Utility of Proton MR Spectroscopy for Differentiating Typical and Atypical Primary Central Nervous System Lymphomas from Tumefactive Demyelinating Lesions

Abstract

BACKGROUND AND PURPOSE: It may be challenging to differentiate primary CNS lymphomas, especially primary CNS lymphomas with atypical MR features, from tumefactive demyelinating lesions by the use of conventional MR. This study aimed to investigate the usefulness of 1 H-MR spectroscopy for making this discrimination.

1H-MRS is useful to reinforce the suspicion of primary central nervous system lymphoma prior to surgery

“…There are few reports in the literature regarding the characteristic 1 H-MRS pattern of PCNSL. An increase in lipid resonances has been reported as the most specific finding for PCNSL on 1 H-MRS [12,[14][15][16]. (Table 3) Harting et al [17] found significantly higher lipid peaks in solid PCNSL than in solid low-and high-grade astrocytomas.…”

Chinese Guidelines for the Diagnosis and Management of Tumefactive Demyelinating Lesions of Central Nervous System

“…[3940] TDLs on MRS show as follows:[4142] elevation of choline (Cho) peak, reduction of N-acetylarginine (NAA) peak, and most of the lesions have some elevation of lactate peak [Figure 6a]. …”

“…[3943] Hyperperfusion is usually observed in glioma [Figure 7a and 7b], which does not occur in TDLs [Figure 7c and 7d]. [24]…”

“…For high grade of astrocytoma with necrosis, bleeds, and cyst, low or mixed signals can be observed within the high signal on DWI [Figure 4d],[8575859] while the signals of TDLs on DWI become weaker gradually with the progression of the disorder;[5] (4) contrast-enhanced MRI: astrocytoma shows diverse patterns of enhancement and the patterns are mainly nodular, massive, or foggy-like, based on different pathological types or WHO grades, and glioblastoma is characterized by becoming more easily become cystic, bleeding, and necrotic on neuroimaging;[832] (5) function MRI (fMRI): fMRI including MRS and ASL can be used for the differential diagnosis. Glioblastoma may have high lip peak, and astrocytoma may have Cho/NAA ≥2;[83960] thus, the significantly elevated levels of lip and Cho/NAA are clinically meaningful [Figure 6b]. Some foci of glioma show hyperperfusion on PWI or ASL, which is more obvious for high-grade glioma [Figure 7a and 7b],[3943] while the lesions of TDLs frequently show isoperfusion or mildly hypoperfusion; (6) specific neuroimaging signs: (a) “comb” sign on contrast-enhanced MRI [Figures 1b and 2d] is relatively specific for TDLs;[225] (b) “wrapped basilar artery” sign in pons highly indicated astrocytoma [Figure 8d].…”

“…Glioblastoma may have high lip peak, and astrocytoma may have Cho/NAA ≥2;[83960] thus, the significantly elevated levels of lip and Cho/NAA are clinically meaningful [Figure 6b]. Some foci of glioma show hyperperfusion on PWI or ASL, which is more obvious for high-grade glioma [Figure 7a and 7b],[3943] while the lesions of TDLs frequently show isoperfusion or mildly hypoperfusion; (6) specific neuroimaging signs: (a) “comb” sign on contrast-enhanced MRI [Figures 1b and 2d] is relatively specific for TDLs;[225] (b) “wrapped basilar artery” sign in pons highly indicated astrocytoma [Figure 8d]. [8]…”