Clinical Study A – Ultrasound Data Collection Manual

1. Introduction

The following is a set of instructions for the collection of the ultrasound images/videos during ThrombUS+ Clinical Study A.

The instructions are addressed to the healthcare professional conventionally performing diagnostic ultrasound scans on patients suspected of having deep vein thrombosis of the lower limb.

2. Overall data collection guidelines

Conventional procedure followed on site

- Perform the conventional ultrasound diagnostic protocol for suspected deep vein thrombosis of the lower limb as you would irrespective of the ThrombUS+ Study A.

- Record your findings in the conventional report as indicated by the protocol followed in your site.

Additional data collection for ThrombUS+ Study A

- For the purpose of ThrombUS+ Study A, and additionally to the conventional diagnosis report, also complete the following structured report:

¨ Right ¨ Left Use one table for each lower extremity, if both are scanned.
Venous system of the lower extremity	Check if assessed	*Compressible No/Partial/Yes**		Thrombosis* No/Yes
Common femoral	¨
Femoral-saphenous junction	¨
Greater saphenous	¨
Deep femoral	¨
Proximal third femoral	¨
Middle third femoral	¨
Distal third femoral	¨
Popliteal	¨
Tibialis/Peroneals/Grastrocnemic	¨
Other pathological findings
Finding	No/Yes/Not Assessed		Location (if relevant)
Varicose plexus
Perforating veins
Subcutaneous oedema
Baker’s cyst
Other (specify)

* Required

- Follow the steps below to collect ultrasound images or videos as detailed.

It is advisable to create a new Ultrasound Study to record the data below for the ThrombUS+ Study.

3. Ultrasound data collection steps


Patient positioning and overall data collection sites
The patient lies supine or in Semi-Fowler's position (on their back with the head and trunk raised to between 15 and 45 degrees), with no rotation of the pelvis. The head and shoulders should be raised to encourage distension of the leg veins. The legs may be tilted downwards from the head by at least 30 degrees. This helps to fill and distend the veins, making imaging easier.
In all scanning positions: The probe should be perpendicular to the vein. During compression ultrasound, the probe should be compressed until the pulsatile artery compresses slightly.

Data collection 1: Common femoral vein (CFV)
Place the transducer in the middle of a line that connects the pubis and the iliac spine, along the inguinal ligament, i.e. transversely to the common femoral vein and artery.
Perform a short exploratory scan around the point. Locate a frame of inadequate diagnostic quality. Save an image of inadequate diagnostic quality. Move the transducer and locate a new frame of inadequate diagnostic quality. Record a second image of inadequate diagnostic quality.
Locate the common femoral vein (CFV) and common femoral artery (CFA). If during the conventional diagnostic exam, you have located a site of vein incompressibility or direct thrombus visualization in this area, choose this frame for collecting data. Start video recording. - Perform compression ultrasound Stop video recording.
Total estimated duration: 5 sec
Collection site 1	Compression video		Image of inadequate diagnostic quality


Data collection 2: Great saphenous vein (GSV)
Slide the probe 1-2 cm down the patient’s leg to find where the great saphenous vein branches off of the CFV.
Perform a short exploratory scan around the point. Locate a frame of inadequate diagnostic quality. Save an image of inadequate diagnostic quality. Move the transducer and locate a new frame of inadequate diagnostic quality. Record a second image of inadequate diagnostic quality.
Locate the junction of the CFV with the Great Saphenous Vein (GSV of SV). If during the conventional diagnostic exam, you have located a site of vein incompressibility or direct thrombus visualization in this area, choose this frame for collecting data. Start video recording. - Perform compression ultrasound Stop video recording.
Total estimated duration: 5 sec
Collection site 2	Compression video	Image of inadequate diagnostic quality


Data collection 3: Femoral Vein (FV)
Slide the probe a few centimeters down the patient’s leg to find where the CFV branches into the deep femoral vein and (superficial) femoral vein.
Perform a short exploratory scan around the point. Locate a frame of inadequate diagnostic quality. Save an image of inadequate diagnostic quality. Move the transducer and locate a new frame of inadequate diagnostic quality. Record a second image of inadequate diagnostic quality.
Locate the femoral vein and artery distal to the bifurcation. If during the conventional diagnostic exam, you have located a site of vein incompressibility or direct thrombus visualization in this area, choose this frame for collecting data. Start video recording. - Perform compression ultrasound Stop video recording.
Total estimated duration: 5 sec
Collection site 3	Compression video		Image of inadequate diagnostic quality


Data collection 4: Femoral Vein (FV) – augmentation with color doppler ultrasound
Locate the femoral vein and artery distal to the bifurcation. Switch to color doppler operation
Perform a short exploratory scan around the point. Locate a frame of inadequate diagnostic quality. Save an image of inadequate diagnostic quality. Move the transducer and locate a new frame of inadequate diagnostic quality. Record a second image of inadequate diagnostic quality.
Locate the femoral vein and artery distal to the bifurcation. If during the conventional diagnostic exam you have located a site of vein incompressibility or direct thrombus visualization in this area, choose this frame for collecting data. Start video recording. - Perform color doppler ultrasound - Squeeze the leg distal to where you are scanning (calf) Stop video recording.
Total estimated duration: 5 sec
Collection site 4	Color doppler video		Image of inadequate diagnostic quality


Data collection 5: Popliteal Vein (PV)
Move the probe into the posterior crease of the knee and scan to find the popliteal vein.
Perform a short exploratory scan around the point. Locate a frame of inadequate diagnostic quality. Save an image of inadequate diagnostic quality. Move the transducer and locate a new frame of inadequate diagnostic quality. Record a second image of inadequate diagnostic quality.
Locate the popliteal vein. If during the conventional diagnostic exam you have located a site of vein incompressibility or direct thrombus visualization in this area, choose this frame for collecting data. Start video recording. - Perform compression ultrasound Stop video recording.
Total estimated duration: 5 sec
Collection site 5	Compression video		Image of inadequate diagnostic quality


Data collection 6 [OPTIONAL]: Direct thrombus visualization or site where compression ultrasound shows pathology
If during the conventional diagnostic protocol, you happen to visualize a clot or locate a site where vein shows pathological incompressibility, locate this site and record image or compression video. Total estimated duration: 3 sec

4. Synopsis

Data collection for Study A:

1. Short, structured report following the table provided (page 1 or in the Annex)

2. Point scanned:

- 4 points scanned via compression ultrasound

- 1 point scanned with color doppler augmentation

- [optional] point of direct clot visualization

3. Ultrasound data collected

- 10 images of inadequate diagnostic quality

- 4 video clips of compression ultrasound (~3 min each)

- 1 video clip with colour doppler augmentation (~3 min)

- [optional] image/video of direct clot visualization

4. Order of collected DICOM files*

- 1 - Inadequate first image of common femoral vein (CFV) - Tag: CFVr-[L/R]

- 2 - Inadequate second image of common femoral vein (CFV) - Tag: CFVr-[L/R]

- 3 - Compression video of common femoral vein (CFV) - Tag: CFV-[L/R]

- 4 - Inadequate first image of great saphenous vein (GSV) - Tag: GSVr-[L/R]

- 5 - Inadequate second image of great saphenous vein (GSV) - Tag: GSVr-[L/R]

- 6 - Compression video of great saphenous vein (GSV) - Tag: GSV-[L/R]

- 7 - Inadequate first image of femoral vein (FV) - Tag: FVr-[L/R]

- 8 - Inadequate second image of femoral vein (FV) - Tag: FVr-[L/R]

- 9 - Compression video of femoral vein (FV) - Tag: FV-[L/R]

- 10 - Inadequate first doppler image of femoral vein (FV) - Tag: FV-Dr-[L/R]

- 11 - Inadequate second doppler image of femoral vein (FV) - Tag: FV-Dr-[L/R]

- 12 - Color doppler video of femoral vein (FV) - Tag: FV-D-[L/R]

- 13 - Inadequate first image of popliteal vein (PV) - Tag: PVr-[L/R]

- 14 - Inadequate second image of popliteal vein (PV) - Tag: PVr-[L/R]

- 15 - Compression video of popliteal vein (PV) - Tag: PV-[L/R]

- 16 - [Optional] Image or compression video of a clot - Tag: OPT-[L/R]

* In case of two legs scanning, you will first acquire the DICOM files for the left leg (L) followed by the files for the right leg (R).

5. Notes

Imaging should be conducted at the highest clinically appropriate frequency, realizing that there is a trade-off between resolution and beam penetration. This should usually be at a frequency of 5 MHz or greater, with the occasional need for a lower-frequency transducer. In most cases, a linear or curved linear transducer is preferable, but sector scanners can be helpful for difﬁcult patients.

The potential beneﬁts and risks of each examination should be considered. The ALARA principle (As Low as Reasonably Achievable) should be observed for factors that affect the acoustical output and by considering transducer dwell time and total scanning time. Further details on ALARA may be found in the current AIUM publication Medical Ultra-sound Safety.

Transducer preparation, cleaning, and disinfection should follow manufacturer recommendations and be consistent with the AIUM Guidelines for Cleaning and Preparing External- and Internal-Use Ultrasound Transducers Between Patients, Safe Handling, and Use of Ultrasound Coupling Gel.

6. References

1. Jessica Ahn, Vi Dinh; et al, DVT Ultrasound Made Easy: Step-By-Step Guide. DVT, Ultrasound Basics, Ultrasound Tutorials POCUS 101, https://www.pocus101.com/dvt-ultrasound-made-easy-step-by-step-guide/

2. Kakkos SK, et al. Editor's Choice - European Society for Vascular Surgery (ESVS) 2021 Clinical Practice Guidelines on the Management of Venous Thrombosis. Eur J Vasc Endovasc Surg. 2021 Jan;61(1):9-82. doi: 10.1016/j.ejvs.2020.09.023.

3. Needleman L et al. Ultrasound for Lower Extremity Deep Venous Thrombosis: Multidisciplinary Recommendations From the Society of Radiologists in Ultrasound Consensus Conference. Circulation. 2018 Apr 3;137(14):1505-1515. doi: 10.1161/CIRCULATIONAHA.117.030687. PMID: 29610129.

4. AIUM Practice Parameter for the Performance of a Peripheral Venous Ultrasound Examination. J Ultrasound Med. 2020 May;39(5):E49-E56. doi: 10.1002/jum.15263. Epub 2020 Mar 12. PMID: 32162338.