Long story short...

• If the MI-SPECT workstation displays a QC Alert indicating QC is missing, that is a a problem.  That means the system is  currently attempting an acquisition without all the required quality control, e.g. Extrinsic Calibration, Head Alignment, etc.

• Conversely, if the MI-SPECT workstation displays a QC Alert indicating QC out of date, that is usually not a problem.  That means the system is currently attempting an acquisition and at least one portion of the required quality control (e.g. Extrinsic Calibration, Head Alignment, etc.) is more than 30 days old.  For more details, continue reading.

Click the link shown below for an unofficial document that explains Siemens Detector Uniformity Corrections and  Quality Control Procedures as of November 2020.  Common questions are, "What is a Head Alignment or MHR Calibration, why is it needed,  and why does my system indicate an alert that it is out of date?"  Those questions are answered on pages 27 thru 31 of the link shown below.

ECAM & SYMBIA Systems: Understanding Quality Control

While a Siemens gamma camera system may have multiple collimators, in most cases end users do not have to perform Extrinsic Flood Calibrations on a daily, weekly or monthly basis.   For this reason, users may see an occasional QC Alert if one of the Extrinsic Flood Calibrations is more the 30 days old.  This alert is merely informing the end user of the number of days since the last "calibration" was performed.

While a Siemens gamma camera system may have multiple MHR (Multi-Head Registration) Calibrations or multiple Head Alignment Calibrations, in most cases, end users do not have to perform those calibrations on a daily, weekly or monthly basis.   For this reason, users may see an occasional QC Alert if one of the aforementioned calibrations is more the 30 days old.  This alert is merely informing the end user of the number of days since the last "calibration" was performed.  That said, most SPECT/CT systems (aka, hybrid systems) usually do require a MHR 180 Calibration or a Head Alignment 180 Calibration on a monthly basis.

Typically, a facility’s License to Use Radioactive Materials states the facility will follow the Original Equipment Manufacturer’s (OEM) Guidelines for Quality Control.  All Siemens gamma cameras have either an Operating Instructions booklet or an Operators Manual that lists the Siemens Guidelines for Quality Control.  Be advised the guidelines vary by system type and software version.  Therefore, it is imperative the facility is completing all the QC listed in the applicable Siemens documentation.

Most systems and most software versions perform either a MHR or Head Alignment “verification” on a monthly basis, and they do not require a monthly MHR or Head Alignment “calibration” on a monthly basis.  However, some systems (primarily SPECT/CT hybrid systems) do require either a MHR 180 Calibration or a Head Alignment 180 Calibration on a monthly basis.

[] With VA70 software and prior, a QC Alert does not indicate a problem, unless the alert indicates QC is missing.

[] With VB10 software and later, the user should check the Operating Instructions or Operators Manual for their system.  It lists the Siemens Guidelines for Quality Control for their specific system type and software version.  A MHR Calibration or a Head Alignment Calibration may be required on a monthly basis for some systems, typically SPECT/CT systems running software version VB10 and later.  See below.

MI > SPECT Systems > (System) > User Documentation

System Type                      Software Version            Monthly Head Alignment Calibration Required

Symbia-S                             VA60                                  No (see Operating Instructions page 233)

Symbia-S                             VB10                                  No (see Operator Manual page 211)

Symbia-S                             VB20                                  No (see Operator Manual page 223)

Symbia-S                             VB21                                  No (see Operator Manual page 223)

Symbia-S                             VB22                                  No (see Operator Manual page 239)

Symbia-T                             VA60                                 No (see Operating Instructions page 255)

Symbia-T                             VB10                                  No (see Operator Manual page 246)

Symbia-T                             VB20                                  Yes (see Operator Manual page 257)

Symbia-T                             VB21                                  Yes (see Operator Manual page 257)

Symbia-T                             VB22                                  Yes (see Operator Manual page 253)

Symbia Evo                         VB20                                  No (see Operator Manual page 225)

Symbia Evo                         VB21                                   No (see Operator Manual page 225)

Symbia Evo                         VB22                                   No (see Operator Manual page 239)

Symbia Evo Excel              VB10                                   No (see Operator Manual page 187)

Symbia Evo Excel              VB20                                   No (see Operator Manual page 193)

Symbia Evo Excel              VB21                                   No (see Operator Manual page 193)

Symbia Evo Excel              VB22                                   No (see Operator Manual page 201)

Symbia Intevo                   VA70                                    No (see Operating Instructions page 260)

Symbia Intevo                   VB10                                    Yes (see Operator Manual page 246)

Symbia Invevo                  VB20                                    Yes (see Operator Manual page 259)

Symbia Intevo                   VB21                                    Yes (see Operator Manual page 257)

Symbia Intevo                   VB22                                    Yes (see Operator Manual page 253)

Symbia Invevo Bold         VB20                                   Yes (see Operator Manual page 259)

Symbia Intevo Bold         VB21                                    Yes (see Operator Manual page 259)

Symbia Intevo Bold         VB22                                    Yes (see Operator Manual page 251)

Symbia Invevo Excel        VB10                                   Yes (see Operator Manual page 246)

Symbia Invevo Excel        VB20                                   Yes (see Operator Manual page 259)

Symbia Intevo Excel        VB21                                    Yes (see Operator Manual page 257)

Symbia Intevo Excel        VB22                                    Yes (see Operator Manual page 253)