Answer for CoW 29 Jan 2017
Tubulonodular type of callosal lipoma
Findings
Pericallosal nodular T1 hyperintense lesion with extension to the left lateral ventricle occipital horn noted. Extensive blooming is noted in the susceptibility weighted images No significant abnormal contrast enhancement noted in the subtracted image. MR spectroscopy of the lesion revealed: Predominant lipid peak within the lesion. No significant increase choline integral values.
Discussion
The findings are suggestive of tubulonodular type of callosal lipoma. The intracranial lipomas are resultant of differentiation of persistent menix premitiva Intracranial lipomas are rare tumors with incidence of 0.1-0.5% of all intracranial tumors. Pericallosal lipomas account for 50% of all intracranial lipomas. On CT scan they show marked hypodensity with a Hounsfield units (HU) value between −40 and −100. Lipomas appears hyperintense on T1W images and show complete suppression of signal after fat saturation pulse. Lipid peaks are reported to occur with lipomas in MR Spectroscopy and must not be mistaken for necrotic high grade tumors . Blooming of lipomas are noted to occur in susceptibility weighted images. This is likely related to Chemical shift artifact The chemical misregistration is a result of the inability of the system to identify the frequency displacement caused by chemical shift and special frequency encoding. This misregistration causes dark or bright band at interfaces. Awareness of blooming on SWI images is very important, since the lesion shows similar MRI characteristic of hematoma. Both hematoma and lipomas appear hyperintense on T1 and shows blooming on SWI images. Fat suppressed T1 weighted imaging will help to differentiate the both the lesions. Lipoma appear hypointense on fat suppressed T1 weighted images, where as hematoma maintains its hyperintense signal. Microscopic mineralization and chemical shift artifact appear to be the major cause of susceptibility blooming.
References:
Neurology India 2013 | Volume : 61 | Issue : 1 | Page : 56-59Susceptibility artifacts in lipomasDayananda Lingegowda1,, Bejoy Thomas2, Chandrasekharan Keshavdas2, Kapilamoorthy2 Characterization of an intracranial neoplasm of lipoid origin by 'H MR Spectroscopy M. Rijpkema', Y. van der Meulen', Intl. SOC. Mag. Reson. Med. 10 (2002)
Findings
Pericallosal nodular T1 hyperintense lesion with extension to the left lateral ventricle occipital horn noted. Extensive blooming is noted in the susceptibility weighted images No significant abnormal contrast enhancement noted in the subtracted image. MR spectroscopy of the lesion revealed: Predominant lipid peak within the lesion. No significant increase choline integral values.
Discussion
The findings are suggestive of tubulonodular type of callosal lipoma. The intracranial lipomas are resultant of differentiation of persistent menix premitiva Intracranial lipomas are rare tumors with incidence of 0.1-0.5% of all intracranial tumors. Pericallosal lipomas account for 50% of all intracranial lipomas. On CT scan they show marked hypodensity with a Hounsfield units (HU) value between −40 and −100. Lipomas appears hyperintense on T1W images and show complete suppression of signal after fat saturation pulse. Lipid peaks are reported to occur with lipomas in MR Spectroscopy and must not be mistaken for necrotic high grade tumors . Blooming of lipomas are noted to occur in susceptibility weighted images. This is likely related to Chemical shift artifact The chemical misregistration is a result of the inability of the system to identify the frequency displacement caused by chemical shift and special frequency encoding. This misregistration causes dark or bright band at interfaces. Awareness of blooming on SWI images is very important, since the lesion shows similar MRI characteristic of hematoma. Both hematoma and lipomas appear hyperintense on T1 and shows blooming on SWI images. Fat suppressed T1 weighted imaging will help to differentiate the both the lesions. Lipoma appear hypointense on fat suppressed T1 weighted images, where as hematoma maintains its hyperintense signal. Microscopic mineralization and chemical shift artifact appear to be the major cause of susceptibility blooming.
References:
Neurology India 2013 | Volume : 61 | Issue : 1 | Page : 56-59Susceptibility artifacts in lipomasDayananda Lingegowda1,, Bejoy Thomas2, Chandrasekharan Keshavdas2, Kapilamoorthy2 Characterization of an intracranial neoplasm of lipoid origin by 'H MR Spectroscopy M. Rijpkema', Y. van der Meulen', Intl. SOC. Mag. Reson. Med. 10 (2002)
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!