Basic Xray, CT and MRI interpretation

1. BASIC IMAGE
INTERPRETATION
RIHAM DESSOUKY, MD
LECTURER OF RADIOLOGY, FACULTY OF MEDICINE,
ZAGAZIG UNIVERSITY

2. X-RAY IMAGES

3. Chest X-ray
1. INCLUSION
2. PROJECTION
3. ROTATION
4. INSPIRATION
5. PENETRATION
6. ARTIFACT
It’s all about QUALITY

4. INCLUSION
1. First ribs?
2. Costophrenic angles?
3. Lateral edges of ribs?

5. INCLUSION
1. First ribs?
2. Costophrenic angles?
3. Lateral edges of ribs?

6. PROJECTION

7. A-P vs P-A

8. A-P vs P-A

9. ROTATION
1. Find the medial ends of the
clavicles
2. Find the vertebral spinous
processes
3. The spinous processes should
lie half way between the
medial ends of the clavicles

10. ROTATION
1. Find the medial ends of the
clavicles
2. Find the vertebral spinous
processes
3. The spinous processes should
lie half way between the
medial ends of the clavicles

12. INSPIRATION

13. INSPIRATION

14. Is there another way ?

15. Is there another way ?

16. PENETRATION
UNDER PENETRATION
1. The left hemidiaphragm is not
visible to the spine
2. Lung tissue behind the heart
cannot be assessed
3. Re-windowing the image using
digital software can
compensate

17. PENETRATION
UNDER PENETRATION
1. The left hemidiaphragm is not
visible to the spine
2. Lung tissue behind the heart
cannot be assessed
3. Re-windowing the image using
digital software can
compensate

18. ARTIFACT

19. ARTIFACT

20. CT IMAGES

21. CT versus MRI images
X-RAY AND COMPUTED
TOMOGRAPHY (CT)
 Map of density of tissues in the body according
to degree of X-ray beam attenuation .
 On X-ray and CT images ; white = high density
= “Hyperdense”. Black = low density
“hypodense”
MAGNETIC RESONANCE
IMAGING (MRI)
 MRI images are a map of proton energy within
tissue of the body
 On MRI images white = high signal =
“Hyperintense” signal.

23. CT BRAIN
It’s all about ANATOMY

24. CT BRAIN
It’s all about ANATOMY

25. CT BRAIN
It’s all about ANATOMY

26. CT BRAIN
It’s all about ANATOMY

27. CT BRAIN
It’s all about ANATOMY

28. CT BRAIN
It’s all about ANATOMY

29. CT BRAIN
It’s all about ANATOMY

30. CT BRAIN
It’s all about ANATOMY

31. CT BRAIN
It’s all about ANATOMY

32. CT BRAIN
It’s all about ANATOMY

33. CT BRAIN
It’s all about ANATOMY

34. CT BRAIN
It’s all about ANATOMY

35. CT BRAIN
It’s all about ANATOMY

36. CT BRAIN
It’s all about ANATOMY

37. MRI IMAGES

38. What are MRI images ?
 MRI images are a map of proton energy within tissue of the body
 On MRI images white = high signal = “Hyperintense” signal.

40. MRI SEQUENCES

41. T1 versus T2 images
T1-WEIGHTED IMAGE
 The timing of radiofrequency pulse
sequences used to make T1 images
results in images which highlight fat
tissue within the body.
 T1 images – 1 tissue type is bright –
FAT
 The timing of radiofrequency pulse
sequences used to make T2 images
results in images which highlight
fat AND water within the body.
 T2 images – 2 tissue types are bright
– FAT and WATER
IT’S ALL ABOUT FAT AND WATER
T2-WEIGHTED IMAGE

42. ANATOMY (SPINE)

44. T1 WEIGHTED IMAGE

46. T2 WEIGHTED IMAGE

47. ANATOMY (BRAIN)

52. Specialized MRI sequences
STIR IMAGE
 STIR (Short Tau Inversion Recovery) images are
highly water-sensitive and the timing of the pulse
sequence used acts to suppress signal coming
from fatty tissues – so ONLY WATER is bright
 A combination of standard T1 images and STIR
images can be compared to determine the
amount of fat or water within a body part
(especially body parts containing bone marrow)
FLAIR IMAGE
 FLAIR images (Fluid Attenuated Inversion
Recovery) are commonly used in brain imaging
 The signal from free fluid – such as
cerebrospinal fluid (CSF) in the ventricles – is
suppressed (compare with the T2 image).
 A combination of standard T2 and FLAIR images
can be used to differentiate pathology from CSF.

53. ANATOMY (SPINE & BRAIN)

54. ANATOMY (KNEE & BRAIN)

55. MRI INTERPRETATION

56. MRI interpretation -Systematic approach
1. CHECK THE IMAGE DETAILS : ALWAYS CHECK THE IMAGE AND PATIENT
DETAILS.

57. MRI interpretation -Systematic approach
1- CHECK THE IMAGE DETAILS : ALWAYS CHECK THE IMAGE AND PATIENT
DETAILS.

58. MRI interpretation -Systematic approach
2- MRI PLANES: ALWAYS CHECK ALL
IMAGES PLANES (AXIAL, CORONAL,
SAGITTAL, OR OBLIQUE)

59. MRI interpretation -Systematic approach
2- MRI PLANES: ALWAYS CHECK ALL
IMAGES PLANES (AXIAL, CORONAL,
SAGITTAL, OR OBLIQUE)

60. MRI interpretation -Systematic approach
3- MRI SEQUENCES:
• LOOK AT THE FAT-SENSITIVE T1
IMAGES WHICH OFTEN PROVIDE
GOOD ANATOMICAL DETAIL OF THE
AREA BEING STUDIED
• COMPARE WITH THE WATER-
SENSITIVE IMAGES – SUCH AS THE
T2-WEIGHTED OR STIR IMAGES

61. MRI interpretation -Systematic approach
3- MRI SEQUENCES:
• LOOK AT THE FAT-SENSITIVE T1
IMAGES WHICH OFTEN PROVIDE
GOOD ANATOMICAL DETAIL OF THE
AREA BEING STUDIED
• COMPARE WITH THE WATER-
SENSITIVE IMAGES – SUCH AS THE
T2-WEIGHTED OR STIR IMAGES

62. MRI interpretation -Systematic approach
4- ABNORMAL MRI SIGNAL:
• CHECK FOR ABNORMALITIES OF MRI
SIGNAL
• DETERMINE THE NATURE OF THE SIGNAL
CHANGE – ABNORMAL FAT OR FLUID?
• NOTE THE ANATOMICAL LOCATION, SIZE
AND SHAPE OF THE ABNORMALITY
• THE COMBINATION OF STANDARD T1
IMAGES (FAT SENSITIVE) AND STIR IMAGES
(WATER SENSITIVE) CAN BE COMPARED TO
DETERMINE THE AMOUNT OF FAT AND
WATER WITHIN A BODY PART

63. MRI interpretation -Systematic approach
4- ABNORMAL MRI SIGNAL:
• CHECK FOR ABNORMALITIES OF MRI
SIGNAL
• DETERMINE THE NATURE OF THE SIGNAL
CHANGE – ABNORMAL FAT OR FLUID?
• NOTE THE ANATOMICAL LOCATION, SIZE
AND SHAPE OF THE ABNORMALITY
• THE COMBINATION OF STANDARD T1
IMAGES (FAT SENSITIVE) AND STIR IMAGES
(WATER SENSITIVE) CAN BE COMPARED TO
DETERMINE THE AMOUNT OF FAT AND
WATER WITHIN A BODY PART

64. MRI interpretation -Systematic approach
4- OTHER IMAGING:
• CORRELATE THE IMAGES WITH PREVIOUS
IMAGING – EITHER PREVIOUS MRI OR
OTHER IMAGING MODALITIES
• THIS PLAIN X-RAY GIVES A GOOD OVERVIEW
OF THE ANATOMY AND SHOWS GOOD
DETAIL OF THE CORTICAL BONE
• THE MRI PROVIDES NO DETAIL OF THE
CORTICAL BONE, BUT SHOWS THE BONE
MEDULLA AND SOFT TISSUE STRUCTURES –
SUCH AS THE CRUCIATE LIGAMENTS – NOT
VISIBLE ON THE X-RAY IMAGE

65. MRI interpretation -Systematic approach
4- OTHER IMAGING:
• CORRELATE THE IMAGES WITH PREVIOUS
IMAGING – EITHER PREVIOUS MRIS OR
OTHER IMAGING MODALITIES
• THIS PLAIN X-RAY GIVES A GOOD OVERVIEW
OF THE ANATOMY AND SHOWS GOOD
DETAIL OF THE CORTICAL BONE
• THE MRI PROVIDES NO DETAIL OF THE
CORTICAL BONE, BUT SHOWS THE BONE
MEDULLA AND SOFT TISSUE STRUCTURES –
SUCH AS THE CRUCIATE LIGAMENTS – NOT
VISIBLE ON THE X-RAY IMAGE

66. REVISION

69. CT BRAIN
It’s all about ANATOMY

70. QUIZ

71. FOR EACH IMAGE
1. Imaging modality / sequence
2. Anatomic location
3. Anatomy (if numbered)

83. References
https://www.radiologymasterclass.co.uk