Patient Timeline

A patient enters the study after SDH evacuation with a ClearFit implant and is followed through their normal imaging schedule for roughly 3–12 months. Each clinically ordered CT or MRI is paired with a research TCUS; nothing in the clinical schedule changes.

1
Surgery (standard care).
SDH evacuation by burr hole, craniotomy, or craniectomy, with ClearFit reconstruction. Window size, location, and implant model are recorded from operative and device records.
2
Screening.
Site PI confirms: age ≥ 18; SDH as the index indication; usable sonic window ≥ 2.0 cm; planned postoperative CT/MRI; no active scalp or wound infection over the scanning site; not pregnant. Poor visibility at a later exam is an evaluability outcome, not a reason to remove the patient.
3
Consent.
Written consent from the patient or legally authorized representative. Surrogate consent early postoperatively if needed; patient re-consents when capacity returns.
4
Enrollment.
Study ID assigned. Baseline data entered. Coordinator begins tracking planned imaging.
5
First paired exam.
TCUS as close as feasible to the first postoperative CT/MRI, preferably same day. Operator maps the window and acquires the exam without reviewing the CT/MRI.
Pairing rules apply
6
Upload.
Coordinator de-identifies and uploads TCUS, CT/MRI DICOM, and the official report within 2 working days.
7
Central reads.
TCUS reader (blinded to CT/MRI) and neuroradiology reader (blinded to TCUS) each lock within 5 working days of a complete upload.
8
Serial paired exams.
Repeated at each clinical follow-up imaging point (typically ~1, 3, and 6 months, or as clinically indicated) and at any urgent imaging. Same landmark and acquisition settings as the first evaluable exam.
Pairing rules apply
9
Follow-up and safety.
Clinical outcomes, return to surgery, and adverse events tracked through the clinical course.
10
Data lock and analysis.
After both reads lock for every pair, the core analyst registers the TCUS field to CT/MRI, clips the segmentation to the matched region, and the coordinating center compares impressions. Adjudication only where triggered.

Pairing rules

Setting	Max TCUS–CT/MRI interval	Conditions
Inpatient, scheduled	72 hours	No intervening evacuation, drain intervention expected to change volume, material treatment change, or neurological deterioration
Outpatient, scheduled	7 days before or after	Same conditions
Urgent / symptom-driven	Before, or within 24 hours after, the urgent CT/MRI	Only if TCUS does not delay imaging, treatment, or transport; intervening surgery or major neurological change makes the pair ineligible for primary comparison

Pairs outside these rules stay in the feasibility record but are excluded from the primary matched-measurement analysis. A same-day subset is analyzed separately.

Per-exam footprint: bedside or clinic; 10–20 minutes; sterile gel and gentle probe pressure; no invasive procedure.

Surgery (standard care).

Screening.

Consent.

Enrollment.

First paired exam.

Upload.

Central reads.

Serial paired exams.

Follow-up and safety.

Data lock and analysis.