Role of magnetic resonance spectroscopy and diffusion-weighted imaging in characterizing intra axial brain tumours

Background: Magnetic Resonance imaging (MRI) is essential for assessing intracranial malignancies, but conventional MRI has limitations in tumour grading and infiltration information. Advanced Magnetic Resonance (MR) sequences, such as diffusion-weighted (DW) and Magnetic Resonance spectroscopy (MRS), can differentiate between low-grade and high-grade tumours, aiding treatment decisions. This study aims to evaluate the efficacy of diffusion-weighted imaging and magnetic resonance spectroscopy in grading intra-axial brain tumours and correlating the results with histopathology. Methods: This retrospective study involved 45 patients over one year at Apollo Hospital. MR imaging included conventional sequences, DW, and MRS with localizers in all three planes. DWI and ADC maps were obtained using specific b-values. Standard mean Apparent Diffusion Coefficient (ADC) values were automatically calculated for intra-lesional and peri-lesional regions. Results: Intralesional ADC values did not significantly differ between high-grade primary tumours (0.4-1 x 10-3 mm2/s, mean 0.7) and metastases (0.4-0.8 x 10-3 mm2/s, mean 0.7). However, peri-lesional ADC values were lower in primary tumours (0.3-1.3 x 10-3 mm2/s, mean 0.8), indicating peri-lesional infiltration, while higher in metastases (1.2-1.6 x 10-3 mm2/s, mean 1.4) due to the absence of peri-lesional infiltration. Additionally, intralesional ADC values showed a significant difference between low-grade tumours (1-2 x 10-3 mm2/s) and high-grade tumours (0.4-1 x 10-3 mm2/s), allowing for their distinction. There were significantly increased Cho/NAA and Cho/Cr ratios in high-grade tumours compared to low-grade tumours. Conclusions: MR spectroscopy and DWI with computation of ADC values can enhance the diagnostic effectiveness of MR imaging in detecting and grading malignant brain tumours.

Distribution of different cerebral lesions showing restriction on diffusion weighted imaging cases

Background: Diffusion Weighted Images (DWI) is conventionally used to identify acute ischemic lesions. It has now become a routine technique in the magnetic resonance protocols for the evaluation of stroke patients. The objective of the present study was to find the distribution of different cerebral lesions showing restriction on DWI and influence of ADC on them.Methods: This was single blinded prospective study. Evaluating the magnetic resonance imaging was blinded for the clinical data of the patient. This study was done at M.R.I. unit of Department of Radio Diagnosis, C.S.M. Medical University, Lucknow, during a period of one year from August 2008 to July 2009.Total 93 subjects with restricted diffusion with age range of (6 to 95 years) were found. Data were analyzed using statistical software package, STATA 9.2 and the difference was considered to be significant if ‘p’ value was found to be <0.05.Results: Ninety-three cases of diffusion restriction were seen of which 55 of infarcts (37 male and 18 female) with age range of 6 to 95 years. 10 cystic lesions which were showing restriction on DWI with low ADC value were found. Total 12 cases of encephalitis were found showing restriction on DWI. Most of the cases of encephalitis were found to have ADC value between 400 to 800 x 10-6 mm2/s that 75% of total encephalitis cases. Fluid-attenuated inversion recovery was superior to T2 sequencing in showing cortical lesions.Conclusions: MRI with DWI and ADC values are helpful in the earlier diagnosis of the encephalitis, infarcts and helpful in better differentiation of infarcts, abscesses and encephalitis in comparison to MRI without DWI and ADC value.

The brain MR features and differential diagnosis of sporadic Creutzfeldt-Jakob Disease / 中国神经精神疾病杂志

Objective To summarize brain magnetic resonance imaging (MRI) features and differential diagnosis of sporadic Creutzfeldt-Jakob disease. Methods The clinic data of 8 probable Creutzfeldt-Jakob disease cases in our hospital were analyzed retrospectively from January 2009 to June 2014. We mainly analysed the characteristics of brain MR and the causes of misdiagnosis. We had followed up the family members of these patients on the progress and progno?sis of disease. We also analyzed the differential diagnosis of sCJD. Results All the patients presented with rapid progres?sive dementia and mental abnormal behavior as the main clinical manifestations. All the patients had abnormal routine EEG and five of them had a periodical sharp wave complexes. The brain MRI of the 8 patients showed high signal intensi?ties in cerebral cortex (and/or basal ganglia) on diffusion weighted images (DWI) and 5 of them had caudate nucleus and (or) putamen involvement. The lesions were first appeared in DWI imaging as“ribbon-like”high signal, followed by Flair as high signal intensities. lesions were low signal intensities on T1WI and high signal intensities on T2WI. Five pa?tients were misdiagnosed. 2 cases were misdiagnosed as having cerebral infarction,1 case was misdiagnosed as having vi?ral encephalitis, 1 case was misdiagnosed as having Alzheimer's disease, 1 case was misdiagnosed as having vertigo and 1 case was misdiagnosed as having corticobasal degeneration. Conclusions The brain MRI of the sCJD patients showed a certain characteristic. DWI is the most sensitive tool in the detection of lesions which is useful in the early diagnosis of this disease. We should distinguish sCJD form ischemic cerebrovascular disease, encephalitis, and other progressive de?mentia identification.

Progressive multifocal leukoencephalopathy restricted to the posterior fossa in a patient with systemic lupus erythematosus

Progressive multifocal leukoencephalopathy is a neurological infectious disease caused by the John Cunningham polyomavirus (JCV), an opportunistic agent with worldwide distribution. This disease is frequently seen in immunosuppresed patients and rarely associated with systemic lupus erythematosus. In the central nervous system PML demyelinating lesions occur in the supratentorial compartment. The authors describe a rare case of PML secondary to SLE treatment with atypical presentation restricted to the posterior fossa.

Hippocampal sclerosis and status epilepticus: cause or consequence? A MRI study

BACKGROUND: Transient imaging abnormalities, including changes on diffusion-weighted imaging (DWI), may be seen in status epilepticus. These abnormalities can be followed by hippocampal sclerosis. CASE REPORT: We report a 15-year-old lady with focal non convulsive status epilepticus (NCSE) and focal slowing on EEG. DWI exhibited abnormal hyperintense signals in bilateral temporal and insular cortices. After 3 weeks, MRI performed a localizated hippocampal atrophy. CONCLUSION: The MRI findings indicated vasogenic and cytotoxic edema during seizure activity and subsequent loss of brain parenchyma.

INTRODUÇÃO: Anormalidades transitórias de imagem, incluindo imagens de ressonância magnética por difusão (DWI), podem ser vistas no status epilepticus. Essas anormalidades podem ser seguidas de esclerose hipocampal. RELATO DE CASO: Nós relatamos uma jovem de 15 anos com status focal não convulsivo e lentificação focal no EEG. DWI mostrava sinal hiperintenso em regiões temporais bilaterais e córtex insular. Após 3 semanas, RM de encéfalo mostrava atrofia localizada do hipocampo. CONCLUSÃO: Os achados de RM indicam edema vasogênico e citotóxico durante as crises epilépticas com subseqüente atrofia de parênquima cerebral.