Designing imaging area

As most of the imaging equipment are permanently fixed to the building, facility planning needs expert inputs from clinical engineers

Imaging, Design

The CAT scan unit being far away from the emergency area led to delayed access of patient scanning. The patient having been instructed to intake plenty of water before ultrasound scanning had inconvenience post scanning as all rest rooms were engaged. The patient needing anesthesia during MRI scan could not be taken inside MRI on anesthesia equip-ment as medical gas lines were not present. The above examples highlight the issues related to imaging areas in any hospital. The imaging area is one of the prominent clinical areas in any hospital, having high daily foot-fall of inpatients and outpatient. As clini-cians across hospital depend on outcome of patient diagnosis and treatment on imaging equipment, efficient imaging facility design is much essential. The design of imaging area should be patient centric and should be guided by adoption of technology both from present to future needs.

The design should have a collaborative approach of imaging team members includ-ing nurses and technicians, facility engi-neering, equipment service providers and architect. The overall clinical service needs of hospital should determine the scope of service of imaging area like a hospital having neurosurgery should plan MRI. The follow-ing medical technologies should planned, depending on hospital clinical needs:

  • Radiography system
  • Fluoroscopy system
  • Ultrasound color Doppler
  • Computer axial tomography
  • Magnetic resonance imaging
  • Bone densitometry
  • Mammogram
  • PACS

As most of the equipment are permanently fixed to the building, the facility planning needs expert inputs from clinical engineers. The following critical points need to be con-sidered while planning imaging area:

The department should be easily accessible to emergency, outpatient, inpatient and operating rooms, as patient flow can be expected from any of these areas. The shortest path of patient movement from all areas in general and emergency area in par-ticular should be an important parameter to determine the location of imaging area. The orientation of most of the fixed equipment should consider patient, staff movement, transportation and storage of material.

For certain X-Ray based technology like radiography and the CAT scan, the minimum area is prescribed by the AERB as a part of statutory requirement. The AERB approval on site plan and post installation quality assurance are major milestones before hospital starts using X-Ray based equipment for clinical services. The planning team must consider at least three major imaging service providers design inputs before arriving at final schematic layout of each area within imaging department. The planning team should not forget to consider future upgrade of technology like 16 slice CT scan to 216 slice while designing the schematic layout plan. The typical 3 Tesla MRI should have 480 square feet for MR examination room, 450 square feet for equipment and UPS room and 120 square feet for control /console room.

The space programme should consider supplementary areas like reception, patient waiting area, MRI holding beds, patient change rooms, rest rooms near ultrasound, reporting room. The patient movement corridor should be 2.4 meter wide for easy movement of two patient transport trollies.

The civil structure should be such that each area should have proper load bearing capacity like 7.5 ton at magnet examina-tion room for 3 T MRI. X-ray equipment like CAT scan and mammogram must be installed in effectively shielded rooms to ensure that public in the vicinity of the X-ray installations are not unduly exposed to the X-ray radiation. The adequacy of shielding depends on the material and thickness used for this purpose. All X-Ray based equipment room should have nine inch brick wall with 2 mm lead lined doors. The design should consider the transpor-tation of equipment which is brought in respective area without/minimum dam-age to existing hospital facility. This is a very important aspect in case equipment is installed in the upper floors in high rise buildings. The location of area to be care-fully planned like vehicular, lift movement power cables must guide the location of MRI magnet room. The radiation safety signages, PC-PNDT related signages at ul-trasound should be prominently displayed at various locations besides direction signages. Special precautions need to be taken to avoid unauthorised person move-ment in area like MRI where there is great risk of safety hazard in case person enters with magnetic material. The MRI examina-tion room construction having RF cage is specialised design which is being carried out by the service provider.

The X-ray equipment must be installed in adequately shielded rooms to ensure that public in the vicinity of the X-ray installations are not unduly exposed to X-ray radiation. The nine-inch brick wall with 2mm lead lined door as per the AERB guidelines can be considered while planning. The false ceiling height of 3 meter from finished floor level must be considered. The finished flooring should have 2 mm tolerance and it should be easy to clean. The provision of cable floor channel, conduits should be done after equipment finalisation.

Most of the electrical power load of imaging area having high need for three phase power supply, it is better to have energy meter for each major modality like CAT scanner, MRI. The dedicated copper earth-lings points, electrical distribution panel and UPS /stabiliser based on power condition must be planned. Typical electrical load of 3 T MRI is around 175 KW. The hospital diesel generator set must be able to handle electrical load of imaging area. The electrical points in each area should be adequate so that extension boards are not used. The lux level of 300 should be provided in X-Ray, CT scan and MRI area.

The controlled lux level with dimmer provision should be provided in ultrasound area. With most hospitals going with the integration of hospital information system with RIS, the patient workflow is getting streamlined The data points should be planned based on service provider’s requirement including the provision of remote diagnostic service to know on a real-time basis the healthiness of installed equipment. The PACS room and teleradiology IT infrastructure can be planned at design stage for filmless environment creation.

The AC is a major design consideration as most of the imaging equipment generate lot of heat load. In most of the examination areas like CAT or MRI gantry room, the room temperature of 20-22 degree centigrade with relative humidity of 55 to 60% can be planned based on service provider’s specifications. Six minimum total air changes for CAT scan, X-Ray and MRI is two with outdoor air changes should be planned while designing the area. The building management system/digital meter should consider online monitoring of temperature and humidity of sensitive equipment like digital X-Ray, MRI. The air handling unit, helium gas exhaust duct, chiller unit location must be decided during the planning phase.

Portable water should be provided in each clinical sink located in imaging area like CAT scan examination room. The RO water for drinking purpose should be provided near ultrasound area. The piped medical gas outlets should be guided by HTM/NFPA standards. The safety alarm and valve boxes for medical gases should be installed. Both MRI, CAT scanner examination room should have one each of following gases: Oxygen, Nitrous oxide, vacuum & air 4. In case of MRI, the outlets should be MRI compatible. All other areas like ultrasound, X-Ray, holding area should have one oxygen 7 one vacuum. The smoke sensors should be installed across imaging area as per the NBC norms. The fire fighting water sprinklers should be provided in all rooms except examination or equipment room to avoid accidental triggering.The gas flooding system can be considered instead of water sprinklers in these area.

The interior and civil finishes at imaging area should match the overall hospital design. Sufficient patient sitting position at waiting area, visible signages, adequate rest rooms having grab bars and emergency call bells, sufficient storage space must be planned meticulously.

Thorough planning followed by proper work execution of imaging area will help the hospital to achieve longevity of the high cost imaging technologies

Deepak Agarkhed is general manager-clinical engineering, quality and facility, Sakra World Hospital, Bengaluru.