European Journal of Cardiovascular Medicine

In neuroimaging, Magnetic Resonance Imaging (MRI) is a cornerstone technique that allows clinicians to see fine aspects of brain architecture and pathology with unparalleled clarity. Ring-enhancing lesions (RELs) in the brain pose a particularly difficult diagnostic scenario among the many abnormalities found. ^[1] Ring-enhancing lesions in brain imaging are widespread in the Indian subcontinent. The two most common causes of inflammatory granulomas seen in pediatric clinical practice are neurocysticercosis (NCC) and tuberculomas.^[2] The size, form, and wall thickness of ring-enhancing lesions, the amount of surrounding oedema, and, most significantly, the patient's clinical history and age should all be considered when distinguishing the illness.^[3]

MRS scans can help diagnose a wide range of diseases, including malignancies, cerebral ischemia, and trauma, when performed in conjunction with an MRI.^[4] It examines the resonant frequencies of several metabolites in the brain, such as choline (Cho), creatinine (Cr), and NAA, and displays the results in the form of a line graph with amplitudes. These readings alone are not diagnostic; nevertheless, they must be analyzed in conjunction with an MRI.^[5]

MRS can be utilized for diagnostic and prognostic purposes, particularly in paediatric age ranges. Thus, MRS is considered the future of neuroimaging. ^[6]

Magnetic resonance spectroscopy (MRS) analyzes the presence and/or ratio of tissue metabolites such as NAA, creatine, choline, and lactate, among others, to determine the potential degree and character of alterations on a typical MRI scan.[5] The widespread use of faster MRS applications with a higher signal-to-noise ratio (SNR) and spatial resolution enables us to detect functional metabolic changes, providing more data for understanding the exact nature of the tumor as well as the morphological and physiological changes occurring in the surrounding brain parenchyma.^[7]

Based on the metabolite level, MRS could distinguish tuberculoma from other lesions with clarity. Based on CT and MRI scans, lesions from neurocysticercosis and tuberculoma were similar in many ways, but they could be distinguished by their location, number, enhancement pattern, and constitutional symptoms. Metabolite levels allowed MRS to distinguish between these lesions. The current study set out to evaluate the utility of magnetic resonance spectroscopy in the assessment of brain lesions that enhance rings.

Objectives:

1. To differentiate neoplastic from non-neoplastic brain lesions using conventional and advanced MR imaging techniques.
2. To study the characteristic imaging findings of various ring enhancing lesions on MRI.
3. To establish differential diagnosis of various ring enhancing lesions on conventional MRI.
4. To study the role of MR spectroscopy in the evaluation of various ring enhancing lesions in the brain with a single voxel proton MR spectroscopy.

Study Design: A prospective hospital-based observational study.

Study area: Department of Radio Diagnosis, Subbaiah Institute of medical sciences, Shivamogga, Karnataka.

Study Period: 1 year.

Study population: All patients referred to the Department of Radio diagnosis with clinically suspected cerebral ring-enhancing lesions.

Sample size: The study consisted of 60 subjects.

Sampling method: Simple random technique.

Inclusion criteria:

• All cerebral ring enhancing lesions detected on contrast MR studies are taken up retrospectively.
• All patients with incidentally diagnosed ring enhancing lesion by CT. Cases of all age groups irrespective of sex.

Exclusion Criteria:

• Patient having history of claustrophobia.
• Patient having history of metallic implants insertion, cardiac pacemakers and metallic foreign body in situ.

Ethical consideration: Institutional Ethical committee permission was taken prior to the commencement of the study.

Study tools and Data collection procedure:

EQUIPMENT USED: The evaluation of cases in the department of radio diagnosis will be done using Siemens Avanto 1.5 Tesla MRI

SEQUENCES:  Conventional spin echo sequences, axial T1, T2 and FLAIR: Coronal T2; Sagittal T1; Post-contrast axial, coronal and sagittal; DWI; T2 GRE Single voxel spectroscopy; multi-voxel spectroscopy will be performed at TE of 135ms and 35ms, TR at 2000 ms. In single voxel studies, the voxel is placed on the lesion so that it covers the maximum area of the solid tumoral area. Spectroscopy was avoided in small lesions close to the bone. Special sequences such as CISS 3D, and VENBOLD were used as and when required.

Statistical analysis:Data wasanalysed using SPSS 21.0 software. Descriptive parameters were represented as mean with SD or median. Continuous variables were compared using unpaired t-test/Mann Whitney u test. Chi-square or t-test will be used to determine significant outcome differences. Categorical data was represented as frequency with percentage. For all tests, a p-value of <0.05 was considered statistically significant.

A total 60 patients presented with various ring-enhancing lesions.

Table 1: Incidence of Various Ring Enhancing Lesions

Table 2: Age-Wise Distribution of Various Ring-Enhancing Lesions

Table 3: Male Female Incidence of Ring Enhancing Lesions

Table 4: Clinical Symptoms Presented by a Patient with Various Ring-Enhancing Lesions

Table 5: DWI in Ring Enhancing Lesions

Table 6: List of Dominant Metabolite Peaks Noted in Various ring enhancing lesions

Table 7: Number of Ring Enhancing Lesions in a Patient

Table 8: Size of Lesion of Various Ring Enhancing Lesions

Case1: TUBERCULOMA

.

Fig.1: On Axial images: Hyperintense lesion with hypointense rim and perilesional edema is noted on left high parital region on T2, postcontrast image showing ring enhancement, showingnorestrictionondiffusion, lipidpeakonMRSSuggestiveofTUBERCULOMA.

Case2: METASTASIS

Fig.4: OnAxialImages: MultipleHyperintenseLesionsNotedinbilateralthalamiOn T2, On Post Contrast, lesions showing ring enhancement, On MRS CholinepeakisnotedsuggestiveofMetastasis.

Case3:NCC