Accelerator pharmaceutical solution

I. Mandatory National Standard Dimensions (Must Comply with Shielding & Equipment Requirements)

MR Main Shielded Magnet Room

• Minimum effective floor area: ≥30 ㎡ for 1.5T MRI systems; ≥40 ㎡ for 3.0T MRI systems. Sufficient space shall be reserved for the magnet, gradient coils, radiofrequency coils and clinical operation.

• Minimum single-side span: ≥5.0 m (1.5T); ≥6.0 m (3.0T) to guarantee safe magnet installation and unobstructed patient access.

• Clear interior height: ≥3.2 m (3.5 m or above recommended), reserving overhead maintenance space for the magnet and installation space for air conditioning and fresh air ducts.

Operator Control Room

• Floor area: ≥20 ㎡, clear height ≥2.8 m. The room shall accommodate operator consoles, display monitors and image archiving equipment, separated from the main shielded room by a shielding partition wall.

Auxiliary Supporting Zones (Equipment Room & Air Conditioning Room)

• Equipment room floor area: ≥15 ㎡; air conditioning machine room floor area: ≥12 ㎡. The equipment room shall be adjacent to the main shielded room to facilitate pipeline connection.

Equipment Foundation

Construction shall strictly follow drawings provided by the MRI equipment manufacturer. The magnet base shall be treated with shock absorption and load-bearing reinforcement with a bearing capacity of ≥150 kN/㎡. Pre-buried grounding terminals and pipeline troughs shall be reserved.

Wall Structure

Reinforced concrete walls are preferred for the main shielded room. The outer wall thickness shall be no less than 240 mm with internal shielding treatment. Lightweight hollow bricks are prohibited as they will degrade shielding performance.

Special MRI Shielded Doors (Patient & Equipment Access)

• Opening size of motorized shielded door for patient/equipment passage: ≥1800 mm × ≥2200 mm

• Opening size of manual shielded door for staff passage: ≥900 mm × ≥2100 mm

• Each door integrates dual functions: electromagnetic shielding and ionizing radiation shielding.

Shielded Observation Window

• Opening dimension: ≥1500 mm × ≥1000 mm; the bottom edge of the window shall be 950 mm above the finished floor.

• Double-layer vacuum shielding glass with embedded lead layer shall be adopted to meet electromagnetic and radiation shielding criteria while delivering distortion-free viewing.

Warning Signs & Indicators

Standard ionizing radiation warning labels and "No Metal Objects Allowed" signs shall be posted externally on all shielded doors. Radiation operation indicator lights shall be mounted outside doors and inside the control room, which activate synchronously during scanner operation.

 

II. Dual Requirements for Radiation Protection & Electromagnetic Shielding (Core Standards)

(I) Electromagnetic Shielding Specifications (MRI Exclusive Mandatory Standard)

Shielding Materials

The entire main shielded room shall be enclosed by integral shielding panels of grade 304 or 316 stainless steel with thickness ≥1.5 mm. Stainless steel panels covering walls, ceilings and floors shall be fully welded with seamless weld joints to eliminate electromagnetic leakage.

Standard Shielding Construction Procedures

1. Ceiling: Welded keel reinforcement → full welding of stainless steel shielding panels → fireproof & moisture-proof base layer → decorative finish

2. Wall: Base wall surface treatment → keel fixation → full welding of stainless steel shielding panels → insulation layer → decorative finish

3. Floor: Floor leveling → moisture barrier layer → full laying & welding of stainless steel shielding panels → concrete protective layer → anti-slip floor finish

Shielded Door Performance

Stainless steel shielded doors shall be equipped with conductive sealing strips along all contact edges between door leaf and frame to eliminate gaps when fully closed. The shielding effectiveness shall reach ≥90 dB within the frequency range of 10 kHz to 1 GHz.

Pipeline & Ventilation Shielding

All penetrating pipelines (power cables, signal cables, air conditioning pipes) shall run through shielding sleeves seamlessly welded to the main shielding panels. Electromagnetic shielding mesh shall be installed on all ventilation ducts with full shielding treatment at air outlet openings.

Grounding Specifications

An independent dedicated shielding grounding system shall be installed with a grounding resistance ≤1 Ω. All shielding enclosures shall be reliably connected to grounding electrodes to suppress external electromagnetic interference.

(II) Radiation Protection Requirements (Compliant with GBZ 130-2020)

Combined Ceiling Shielding Schemes (Electromagnetic + Radiation Protection)

1. Fully welded stainless steel shielding panels + fire-retardant boards + barium sulfate radiation shielding layer

2. Stainless steel shielding panels + lead-wood composite shielding panels

3. High-density barium sulfate shielding mortar laid on the upper floor + stainless steel shielding layer

Combined Wall Shielding Schemes (Electromagnetic + Radiation Protection)

1. Fully welded stainless steel shielding panels + troweled barium sulfate shielding mortar

2. Stainless steel shielding panels with embedded lead sheets (for primary radiation exposure zones)

3. Stainless steel shielding panels + prefabricated barium sulfate shielding boards

Combined Floor Shielding Schemes (Electromagnetic + Radiation Protection)

1. Fully welded stainless steel shielding panels + barium sulfate shielding mortar + concrete protective layer

2. Stainless steel shielding panels + lead sheets + anti-slip floor finish

Lead Equivalency Standards

• Primary radiation walls (direct beam exposure direction of MRI scanner): ≥3.0 mmPb

• Side walls, ceilings and floors (scattered radiation exposure zones): ≥2.0 mmPb
  Applicable shielding materials: barium sulfate mortar/sand, pure lead sheets, lead-wood composite panels and precast barium sulfate shielding boards.

• Lead equivalency for shielded doors and observation windows: ≥3.0 mmPb, while meeting the required electromagnetic shielding effectiveness.

• Approved shielding materials include medical lead sheets, high-density barium sulfate sand/mortar, lead-wood composite panels and medical barium sulfate shielding boards. All stainless steel shielding plates and radiation shielding materials shall pass national standard testing.

• All penetration holes, cable troughs and reserved equipment openings shall be double-sealed with lead sheets plus auxiliary shielding materials to eliminate gaps and block radiation and electromagnetic leakage completely.

• Mandatory door-scanner interlock system: The MRI scanner cannot be activated unless the shielded door is fully closed. Emergency stop devices and emergency lighting shall be installed to protect medical staff and patients.

(III) Auxiliary System & Construction Compliance Procedures

Environmental Control Requirements

The scanner room shall be equipped with a constant temperature & humidity system (operating temperature: 18–24 ℃, relative humidity: 40%–60%), plus dedicated fresh air and exhaust ventilation systems to prevent environmental fluctuations from interfering with scanner performance.

Power Supply Requirements

An independent dedicated distribution box shall be configured to maintain stable voltage and avoid equipment malfunctions caused by voltage fluctuations. An emergency backup power supply shall be installed to enable safe scanner shutdown during power outages.

Compliance Inspection Flow

A pre-construction radiation shielding safety assessment must be completed before construction commences. Upon project completion, third-party acceptance testing for radiation and electromagnetic shielding shall be conducted to apply for the official Radiation Safety License.