Emergency Cases

Dr Grobbelaar is available for emergency cases.

082 55 16 222 / 200

Practice Location

Suite 5, Hermanus Mediclinic
Ravenscroft Street, Hermanus.

Consulting Hours


8:00am - 4:30pm


8:00am - 4:30pm


8:00am - 4:30pm


8:00am - 4:30pm


8:00am - 4:30pm

Weekends & Public Holidays


Practice Background

Dr Deirdré Grobbelaar MBChB (UP) 1987 completed ultrasound training 1988 – 1991 at Steve Biko Pretoria Academic Hospital. Dr Grobbelaar started her practice in Pretoria at Eugene Marais hospital in 1991 and then moved to Hermanus Mediclinic in 1995, where she has practiced soley in ultrasound since then.

Specialised Services

Ultrasound Technology

Ultrasound is safe and painless and produces images of the inside of the body using sound waves. The imaging, also called ultrasound scanning or sonography, involves the use of a transducer (probe) and specialised sound conducting gel placed directly on the skin.

High-frequency sound waves are transmitted from the probe through the gel into the body. The transducer collects the sounds that bounce back and a computer then uses those sound waves to create an image. These examinations do not use ionizing radiation (as used in x-rays), thus there is no radiation exposure to the patient. Because ultrasound images are captured in real-time, they can show the structure and movement of the body’s internal organs, as well as blood flowing through blood vessels.

You should wear comfortable, loose-fitting clothing for your ultrasound exam. You may need to remove all clothing and jewelry in the area to be examined. You may be asked to wear a gown during the procedure.

Preparation for the procedure will depend on the type of examination you will have. For some scans your doctor may instruct you not to eat or drink for up to 12 hours before your appointment. For others you may be asked to drink up to six glasses of water two hours prior to your exam and avoid urinating so that your bladder is full when the scan begins.

Diagnostic Ultrasound

The following situations can benefit from an ultrasound examination:

  • Abdominal pain, abdominal masses
  • TIA or “blackouts”, loss of consciousness
  • Dizziness
  • Blood in the urine
  • Swollen or painful calves for blood clots (called DVT)
  • Pain in legs when doing exercise, walking or after a flight or long trip or period of immobility, like hospitalisation
  • Swallowing problems (neck masses)
  • Abnormal vaginal bleeding
  • Pregnancy diagnosis, bleeding, fetal growth, sex determination and other problems antenatally
  • Shoulder pain, knee swelling or pain
  • Elbow or ankle pain
  • Breast nodules, follow up of cysts or fibroadenoma
  • Routine breast examinations
  • Lymphglands
  • Hernias
How Diagnostic Ultrasound Works
  • We use inaudible sound (frequencies between 2-18MHz) to examine and scan organs, joints and blood vessels.
  • A transducer or probe is used to scan an organ, limb or joint.
  • We use higher frequencies for more superficial organs and lower for deeper organs.
  • A sound wave of known frequency is sent into an organ, the tissue (depending on density) changes the wavelength and sends( reflects) it back to the probe.
  • The ultrasound machine then uses the altered wave length to produce a “live” image on the machine screen.
  • The denser the tissue, the “whiter” the image and the less dense tissues produce scales of grey image. Clear fluid produces a black image which helps with the delineation of anatomy and pathology.

Directional Doppler is used to measure velocity and direction of flow, useful in heart and blood vessel examinations.

Types of Doppler:

1: Directional: PW / CW/ AngioDoppler
2: Colour: Colour Doppler is superimposed on the 2D picture to indicate direction of flow turbulence, laminar flow , incompetence, short circuits etc.
3: Angio Doppler: Non directional, but pick up very low and slow flow and perfusion.

Doppler is essential to measure flow in the heart and to pick up valves that leak or does not open properly due to pathology. We also pick up openings in the septums of the hearts of babies or children that are born with short circuits like (ASD, VSD, open foramen ovale, PDA etc.) CW Doppler is used for higher flow velocities in one plane.

To evaluate blood vessels doppler is also essential. The important relevant vessels we examine are the following:

1: Leg veins (for deep vein thrombosis) after long flights or periods of immobility;
2: Leg arteries: when arteries narrow that supplies the muscles and feet of blood – these patients develop pain when they walk or climb stairs,with then would disappear in rest.
3: Abdominal Aorta: Some patients develop a widening or weakening of their main abdominal artery wall, called an aneurysm.


Abdominal Aorta Aneurism:

  • When the main blood vessel wall weakens for any reason, mainly due to atherosclerosis the vessel starts dilating.
  • When it dilates above 3 cm in diameter in patients, we follow it up yearly to monitor the growth.
  • We refer our patients to vascular surgeons when it dilates more than 4,5 cm to be considered for a stent.
Neck Vessels

Carotid duplex studies:

  • When patents get a “blackout”, dizzy spells, strokes, or lose consciousness temporarily, we study the arteries (called the carotid arteries), we look at the 2D image for calcifications, plaque, norrowing or thickening of the lining of the vessels to assess if the flow is disturbed and becomes turbulent , which then will cause embolism of inner artery wall deposits, leading to strokes.
  • We can also look at the intima, inner lining of the common carotid, and measure the IMT, intimate media thickness that can predict a patient’s risk for cardio vascular disease. It’s means we measure the inner layer of the CCA (main neck artery).
  • There are tables of normal values available to predict if a patient is at high risk for Cardiovascular disease.

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