a 46-year - old caucasian man presented with a 10-year history of mild gait ataxia and undirected vertigo after fast head movements . he had a past medical history of resection of a thyroid adenoma and also for benign polyposis of the sigmoid colon . at the age of 41 years physical inspection revealed megalocephaly , congenital facial asymmetry and left thenar aplasia . at the latest presentation , the neurological examination showed minimal intention tremor , gait ataxia without visual compensation , an undirected imbalance on romberg 's test and bradydiadochokinesia . with approval of the local ethic committee and with the patient 's informed written consent , mri examinations of the brain were performed on a 1.5 t scanner ( avanto , siemens medical solutions , erlangen , germany ) in combination with using a vendor supplied 12-channel receive - only head coil and then mri examinations of the brain were done on a 7 t scanner ( magnetom 7 t , siemens medical solutions , erlangen , germany ) in combination with an 8-channel transmit - and - receive head coil ( rapid biomed , wuerzburg , germany ) . the gradient - echo and turbo spin echo sequences were performed to obtain the axial proton density ( pd ) , t2 , t2 and susceptibility weighted images ( swi ) , which were optimized for each field strength ( table 1 ) . in addition , proton ( h ) mr spectroscopy ( mrs ) was performed at 1.5 t . the spectroscopic data was acquired from the patient 's cerebellar lesion using a single - voxel , point - resolved technique ( te = 135 ms ; tr = 1500 ms ) . the resulting prominent resonances representing choline ( cho ) , creatine ( cr ) and n - acetylaspartate ( naa ) within the lesion were compared to the mirror image voxels on the white matter of the normal contralateral hemisphere . spectral post - processing was performed using the software provided by the mri system manufacturer ( siemens syngo , vb 15 , siemens medical solutions , erlangen , germany ) . for 11 years , repeated 1.5 t mri examinations revealed a slowly growing , non - enhancing tumor mass in the left cerebellar hemisphere with preservation of the gyral pattern . thus , the present study was done without administration of contrast media . on mri at 1.5 t and 7 t , the posterior fossa tumor ( 493432 mm in size ) appeared mainly hyperintense on the t2-weighted images ( fig . 1a ) and iso - hypointense on the proton density images ( not shown ) . the characteristic striated pattern of the lesion was best displayed on the t2-weighted images at both field strengths ( fig . the tumor caused descensus of the cerebellar tonsils , but any obstructive supratentorial hydrocephalus was absent . due to their high sensitivity for paramagnetic substances like deoxyhemoglobin , the swi and t2 weighted images revealed thin veins running deep between the thickened folia of the cerebellar lesion in great detail ( fig . the 7 t swi minimal intensity projection ( mip ) images depicted thin vessel branches as small as 250 m , whereas the 1.5 t swi mip images could only resolve larger vessels to a size of 450 m . compared to the 1.5 t swi images ( fig . 1c ) the medial displacement and compression of the dentate nucleus by the tumor were much better registered on 7 t swi images ( fig . the h - mrs at 1.5 t demonstrated a reduction in naa and a prominent lactate peak . contrary to other previous reports , the cho , cr and the resulting cho / cr ratio were slightly elevated in the lesion and the myoinositol ( mi ) levels were not changed ( 3 , 4 ) . thus far , neurosurgical therapy and histopathological examination have not been performed because the lesion exerted only mild compression of the iv ventricle without any hydrocephalus . a dna analysis revealed a heterozygous mutation in exon 5 of the pten gene ( chromosome 10 q23 ) , and this supported the diagnosis of ldd ( c. 388c > t ; p. arg130x ) . for 11 years , repeated 1.5 t mri examinations revealed a slowly growing , non - enhancing tumor mass in the left cerebellar hemisphere with preservation of the gyral pattern . thus , the present study was done without administration of contrast media . on mri at 1.5 t and 7 t , the posterior fossa tumor ( 493432 mm in size ) appeared mainly hyperintense on the t2-weighted images ( fig . 1a ) and iso - hypointense on the proton density images ( not shown ) . the characteristic striated pattern of the lesion was best displayed on the t2-weighted images at both field strengths ( fig . the tumor caused descensus of the cerebellar tonsils , but any obstructive supratentorial hydrocephalus was absent . due to their high sensitivity for paramagnetic substances like deoxyhemoglobin , the swi and t2 weighted images revealed thin veins running deep between the thickened folia of the cerebellar lesion in great detail ( fig . images depicted thin vessel branches as small as 250 m , whereas the 1.5 t swi mip images could only resolve larger vessels to a size of 450 m . compared to the 1.5 t swi images ( fig . 1c ) the medial displacement and compression of the dentate nucleus by the tumor were much better registered on 7 t swi images ( fig . the h - mrs at 1.5 t demonstrated a reduction in naa and a prominent lactate peak . contrary to other previous reports , the cho , cr and the resulting cho / cr ratio were slightly elevated in the lesion and the myoinositol ( mi ) levels were not changed ( 3 , 4 ) . thus far , neurosurgical therapy and histopathological examination have not been performed because the lesion exerted only mild compression of the iv ventricle without any hydrocephalus . a dna analysis revealed a heterozygous mutation in exon 5 of the pten gene ( chromosome 10 q23 ) , and this supported the diagnosis of ldd ( c. 388c > t ; p. arg130x ) . lhermitte - duclos disease or dysplastic cerebellar gangliocytoma is a slowly enlarging mass within the cerebellar cortex , and patients with this malady present with headaches , occlusive hydrocephalus , cranial nerve palsies , gait ataxia and other symptoms of cerebellar dysfunction ( 1 ) . beside some pediatric cases , the majority of patients are diagnosed in the third or fourth decade of life without a gender predilection . histopathologically , ldd is characterized by regional enlargement of the cerebellar stratum granulosum , an absence of the purkinje cell layer and progressive hypertrophy of the granular cell neurons with increased myelination of their axons in the expanded molecular layer ( 5 ) . mri has proven to be the best imaging modality for revealing the characteristic appearance of ldd , and mri often enables physicians to make the diagnosis of ldd even without histopathological confirmation ( 3 , 4 , 6 - 10 ) . the striated pattern of ldd is a result of the close apposition of the thickened cerebellar folia that are lacking their secondary arborization . a non - enhancing , unilateral cerebellar mass in a middle - aged patient , which is characterized by a ' tiger - striped ' pattern of hyperintensity on the t2-weighted mr images and this respects the cerebellar margins , is typical of ldd ( 8) . to the best of our knowledge , this is the first reported case of ldd that has been examined by 7 t mri ultrahigh field mri systems (  7 t ) with their increased signal - to - noise ratio ( snr ) and higher sensitivity to susceptibility contrast . these systems are currently being tested for clinical applications and they allow for imaging anatomical structures with thinner sections , larger matrices and reduced acquisition times . however , the clinical challenges associated with 7 t mri include higher specific absorption rates ( sar ) , non - uniformity of the transmitted radiofrequency field , non - homogeneity of the static magnetic field , increased susceptibility artifacts and potential physiological side - effects . moving from 1.5 t to 7 t mri , the t2 is shortened and the susceptibility contrast of paramagnetic substances ( e.g. deoxyhemoglobin , neuromelanin , iron ) is significantly amplified , which enables a superior illustration of the venous vasculature and cerebellar nuclei . 1.5 t swi was found to be helpful for detecting deep running veins around the thickened folia of ldd ( 3 ) . 7 t swi can demonstrate in greater detail veins that are even smaller than the voxel size , due to the associated paramagnetic effect , than the corresponding 1.5 t images ( fig . 1c - f ) because the sensitivity of mri scanners for paramagnetic substances increases in proportion to the applied magnetic field . the deoxyhemoglobin in these veins helps to resolve the outer most layer of the ldd , which consists of the outer molecular layer , the leptomeninges and the associated abnormal vessels . ( 3 ) and kulkantrakorn et al . ( 7 ) reported good correlation of this mri pattern with the histological specimen . beside the characteristic striated pattern on the t2-weighted images , these abnormal veins surrounding the thickened folia on the swi images seem to be another unique feature of ldd . beside the preoperative identification of ldd , the higher resolution of 7 t swi their anatomical relation is of clinical importance for planning surgical procedures because lesions affecting the cerebellar nuclei are associated with more severe symptoms than are cortical lesions . h - mrs demonstrated a prominent lactate peak , suggesting increased glycolysis and the high metabolism of this ldd lesion ( 4 , 9 ) . decreased levels of cho , cr , naa and mi and the chr / cr are normally found on the side affected by the ldd ( 9 ) . the slightly increased cho levels in our patient suggested increased demyelination and membrane turnover , whereas the decreased cho levels in the lesion suggested a non - neoplastic etiology of this lesion ( 4 , 9 ) . making the preoperative diagnosis of ldd via mri obviates the need for biopsy and this allows surgeons to plan an appropriate therapy , which consists of decompression of the posterior fossa by total surgical resection . tumor resection has not yet been performed in our patient due to the mild clinical symptoms . in conclusion , as seen on mri , a non - enhancing , ' tigers striped ' cerebellar lesion with unilateral hemispheric expansion and preservation of the gyral pattern should be considered specific for ldd and these findings often allow making the preoperative diagnosis . 7 t mri more precisely reveals the known morphology and microstructure of this tumor entity than can 1.5 t mri . especially , 7 t swi enables the identification of the outermost layer of ldd due to its inherent venous vasculature , and 7 t swi better displays the iron containing dentate nuclei . hence , 7 t mri is expected to become a valuable tool for studying the cerebral microvascularity and tumor angiogenesis not only for ldd , but also for other resectable brain tumors .