20 High Yield Radiology Flashcards NEET PG 2025

Flashcard 1 

Damage and Penetration 

• Damage and penetration are inversely related
• Gamma rays have the maximum penetration power out of alpha, beta, X-rays
• They go through the body with a higher penetration
• Gamma, with a maximum penetration causes minimum damage to the body
• Alpha, with a minimum penetration uses maximum damage to the body
• Damage caused: Alpha > beta > X-ray > Gamma
• Penetration caused: Gamma > X-ray > Beta > Alpha
• Decreased penetration means increased damage
• Alpha is the most damaging/most ionizing/maximum linear energy transfer (LET)
• The penetrating power of Neutrons > Gamma

Flashcard 2

CT vs MRI

• Tunnel is absent in CT machine (Image 1)
• In MRI machine, tunnel is present (Image 2)
• MRI is contraindicated in claustrophobic patients
• MRI can be done in Claustrophobic patients using sedation
• Unit to measure the strength of the magnet used in MRI - Tesla
• MRI is contraindicated with metallic foreign body, pacemaker, cochlear implant, knee implant, Now MRI compatible implants are available
• The walls of the CT room are coated with Lead
• The walls of the MRI room have Faraday's cage. It is used in MRI room to prevent the disturbance from the outside radiowaves with the MRI radiowaves
• CT is always faster as it takes only 2 mins for CT brain whereas MRI brain takes 20 mins, hence CT is preferred in emergencies.

• White skull bone cortex - CT (Image 1)
• Black skull bone cortex - MRI (Image 2)
• White outline that is seen is the outer most fat in the scalp, Fat appears white on MRI
• Knee image - The bone cortex is white → CT (image 3)
• Marrow containing fat appears black on CT and white on MRI (image 4)
• Always look for the bone cortex

Flashcard 3

Acute Radiation Syndrome

Flashcard 4

Coin in Trachea vs Esophagus

Trachea	Esophagus
Appears as a SLIT in AP view Appears CIRCULAR in lateral view	Appears CIRCULAR in AP view Appears as a SLIT in lateral view

Flashcard 5

White Out Hemithorax

	Increased density	Decreased air	Fluid
Seen in	Consolidation	Collapse Pneumonectomy	Pleural Effusion
Tracheal shift	No tracheal shift	Shift to the same side	Shift to the opposite side

Black Out Hemithorax

	Increased air	Decreased density	Decreased vascular markings
Seen in	Pneumothorax Emphysema	Post mastectomy Poland syndrome	Pulmonary embolism (Westermark sign)

Flashcard 6

Pneumomediastinum

• Air in the mediastinum (Image 1): air surrounds the mediastinal structures
• Due to esophageal rupture- Boerhaave's syndrome
• On X-ray: Continuous diaphragm sign (Image 2a & 2b)- Entire diaphragm is visualized well (heart separated from diaphragm)
• Naclerio V sign (Image 3): Lucency in cardiophrenic region
• Spinnaker sail sign: Separation of thymus from heart due to air in between
• Angel wing sign (Image 4a & 4b): Thymus seen bilaterally
• Gingko leaf sign (Image 5): Air between fibers of pectoralis major i.e pneumomediastinum along with subcutaneous emphysema going into the muscle fibers.

Flashcard 7

Pleural effusion vs Hydropneumothorax

Pleural effusion	Hydropneumothorax
Ellis s curve Blunting of costophrenic angle	Horizontal air fluid level

Flashcard 8

Bronchiectasis

• Dilatation of bronchi
• Normally, bronchus tapers down peripherally
• In Bronchiectasis, there is no tapering and bronchi remain parallel- Tram track sign (Image 1)
• Signet ring sign (Image 2): Vessel adjacent to the dilated bronchus

Flashcard 9

Hydatid Cyst

• Caused by echinococcus granulosus
• H/O contact with cattle or dog
• Water lily sign (Image 1): Lesion with air fluid level, and membranes floating in the fluid level.

Flashcard 10

Congenital Diaphragmatic Hernia

1. Bochdalek:
   • Left posterolateral
   • More common
   • Pulmonary hypoplasia
   • Shift to opposite side
2. Morgagni:
   • Right anterior
   • Bag Mask Ventilation is C/I.
   • Clinical Features : Scaphoid abdomen with respiratory distress.

Flashcard 11

Heart Chambers on CT

• Anteriormost chamber of the heart: Right ventricle
• Posterior most chamber of the heart: Left atrium
• Chamber On the left: Right atrium
• Chamber On the right: Left ventricle

Flashcard 12

Mickey Mouse Sign

In the groin region- saphenofemoral junction

• Femoral vein
• Femoral artery
• Great saphenous vein

• Portal triad:
  • Portal vein
  • CBD
  • Hepatic artery

Flashcard 13

Biconvex hemorrhage/Lentiform hemorrhage

• Do not cross the sutures
• Is Extradural Hemorrhage (EDH)
• Is due to rupture of Middle Meningeal Artery
• Associated with adjacent bone fractures
• Lucid interval is common
• Hypodense area: S/O active hemorrhage → swirl sign; in need of surgical management
• Acute hemorrhage → hyperdense on CT

Flashcard 14

Hummingbird Sign (Midbrain atrophy with Bulging of pons)

seen in progressive supranuclear palsy (patient has history of frequent falls)

Flashcard 15

Vascular Malformations

When a neonate presents with hydrocephalus and heart failure → Vein of Galen Malformation (VOGM).

VOGM is an AV fistula → lead to heart failure. Multiple prominent vessels give off a bag of worms appearance (Image A)→ AV malformation. In angiography (Image B)→ entanglement of vessels is called Nidus. Popcorn appearance on MRI brain → Cavernoma (Cavernous angioma) (Image C).

Flashcard 16

Craniopharyngioma Vs Pituitary adenoma

Craniopharyngioma	Pituitary adenoma
More common in a childIt is in the center /midline It has calcification It has cystic components Seen in suprasellar region	Widened sella turcica Figure of 8 appearance Its s/o primary pituitary macroadenoma

Flashcard 17

Epiglottitis Vs Croup (laryngotracheobronchitis) 

Epiglottitis	Croup
Inflammation of the epiglottis	Inflammation of the airway
Thumb sign: Edematous and thickened epiglottis	Steeple sign: Narrowed lumen due to wall edema

Flashcard 18

Pneumoperitoneum 

Air in the peritoneal cavity due to rupture of hollow viscus organ (perforation, post laparoscopy).

Flashcard 19

Zenker's Diverticulum 

Triad of:

• Dysphagia
• Regurgitation
• Halitosis

Present in upper esophagus. False diverticulum; seen in killian's dehiscence; directed posteriorly towards vertebra. Age group: Elderly (with weak killian's dehiscence). IOC- Barium swallow.

Flashcard 20

Acute Appendicitis

• RIF pain- tenderness at McBurney's point
• 1st investigation: USG
• Best investigation: CECT (helps to visualize retrocecal appendix)
• Distended appendix >6mm with surrounding fluid
• Inflamed appendix is non compressible

Download the PrepLadder app now and unlock a 24-hour FREE trial of premium high-yield content. Access Smarter Video Lectures also in हिंglish, Game Changing Qbank, Audio QBank, Structured Notes, Treasures, Mock test for FREE to ace your NEET PG preparation. Elevate your study experience and gear up for success. Start your journey with PrepLadder today!