Interventional & Treatment Instruments, Artificial Intelligence, New Transducers, New Physics Paradigm

Intravascular/Endovascular Ultrasound

Imaging within blood vessels

Femoral V access in cath lab

Specialized catheter with mini transducer at the tip - produces multi-element electronic (annular) arrays

Uses of Intravascular/Endovascular Ultrasound

Supplement to contrast angiography of coronary arteries

Supplement to contrast angiography of peripheral arteries

Evaluation of venous thrombosis

Assessment of AAA before, during and after interventions/repair

Endosonography

Visualizes GI tract or bronchial tract

Radial Tx - visualization

Linear Tx - FNA or therapeutic interventions

Uses of Endosonography

Staging GI malignancies

Evaluating pancreaticobiliary disease

Evaluating subepithelial abnormalities (GI lining)

Evaluating extraluminal abnormalities (ABNL lymph nodes)

Staging of lung cancer

Therapeutic - Drainings, nerve blocks, drug delivery

High Intensity Focused Ultrasound (HIFU)

Uses heat & cavitation from ultrasound to deliver therapeutic treatments

Performed under ultrasound or MRI guidance

Transducers designed and manipulated to have a very accurate focal spot - goal is to heat/cavitate tissues

Uses of High Intensity Focused Ultrasound (HIFU)

Benign & malignant tumor ablation

Intervention with essential tremors, Alzheimer's, Parkinson's, Depression/Anxiety, etc...

Disruption of blood brain barrier for delivery of treatment agents into brain tissue

Liquifying intracerebral hemorrhage clot

Advantages of High Intensity Focused Ultrasound (HIFU)

Reduced toxicity compared to other ablation techniques

Less painful & invasive

Lower cost than surgery

Less anesthesia

No scarring

Decreased risk of infection

Disadvantages of High Intensity Focused Ultrasound (HIFU)

Limited by patient movement

Near field heating (possible skin burns) & pain

May have long treatment times

Localized unintended tissue damage

Fusion Imaging

Overlaying/co-registration of images from the same or different imaging modalities

Computer software matches ultrasound imaging with CT, MRI, or PET/CT

Uses of Fusion Imaging

Liver biopsies

Guiding ablations

Other guidance procedures

Advantages of Fusion Imaging

Improved diagnostic accuracy

More accurate guidance during procedures

Better characterization of pathologies

Disadvantages of Fusion Imaging

Breathing motion real-time registering with static MRI/CT images

Misregistration of data

Still relatively new

Artificial Intelligence (AI)

Use of computer software to develop machine learning - recognition of patterns in medical images to assist with diagnosis - to mimic human cognition

Ways AI is Used in Ultrasound

Used to assist in recognizing patterns in pathology to speed up workflow & aid diagnosis

TIRADS

BIRADS

Scoring liver fibrosis

Fetal lung maturity

Fetal brain

Ventricular wall motion

Detection of heart diseases

Carotid artery intimal thickness

Micromachined Ultrasound Transducers (MUTs)

Tiny transducers

Usually much higher frequencies

Often used for interventional type imaging or newer hand-held transducers that connect to tablets/cell phones - Butterfly

Capacitive Micromachined Ultrasonic Transducer (cMUT)

Parallel-Plate Capacitor

Integrated with circuitry - "plug and play" design

Higher frequency range

Piezoelectric Micromachined Ultrasonic Transducer (pMUT)

Thin piezoelectric film rather than thick crystal

Integrated with circuitry - "plug and play" design

Lower frequency range

Principle 1

Physical beams

1:1 ratio of pulses to scan lines

Pulse length & width determines detail resolution

Best resolution at focus

Adjusting focus affects frame rate & reduces temporal resolution

Principle 2

Virtual beams

Fewer pulses to scan lines

Computer processing determines resolution & frame rate

Traditional calculations of resolution & frame rate are not applicable

Sonographic Improvements from Principle 2 Instrumentation

Detail resolution

Contrast resolution

Temporal resolution

Sensitivity & penetration

Doppler operation

Reduced artifacts