NMD-15

Recovery coefficient

RC = C_meas / C_true. Partial-volume recovery of a hot sphere.

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QuantificationRecovery coefficient

Governing equation

\mathrm{RC}=C_{\mathrm{meas}}/C_{\mathrm{true}}

$C_{meas} \in \left[0.1, 80\right]$

where

C_{meas}: Measured concentration (kBq/ml)
C_{true}: True concentration (kBq/ml)
RC: Recovery coefficient (—)

The figure, part by part

Each numbered marker wears the color of its card. Hover a card to light the marker. Tap a marker to jump to that card. The slider walks a red point along the curve; Animate drawing traces it like a pen.

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①

Governing law — red

\mathrm{RC}=C_{\mathrm{meas}}/C_{\mathrm{true}}

$C_{meas} \in \left[0.1, 80\right]$

$C_{meas} = 0.1$ $RC = 0.008$

Along the curve

②

Domain of the variable — blue

C_{meas}_{\min} = 0.1,\quad C_{meas}_{\max} = 80

$C_{meas} \in \left[0.1, 80\right]$

$C_{meas} = 0.1$ $C_{meas} = 0.1$

Along the curve

③

Response curve — green

\mathrm{RC}=C_{\mathrm{meas}}/C_{\mathrm{true}}

$C_{meas} \in \left[0.1, 80\right]$

$C_{meas} = 0.1$ $RC = 0.008$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}RC}{\mathrm{d}C_{meas}}

$C_{meas} \in \left[0.1, 80\right]$

$C_{meas} = 0.603$ $RC^{\prime} = 0.083$

Along the curve

Lecture brief

Historical brief

MIRD schema, in-vivo decay, uptake fractions and PET coincidence turned unsealed sources into organ dose. The sheets compute activity, residence and well-counter geometry. This sheet (NMD-15 — Recovery coefficient) is the form associated with Recovery coefficient. Working symbols: $C_{meas}$ , $C_{true}$ $\rightarrow$ $RC$ . RC → 1 for objects ≫ FWHM. NEMA spheres of 10–37 mm map the RC curve of a PET scanner.

Purpose

Purpose: compute

RC

from

C_{meas}

C_{true}

in Nuclear medicine via

\mathrm{RC}=C_{\mathrm{meas}}/C_{\mathrm{true}}

RC = C_meas / C_true. Partial-volume recovery of a hot sphere. Use it when a real nuclear medicine question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

C_{meas} = 8.000\,\mathrm{kBq/ml}

C_{true} = 12.000\,\mathrm{kBq/ml}

, the governing relation

\mathrm{RC}=C_{\mathrm{meas}}/C_{\mathrm{true}}

yields

RC = 0.667\,\mathrm{—}

. A hot sphere, a measured mean, a true mean. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Measured concentration C_{meas}8 kBq/mlTrue concentration C_{true}12 kBq/ml

Outputs

Recovery coefficient RC0.667 —

Reading speed

Watch on YouTube

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Narration of this film

A hot sphere, a measured mean, a true mean.

RC → 1 for objects ≫ FWHM. NEMA spheres of 10–37 mm map the RC curve of a PET scanner.

Reading speed

Watch on YouTube