NEET MDS Lessons
Radiology
Fractures of the Zygomatic Arch
- Structures: Zygomatic arch, zygomatic bone.
- Best Views:
- Submento-Vertex View: Provides a clear view of the zygomatic arch and helps assess fractures.
- Waters View: Useful for visualizing the zygomatic bone and maxillary sinus.
- Reverse Townes View: Can also be used to visualize the zygomatic arch.
Base of Skull
- Structures: Base of the skull, cranial fossae.
- Best Views:
- Submento-Vertex View: Effective for assessing the base of the skull and related fractures.
Maxillary Sinus
- Structures: Maxillary sinus, zygomatic bone.
- Best Views:
- Waters View: Excellent for visualizing the maxillary sinus and any associated fractures.
Fractures of Zygoma
- Structures: Zygomatic bone, zygomatic arch.
- Best Views:
- Waters View: Good for assessing zygomatic fractures.
- PA View: Provides a frontal view of the zygomatic bone.
- Reverse Townes View: Useful for visualizing the zygomatic arch.
Nasal Septum
- Structures: Nasal septum, nasal cavity.
- Best Views:
- PA View: Useful for assessing the nasal septum and any associated fractures.
Condylar Neck Fractures
- Structures: Mandibular condyle, neck of the condyle.
- Best Views:
- Lateral Oblique View (15°): Good for visualizing condylar neck fractures.
- Transpharyngeal View: Useful for assessing the condylar region.
Medially Displaced Condylar Fractures
- Structures: Mandibular condyle.
- Best Views:
- Lateral Oblique View (30°): Effective for visualizing medially displaced condylar fractures.
Coronoid Process of Mandible
- Structures: Coronoid process.
- Best Views:
- PA View of Skull: Can help visualize the coronoid process.
Fractures of Ramus and Body of Mandible
- Structures: Mandibular ramus, body of the mandible.
- Best Views:
- Lateral Oblique View (15°): Useful for assessing fractures of the ramus and body of the mandible.
Horizontal Favorable and Unfavorable Fractures of Mandible
- Structures: Mandible.
- Best Views:
- Lateral Oblique View (30°): Effective for evaluating horizontal fractures.
Bony Ankylosis of TMJ
- Structures: Temporomandibular joint.
- Best Views:
- CT Scan: Provides detailed imaging of bony structures and ankylosis.
Fibrous Ankylosis of TMJ
- Structures: Temporomandibular joint.
- Best Views:
- CT Scan: Useful for assessing fibrous ankylosis.
Internal Derangement of the Disk
- Structures: TMJ disk.
- Best Views:
- MRI: The best modality for evaluating soft tissue structures, including the TMJ disk.
Disk Perforation
- Structures: TMJ disk.
- Best Views:
- MRI: Effective for diagnosing disk perforation.
Arthrography
- Structures: TMJ.
- Best Views:
- Arthrography: Can be used to assess the TMJ and visualize the disk and joint space.
RELATIVE RADIO SENSITIVITY OF THE TISSUES
Radiosensitive (2500 r or less kills or seriously injures many cells)
Lymphocytes and lymphoblasts
Bone marrow (myeloblastic and erythroblastic cells)
Epithelium
Germ cells (testes and ovary)
Radioresponsive (2500-5000 r kills or seriously injures many cells)
Epithelium of skin and many appendages.
Endothelium of blood vessels
Salivary glands
Growing bone and cartilage.
Conjunctiva, cornea and lens of eye
Collagen and elastic tissue(fibroblasts themselves are resistant)
Radioresistant (over 5000 r are required to kill or injure many cells)
Kidney
Liver
Thyroid
Pancreas
Pituitary
Adrenal and parathyroids
Mature bone and cartilage
Muscle
Brain and other nervous tissue.
The numbers represent the minimum damaging doses; a gray and a sievert represent roughly the same amount of radiation:
• Fetus--2 grays (Gy).
• Bone marrow--2 Gy.
• Ovary--2-3 Gy.
• Testes--5-15 Gy.
• Lens of the eye--5 Gy.
• Child cartilage--10 Gy.
• Adult cartilage--60 Gy.
• Child bone--20 Gy.
• Adult bone--60 Gy.
• Kidney--23 Gy.
• Child muscle--20-30 Gy.
• Adult muscle--100+ Gy.
• Intestines--45-55 Gy.
• Brain--50 Gy.