Comparative Study Between Brain MRI Perfusion and Diffusion Weighted Including Apparent Diffusion Coefficient Value in Assessment of Brain Penumbra and Infarction Core in Acute Cerebral Infarction

Abstract

Rapid and precise identification of the penumbra is important for decision-making in acute stroke.  The perfusion weighted imaging/diffusion weighted imaging PWI/DWI mismatch region may exceed the true penumbral area and is usually much larger than the final size of the infarct. These limitations led us to investigate the value of an ADC quantitative assessment of early tissue changes, especially in the mismatch area.

    Early detection of decrease in apparent diffusion coefficient (ADC) within infarcted area which eventually evolve toward infarction may help to identify diffusion/perfusion (DWI/PWI) mismatch. Perfusion imaging can identify patients who benefit from reperfusion beyond the conventional time window or in whom time of symptom onset is unknown.

The Aim of The Study:

The aim of this study is to evaluate apparent diffusion coefficient (ADC) value in assessment of area of penumbra and infarction core in acute cerebral infarction and this may replace using of brain perfusion study.

Patients and methods:

A prospective study  include 30 patients with acute cerebral infarction were examined with MRI 1.5 T. performing perfusion brain study and DWI/ADC concentrating on area of penumbra assessing ADC value in relation to PW (CBF ,CBV, TTP)

   This study carried out in the Middle Euphrates Neuroscience Center in AL-Sadir Medical City from February 2023 till November 2023 in AL-Najaf AL-Shraf.

Results:

Total of 30patients were included in this study which were divided into subgroups based on age, gender and BMI groups

Mean age (63.8±8.7 years) and BMI (27.4±3.5).

The apparent diffusion coefficient(ADC) mean value in the central area of infarction was (0.47±0.11x10^-6 mm²/s),peripheral area of infarction (0.66±0.15x10^-6 mm²/s), penumbra area (0.81±0.07 x10^-6 mm²/s) and the normal brain area (0.94±0.16 x10^-6 mm²/s) which was of significant difference P-value=0.001.

Regarding perfusion, the time to peak (TTP) mean value in the center of infarction was 56.6 ±28.6s and in the periphery of infraction 70.5±36.5 s, 60.2 ±31.9s in penumbra and in normal area was 59.9±35.1 s, the difference was insignificant,  P-value = 0.4 .

The cerebral blood flow (CBF) mean value were different among different regions of infarction without significance difference P-value=0.9. In  the center of infarction was 15.57± 24.6 mL/100 g/min and in the periphery of infraction 14.1 ± 23 mL/100 g/min , 16.8 ± 27.2 mL/100 g/min in penumbra and in normal area was 14.5±  21.3 mL/100 g/min.

The cerebral blood volume (CBV) mean value in the center of infarction was 24.7 ± 34.7 ml/100gm and in the periphery of infraction 40.5± 46.5 ml/100gm, 72± 86.1 ml/100gm in penumbra and in normal area was 59.5± 85.7 ml/100gm this difference was significant ( P-value= 0.04 ).

Conclusion:

1) The only CBV perfusion parameter was of significant difference in different areas of infarction.

2) ADC value was rapid and easy to be measured with significant difference among different regions of infarction.

3) The perfusion parameter TTP was of no significant difference in different areas of infarction.

4) The perfusion parameter CBF was of no significant difference in different areas of infarction.