Neuroimaging updates on neonatal hypoxic ischemic injury and hypothermia

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1 Neuroimaging updates on neonatal hypoxic ischemic injury and hypothermia Fabio Triulzi Neuroradiology Dept. Cà Granda Foundation Ospedale Maggiore Policlinico Università degli Studi, Milan ITALY

2 Term Neonate Asphyxia background Hypoxic-Ischemic Encephalopathy HIE has still an incidenceof1 to6 per 1,000 live full-termbirths, representing the third most common cause of neonataldeath(23%) afterpretermbirth (28%) and severe infections(26%) However the introduction in the last ten years of hypothermia has significatively improved neurocognitiveoutcomesin middle childhood, changingthe roleofdiagnosticimagingin the perinatal period

3 MR in Hypoxic-Ischemic Encephalopathy (HIE) Overview 1.Selective brain damage in HIE and temporal evolution 2.MR biomarkers and their prognostic value 3.Hypothermia and MR 4.MR featuresof HIE in the chronicphase

4 Selective brain damage 2 PATTERNS A. Acute Profound Asphyxia Basal ganglia Thalamus Perirolandic cortex B. Partial Prolonged Asphyxia Hypotension Infection Hypoglicemia Watershed territories

5 Selective brain damage Pattern A - Acute Profound Asphyxia Moderate to Severe HIE T1WI T2WI > 1 week 10 days

6 T1WI hyperintensities Selective brain damage A- Acute Profound Asphyxia 10 days Lentiformnuclei (post. part) Thalami(VPL nuclei) Heschl s gyri Rolandic cortex Optic radiation No PLIC

7 Selective brain damage A- Acute Profound Asphyxia T1WI hyperintensities Rolandic cortex Rolandic cortex 20 days Basal ganglia hippocampus Primary auditory cortex Heschl s gyrus

8 Selective brain damage Patter B - Partial Prolonged Asphyxia 4 days T2WI T1WI DWI ADC Watershed territories

9 3 yrs Chronic stage Selective brain damage Patter B - Partial Prolonged Asphyxia

10 3 yrs Chronic stage Selective brain damage Partial Prolonged Asphyxia

11 Selective brain damage 2 PATTERNS A. Acute Profound Asphyxia Basal ganglia Thalamus Perirolandic cortex B. Partial Prolonged Asphyxia Hypotension Infection Hypoglicemia Watershed territories More frequent and typically related to HIE

12 Phatophysiology of selective brain damage in acute profound asphyxia In term neonates some brain regions have a greater energetic requirement than others due to different active processes such as myelination, synaptogenesis,, etc.. Normal neonatal brain

13 Phatophysiology of selective brain damage in acute profound asphyxia Greater energetic requirement greater local CBF Normalnewborn, 10 days CBF map ASL technique

14 Progressive modification of local CBF in the developing brain ASL 10 days ASL 45 days ASL 7 months

15 Phatophysiology of selective brain damage in acute profound asphyxia Greater energetic requirement greater glucose consumption PET-FDG 15 days 4 yrs Local Cerebral Metabolic Rate for Glucose in Neonate Chugani HT et al. Ann Neurol 22:487-97,1987

16 Phatophysiology of selective brain damage and temporal evolution JK Hassell Arch Dis Child Fetal Neonatal Ed 2015

17 MR CBF (ASL) acute phase Following HIE a decrease of CBF in the first day followed by a stable increase of CBF has been demonstrated Day1 Day2

18 MR CBF (ASL) acute phase Following HIE a decrease of CBF in the first day followed by a stable increase of CBF has been demonstrated Day1 Day2

19 PET glucose metabolism subacute phase Following HIE further increase of glucose consumption Transient hypermetabolism of the basal ganglia following perinatal hypoxia. Batista CE, Chugani HT, Juhasz C, Behen ME, Shankaran S Pediatr Neurol May;36(5): HIE 15 days 4 years Normal

20 MR early acute phase (12-36 hrs) 1 daysevere HIE Diffuse edema and DWI+ADC alteration

21 MR early acute phase (12-36 hrs) Severe HIE Normal

22 3 daysmoderate to SEVERE HIE MR acute phase (2-4 days)

23 4 days MODERATE HIE MR acute phase (2-4 days)

24 MR subacute phase (5-10 days) 8 dayssevere HIE DWI-ADC pseudonormalization

25 MR subacute phase 2 (>10 days) ADC increase 21 daysmoderate to SEVERE HIE

26 Diffusion(ADC): underestimation of final damage Acute phase (12-36 hrs) Subacute ph. (7-10 d)

27 MR Spectroscopy 31 P-MRS (research) 1 H-MRS (clinical) JK HassellArchDisChildFetalNeonatalEd 2015

28 Mild-Moderate HIE 1 day(few hours after birth before cooling) 2 weeks After cooling 1 yrfu Normal

29 Moderate HIE (cooling) 4 days 2 weeks

30 HIE TEMPORAL EVOLUTION Summary of imaging features Cooling DAYS T1 neg/edema neg/edema neg/edema pos pos++ T2 neg/edema neg/edema neg/edema pos pos DWI/ADC neg/restriction restriction++ restriction++ pseudonormalization increase Spectroscopy LAC increase+ LAC incr/norm LAC increase++ LAC incr/norm neg Perfusion hypoperfusion hyperperfusion+ hyperperfusion++ hyperperfusion? PET FDG???? hypermetabolism

31 Overview 1.Selective brain damage in HIE and temporal evolution 2.MR biomarkers and their prognostic value 3.Hypothermia and MR 4.MR featuresof HIE in the chronicphase

32 Biomarker Sensitivity Specificity Spettroscopy Time interval (days) Lac/Naa (BG Th) 82% 95% 1 30 Lac/Cr (BG Th) 77% 94% 1 30 Lac/Cho 84% 81% 1 30 NAA/Cho 59% 72% 1 30 NAA/Cr 61% 71% 1 30 Conventional MR 32 articles ( ) 860 newborn at least1 yr follow up Overall 91% 51% 1 30 Early MRI 85% 86% 1 7 Late MRI 99% 53% 8 30 PLIC 71% 86% 1 4 ADC 66% 64% 1 4

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34 NICHD brain injury pattern Score 0 - normal Score 1A Score 1B Score 2A Score 2B Score 3

35 The NICHD score predicts moderate to severe disability for score > 2, i.e. for extensivebrain damage

36 False - positive False - negative False - negative False - positive

37 Overview 1.Selective brain damage in HIE and temporal evolution 2.MR biomarkers and their prognostic value 3.Hypothermia and MR 4.MR featuresof HIE in the chronicphase

38 2005 Hypothermia in HIE

39 2011 Hypothermia in HIE

40 2014 Hypothermia in HIE (6-7 years)

41 Hypothermia in HIE 33.5 C 72 h 6 h oflife Metabolic rate O2 consumption Excitotoxicity Reactive oxygen species production Oedema Modulation of inflammatory cascade Courtesy Fumagalli M

42 Hypothermia potential side effects From subcutaneous fat necrosis to nephrocalcinosis Fumagalli M Arch Dis Cild 2011

43 Hypothermia in HIE and MRI

44 Hypothermia in HIE and MRI 136 MRI 73 hypothermia 63 control

45 Hypothermia in HIE and MRI 83 MR hypothermia 34 selective head 49 whole body

46 Hypothermia in HIE and MRI 41 Severe/Moderate HIE

47 Hypothermia in HIE and MRI

48 Hypothermia in HIE and MRI Predictive value of MRI is not affected by hypothermia MRI can beusedtoevaluatethe effectof cooling Conventional sequences are not fully appropriate to assess brain damage after coling in asphyxiated newborn Is a immediately post-cooling MR study still useful in a clinical setting?

49 Overview 1.Selective brain damage in HIE and temporal evolution 2.MR biomarkers and their prognostic value 3.Hypothermia and MR 4.MR featuresof HIE in the chronicphase

50 HIE chronic phase 1 WEEK 2 YEARS

51 HIE chronic phase

52 HIE chronic phase

53 HIE chronic phase

54 Acute phase Chronic phase

55 MR features of HIE in chronic phase and Highly suggestive for HIE

56 Thank you for your attention!