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Radiological Anatomy First YearILOs ● Imaging Techniques ○ X-ray ○ CT ○ MRI ○ Ultrasound ○ Nuclear Medicine ● Anatomy ○ Bony ○ Cardiorespiratory ○ GI ○ GU ○ Special Senses ● Pathology Link to MedAll page to join the chat and take ○ Osteoarthritis part in polls for those in person We’ve included cases to illustrate the anatomy and make it more memorable, we do not expect you to recognise these conditions on imaging for your exams!!Imaging ModalitiesX-Ray ● What is it? ○ X-ray radiation is passed through the body. ○ Areas with high levels of density block the radiation - appear white. ■ Metal (very white), bone or calcium (white) ○ Soft tissues allow some radiation to pass through - appear gray. ■ Fat, soft tissue, fluid ○ Air allows all radiation to pass through - appear black. ■ Lungs, bowel gas ● Indications ○ Boney pathology ■ Fractures, dislocations ○ First line investigations ■ CXR, AXR ● Benefits ○ Fast (seconds) ● Negatives ○ Uses ionising radiation + ○ Structures overlapCT ● What is it? ○ Uses rotating X-ray source and detector ■ Creates 360 degree views of body structures. ● Indications ○ Trauma (CT brain for bleed) ○ Malignancy ○ Assessing abnormalities seen on X-ray ● Benefits ○ Fast (often <10 minutes) ○ Structures can be viewed in different planes ■ Overlapping structures not an issue ○ 3D reconstructions ● Negatives ○ Ionising radiation +++MRI ● What is it? ○ Powerful magnet and radiofrequency pulses through the body. ○ Protons (hydrogen ions) are excited by the signal. ○ Protons relax after each pulse and give off a signal that is detected by the receiver. ○ Highly detailed images are created. ● Indications ○ Soft tissue ■ Brain, MSK (muscles, ligaments) ● Benefits ○ Good at imaging soft tissues. ○ No ionising radiation ● Negatives ○ Slow (often 10+ minutes) ○ Patient must remain motionless ○ Claustrophobic ○ Ferrous metallic objects cannot go near the scanner ■ May include pacemakers, cochlear implants, prosthetic heart valves ○ Not available at smaller hospitalsMRI T1 vs T2 ● T1 fat is bright. ● T2 fat and water are bright. ○ E.g. CSF Sarah Connor, you’re terminated!CT (and MRI) Planes ● Coronal ○ Crown ● Sagittal ○ Arrow ○ Side on view ● Axial ○ AxleUltrasound ● What is it? ○ Sound waves travel inside patient and bounce back to the probe ○ Different tissues reflect different amounts of the signal. ○ A picture is created. ○ Use of the Doppler effect can show direction and velocity of blood ● Indications ○ Good at differentiating between cysts (fluid filled) or solid lesions ○ Kidneys ○ Pregnancy scans ○ Cannula placement ● Benefits ○ No ionising radiation ● Negatives ○ Operator error ○ Cannot see past air and bone Nuclear Medicine ● What is it? ○ Patients ingest or are injected with radioactive substance. ■ E.g. radioactive substance may accumulate in tumours. ○ This radioactive substance can be detected and an image created. ○ Often combined with CT to created a hybrid image showing anatomy and physiology (PET- CT). ● Indications ○ Evaluation of masses ?cancer ■ Cancers are highly metabolically active and likely to take up radioactive substance and appear bright. ○ Evaluation for metastatic disease ○ Evaluation of lung disease ■ Patients breathe in radioactive substance, allows dead space in lungs to be seenBony AnatomyHand Hand (annotated) She Looks Too Pretty, Try To Catch Her 1. Red: Scaphoid a. Boat shaped 2. Orange: Lunate a. Half moon 3. Green: Pisiform a. Pea shaped 4. Yellow: Triquetrum 5. L. Blue: Hamate a. Hooked 6. D. Blue: Capitate a. Head 7. D. Purple: Trapezoid a. Inside 8. L. Purple: Trapezium a. Thumb 9. Pink: Metacarpals 10. White: Phalanges (Prox./Medial/Distal) 11. Brown: Sesamoid bone 12. Grey: Radius a. RST: Radius, Scaphoid, Thumb 13. Black: UlnaHand: Pathology ● 70F with chronic pain and stiffness in fingers. ● What’s the diagnosis? ○ A: Osteoporosis ○ B: Osteoarthritis ○ C: Gout ○ D: Fracture Osteoarthritis ● Findings (LOSS) ○ Loss of joint space ■ I.e. loss of cartilage ○ Osteophytes ■ Bony lumps/spurs ○ Subchondral sclerosis ■ Whitening of bone beneath cartilage ○ Subchondral cysts ■ Look like black holes in boneHand: Pathology ● 20M with hand pain following fall onto outstretched hand. Tender in anatomical snuffbox. ● What bone has been fractured? ○ A. Scaphoid ○ B. Lunate ○ C. 4th Metacarpal ○ D. TrapezoidHand: Scaphoid Fracture ● Important not to miss! ○ Blood supply for the scaphoid comes in one direction. ■ Risk of avascular necrosis due to disrupted blood supply in fracture. ○ Not always seen on X-ray, MRI is the gold standard. Waist and proximal scaphoid fractures disrupt the blood supply to prox. scaphoid!Elbow Elbow: Annotated Left image: lateral view, Right image: frontal view. 1. Green: Humerus 2. Blue: Radius/Radial Head 3. Purple: Ulna/OlecranonElbow: Pathology ● 30M, sore elbow following fall onto outstretched hand. ● What is the diagnosis? ○ A. Fracture ○ B. Normal anatomical variant ○ C. Elbow dislocation ○ D. OsteoarthritisElbow: Posterior Dislocation ● Common dislocation, most common dislocation in children. ● Often occurs after falling onto an outstretched hand. ● Olecranon and radial head do not articulate with humerus.ShoulderShoulder: Annotated 1. Red: Humerus 2. Orange: Glenoid Fossa 3. Yellow: Scapular spine and acromion 4. Green: Coracoid Process 5. Blue: Clavicle 6. Purple: ScapulaPelvis/Hip Pelvis: Annotated 1. Red: Acetabulum 2. Orange: Sacroiliac Joints 3. Yellow: Femoral head 4. Green: Femur 5. L. Blue: Ilium 6. D. Blue: Pubic Symphysis 7. Purple: Obturator Foramen 8. Grey: Pubis 9. Black: IschiumKneeKnee: Annotated 1. Red: Femur 2. Orange: Tibia 3. Yellow: Fibula 4. Green: PatellaKnee: Pathology ● 70M presenting with 4/12 of worsening knee stiffness and pain. ● What is the management for this condition? ○ A. Steroids ○ B. Knee replacement ○ C. Immunosuppression ○ D. Rest Knee: Osteoarthritis ● Findings (LOSS) ○ Loss of joint space ○ Osteophytes ○ Subchondral sclerosis ○ Subchondral cysts ● Management: ○ Total knee replacementFoot and AnkleFoot and Ankle: Annotated 1. Red: Phalanges 2. Orange: Metatarsals 3. Yellow: Cuneiforms a. Lateral, intermediate, medial b. Earliest known writing system 4. L. Green: Cuboid 5. D. Green: Navicular a. Little ship 6. L. Blue: Talus 7. D. Blue: Calcaneus 8. Purple: Tibia 9. Pink: Fibula 10.Black: Sesamoid bonesFoot and Ankle: Annotated 1. Red: Phalanges 2. Orange: Metatarsals 3. Yellow: Cuneiforms a. Lateral, intermediate, medial 4. L. Green: Cuboid 5. D. Green: Navicular a. Little ship 6. L. Blue: Talus 7. D. Blue: Calcaneus 8. Purple: Tibia 9. Pink: Fibula 10.Black: Sesamoid bonesCardiorespiratoryCardiorespiratoryCR: AnnotatedCR: Pathology ● 7M, acute onset wheeze. Parents report that he swallowed something. ● Where is the abnormality? ○ A. Right bronchus ○ B. Oesophagus ○ C. Left bronchus ○ D. HeartCR: Aspirated Foreign Body ● The screw (?) is stuck in the right bronchus! ○ Aspirated foreign bodies are more likely to enter the right bronchus as it is straighter and wider. ● You should suspect an aspirated foreign body in young children with sudden onset respiratory symptoms.CR: Pathology ● 60M, acute onset abdominal pain with guarding. ● Look at the diaphragm, what does this abnormality suggest? ○ A. Pneumoperitoneum ○ B. Pneumonia ○ C. Hepatitis ○ D. Normal anatomical variantCR: Pneumoperitoneum ● Air in the abdominal cavity ● Findings include free air under the diaphragm. ○ Note how thin the diaphragm is! ● Can be caused by bowel perforation. ● Can be a normal finding following recent abdominal surgery.CR: Pathology ● 60M presenting with tearing pain in chest. PMHx of hypertension. ● What vessel has been affected? ○ A: Inferior vena cava ○ B: Femoral artery ○ C: Aorta ○ D: Pulmonary arteryCR: Aortic Dissection ● Tear in tunica intima leading to a collection of blood in aorta’s medial layer. Visualized as a false/double lumen on imaging. ○ Red and Orange: Double lumen ○ Yellow: Pulmonary trunk ○ Green: SVCCR: Pathology ● 40F presenting with shortness of breath and haemoptysis. She has then collapsed. Her D- dimer is raised. ● What is the diagnosis? ○ A: Myocardial infarction ○ B: Pneumonia ○ C: Trauma ○ D: Pulmonary embolismCR: Saddle Pulmonary Embolism (PE) ● PE which extends into both pulmonary arteries. ○ Blue: Pulmonary trunk ○ Red: PE ○ Green: Aorta ■ Ascending and descending ○ Yellow: Superior Vena CavaSpecial Senses Special Senses Axial CT at level Axial CT at level Axial CT at just of upper part of of lower part of below eye level eyes eyesSpecial Senses: Annotated 4. L. Green: Sphenoid sinus 1. Red: Optic nerve 2. Orange: Ethmoid sinuses 5. L. Blue: Ear canal 3. Yellow: Maxillary sinuses 6. D. Blue: Mastoid air cellsSpecial Senses: Pathology ● 8M, 4/7 history of sore right ear with fever. Now presents with pain and swelling behind ear. ● This boy is presenting with a complication of what pathology? ○ A: Acute otitis media ○ B: Meningitis ○ C: Common cold ○ D: Flu L: normal ear, R: sore earSpecial Senses: Otitis Media ● Mastoid cells should be filled with air. On the right, the middle ear is filled with fluid → mastoiditis ● This is a common complication of otitis media.Special Senses: Pathology ● 30F with 5/12 blocked and runny nose and reduced sense of smell. ● What sinus(es) have been affected? ○ A: Ethmoid ○ B: Frontal ○ C: Maxillary ○ D: Both A and CSpecial Senses: Chronic Sinusitis ● Paranasal sinuses should be filled with air. Here the maxillary and ethmoid sinuses are filled with fluid.Special Senses: Pathology ● 50F with left sided sensorineural hearing loss and left sided facial weakness. ● MRI shows a tumour at the left cerebellopontine angle. ● What cranial nerve(s) have been affected? ○ A: VII and VIII ○ B: VII only ○ C: III ○ D: VIII onlyCNS: Acoustic Neuroma ● Aka vestibular schwannoma ● Benign tumour of Schwann cells on cranial nerve VIII. ○ Usually develops at cerebellopontine angle. ○ Looks like an ice cream cone (kind of). ● Can compress CN VIII (vestibulocochlear) and CN VII (facial) and cause problems with hearing, balance, and facial weakness.GIAXRAXR Annotated ● Large bowel in red ○ Large diameter ○ More peripheral ○ Sections ■ Ascending (pink arrow) ■ Transverse (orange arrow) ■ Descending (yellow arrow) ■ Sigmoid (blue arrow) ○ Flexures ■ Hepatic (green arrow) ■ Splenic (purple arrow) ● Small bowel (not annotated) ○ Central ○ Smaller diameterCT Abdomen Axial CT Abdomen: Annotated 1. Red: Gallbladder 2. Orange: Stomach/bowel 3. Yellow: Pancreas a. Sausage like 4. Pink: Aorta 5. D. Green: Spine 6. L. Green: Spleen 7. L. Blue: Kidneys 8. Purple: LiverCT Abdomen: CoronalCT Abdomen Coronal: Annotated GI: Pathology ● 30F presenting with chronic epigastric abdominal pain. ● Which organ is affected? ○ A; Kidney ○ B: Pancreas ○ C: Liver ○ D: StomachGI: Chronic Pancreatitis ● Chronic pancreatitis can lead to calcification of the pancreas. ● The pancreas looks like sausage on CT GI: Pathology ● 40F with 3/12 RUQ pain after eating. ● What is the diagnosis? ○ A: Gastritis ○ B: Cholecystitis ○ C: Gallstones ○ D: Cirrhosis RUQ: Right Upper QuadrantGI: Pathology ● Cholelithiasis: ○ Gallstones in the gallbladder. Can sometimes be multiple (as in the x-ray) or single (as in the CT) ○ Often cause pain in the RUQ after eating.GI Pathology ● 30M with left sided back pain and intermittent haematuria. ● What is the GI abnormality? ○ A: Kidney stone ○ B: Bowel cancer ○ C: Gallstones ○ D: Renal cancerGI: Staghorn Calculus ● Branching kidney stone.GenitourinaryGU: Case 1 ● 70M presenting with 3/12 haematuria and weight loss. ● Where is the abnormality? ○ A: Bowel ○ B: Hip ○ C: Bladder ○ D: kidneyGU: Bladder CancerConclusion ● Lots of imaging techniques exist ○ Know the basics of XR, CT, MRI, US ■ Are they good for bones, soft tissue? ■ Ionising radiation? ○ Know the imaging planes (sagittal, coronal, axial). ○ Know how to recognise T1 vs T2 MRI scans. ● One of the best ways to learn anatomy is by comparing normal with the abnormal! ● The key to imaging is exposure ○ Radiology masterclass (beginner interpretation), MRI master (scrollable scans with labelled anatomy), Radiopedia (more advanced) ○ Use PACS on placement/ask Drs to show you scansQuestions/Feedback Link to our second year event on Thursday! Covering GI, biliary, renal, Feedback Form genitourinary anatomy, and more imaging techniques!!
