1/Radiologist not answering the phone? Just want a quick read on that stat head CT? Here's a little help on how to do it yourself w/a thread on how to read a head CT!

1/Do you feel like you are drowning in an alphabet soup of stroke trials? Just want to know who to scan and what to look for? This month’s @the AJNR has the latest you need to know! ajnr.org/content/47/10/2510

1/Raise your hand if you’re confused by the BRACHIAL PLEXUS! I could never seem to remember or understand it—but now I do & I’ll show you how! A thread so you will never fear brachial plexus anatomy again!

1/Asking “How old are you?” can be dicey—both in real life & on MRI! Do you know how to tell the age of blood on MRI? Here’s a thread on how to date blood on MRI so that the next time you see a hemorrhage, your guess on when it happened will always be in the right vein!

Do you feel there’s a back-log of findings in a spine MRI report? Everyone talks about discs & facets, but not everyone talks about the endplates. Do you? Do you need to talk about degenerative changes (Modic changes) of the endplates? Here’s thread w/all you need to know! Over 30 years ago, Modic et al. found there were 3 types of degenerative endplate changes: (1) T2 bright changes (indicating edema, Modic 1) (2) T1 bright changes (indicating fat, Modic 2) (3) T1 & T2 dark changes (indicating sclerosis, Modic 3) But what do they mean? MODIC 1 --Bright on T2, indicating edema. --Pathology shows inflammation, vascular granulation tissue, & high cellular turnover --Vascular granulation tissue means these can enhance on post contrast images—mimicking discitis! MODIC 2 --Bright on T1, indicating fat. --Show fatty conversion of the marrow & low cellular turnover. --I think of them as the middle-aged dad bod of degenerative change—lots of fat & slow to change! MODIC 3 --Dark on T1 & T2, indicating sclerosis --Pathology showsdense fibrous tissue & sclerosis. --Like endplates get fossilized—once you turn into rock, you are never going back. I remember these bc the forces at work in the endplates are like the famous astrology signs—almost. Earth (sclerosis) Wind (fatty changes, when you feel fat & full, you tend to give off wind!) Fire (inflammation, edema) Now you can use this when you go BACK to work on reading spine MRIs!

Is trying to remember toxic encephalopathy patterns making you toxic? Does memorizing metabolic encephalopathy patterns put you into a metabolic coma? Don't become encephalopathic! Here is the cheat sheet of the encephalopathy patterns you NEED to know & how to remember them! ➡️Corpus Callosum: 🔸Lesions here are called cytotoxic lesions of the corpus callosum or CLOCC. 🔸Usually transient from cytotoxicity, especially viral infections. 🔸Remember they are commonly viral & transient bc CLOCC lesions are on the CLOCK ➡️Central Pons: 🔸Usually osmotic demyelination 🔸Remember this bc the T2 hyperintensity is in the shape of O for Osmotic ➡️Dentate: 🔸Usually flagyl toxicity 🔸Remember this bc the wavy appearance of the dentate looks like a FLAG for FLAGyl ➡️Corticospinal tract: 🔸Usually from cobalamin deficienty 🔸Remember cortiCOspinal for CObalamin ➡️Symmetric Gray Matter: 🔸Differential is EXTENSIVE 🔸Remember the differential list for deep gray is deep! ➡️Cortical Gray Matter: 🔸Typically hypoglycemia & hyperammonemia 🔸Remember it looks like the brain has been coated in shimmering sugar = related to glucose 🔸Hyperammonemia has about 1000 Ms in it & the undulated cortex looks like an M ➡️Symmetric White Matter: 🔸Commonly from chasing the dragon (heroin) & methotrexate 🔸Remember that the puffy white matter signal looks like the smoke from a dragon 🔸Remember methotrexate as methoTRACTSate = affects many white matter TRACTS ➡️Posterior subcortical edema: 🔸This is PRES or posterior reversible encephalopathy 🔸So if it’s all POSTERIOR, think POSTERIOR reversible encephalopathy ➡️Asymmetric White Matter: 🔸This is usually demyelinating from chemotherapy 🔸Demyelinating lesions have a C shaped pattern of enhancement 🔸So if you see a C enhancing think of C-hemotherapy Now you know all the toxic/metabolic encephalopathy patterns. So hopefully now remembering the patterns of toxic/metabolic won’t seem so diabolic!

Anyone can see the bright spot of diffusion imaging! What sets you apart is your ability to tell them where it is—what vascular territory Here are the vascular territories you need to know: * Posterior Inferior Cerebellar Artery (PICA) Soft under surface of the cerebellum * Superior Cerebellar Artery (SCA) The SCA territory is the top of the cerebellum (SCA is the SCAlp of the cerebellum) * Basilar perforators Make a line in the pons like a penetrating injury. So perforator infarcts look like perforating injuries * Anterior Choroidal artery This supplies the posterior limb of the internal capsule & corticospinal tract. Remember COR-roidal is COR-ticospinal * Lenticulostriate arteries Infarct territory looks like a tadpole * Heubner's artery: infarct is the caudate head. Remember "who called" which sounds like "heu caud" so heubner takes out the caudate * Anterior cerebral artery (ACA) Medial, anterior surface of the cerebral hemispheres * Middle cerebral artery (MCA) Lateral surface of the cerebral hemispheres * Posterior cerebral artery (PCA) Medial, posterior surface of the cerebral hemispheres Hopefully now when it comes to the vascular territories, you will always be right when it's bright!!

If you are only looking at the optic nerve on Orbital MRIs, you need to open your EYES! Don’t be blind to all the other nerves in the orbit! Branches of trigeminal V1 &V2 and the oculomotor nerve all can cause pathology in the orbit But if you don’t look, you won’t see! Let this figure show you some of the nerves you can see in the orbits (CN6 is only seen proximally bc its orbital course is so short & CN4 is too small to reliably see)

Pondering how to remember pontine syndromes?   Don’t become despondent about syndromes of the pons!   Here’s an easy way remember the basic parts of pontine syndromes:   Pontine lesions are usually vascular and are either from an infarct in the AICA territory (lateral) or paramedian branches of the basilar artery (medial)   Lateral & medial pontine syndromes can be remembered by the easy mnemonic THE PONS, w/ “THE” representing lateral syndromes & “PONS” representing medial syndromes   LATERAL SYNDROMES: T = Temperature (spinothalamic = loss of pain & temp contralateral body, trigeminal nucleus = ipsilat face) H = Horner’s (sympathetic pathway) E = Equilibrium problems (spinocerebellar = ataxia of ipsilateral arm & leg)   MEDIAL SYNDROMES: P = Proprioception (medial lemniscus = loss of contralateral vibration & proprioception) O = Ophthalmoplegia (MLF = internuclear ophthalmoplegia) N = Nonmobile (corticospinal tract = weakness of contralateral body) S = Sixth nerve (Sixth nerve nucleus = loss of ipsilateral CN 6)   There are many different syndromes that vary by what exact structures are involved, but if you always remember THE PONS, you can easily pontificate about pontine lesions!

1/Sometimes the tiniest thing can be the biggest pain—that’s microvascular compression of the trigeminal nerve! But seeing such a tiny finding can be hard! Here’s a thread about how to look at the trigeminal nerve on MRI.

1/Time to FESS up! Do you understand functional endoscopic sinus surgery (FESS)? If you read sinus CTs, you better know what the surgeon is doing or you won’t know what you’re doing! Here’s a thread to make sure you always make the important findings!

1/Ready for a throw down? MMA fights get a lot of attention, but MMA (middle meningeal art) doesn’t get the attention it deserves! This month’s @theAJNR SCANtastic tells you all you need to know! ajnr.org/content/47/6/1515

Having trouble remembering what to look for on scans for Alzheimer’s dementia?   Want the key findings to stay in your memory?   Medial temporal atrophy (MTA) score quantifies hippocampal volume loss   It rates the amount of CSF around the hippocampus as a marker of volume loss   CSF surrounds the hippocampus like a snake surrounding its prey—how far the snake has gone in getting its prey determines the MTA score:   MTA-1: Choroidal fissure opens, looks like the snake has started to slither in Remember: the number one looks flat like a slightly opened choroidal fissure   MTA-2: Temporal horn widens, looks like the snake has surround the hippocampus Remember: the number two look like the CSF curving around as the temporal horn opens   MTA-3: Moderate hippocampal atrophy, looks like the snake has begun to squeeze the hippocampus Remember: the number three has a tight curve, so it looks like it is crushing the hippocampus & it looks small (atrophied)   MTA-4: Severe hippocampal atrophy, looks like the snake has crushed the hippocampus Remember: Number four has only a tiny hole in it, so the hippocampus has to be super tiny & atrophied to fit inside!   Hopefully, this will help you commit this rating system to memory so you’ll never forget what you need to say for Alzheimer’s!

1/Do you get a Broca’s aphasia trying remember the location of Broca's area? Does trying to remember inferior frontal gyrus anatomy leave you speechless? Don't be at a loss for words when it comes to Broca's area Here how to remember the anatomy of this key region!

Tired of always speculating about MR spectroscopy?   If you've ever looked at an MR spectroscopy & thought: "I have no idea what I’m looking at!"--then this cheat sheet is for you!   Here are the 4 basic rules you need so you can understand the spectrum of basic spectroscopy! First you need to know the peaks.  3 main peaks: Choline, Creatine, NAA Remember the order bc a spectrum looks like mountain peaks & it is cold in the mountains.  And CHOld CREATures NAp or hibernate in the mountains   Choline Marker of membrane turnover Remember: membranes coat or “CHOat” the cell Choline = ChoLEAN, choline LEANS into the creatine peak, it’s right next to it   Creatine Marker of energy, basically an internal control Remember, everyone takes Creatine powder for energy! Creatine is at ~3—creatine almost rhymes with 3   NAA
Marker of neuronal health N = Neuron NAA has double As so it is at ~2!   Four rules:   1. Hunter’s angle: —Most people know that the peaks of the spectrum should go up at you move lateral, called Hunter’s angle —Most bad things reverse Hunter’s angle —Ask yourself: Is my arrow pointed up to shoot into the air at the enemy (good) or is point to the ground where it will hit the dirt (bad)   2. TE & spectrum length are inversely related —Spectroscopy follows the rule: speak softly & carry a big stick.  —Short TE = long spectrum, lots of extra peaks for glutamate/glycine, myoinsitol —Long TE = short spectrum, mainly the basic 3 peaks   3. Each region has its own unique signature —Each brain region has its own unique composition of compounds that might alter Hunter’s angle a bit, but not reverse it —Need a control in contralateral normal brain so compare apples to apples   4. Lactate peak goes like a sine wave —Lactate peak represents anerobic metabolism—sign of cells in trouble It’s at 1.3ppm. Remember this bc 13 is an unlucky number & lactate is an unlucky sign! —It’s like a sine wave: up at short TE (35), down at intermediate TE (144), and up again at long TE (244) —You can use this flipping to better visualize the lactate peak —You can remember it’s down in the middle TE bc when you’re caught in the middle, you’re down & out   Just remember these tricks & you will be spectacular at basic spectroscopy!

Sink or swim!   Brain is swimming in CSF!   CSF is key for protection, buoyancy, & hormone/waste transport   Most know basic ventricular anatomy well, but not subarachnoid anatomy.   How many cisterns do YOU know?   Here’s a quick guide to the key midline cisterns & what to know for each   —Cisterna Magna: Largest of the cisterns Contains CN 9-11 & vertebral arteries Remember this bc the LARGEST cistern contains the LARGEST cranial nerve (vagus) and the two cranial nerves around it   —Prepontine cistern: Contains CN 6 & basilar artery Remember this bc the shape of the number 6 mirrors the curvature of the anterior pons, where this cistern lies   —Chiasmatic cistern Contains CN 2 & pituitary stalk Easy to remember bc the CHIASM is CN 2   —Interpeduncular cistern: Contains CN 3 & mammillary bodies Remember this bc if you lay the number 3 on its side it looks both like the two cerebral peduncles (where this cistern lies) & well, two mamillary bodies   —Quadrigeminal cistern Contains CN4 & pineal gland East to remember bc QUAD is the prefix for FOUR   —Lamina terminalis: Contains the ACOMM Remember this bc the shape of subarachnoid hemorrhage after ACOMM rupture follows this cistern anteriorly   Now when you look at cisternal anatomy, you will definitely be able to go with the flow!

1/Having trouble remembering how to differentiate dementias on imaging? Is looking at dementia PET scans one of your PET peeves? Here’s a thread to show you how to remember the imaging findings in dementia & never forget!

Stuck between a rock & a hard place when it comes to brain calcifications?!   Calcification pattern is key to rocking the diagnosis!   Here's a quick guide to the most common entities associated w/different patterns   For the three most common patterns, I remember what you do when ROCK music plays:   I HeaR = Infection & Hematoma give a Rock pattern I GYRate = Infarct give a GYRiform And finally... I Dab = Infection gives tiny Dabs or Dots everywhere   For the rest: If they are grouped: think tumor or vascular If they are diffusion: think metabolic If they are along the ventricle: think TORCH   Now hopefully you can rock & roll when it comes to the diagnoses for intracranial calcifications!