Annals of Indian Academy of Neurology
  Users Online: 1197 Home | About the Journal | InstructionsCurrent Issue | Back IssuesLogin      Print this page Email this page  Small font size Default font size Increase font size


 
IMAGES IN NEUROLOGY
Year : 2010  |  Volume : 13  |  Issue : 3  |  Page : 223-224
 

Lobar pattern of microbleeds on susceptibility-weighted magnetic resonance imaging


1 Calgary Stroke Program, Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
2 Calgary Stroke Program, Department of Clinical Neurosciences; Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada

Date of Submission31-Dec-2009
Date of Decision01-Apr-2010
Date of Acceptance14-Aug-2010
Date of Web Publication5-Oct-2010

Correspondence Address:
Eric E Smith
Department of Clinical Neurosciences, Room C1212, Foothills Medical Center, 1403-29th Street NW, Calgary, AB T2N 2T9, Canada

Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-2327.70885

Rights and Permissions

 


Keywords: Amyloid angiopathy, microbleeds, susceptibility-weighted imaging


How to cite this article:
Shobha N, Smith EE. Lobar pattern of microbleeds on susceptibility-weighted magnetic resonance imaging. Ann Indian Acad Neurol 2010;13:223-4

How to cite this URL:
Shobha N, Smith EE. Lobar pattern of microbleeds on susceptibility-weighted magnetic resonance imaging. Ann Indian Acad Neurol [serial online] 2010 [cited 2019 Oct 14];13:223-4. Available from: http://www.annalsofian.org/text.asp?2010/13/3/223/70885


A 75 year old lady presented with progressive speech difficulty of one month duration with no history of motor weakness, ataxia, sensory, or visual symptoms. She did not have history of fever, headache, or seizures. She had no history of hypertension, diabetes mellitus, coronary artery disease, atrial fibrillation, or smoking. Details of her cognitive status were not known as she lived alone. Examination revealed a conscious and alert woman with fluent aphasia and no visual or sensorimotor deficits or meningeal signs. A detailed mental status examination was not possible due to aphasia. Her vitals were stable with a blood pressure of 108/70 mm Hg. Systemic examination was unremarkable. An MRI (Magnetic Resonance Imaging) of her brain showed this picture [Figure 1]a-d. She was diagnosed to have cerebral amyloid angiopathy (CAA).
Figure 1: (a) Multiple hypointense lesions seen on MR - SWI susceptibility-weighted imaging involving the lobes of the cerebrum and cerebellum suggestive of microbleeds. (b and c) (T2WI) and (T1WI), respectively, demonstrate no hyperintense lesions. (d) The absence of microbleeds in the basal ganglia and deep white matter and an acute lobar macrobleed in the left temporoparietal region on MR - SWI

Click here to view


CAA is caused by progressive accumulation of congophilic amyloid in the walls of small- and medium-sized cerebral arteries with subsequent degenerative vascular changes. One of the most recognized complications of CAA is spontaneous, intracerebral hemorrhage, involving the cortex, subcortical white matter ("lobar hemorrhage"), which is recurrent. It can also present with dementia, stereotyped focal neurological symptoms or the patients can be asymptomatic.

The MRI of our patient showed numerous microbleeds involving the lobes of the cerebrum and cerebellum, sparing the basal ganglia and the deep white matter and an acute lobar macrobleed in the left temporoparietal region.

Cerebral microbleeds (CMBs) are small (<5.7 mm) MRI signal voids indicative of perivascular collection of hemosiderin deposits that are foci of past hemorrhages. There are several recommended criteria for CMBs. [1] Microbleeds are round or ovoid lesions hypointense on T2* gradient recalled echo (GRE) and susceptibility weighted imaging (SWI) and devoid of signal hyperintensity on T1 and T2 weighted imaging. At least half of the lesion is surrounded by brain parenchyma. An acute macrobleed on SWI sequence appears hyperintense in the center and hypointense in the periphery as deoxygenation occurs first at the periphery of the hematoma and progresses toward the center. This pattern appears because intrahematoma oxygen tension is lowest in the periphery, where red cells are adjacent to oxygen-starved tissue, and highest in the center, because red cells do not use oxygen for their metabolism. [2] Susceptibility effect is present when iron atoms are compartmentalized within the red cell membrane, causing magnetic field inhomogeneity, with resulting loss of phase coherence and selective shortening of the T2 relaxation time. After degradation of red cell membranes, the iron becomes more homogenously distributed, and this effect is nullified.[2]

SWI is a recently developed MR sequence where the image is generated from differences in susceptibility effect between tissues, and is just entering clinical practice. SWI is more sensitive than the commonly used T2* gradient recalled echo (GRE) for detection of microbleeds. [3] Based on the Boston criteria, [4] our patient was classified as probable CAA.

In population-based studies, CAA prevalence was consistently higher in the demented as compared to the non-demented subjects. [5] This supports a significant role for CAA in the pathogenesis of dementia. As the life expectancy of the Indian population increases, the incidence of CAA and dementia are expected to surge making it necessary for physicians to familiarize themselves with the clinical and imaging picture of CAA.

 
   References Top

1.Greenberg SM, Vernooij MW, Cordonnier C, Viswanathan A, Al-Shahi Salman R, Warach S, et al. Cerebral microbleeds: a guide to detection and interpretation. Lancet Neurol 2009;8:165-74.  Back to cited text no. 1  [PUBMED]  [FULLTEXT]  
2.Smith EE, Rosand J, Greenberg SM. Hemorrhagic stroke. Neuroimaging Clin N Am 2005;15:259-72.  Back to cited text no. 2  [PUBMED]  [FULLTEXT]  
3.Mittal S, Wu Z, Neelavalli J, Haacke EM. Susceptibility-weighted imaging: Technical aspects and clinical applications, part 2. AJNR Am J Neuroradiol 2009;30:232-52.  Back to cited text no. 3  [PUBMED]  [FULLTEXT]  
4.Knudsen KA, Rosand J, Karluk D,Greenberg SM. Clinical diagnosis of cerebral amyloid angiopathy: validation of the Boston criteria. Neurology 2001;56:537-9  Back to cited text no. 4      
5.Keage HA, Carare RO, Friedland RP, Ince PG, Love S, Nicoll JA, et al. Population studies of sporadic cerebral amyloid angiopathy and dementia: a systematic review. BMC Neurol 2009;9:3.  Back to cited text no. 5  [PUBMED]  [FULLTEXT]  


    Figures

  [Figure 1]


This article has been cited by
1 result 1 Document Application of 3. 0T susceptibility weighted imaging in the diagnosis of hemorrhagic foci and the outcome prediction of rabbits with brain blast injury
Wu, P., Lü, G.-S., Han, F., Xu, K.-N.
Acta Academiae Medicinae Sinicae. 2013;
[Pubmed]
2 Cerebral lobar microhemorrhages detection by high magnetic field susceptibility weighted image: A potential diagnostic neuroimage technique of Alzheimerćs disease
Ku, H.-L., Chi, N.-F.
Medical Hypotheses. 2011; 76(6): 840-842
[Pubmed]
3 Cerebral lobar microhemorrhages detection by high magnetic field susceptibility weighted image: A potential diagnostic neuroimage technique of Alzheimer’s disease
Hsiao-Lun Ku,Nai-Fang Chi
Medical Hypotheses. 2011; 76(6): 840
[Pubmed] | [DOI]



 

Top
Print this article  Email this article
Previous article Next article

    

 
   Search
 
   Next article
   Previous article 
   Table of Contents
  
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Article in PDF (945 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  


    References
    Article Figures

 Article Access Statistics
    Viewed2199    
    Printed140    
    Emailed0    
    PDF Downloaded53    
    Comments [Add]    
    Cited by others 3    

Recommend this journal