MR Imaging and Spectroscopy of a Tuber Cinereum Hamartoma in a Patient with Growth Hormone Deficiency and Hypogonadotropic Hypogonadism

American Journal of Neuroradiology

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Fig 1.
MR image of hypothalamic hamartoma. Top row, pre- (A) and postcontrast (B) T1-weighted sagittal images T2-weighted coronal image (C). Bottom row, T2-weighted axial images at the level of the supracellular cistern (D) and the interpenduncular fossa (E). Panel F shows a diffusion-weighted image acquired at the level of the interpenduncular fossa. Note the lack of contrast enhancement of the hamartoma (B); signal intensity of the harmartoma is similar to that of cortical gray matter and the amygdala (C). Dorsal fusion with the mammilary body is also apparent (F).
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Fig 2.
Short-TE spectra of the thalamus (left), hamartoma (middle), and amygdala (right). The locations of the respective volumes of interest are shown in the MR images above the spectra.

TABLE 1:

Estimated concentrations (mmol/l) from LCModel fit

Metabolite	Hamartoma	Thalamus	Amygdala
NAA	6.28 (12)	^*9.22 (9)	6.12 (12)
Cho	1.87 (10)	^**1.29 (12)	1.93 (11)
Cr	5.31 (14)	6.17 (12)	5.71 (13)
MI	10.5 (8)	^*3.1 (20)	^*6.0 (12)
Glx	9.5 (25)	7.7 (22)	10.1 (21)
NAA/Cho^†	3.36 (15)	*7.15 (14)	3.17 (16)
NAA/Cr^†	1.18 (18)	^**1.49 (15)	1.07 (17)
Cho/Cr^†	0.35 (15)	0.21 (18)	0.34 (19)

Note.—The numbers in parentheses are the estimated LCModel SD expressed as percentages of the estimated concentrations.
* Value differs significantly from that of the hamartoma (no overlaping of the 95% confidence intervals [ie, t > 3.9; P < 0.001])
** P < .02.
† The calculated ratios represent concentration ratios and not ratios of peak areas; effects of T2 are negligible, because of the short TE. The SDs of the ratios were derived from the SD of the concentrations by error multiplication.

TABLE 2:

Results of hypothalamus hamartoma spectroscopy compared with the literature

Author/Year	Hamartoma Type	Reference Structure	NAA/Cho Ratio	NAA/Cr Ratio	Cho/Cr Ratio	Myo-inositol Concentration
Present report	Hypothalamic hamartoma	Thalamus	⇓^**	⇓(n.s.)	⇑^*	⇑^**
		Amygdala	=	=	=	⇑^**
Pascual et al. 2000 (Pascual et al [4])	Hypothalamic hamartoma (seizures; one case)	Temporal lobe	⇓(n.i.)	⇑(n.i.)	⇓(n.i.)	...
Tasch et al. 1998 (Tasch et al [5])	Hypothalamic hamartoma (seizures; five cases)	Temporal lobe and hypothalamus	⇓(n.i.)	⇓^**	=	...

Note.—The arrows indicate higher (⇑), lower (⇓), or similar (=) values compared to the reference spectra. n.s., not significant n.i., significance level not indicated in the literature
* P < .02.
** P < 0.001.