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Ultrasound

Can be used to examine blood flow

Ultrasound Principle

 

Ultrasound uses high-frequency sound waves to produce images of inside organs. Prior to the examination, a special lubricating jelly, which helps transmit sound wave, is applied on the skin surface. When the transducer sends high-frequency sound waves through the body, the waves echo as an internal structure is reached and these echoes are subsequently reflected back to form images. Depending on the area being examined, the differences in echo time and intensity give rise to a unique image.

 

The ultrasound image is white or grey depending on the intensity of the reflection. Unlike other imaging modalities, ultrasound does not detect tissue density but rather the reflection of sound. Water, such as in cystic lesions, hardly reflects echoes and thus appear black on an ultrasound image. Conversely, highly dense tissues, such as bone or stones, readily reflect echoes and thus appear bright white on an ultrasound.

 

Moreover, as ultrasound produces real-time images, it can be used to examine blood flow. Coupled with the advantage of being radiation-free, it is widely used in pregnancy women for assessing fetal heart rate or detecting the location of placenta.

 

However, as Ultrasound does not travel well through air or bone, it might not be effective at imaging bony structures or hollow organs, such as the stomach and intestines. Should there be any concerns, patients may seek advice from doctors for the most effective imaging option.

 

Below is the information regarding the uses, safety issues, concerns of undergoing an Ultrasound examination and its advantages and limitations in comparison with other types of imaging modalities.

Ultrasound Uses

 

  • Obstetric examination
  • Diagnosing gallbladder diseases
  • Assessing blood flow
  • Localizing the site for biopsy
  • Detecting breast tumour
  • Examining thyroid
  • Examining reproductive organs and prostate
  • Examining inflammatory joint diseases
  • Diagnosing degenerative bone diseases
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Ultrasound Safety

 

Ultrasound is by far the safest diagnostic examination without any known risks. Rarely do patients experience mild discomfort when the transducer is applied. Should you experience it, please inform our healthcare professionals immediately.

Diagnosis of Cancer|Imaging Tests

 

Common tests for diagnosing cancer includes blood test, urine test, imaging test, biopsy and genetic test. Apart from diagnosing cancer, these investigations can also localise the primary site, differentiate the specific cancer cell type, perform cancer staging, identify whether there is metastasis, formulate treatment plan, monitor disease progression and detect recurrence. Below is the information regarding different tests.

 

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Ultrasound

Applications:

  • Localize the site of primary cancer
  • Guide biopsy
  • Detect pathological change of tissues and vascular flow

Strengths:

  • No radiation is involved
  • Short examination time
  • Real-time monitoring of change is allowed

Limitations:

  • Low penetration power to deep tissues
  • Low spatial resolution
  • Operator-dependent result
電腦掃描

CT

Applications:

  • Localize the site of primary cancer
  • Detect pathological change of tissues
  • Guide biopsy
  • Allow cancer staging
  • Formulate treatment plan
  • Evaluate treatment effectiveness
  • Detect recurrence

Strengths:

  • Short examination time

Limitations:

  • Radiation is unavoidable
  • Relatively low spatial resolution for soft tissue structures such as muscle and nerve
  • Risk of contrast allergy
正電子掃描

PET-CT

Applications:

  • Localize the site of primary cancer
  • Detect pathological change of tissues
  • Guide biopsy
  • Allow cancer staging
  • Predict prognosis
  • Formulate treatment plan
  • Evaluate treatment effectiveness
  • Detect metastasis or recurrence

Strengths:

  • High sensitivity in picking up cancer at early stage
  • High accuracy

Limitations:

  • Radiation is unavoidable
  • Injection of radiotracers is needed
  • Might not be suitable for diabetic patients
磁力共振

MRI

Applications:

  • Localize the site of primary cancer
  • Detect pathological change of tissues
  • Differentiate benign tumor from malignant cancer
  • Formulate treatment plan (i.e. localisation for surgical planning or radiation therapy)
  • Monitor treatment progress
  • Evaluate treatment effectiveness
  • Detect recurrence

Strengths:

  • No radiation is involved
  • Better image resolution for soft tissue structures such as muscle and nerve
  • Multi-planar 2D and 3D images are available
  • Contrast allergy is rare

Limitations:

  • Metallic object is contraindicated in a MRI suite
  • Risk of claustrophobia
  • Long examination time

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Our Screening Service

  • MRI
  • PET-CT
  • CT
  • 3D Mammography
  • Ultrasound
  • X-Ray
  • Blood Test