title: MRI findings of primary CNS lymphoma in 26 immunocompetent patients.
abstract: OBJECTIVE
  To record the MR imaging features of primary central nervous system lymphoma (PCNSL) and compare these features in monofocal and multifocal disease.
  
  
  METHODS
  Twenty-one cases of monofocal disease were compared to five cases of multifocal disease. All patients were examined by non-enhanced and contrast-enhanced MRI. Tumor location, tumor size, signal intensity, enhancement characteristics, age distribution, peritumoral edema, cystic changes, and the presence of calcifications were assessed. The MRI features were compared between the monofocal and multifocal disease cases.
  
  
  RESULTS
  The 26 cases, including both the monofocal and multifocal cases, exhibited 37 lesions. Contrast-enhanced images showed variable enhancement patterns: homogeneous enhancement (33 lesions), ring-like enhancement (2), and 'open-ring-like' enhancement (2). The 'notch sign' was noted in four of 33 homogeneously enhancing lesions. One case of hemorrhage and three cases of cystic formation were observed. Intra-tumoral calcification was not found. The frontal lobe, the corpus callosum and the basal ganglia were commonly affected in both the monofocal and multifocal groups. Tumor size differed significantly between the two groups (t = 3.129, p < 0.01) and mildly or moderately enhanced lesions were more frequently found in the monofocal group (p < 0.05). There was no statistical difference between perifocal edema (p > 0.05) and the signal characteristics (p > 0.05) between the two groups.
  
  
  CONCLUSIONS
  Our data show that PCNSL has a variable enhancement pattern on MR images. We first reported two lesions with an 'open-ring' enhancement as well as four cases with a 'notch sign'. Monofocal PCNSL cases typically have larger sized tumors with mild or moderate enhancement.
authors.affiliation: Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, P.R.China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.forename: Liang-Bo
authors.initials: LB
authors.lastname: Hu
authors.forename: Tobias D
authors.initials: TD
authors.lastname: Henning
authors.forename: Elisabeth M
authors.initials: EM
authors.lastname: Ravarani
authors.forename: Li-Guang
authors.initials: LG
authors.lastname: Zou
authors.forename: Xiao-Yuan
authors.initials: XY
authors.lastname: Feng
authors.forename: Wen-Xian
authors.initials: WX
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Wen
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007121:Immunocompetence; D008223:Lymphoma / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
references.citation: AJNR Am J Neuroradiol. 1997 Mar;18(3):563-72
references.pmid: 9090424
references.citation: Clin Neurol Neurosurg. 2004 Dec;107(1):55-63
references.pmid: 15567554
references.citation: Neuroradiology. 1999 Nov;41(11):820-5
references.pmid: 10602854
references.citation: Neuroradiology. 2000 Oct;42(10):738-41
references.pmid: 11110076
references.citation: AJR Am J Roentgenol. 1986 Feb;146(2):271-6
references.pmid: 3484575
references.citation: J Neurooncol. 2005 Apr;72(2):169-77
references.pmid: 15925998
references.citation: J Neurooncol. 1999 Jul;43(3):199-201
references.pmid: 10563423
references.citation: Clin Radiol. 1982 May 3;33(3):331-6
references.pmid: 7075140
references.citation: AJR Am J Roentgenol. 2005 May;184(5):1679-85
references.pmid: 15855138
references.citation: Neuroradiology. 1992;34(1):36-42
references.pmid: 1553036
references.citation: J Neurooncol. 1999 Jul;43(3):219-26
references.pmid: 10563426
references.citation: J Neurosurg. 1988 Jun;68(6):835-53
references.pmid: 3286832
references.citation: J Neurosurg. 1995 Jan;82(1):77-82
references.pmid: 7815138
references.citation: Brain Tumor Pathol. 1999;16(1):29-35
references.pmid: 10532421
references.citation: AJR Am J Roentgenol. 1995 Sep;165(3):626
references.pmid: 7645482
references.citation: Clin Radiol. 1998 Jun;53(6):428-34
references.pmid: 9651058
references.citation: Neuroradiology. 1996 Jan;38(1):34-7
references.pmid: 8773272
references.citation: Neurology. 2000 Apr 11;54(7):1427-33
references.pmid: 10751251
references.citation: Eur Radiol. 2002 Feb;12(2):329-40
references.pmid: 11870430
references.citation: Radiology. 1995 Jan;194(1):271-6
references.pmid: 7997566
references.citation: Neurochirurgie. 1997;43(6):385-7
references.pmid: 9706618
references.citation: Clin Neurol Neurosurg. 2003 Apr;105(2):78-86
references.pmid: 12691795
references.citation: Ann Oncol. 1997 Mar;8(3):227-34
references.pmid: 9137790
references.citation: Ann Neurol. 1993 Mar;33(3):308-11
references.pmid: 8498814
references.citation: Neuroradiology. 1984;26(6):485-92
references.pmid: 6504318
references.citation: Clin Radiol. 1994 Oct;49(10):696-702
references.pmid: 7955832
references.citation: Cancer. 1994 Aug 15;74(4):1383-97
references.pmid: 8055462
references.citation: Radiology. 1988 Apr;167(1):211-5
references.pmid: 3279454
references.citation: J Neurosurg. 1986 Nov;65(5):592-9
references.pmid: 3772444
references.citation: AJR Am J Roentgenol. 2001 May;176(5):1319-26
references.pmid: 11312202
references.citation: Radiographics. 1997 Nov-Dec;17(6):1497-526
references.pmid: 9397461