DICOM PS3.17 2024a - Explanatory Information

UUU.3 Ophthalmic Tomography Angiography Examples

OCT en face images are derived from images obtained using OCT technology (i.e., structural OCT volume images plus angiographic flow volume information). With special image acquisition sequences and post hoc image processing algorithms, OCT-A detects the motion of the blood cells in the vessels to produce images of retinal and choroidal blood flow with capillary level resolution. En face images derived from these motion contrast volumes are similar to images obtained in retinal fluorescein angiography with contrast dye administered intravenously, though differences are observed when comparing these two modalities. This technology enables a high resolution visualization of the retinal and choroidal capillary network to detect the growth of abnormal blood vessels to provide additional insights in diagnosing and managing a variety of retinal diseases including diabetic retinopathy, neovascular age-related macular degeneration, retinal vein occlusion and others.

The following are examples of how the ophthalmic tomography angiography DICOM objects may be used.

UUU.3.1 Clinical Examples

UUU.3.1.1 Diabetic Macular Ischemia

A 54 year old female patient with an 18 year history of DM2 presents with unexplained painless decreased visual acuity in both eyes. The patient was on hemodialysis (HD) for diabetes related renal failure. She had a failed HD shunt in the right arm and a functioning shunt in the left. SD-OCT testing showed no thickening of the macula. Because of her renal failure and HD history IVFA was deferred and OCT angiography of the maculae was performed. This showed significant widening of the foveal avascular zone (FAZ) explaining her poor visual acuity and excluding treatment opportunities.

Diabetic Macular Ischemia example

Figure UUU.3.1-1. Diabetic Macular Ischemia example

UUU.3.1.2 Age Related Macular Degeneration

A 71 year old male patient presents with a 3 month history of decreased visual acuity and distorted vision in the right eye. He demonstrates a well-defined elevation of the deep retina adjacent to the fovea OD by biomicroscopy that correlates to a small pigment epithelial detachment (PED) shown by SD-OCT. OCT angiography demonstrated a subretinal neovascular network in the same area. This was treated with intravitreal anti-VEGF injection monthly for three months with resolution of the PED and incremental regression of the subretinal neovascular membrane by point to point pegistration OCT angiography and finally non-perfusion of the previous SRN.

Age Related Macular Degeneration example

Figure UUU.3.1-2. Age Related Macular Degeneration example

UUU.3.1.3 Branch Retinal Vein Occlusion

A 59 year old male patient with hypertension and long smoking history presents with a six week history of painless decrease in vision in the right eye. Ophthalmoscopy showed dilated and tortuous veins inferior temporally in the right eye with a superior temporal distribution of deep retinal hemorrhages that extended to the mid-periphery, but did not include the macula. SD-OCT showed thickening of the macula and OCT angiography showed rarefaction of the retinal capillaries consistent with ischemic branch retinal vein occlusion and macular edema.

Branch Retinal Vein Occlusion example

Figure UUU.3.1-3. Branch Retinal Vein Occlusion example

DICOM PS3.17 2024a - Explanatory Information