Lecture CXR CT MRI and Chloroquine Cardiomyopathy

LECTURE HEART CXR CT MRI CARDIOMYOPATHY

Notes Scales and Music

The Cardiac Evaluation on the CXR – PA

First step – Is the heart enlarged?

Cardiothoracic ratio as a global method

Cardiothoracic Ratio

Border Forming Parts of the Heart

FRONTAL CXR AND PARTS OF THE HEART

Two Basic Shapes of Cardiomegaly

- Oval down and outer of LV
- Triangular RV disease
Each of the Chambers
LA, LV, RA, V

CARDIOMEGALY – TWO BASIC TYPES -OVOID and TRIANGULAR
The ovoid form which suggests left ventricular dominance and triangular form which suggests right ventricular dominance.
Ashley Davidoff MD

LVE

Subtle Ovoid Form Suggestive on the PA and Confirmed on the Lateral – Using Both Views

ISCHEMIC CARDIOMYOPATHY S/P RCA OCCLUSION
62 year old female with acute chest pain atrial fibrillation, hypotension admitted to ICU. Clinical evaluation was considered to be non-ischemic cardiomyopathy with EF by echo of about 20%. She was hypotensive and, in the ICU, and CXR showed acute CHF with cardiomegaly. The TEE was more in keeping with segmental dyssynergy, Cardiac cath showed occluded RCA bot good collateralization from the LAD. MRI showed subendocardial LGE in the inferior and inferolateral portions of the LV consistent with a prior infarction and EF of 20%
Ashley Davidoff MD

Triangular Heart with RVE

With Mitral Stenosis

MITRAL STENOSIS
Triangular shaped heart with RVE LAE
Ashley Davidoff MD

With Pulmonary Hypertension

PULMONARY HYPERTENSION
Frontal x-ray with triangular shaped heart due to pulmonary hypertension with enlarged MPA and enlarged descending RPA .
Ashley Davidoff MD

The Enlarged Left Atrium

Widened Carinal Angle

Double Density

Straightened right Heart Border – prominent LA appendage

Triangular Heart

Right Atrial Enlargement

- enlarged, globular heart
- narrow pedicle
- gross enlargement of the right atrial shadow, i.e. increased convexity in the lower half of the right cardiac border
  - right atrial convexity is more than 50% of the cardiovascular height
  - right atrial margin is more than 5.5 cm from the midline

RIGHT ATRIAL ENLARGEMENT ON FRONTAL X-RAY
The right atrium is the most difficult chamber to assess unless it is very large in which case it will present on the frontal CXR with a very large right paravertebral border. This is a 71 year old female person with rheumatic heart disease with pulmonary hypertension and tricuspid regurgitation hence resulting in a large right atrium (RAE)
Ashley Davidoff MD

If there is time you may want to run through the collage of congenital heart disease cases

The Shapes of the Heart in Health and Disease

From top left ti right and across the rows they are: The normal heart , the “football” of LV enlargement the “triangle” or “proud breast” of RV enlargement, “snowman” of total anomalous pulmonary venous return, big PA mogul of pulmonary hypertension, “egg on its side” of D transposition of the great vessels, “boot shaped” heart seen in both pulmonary atresia and Tetralogy of Fallot, the long smooth combined Ao and PA mogul that has a differential diagnosis of L transposition, absence of the pericardium, and juxtaposition of the atrial appendages, the box shaped large heart of Ebstein’s anomaly, dextrocardia , and the water bottle” heart of a large pericardial effusion.

07197 Images are a combination of images from a personal collection and borrowed from the internet for educational purposes only. Some of the sources are unknown and are used for educational purposes alone 86774b02

TCV Links for extra info

Frontal CXR and Cardiomegaly

The Cardiac Evaluation on the CXR -Lateral Exam

Normal and Abnormal

THE CV STRUCTURES VISIBLE ON THE LATERAL EXAM –

A normal lateral examination of the chest X-ray is shown to exemplify the positioning of the cardiac chambers showing the right ventricular outflow tract (RVOT) anteriorly, the left atrium (LA) posteriorly and superiorly, the left ventricle (LV) posteriorly and inferiorly and the inferior vena cava (IVC) as a separate shadow posterior to the LV.
Ashley Davidoff MD

RULE OF 1/3 rds

Normal Anteriorly
- RV takes up 1/3 of retrosternal space ((Sternomanubrial jn to xiphi)
Inferiorly
- LV takes up 1/3 of the hemidiaphragm
Posteriorly
- LA 1/3, LV 2/3

The rule of thirds on the lateral examination states that;
the anterior border of the chest is divided into thirds; 1/3 for the RVOT and 2/3 for the retrosternal air space
the posterior border of the heart is divided into thirds; 1/3 for the LA and 2/3 for the LV.
the diaphragmatic border is divided into thirds; 1/3 for the LV and 2/3 for the rest of the diaphragm
Ashley Davidoff MD
15416C02Wlateral.8 rule of thirds

Abnormal
- - Anteriorly
    - RVE
      - RV > 1/3 of retrosternal space
  - Posteriorly
    - LAE
      - LA >1/3 of posterior heart border
      - Also elevates left main stem bronchus

Normal vs Abnormal – Left Ventricular Enlargement

Assessment of the Size of the left Ventricle (LV) on the Lateral CXR
Lateral examination of a chest x-ray (CXR) shows the normal in the upper row (a,b) and the abnormal and enlarged in the bottom row (c,d).
The objective evaluation is based on the relative positioning and size of the LV (white arrowhead) in relation to the IVC, (blue arrowhead), and the left hemidiaphragm (pink arrowhead)
Ashley Davidoff MD
15416C02Wlateral LV01L.8

RVE

NORMAL and RVE
The normal lateral CXR (a,b), shows anterior and superior border of the heart (anterior white arrowhead) occupying 1/3 of the border between the sternomanubrial junction and the diaphragm.
The posterior and inferior white arrowhead shows the posterior border of the heart occupied by the RV taking up 1/3 of the distance of the diaphragm.
Images c and d represent left ventricular enlargement showing that the LV occupies about half the length of the diaphragm, (red arrowhead) while the retrosternal distance is unchanged and normal (white arrowhead).
Ashley Davidoff MD

Normal vs Abnormal – RVE and LAE

LATERAL EXAMINATION RVE AND LAE – MITRAL STENOSIS PULMONARY HYPERTENSION AND COR BOVINUM
71 year old Asian female with rheumatic heart disease dominated by calcific mitral stenosis mild MR, moderate tricuspid regurgitation

Right Atrial Disease on the Lateral _ Only when it is very enlarged

Where is the Right Atrium?

RIGHT ATRIUM (RA) on the LATERAL
In the normal patient the RA is not border forming and is not visible. It lies to the right and slightly inferior and anterior to the left atrium, posterior and superior to the right ventricle, and to the right and superior to the left ventricle
Ashley Davidoff MD

Axial Imaging Explaining why the RA cannot be see on the Lateral –
- since it is neither anterior nor posterior border forming

NORMAL CARDIAC ANATOMY ON A GATED CT SCAN
Axial images through the RA show the right atrial appendage in the top row and the body of the RA in the bottom row, neither of which would be visible on the lateral exam.
Ashley Davidoff MD

When the RA enlarges-
- it moves laterally and anteriorly see CT below so that it can now be an anterior border forming structure

DOMINANT RIGHT ATRIAL ENLARGEMENT CT SCAN – RETROSTERNAL AIRSPACE OCCUPIED MOSTLY BY THE RA
83-year-old male with significantly enlarged right atrium, as well as a mildly enlarged left atrium with evidence of CAD, atrial fibrillation and hypertension.
On CT scan the right atrium and appendage (blue overlay (b,d,f) are positioned against the anterior chest wall and sternum (red arrowheads). On the superior most images (b,d) the RV is not present and only takes up a retro-sternal position alongside the right atrium on the most inferior image (f)
Ashley Davidoff MD

RAE on the Lateral

DOMINANT RIGHT ATRIAL ENLARGEMENT. LATERAL EXAMINATION
83-year-old male with significantly enlarged right atrium, as well as a mildly enlarged left atrium with evidence of CAD, atrial fibrillation and hypertension.
On the lateral CXR, the right atrium the blue line overlay indicates the position of the RV against the anterior chest wall. In addition, the right atrial appendage is so large (see CT below) that it lies against the sternum. The RA therefore occupies the entire retrosternal air space and results in decrease of the retrosternal airspace. This is the rare instance when the RA shares with, but dominates the anterior retrosternal position with the RV.
Ashley Davidoff MD

DOMINANT RIGHT ATRIAL ENLARGEMENT
83 year old male with significantly enlarged right atrium, as well as a mildly enlarged left atrium with evidence of CAD, atrial fibrillation and hypertension.
On CT scan the right atrium is positioned against the anterior chest wall. In addition, the right atrial appendage is so large that it lies against the sternum as well resulting in a decrease in the retrosternal air space. On the lateral, the cardiac shadow takes up more than 1/2 of the diaphragm. In this uncommon instance this finding is caused by the enlarged right atrium rather than LVE
Ashley Davidoff MD

Davidoff with Notes Scales and Music of the Axial Imaging of the Heart

NOTES SCALES AND MUSIC – AXIAL IMAGING OF THE HEART

Notes

As we scan from superior to inferior

NOTES OF THE HEART ON CT
As we start from top to bottom we scan through the PA, aorta, then LA RA, RV and LV
Ashley Davidoff MD

Scales

Going superior to inferior and clockwise

1st stop Aorta LA

- - FIRST STOP
    Max AP dimension of the LA in the region of the aorta. At this point the LA looks rectangular
    Ashley Davidoff MD

2nd Stop
4 chamber

NORMAL VOLUME EVALUATION OF THE ATRIA AND VENTRICULAR CAVITIES ON A GATED CT SCAN
Axial images through the 4 chambers at the level of the A-V valves during diastole (mitral valve open) enables an approximate volume evaluation of the chambers. The atria are approximately the same volumes, and are about 1/3 the volume of the ventricles. The right ventricle (RV) is about 2/3 the volume of the left ventricle (LV)
Ashley Davidoff MD

3rd Stop MPA and Bifurcation

What to do at each stop

Stop 1

NORMAL LINEAR DIMENSION OF THE LA ON A GATED CT SCAN

Stop 2

HOW THE SCALES PROCEED
Clockwise Rotation

NORMAL LINEAR DIMENSION OF THE RIGHT ATRIUM ON A GATED CT SCAN
Axial images through the body of the right atrium (RA) at the level of the tricuspid valve shows a linear dimension of 4.2cms (normal up to about 5cms)
Ashley Davidoff MD

NORMAL LINEAR DIMENSION OF THE RIGHT VENTRICULAR CAVITY ON A GATED CT SCAN

NORMAL LINEAR DIMENSION OF THE LEFT VENTRICULAR CAVITY ON A GATED CT SCAN

NORMAL THICKNESS OF THE LV SEPTUM AND FREE WALL ON A GATED CT SCAN

Get a Sense of Relative Volumes

NORMAL VOLUME EVALUATION OF THE ATRIA AND VENTRICULAR CAVITIES ON A GATED CT SCAN

3rd Stop PA and Aorta

NORMAL LINEAR DIMENSION OF THE MPA AND AORTA ON A GATED CT SCAN

Practice Practice Practice

Music
- LAE
- RAE
- RVE
  - RV dilated
  - RVH
- LVE
  - Dilated LV
  - LVH

Thus

First Image
- top left image
  - sizes to remember (approximate +/- 1cms) Mantra 4,5,4,5
- top right image –
  - at the level of the mitral valve the atria are about the same size and about 1/3 the size of their respective ventricles
- bottom left
  - at this level the overall volume of the RV is about 2/3 the size of the LV
- bottom right
  - In diastole (if you can appreciate open mitral valve) thickness is up to 1.2 cms – 1.4 is upper limits normal
Next series of images – as you start from the top of the heart on the axial image and follow the order so you can remember mantra (4,5,4,5 – of the approx sizes of the structures)
- Where to measure LA –
  - Look for the aorta – and then look up and down till you find max dimension
- Where to measure RA
  - See where the approx position of TV and the from posterior wall to the TV
- Where to measure RV and LV cavity dimensions
  - – at at the level of the A-V valves or mid septum by the moderator band
- LV wall thickness
  - Same level
- Overall Volume Assessment
  - At the same level Rule of thirds for volume
- MPA and Ao
  - At bifurcation of MPA
- Systole and diastole to look assess EF
  - On gated images – compare peak systole to diastole using eyeball and mitral or tricuspid valve and use rule of thirds

Summary

NOTES SCALES AND MUSIC
At the level of the mitral valve which is also about mid septum, the chambers are relatively all best visualised. This is a place where approximate size can be evaluated