly content. The presence of an unusual resonance at 1.95 ppm was detected and assigned to acetate.

Fig 3.

Long-TE (135 milliseconds) ¹H spectra obtained at 1.5 T with the CSI sequence in the occipitoparietal region. The main feature common to both spectra is the high Ins-Gly content. A, Gray matter. B, White matter.

Fig 4.

¹H MR spectrum in blood serum analyzed at 400 MHz shows a high concentration of lactate, creatine, and glutamate, whereas ketone body levels are normal. 1 indicates lactate; 2, myo-inositol; 3, glycine; 4, glucose; 4*, mostly glucose; 5, creatinine; 6, creatine; 7, citrate; 8, glutamine; 9, glutamate; 10, acetone; 11, lysine; 12, alanine; 13, butyrate, valerate, malonate, and succinate derivatives; 14, valine; 15, leucine; 16, α-hydroxybutyrate; 17, 3-(trimethylsilyl)propionate-2,2,3,3-d4; *, traces of glycerol from ultrafiltration.