CT CHEST TYPE

CT Types

1.Standard 2.High Resolution3.Low Dose4.CT Angio

Axial lung window Coronal C+ arterial phase

Normal CT chest

STANDARD CT Slice thickness: 3-10 mm scans a large volume, very quickly Covers the full lung +/- contrast

Indications CXR abnormality Pleural and mediastinal abnormalities Lung cancer staging F/U metastases Empyema vs abscess

HIGH RESOLUTION (HRCT)

HIGH RESOLUTION (HRCT)

It is used in the diagnosis of various health problems, though most commonly for lung disease. It involves the use of special computed tomography scanning techniques to assess the lung parenchyma.

STANDARD CT HRCT

HIGH RESOLUTION (HRCT)

narrow x-ray beam collimation:1-1.3mm vs. conventional 3-10mm

cross sections are further apart: 10 mm

high definition images of lung parenchyma:vessels, airspaces, airway and interstitium

No contrast

HIGH RESOLUTION (HRCT)

 Indications Hemoptysis Diffusely abnormal CXR Normal CXR with abnormal PFT’s Baseline for pts with diffuse lung disease Solitary pulmonary nodules Reversible (active) vs. non-reversible (fibrotic)

lung disease Lung biopsy guide F/U known lung disease Assess Rx response

LOW DOSE

Baseline Findings - ELCAP

According to ( Early Lung Cancer Action Program)Low dose CT greatly increases the likelihood

of detection of NCN and early lung cancer compared with chest radiography NCN: 3 times as commonly Malignant tumors: 4 times as commonly Stage I tumors: 6 times as commonly

Low-dose CT: Lung cancer

LOW DOSE

• Premise:lower dose radiation will not reduce the diagnostic

functionality of the scan (eg. 250 mAs › 50 mAs)• Detail is decreased

Uses Screening– ongoing trials

F/U– infections– post lung transplant– metastases

ANGIOGRAPHY (CTA) • contrast injected into peripheral vein• injection timing/rate controlled automatically • dye is where you want it during scan• replaced conventional catheter angiogram

Indications Pulmonary embolism Aortic aneurysms Aortic dissection

Risks Iodinated contrast:– Allergic/ nephrotoxic

69- year old female with shortness of breath

ANGIOGRAPHY (CTA)

CT pulmonary angiogram (CTPA)Example of a CTPA ,

demonstrating a saddle embolus.

The white area above the center is the pulmonary artery, opacified by radiocontrast. Inside it, the grey matter is blood clot. The black areas on either side are the lungs, with around it the chest wall.

References

1. https://radiopaedia.org/cases/normal-ct-chest2. http://www.slideshare.net/divitto1/approach-to-ct-chest-5783. https://en.wikipedia.org/wiki/High-resolution_computed_tomography4. http://slideplayer.com/slide/download/5. Henschke et al, Lancet 1999; 354:99-1056. I-ELCAP is an international, collaborative group consisting of experts on lung cancer and related issues

from around the world.

Made by; Abdullah Salem Al-habeeb