**3. Primary standard radionuclide metrology laboratory**

From the content of section 2, one can conclude that the nuclear medicine applications of radionuclides raise many challenges to the nuclear physicists, from several points of view:


The adequate solutions of these tasks are offered by the Radionuclide Metrology Laboratories, generally responsible national entities, which assure the continuity of the metrological traceability chain from the international level up to the nuclear medicine units.

General Metrology uses the basic terms which are defined according to the *International vocabulary of metrology – Basic and general concepts and associated terms (VIM), JCGM 200: 2008*:

**Primary reference measurement procedure, Primary reference procedure** *= Reference measurement procedure used to obtain a measurement result without relation to a measurement standard for a quantity of the same kind.* 

**Calibration** *= Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication.* 

**Measurement uncertainty** *= Non-negative parameter characterizing the dispersion of the quantity values being attributed to a measurand, based on the information used.* 

**Metrological traceability** *= Property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty.* 

### **3.1 Activity measurement**

The national metrology laboratories dispose of two modalities to assure traceability in activity measurement. In many cases, they are Secondary Standard Laboratories (SSL), transferring the activity unit, Becquerel, from the well know and internationally recognized primary standard laboratories, like NIST (USA), LNHB (France), NPL (UK), PTB (Germany), etc. Alternatively, a national primary standard laboratory, recognized at the international

deteriorate the labeling yield of the kits. They are usually determined in the radiopharmacy, but in some cases, the medicine units can dispose of the necessary equipment for control. The methods are specific to the analytical non radiation chemistry, such as

These parameters are of maximum importance mainly when the radiopharmaceutical is administrated as an injection, but they are beyond the scope of this chapter and will not be

From the content of section 2, one can conclude that the nuclear medicine applications of radionuclides raise many challenges to the nuclear physicists, from several points of view: - A very long list of radionuclides is used for the production of radiopharmaceuticals. Other new radionuclides, presenting convenient physico-nuclear and chemical


The adequate solutions of these tasks are offered by the Radionuclide Metrology Laboratories, generally responsible national entities, which assure the continuity of the metrological

General Metrology uses the basic terms which are defined according to the *International vocabulary of metrology – Basic and general concepts and associated terms (VIM), JCGM 200:* 

**Primary reference measurement procedure, Primary reference procedure** *= Reference measurement procedure used to obtain a measurement result without relation to a measurement* 

**Calibration** *= Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties and, in a second step, uses this information to establish a relation for obtaining a measurement result from an indication.*  **Measurement uncertainty** *= Non-negative parameter characterizing the dispersion of the quantity* 

**Metrological traceability** *= Property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the* 

The national metrology laboratories dispose of two modalities to assure traceability in activity measurement. In many cases, they are Secondary Standard Laboratories (SSL), transferring the activity unit, Becquerel, from the well know and internationally recognized primary standard laboratories, like NIST (USA), LNHB (France), NPL (UK), PTB (Germany), etc. Alternatively, a national primary standard laboratory, recognized at the international

properties, are discovered and introduced in the radiopharmaceutical use.

aspects are interconnected, each one depending strongly on the other.

traceability chain from the international level up to the nuclear medicine units.

*values being attributed to a measurand, based on the information used.* 

spectrophotometry or colorimetry.

*standard for a quantity of the same kind.* 

*measurement uncertainty.* 

**3.1 Activity measurement** 

further presented.

*2008*:

**2.2.3 Biological and microbiological parameters** 

**3. Primary standard radionuclide metrology laboratory** 

level, by demonstrating the equivalence of its standards to the International System (SI), can solve entirely this task.

Figure 1 presents the equivalence and traceability chain to be established in activity measurement, from the International System (SI), assured by the International Bureau of Weights and Measures (Bureau International des Poids et Mesures-BIPM) through primary standard laboratories which disseminate the standards to the SSLs and end users, in our case the nuclear medicine units. In order to accomplish its duties, one primary laboratory has to solve the following tasks: it must set up the installations for absolute standardization of radionuclides, demonstrate its international equivalence and assure traceability to the lower levels.

Fig. 1. Dissemination pathways for SI values of activity (From Woods & Sahagia. 2008).
