Critical Imaging Diagnoses: - Radiology

Disclosures 

Critical Imaging Diagnoses: 

When and Where We Make a Difference 

James G. Smirniotopoulos, M.D. 

Radiology and Radiological Sciences 

Uniformed Services University 

Bethesda, MD 

• No financial disclosures nor conflict of 

interest to report 

I’m from the Government … 

… and I here to help! 

Learning Objectives 

MR and CT Imaging Checklists 

• Develop a “checklist” for imaging to 

improve your ability to identify significant 

findings 

• Recognize imaging findings that will 

acutely change patient management 

• Anatomic Locations 

– Sagittal Images 

• Sup. Sag. Sinus 

• Corpus Callosum 

• Sella Region 

• Clivus 

– Axial Images 

• Skull, Epi/Sub Dural 

• SAS 

• Cortical Gray Matter 

• White Matter 

• Deep Gray Matter 

• Ventricles 

• Morphologic Features 

– Mass Effect 

• Yes, proportional 

• Less than expected 

• No mass effect 

– Abnormal WM Signal 

• Vasogenic Edema 

• Demyelination 

• Infiltrating neoplasm 

– Enhancing Ring Lesion 

• Necrotic Neoplasm 

• Reactive (e.g. abscess) 

• Fluid or Inflammatory 







• Clivus 



• SAS 





Superior Sagittal Sinus Thrombosis 

Venous Infarct: Deeper, white matter, may spare parts of cortex

Sup. Sag. Sinus Thrombosis 

• Dehydration 

• Paraneoplastic Syndromes w/hypercoag 

• Spinal Anesthesia 

• Post-partum 







• Clivus 



• SAS 





Gliomatosis Cerebri 

Diffuse Astrocytoma of Corpus Callosum: 

“Butterfly Glioma” 

Gliomatosis cerebri: 2 or more lobes infiltrated by a diffuse astrocytoma 

Courtesy of R.D. Zimmerman, NY 

Diffuse Astrocytoma of Corpus Callosum: 

“Butterfly Glioma” 

Corpus Callosum Lesions 

Glioblastoma: 

Central Necrosis 

CNS Lymphoma: 

Hyperdense

Lymphoma: hyperdense 

PCNSL 

FLAIR 

Low water content … hyperattenuation 

T2W 

Low water content … restricted diffusion 

T1W Gd+ 

CNS Lymphoma Micro Pathology 

Small * Round * Blue-Cell Tumor 

• DENSELY CELLULAR 

• Perivascular infiltration 

• Increased RETICULIN fibers 

• HIGH N/C (nuclear/cytoplasm) 

• Small Round Blue Cell Tumor 

• High attenuation/low signal intensity 

Perivascular 

Infiltrate 

Rimphoma 

RIM PHOMA







• Clivus 



• SAS 





Agenesis of the Corpus Callosum 







• Clivus 



• SAS 





Bitemporal Hemianopsia 

Mass Lesion Presentation 

Bitemporal Hemianopsia 

Met Hemoglobin in 

Sella Region 

Macroadenoma 

Pituitary Adenoma 

• Adult Patient 

• Microadenoma 

– < 10 mm 

– entirely within gland 

– Endocrine Sx. 

• Prolactinoma F 

• Acromegaly 

• Gigantism 

• Cushing Disease 

• Macroadenoma 

– > 10 mm 

– balloon sella 

– Visual Sx 

• if >6 mm above sella 

• bitemporal hemianopsia 

Pituitary MACRO-Adenoma 

Adenoma

Met Hemoglobin in 

Sella Region 

Macroadenoma 

Pituitary Apoplexy 

Pituitary Apoplexy 

David and Goliath 

• Did Goliath have Gigantism and/or 

Acromegaly? 

• He was a “Giant” 

• He was an Angry Giant from HA and ICP 

• Did he have a Macroadenoma? 

– David was able to sneak up to him 

• bitemporal hemianopsia 

• “Tunnel Vision” 

– One stone to the head killed him 

• Pituitary Apoplexy 

• Hemorrhage into a macroadenoma 







• Clivus 



• SAS 





Craniopharyngioma – Bright T1W 







• Clivus 



• SAS 





Bilateral Abducens (CNN6) Palsy

Chordoma 

Bulky Clival Mass 

Chordoma 

Midline Bone 

Destruction 







• Clivus 



• SAS 





Depressed Skull Fx 







• Clivus 



• SAS 





Small EDH, no herniation, can be 

managed with observation 

☺ 

Smile of the Quadrigeminal Cistern







• Clivus 



• SAS 





2 y.o. with Lethargy 

Child Abuse? 







• Clivus 



• SAS 





Headache, Kernig & Brudzinski+ 

History 

• 42 y.o. . woman with acute onset of: 

– “the worst headache of my life” 

• No papilledema 

• Kernig Sign + 

• Brudzinski Sign + 

Kernig sign: Pain elicited by 

straightening the knee with the 

hip/thigh flexed. 

Brudzinski sign: Pain and/or rigidity 

with simultaneous neck and knee/hip 

flexion. 

ICA Aneurysm 

ICA Aneurysm







• Clivus 



• SAS 





Fever, Kernig +, Brudzinski + 

Subarachnoid Space Enhancement 

Leptomeningeal Enhancement - Pneumococcal Meningitis 

Bacterial glycopeptides cause Breakdown in the BBB 

and contrast leaks into CSF in the SAS 

Zulmarie Roig, , MD and Gil Gonzalez, MD, MGH 

CSF Spread - Zuckerguss 

Serpentine - Cortical Gyral 

Carcinomatous Meningitis 

Meningitis 

Encephalitis 







• Clivus 



• SAS 





Hx: 23 y.o. w/confusion 

HSV Encephalitis







• Clivus 



• SAS 





Hx: 53 y.o. left sided weakness 

CVA: Progression Over 3 Days 

Day 1 Day 3 

No Sulci 

Low attenuation 

“Insular Ribbon” Sign 

Cerebral Infarction 


MCA 

MCA 

2 hrs of Sx 4 hrs of Sx 


DWI 

ADC 

Chronic Infarct 

DWI 

ADC 

Hemorrhagic Transformation 

• Reperfusion Injury 

– Restoration of Systemic pressure into dead 

brain 

• Function of Ischemic Volume 

– Entire MCA vs. branch 

• Function of Time 

– IV TPA up to 3 hrs 

– IA up to 6 hrs 

– Desmoteplase up to 9 hrs 

Anterior Cerebral Artery

PCA Infarct 

DWI 







• Clivus 



• SAS 





Hx: 13 y.o. w/ Seizures 

Another Cortical Wedge Lesion 

Dysembryoplastic Neuroepithelial Tumor (DNET) 







• Clivus 



• SAS 





65 y.o. HT had TAH/BSO 

Proton Density 

T1W 

Anoxia During Surgery 

Anoxia During Surgery 

Diffuse patchy abnormal loss of normal attenuation in cortical gray-matter. 

Ischemic gray-matter, cortical (ACA & MCA) and basal ganglia (caudate). 

NOTE: Relative sparing of the PCA (occipital lobes and thalami)







• Clivus 



• SAS 





34 y.o. woman w/Coma 

34 yo comatose woman, psychiatric pt. 

Courtesy Aimee Hawley, M.D. MGAFMC 

Findings 

• Intraaxial 

• Diffuse Bilateral abnormalities 

– Low attenuation in Cortical Gray Matter 

– Low attenuation in basal ganglia 

• “Edema” 

– What Kind? 

• Interstitial 

• Cytotoxic 

• Hydrostatic 

Lab: Serum Na+ 121 

• Psychogenic polydipsia 

• Overhydration 

Water Intoxication 

– Athletes drinking too much water 

• Iatrogenic 

– D5W w/o salts 

• Treatment 

– Fluid restriction 

– Ringer’s s Lactate or Hypertonic Saline 

• 1.8% saline (not 4%NS and NOT D5W) 







• Clivus 



• SAS 





Woman w/confusing symptoms 

Multiple Sclerosis 

Small Ovoid Lesions perpendicular to lateral ventricle







• Clivus 



• SAS 





Acute Pure Motor Hemiplegia 







• Clivus 



• SAS 





14 yo girl with congenital HIV 

TOXOPLASMOSIS 

14 yo AA girl with congenital HIV and CD4 count of 50 presents with 

mental status change, high fever, and two weeks of watery diarrhea 

Toxoplasmosis 

Left thalamic 

mass –low 

attenuation with 

hyperdense rim; 

hypointense T2 

rim (collagen 

capsule); smooth, 

round rim 

enhancement, 

surrounding 

vasogenic 

edema, restricted 

diffusion 

Typical deep gray matter paracentral abscesses with rim 

enhancement and surrounding edema 

Toxoplasmosis: Calcification after Treatment 







• Clivus 



• SAS 





71 yo man with HIV/AIDS 

Lesions shrinks, vasogenic edema resolves, calcification

1° CNS Lymphoma 

71 yo AA man with a history of 

HIV/AIDS presented with gait instability 

Low SI mass 

lesions in the 

right MCP, left 

insula, and left 

thalamus 

with 

surrounding 

vasogenic 

edema 

The T1- 

weighted post 

gadolinium 

images show 

predominantly 

ring 

enhancement 

with areas of 

central 

necrosis 







• Clivus 



• SAS 





Coma at home after Ice Storm 

Medial Lenticular – Globus Pallidus 

Toxic and Metabolic 

•Intrinsic 

–Diabetic 

Ketoacidosis 

–Hypoglycemic Coma 

CO Poisoning: Selective for Globus Pallidus 

•Extrinsic 

Toxic Exposure 

–CO 

–Methanol, Ethylene Glycol 

–Solvent 

Leukoencephalopathy 







• Clivus 



• SAS 





Bruns Syndrome – Positional HA 

Chronic HA – Acutely Worse 

Hydrocephalus: Vents > Sulci







• Clivus 



• SAS 





Positional Headaches 

3 rd Ventricle Cysticercosis 







• Clivus 



• SAS 











• Clivus 



• SAS 





Intraventricular Meningioma 

McCain - Palin - Smirniotopoulos 

John … How did 

we Lose?








• Clivus 



• SAS 














– Ring Lesion 


















Obtunded w/blown pupil 














Brain Herniation Syndromes 

t 

f 

t 

Brain Herniation Syndromes 

Pupillary Reaction 

f 

C 

t 

U 

M 

t 

T 

T 

Blown Pupil: 

CNN3 (Oculomotor) nerve 

ipsilateral to the mass 

lesion. Note CNN4

Pupil - Intrinsic Ocular Muscle 

“Blown Pupil” 
















BP 180/135, HA, Hemiplegia 















Long-standing Headache (yrs) 














Two Pts: Compare Mass Effect 


New onset Seizures 

AVM – No Mass Effect 

GBM – Has Mass Effect















Vasogenic Edema 

• A type of interstitial edema produced by 

abnormally increased capillary permiability 

• Spreads from site of abnormal vessels at 

~7-10 mm/week 

• May reach a steady-state 

state – can’t t estimate 

age of lesion from extent of edema 

• Spreads along association tracts > cortico- 

spinal tracts >>> commissures 

• Finger-like 

pseudopods of watery white 

matter 

Meningioma with extensive Edema 


Glioblastoma Multiforme 














T1-gad 

Neoplastic cells 

extend into the 

edema … and 

beyond, into the 

“normal” WM 

T2


Seizure and Obtundation 




• More than expected 










Hemorrhage into a Pre-existing existing mass 

Acute hemiplegia and confusion in a 68 year old man 

NOTE: Vasogenic Edema 

Courtesy Doug Phillips, UVA 

GBM 


Variable and Confusing Sx 
















Severe HA, HIV+ 














Lesion w/o Mass Effect - PML

T2W – Geographic hyperintensity 

FLAIR Geographic hyperintensity, no mass 

Looks like vasogenic edema 

Courtesy Jacqueline Bello, M.D. 

Looks like vasogenic edema … 

but, affects the corpus 

callosum 


T1 w/Gd – No enhancement 

PML 

Looks like vasogenic edema … 

but, no enhancement ! 


No Mass, No Enhancement 


Progressive 

Multifocal 

Leukoencephalopathy 

• WM Disease - JC Papova/Polyoma Virus 

– Initials of first patient cultured (1) 

• John 

Cunningham 

• Tx for Hodgkins, , died from PML in 1971 

• Lysis of Oligodendrocytes 


• Geographic and Peripheral 

– Little or No Mass Effect 

– Little or No Enhancement 

• Poor Survival of 2-62 

6 months reported 

• Improved survival w/ HAART - up to 3-43 

4 years 


Severe HA, HIV+ 













• Fluid or Inflammatory

PML 















WHO Gr 2 Astrocytoma (“gliomatosis 

gliomatosis cerebri”) 

(“edema” w/o contrast enhancement) 

Gliomatosis Cerebri: 

Diffuse Astrocytoma – 2 lobes 

NOTE: Although this looks like “vasogenic edema” – there is no enhancement. 

Vasogenic edema often spares the internal capsule. This is NOT edema secondary to 

a lesion. This is the tumor itself infiltrating through the white-matter. 

T2 

T1-gad 

Infiltrates through White Matter Tracts 

Gliomatosis Cerebri 

CHO 

Cr 

NAA ? 

{

T1W Gd+ + in Two Astrocytomas 

Without Contrast Enhancement, it 

can’t be “vasogenic” edema? 

Why does it look like like interstitial 

vasogenic edema? Microcystic change 

Gr 4 Astrocytoma 

Neovascularity w/BBB causes 

contrast Enhancement and 

“vasogenic” edema 































Fever, HA, Recent Dental work 














Abscess 

Mag. susceptibility from 

atomic oxygen in 

macrophages

Abscess 

Brain Abscess 

AA 

Peaks 

Inverted 

AA Peaks 

DWI 

Short TE MRS 

Long TE MRS 

Viscous Pus and Coagulation Necrosis 

MRS Courtesy of Mauricio Castillo - UNC 

DWI: Necrosis vs. PUS 

Ring Lesion Differences 

GBM 

Abscess 

“We conclude that viable cell density is the main biological parameter 

responsible for restricted diffusion in brain abscess, and it is not 

influenced by the etiological agents responsible for its causation.” 

Magn. reson. med. 2005, vol. 54, no4, pp. 878-885 

GBM 

Abscess - Toxo 


Fluid Secreting Pilocytic Astrocytoma 

Nodule 

“Cyst” 














5 min. 

Neoplasm + thin 

rim of enhancing 

gliosis

Fluid Secreting Tumor: Pilocytic Astrocytoma 

Fluid Secreting Tumor: Pilocytic Astrocytoma 

NOTE: Fluid has protein – not identical to CSF signal nor attenuation 

Fluid Secreting Tumor: Ganglioglioma 

Enhancement w/o Vasogenic Edema 

“open ring 

sign” 

Absent vasogenic edema … signal abnormality ends at 

edge of enhancement 

Open (Incomplete) Ring Sign 

• Demyelinating Disease 

• Fluid-secreting 

“Cystic” Neoplasms 

Inflammatory Breakdown of the blood-brain-barrier from 

Enhancement w/o Vasogenic Edema 

a Demyelinating Lesion 

Masdeau JC, Moreira J, Trasi S, Visintainer P, Cavaliere R, Grundman M: 

The open ring. A new imaging sign in demyelinating disease. 

J.Neuroimaging 1996; 6(2):104-107. 

Masdeu JC, Quinto C, Olivera C, Tenner M, Leslie D, Visintainer P: Openring 

imaging sign: highly specific for atypical brain demyelination. 

Neurology 2000; 54(7):1427-1433. 

“incomplete ring” 


edge of enhancement & incomplete ring

31 yo ♀- Multiple Sclerosis 

“open ring sign” 

Enhance for 3-8 weeks 

Summary 

Perivenular 


inflammation 

edge of enhancement & incomplete ring 








• Clivus 



• SAS 














– Enhancing Ring Lesion 









• Clivus 



• SAS 





2 y.o. with Lethargy 


MCA 








• Clivus 



• SAS 





Coma at home after Ice Storm 

DWI 

ADC 

Medial Lenticular – Globus Pallidus

T1W Gd+ + in Two Astrocytomas 

Without Contrast Enhancement, it 

can’t be “vasogenic” edema … 

it must be tumor infiltration 

Two Pts: Compare Mass Effect 


New onset Seizures 


Neovascularity w/BBB causes 

contrast Enhancement and 

“vasogenic” edema 


AVM – No Mass Effect 

GBM – Has Mass Effect 

Hemorrhage into a Pre-existing existing mass 

Acute hemiplegia and confusion in a 68 year old man 

NOTE: Vasogenic Edema 


Thank You! 

ありがとうございます。 Visit 感謝 us いたします。 on the web: 

rad.usuhs.edu 

Muito Obrigado 

EUXAPIΣTΩ ! 

Muchas 

Gracias 

Mahalo ! 

Dank u wel ! 

Go Raibh Maith Agat 

Merci Beaucoup 

Danke Schön !

Critical Imaging Diagnoses: - Radiology

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