Penumbra

Overview

Penumbra is the radiation protection and quality-assurance record of a hospital's diagnostic radiology physics department — the office that proves every X-ray beam in the trust is safe, legal and in calibration. St Cuthbert's keeps 84 radiation-emitting units across 6 hospital sites and 19 designated areas, each one tested, dose-audited, shielded and entitled, with the evidence kept where an inspector can read it.

This is not a PACS viewer and not a generic asset register. It is the department's own file, drawn in the idiom of radiographic film on a lightbox crossed with a 1970s medical-physics technical report — a near-black ground, film-grey panels, a cold lightbox cyan as the only light, drawn step-wedge dividers, beam-geometry diagrams showing source, collimated field and penumbra, and tabular monospace numerals for every dose and tolerance figure. One caution amber is held strictly for exceedance, overdue QA and open notifications.

What it holds

• Equipment inventory — every unit by asset number, modality (general radiography, fluoroscopy, interventional, CT, mammography, dental, mobile, theatre), manufacturer, model, tube serial and cumulative tube loading.
• Quality assurance schedule — the routine test programme by unit (output reproducibility, kVp accuracy, half-value layer, beam alignment and collimation, AEC consistency, image uniformity, CT number accuracy, mammographic image quality) with frequency, next due, and a PASS / REMEDIAL / SUSPEND result against tolerance and suspension levels.
• Dose audit and diagnostic reference levels — median patient dose per examination in dose-area product and milligray, sample size, local DRL against the national DRL, with every exceedance flagged.
• Controlled areas and local rules — each designated area with its designation basis, local rules in force, named radiation protection supervisor, shielding survey date and measured transmitted dose rate.
• Staff dosimetry — classified and non-classified workers by dosimeter type, whole-body and extremity dose per period against the annual limit, with investigation levels.
• Incidents and notifications — accidental and unintended exposures, clinical evaluation, root cause, and whether the regulator was informed inside the statutory period, on a determination clock.
• Entitlement and training — operators and practitioners entitled under the employer's procedures, scope of entitlement, training evidence and expiry.
• Adviser, commissioning and service — formal radiation protection adviser advice and outstanding recommendations, critical examination and acceptance tests for new units with baselines carried into the QA programme, and the engineer visit and downtime log.
• Clinical portal and physics dashboard — the real product behind the record: a clinical department sees which of its units are available or suspended, QA due dates, its examinations against the local DRL and how to report an unintended exposure; physics sees units overdue, results at suspension level, DRL exceedances, dosimetry investigation levels and open notifications against the clock.

Who it is for

Hospital medical physics and radiation protection departments, radiology services, dental and veterinary imaging groups, radiation protection advisers and consultancies, and any organisation that must hold equipment, dose, dosimetry and entitlement evidence to a statutory standard.

Make it yours

Swap the trust, the sites and the unit inventory for your own; change the test battery, the tolerance and suspension levels, the reference levels and the notification period. The lightbox idiom and the chain of evidence survive the swap.