Evaluation of magnetic resonance imaging characteristics of malignant gliomas

Journal OF MILITARY PHARMACO MEDICINE N02 2022 151 EVALUATION OF MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF MALIGNANT GLIOMAS Pham Van Huu1, Bui Quang Tuyen2 Dong Van He3, Nguyen Thanh Bac2 SUMMARY[.]

EVALUATION OF MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF MALIGNANT GLIOMAS

Pham Van Huu 1 , Bui Quang Tuyen 2 Dong Van He 3 , Nguyen Thanh Bac 2

SUMMARY

Objectives: The describe MRI characters of malignant gliomas Subjects and methods: A

descriptive study with no control group on 77 patients at Viet Duc University hospital from July

2015 to June 2017 Results: The medium size of tumor: 5.45, the smallest was 2.4 cm, the

largest was 12cm, hyperintense on T2W was 88.3%, hypointense on T1W was high at 72.7% Unclear margin after injecting contrast made up to 49.4% heterogeneous intense was 85.7%, including calcified, necrotic, cystolic and haemorrhage tumor was 6.5%, 58.4%, 22.1%, and 13%, respectively 5 - 10 mm midline shift was 31.2% Most patients had grade II edema with a

heterogeneity, and edema are the most crucial features in diagnosing malignant gliomas

* Keywords: Malignant gliomas; MRI

INTRODUCTION

A glioma is a type of tumor that starts

in the glial cells of the brain According to

previous studies, gliomas were mostly

malignant and comprised 80 percent of all

malignant central nervous system tumors

[1] In recent years, with advances in

technology, many modern diagnostic

imaging equipment enable the physician

to easily diagnose and treat malignant

gliomas Of all these facilities, MRI especially

improved MRI can evaluate the extent,

margin, and invasion of tumor into the

adjacent brain tissue, which leads to radical

surgery and enhancing treatment results

SUBJECTS AND METHODS

1 Subjects

77 patients were under diagnosis of malignant gliomas and underwent micro surgery at Viet Duc University Hospital from July 2015 to June 2017 All of these had the pathologic results of WHO grade III and grade IV

2 Methods

* Study design: A descriptive study

with no control group

All patients experienced MRI-SIGNA creator 1.5 Tesla, by GE Healthcare in America, with and without contrast in T1-weighted and T2-weighted

1

Thai Binh General Hospital

2

Military Hospital 103

3

Viet Duc University Hospital

Corresponding author: Pham Van Huu (pham.huu30@yahoo.com)

Date received: 17/01/2022

Date accepted: 25/01/2022

* Evaluation criteria:

- Location: Define the left and right

hemispheres Location of lobes was

defined by Orringer D if the tumor has

a strong correlation with lobe, the

classification will be given by the lobe in

which the tumor mainly is Classification

according to the frontal lobe, parietal lobe,

temporal lobe, occipital lobe, internal

capsule and falx cerebri

- Size: The largest diameter of tumor

calculated on contrast T1-weighted

- Edema: On T2-weighted of MRI

+ Grade I: 2 cm from the tumor margin

to the outer edge of edema

+ Grade II: Over 2 cm from the tumor

margin

+ Grade III: Edema over half of the

brain hemisphere

- Extent of midline shift:

+ Grade I: Under 5 cm

+ Grade II: Between 5 and 10 cm + Grade III: Over 10 cm

- Intense on MRI:

+ T1W: Hyper, hypo, homogenous, heterogeneous intense

+ Contrast T1W: Enhancement of tumor capsule or tumor core, non-enhancement + T2W: Hyper, hypo, homogenous, heterogeneous intense

+ Margin: Clear or not

+ Intense: Heterogeneous or homogenous Heterogeneous (cystolic, calcified, necrosis and haemorrhage)

- Karnofski (KPS): I: 80 - 100; II: 60 - 70; III: 40 - 50; IV: 10 - 30

- Pathological classification by WHO

2016

- Data was analysed by SPSS 22.0

RESULT

- Size: smallest 2.4 cm and largest 12 cm

- Medium tumor size 5.45 cm, standard deviation 1.88

Table 1: Tumor size and Karnofski score

Tumor size KPS

< 3

n (%)

3 - 5

n (%)

> 5

- With the group of tumors over 5 cm: KPS III made up to 79% and KPS IV was 9.3%

- In the group of tumors under 3 cm: KPS III was 66.6%, KPS IV was 16.7%

- There was one patient having over-5 cm tumor with KPS I

The larger the tumor was, the lower KPS was (p < 0.05)

Table 2: Tumor features on non-contrast MRI

Intense

- Patients mainly had hyperintense on T2W, accounting for 88.3%

- Hypointense on T1W was major with 72.7%

Table 3: Tumor features on contrast MRI

Margin

Homogenous

Heterogenous

- Unclear margin on contrast MRI amounted to 49.4%

- Heterogenous tumor was 85.7% including calcified 6.5%, necrosis 58.4%, cystolic 22.1% and haemorrhage 13%

Table 4: Pathological classification and tumor features on MRI

Pathology

Cystolic and necrosis tumors are the majority in grade IV gliomas with the percentage of 58.8% and 57.8%, respectively

With grade III malignant gliomas, calcified and haemorrhage tumors are more common with the rate of 80% and 60%

This difference has statistical significance with p < 0.05

Table 5: Pathological classification and enhancement on MRI

Enhancement on MRI Enhancement

n = 74 (%) Malignant extent

Non-enhancement

n = 3 (%)

- There were 74 out of 77 patients having enhancement MRI after injection

- Grade IV malignant gliomas mainly enhanced contrast in the cortex with 82.9%, while in grade III, this rate was 39.4%

Table 6: Pathological classification and Brain edema

Pathology Edema extent

Total (%)

- 44.1% of all patients had grade II edema

- 3.9% of patients had no edema

- Severe edema appeared when the tumor had great extent of malignancy with p = 0.003

DISCUSSION

The smallest tumor was 2.4 cm, and

the largest was 12 cm Medium tumor

size was 5.45 cm In our study, tumor was

mainly over 5 cm, amounting to 55.8%

Tumor over 5 cm in the temporal lobe was

at the highest rate of 37.2% This can be

explained by a tumor in this area having

the highest rate of grade IV and rapid

growth, representing when tumors turn

into big size Our study has shown that

tumor size is related to neurofunction at the time of admission The bigger tumor was, the lower KPS was, with p < 0.05 our study is similar to the results of Lê

Văn Phước when investigating gliomas

on MRI, with an average tumor size of 5.28 cm In that research, gliomas tumor size was 5.48 ± 1.88 cm, and the author reported that the tumor size rose after the extent of malignancy [2] According to the research of Chaichana, K.L (2014) about

surgery on glioblastoma, the medium

tumor size was 27 cm3, smallest 13.8 and

largest 54.4 [3] The tumor size in this

study is smaller than in ours This can

result from the consciousness and living

conditions in our country, patients only

represented to the hospital when the

tumor was large Besides, gliomas had no

tendency of invading the brain tissue, only

localizing partly in the brain, isolating in

these areas, presenting with minimal

symptoms, sporadic and sometimes no

clinical symptoms Some kinds of gliomas

had no symptoms even the tumor is huge,

accidentlly detected by MRI when

investigating other diseases in the head

and neck

In our study, hypointense was common

on T1W with 71.7%, while the mixed

signal was 16.9% Authors believed

that gliomas at low grade are almost

hypointense on T1W However, gliomas

at high grade had mixed signals because

of calcification, necrosis and haemorrhage

Hypointense of tumor is heterogeneous

due to necrosis and old haemorrhage

resulting in cysts, which is most evident

in gliomas

By contrast to hypointense on T1W,

T2W images serve to supply the extent of

perfusion and edema There were 88.3%

heterogeneous hypointense images resulting

from necrotic and cystolic tumor in high

grade gliomas, which is similar to the

research of other authors

Studying on T1W and T2W in brain

tumors, Just M (1988) [4] learnt that

gliomas often had isointense and

hyperintense on T1W and T2W compared

with the brain tissue However, there are

light hyperintense and heterogeneous enhancement after injecting contrast

Necrosis and cysts even having hyperintense on T2W, hypointense on T1W, and FLAIR, higher intensity than CSF

In our research, there were 58.4% of necrosis and 22.1% of cysts These forms are more common in grade IV gliomas with p = 0.042 Authors believed that cysts and necrosis rarely appear in low grade gliomas, but are the characters of high grade gliomas The rate of necrosis

in the study of Nguyen Duy Hung (2018) [5] was 77.5%, of Le Van Phuoc (2012) [2] was 51.4% in high grade gliomas And Dean confirmed that internal necrosis of tumors had value in diagnosing high grade gliomas [6]

The contrast enhancement on MRI serves as the extent of malignancy of tumors In our research, 96.1% of the tumor had contrast enhancement after injecting the contrast agent Heterogenous enhancement generally appeared in grade III gliomas and edge enhancement

in grade IV gliomas (34/41 patients) Nguyen Duy Hung (2018) [5] reported that divergent from low grade gliomas, high grade tumors often enhanced strongly after injecting the contrast agent Grade III tumor had heterogeneous enhancement, and grade IV got edge enhancement

Le Van Phuoc (2012) [2], there were 98.3% of low grade tumors having non-enhancement and 89.8% high grade tumors having enhancement Tynninen O’s research (1999) proved that there was arelation between enhancement area

on MRI and extent of mitosis and vascular density on pathology [7]

In our research, grade I edema was

40.3%, which is similar to the study of

Le Van Phuoc (2012) [2] that malignant

gliomas had a percentage of 33.9% edema

Ishtiaq A (2012) [8] reported that the

extent of edema had a correlation with the

extent of malignancy of gliomas

CONCLUSION

By this study, we come to the conclusion

that malignant gliomas had the salient

characteristics, including: Internal necrosis,

the large hyperintense area around the

tumor, shape effect, vivid enhancement

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