Fluke 07-645 User Manual

Nuclear Associates 07-645

Fluoro-Test™ Tool

Users Manual

Fluke Biomedical

Radiation Management Services

6045 Cochran Road Cleveland, Ohio 44139

440.498.2564

www.flukebiomedical.com/rms

Table of Contents

Section 1: Instructions ................................................................................................ 1-1

1.1 Description................................................................................................... 1-1

1.2 Instructions for Use...................................................................................... 1-1

1.2.1 Example One ............................................................................................... 1-2

1.2.2 Example Two ............................................................................................... 1-2

1.2.3 Example Three ............................................................................................ 1-2

1.3 Discussion ................................................................................................... 1-2

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Instructions

Description

Section 1

Instructions

1.1 Description

The Fluoro-Test Tool™ is a fluoroscopic contrast resolution test tool that is based on the work of Wagner, Barnes and Wu [1]. The test tool consists of two 6" x 6", 6.1 mm (¼") thick aluminum plates with each plate containing an array of 1.1 cm targets of varying contrast. Also included in the Fluoro-Test kit are three 6" x 6", 1 mm thick copper sheets. The test tool is designed to be used with the copper attenuator sheets positioned close to the source (i.e., at table top) and the aluminum test plate located close to the image intensifier input as illustrated in Figure 1-1. With 2 mm of copper attenuator in the beam and a fluoroscopic x-ray tube potential of 80 kVp, the contrast of the targets in Plates A and B are given in Figure 1-2A and 1-2B, respectively. Each plate has three rows of three targets with a moderately large (≅3%) contrast increment between adjacent targets in the same row. The outer two rows have increasing target contrast increments while the middle row is offset and has decreasing increments. At 80 kVp with 2 mm of Cu attenuator the targets range in contrast from ≅1% to ≅9% in Plate A (integer phantom) and from ≅0.5% to ≅8.5% in Plate B (half-integer phantom).

1.2 Instructions for Use

1. For conventional geometry fluoroscopic units (under-table x-ray tube/over-table imaging chain)

place two copper sheets (i.e., a total copper thickness of 2.0 mm) on the tabletop and aluminum Test Plate A directly beneath the image intensifier input phosphor or spot film device cover as shown in Figure 1-1. The spot film device/imaging chain should be positioned 12" to 16" above the tabletop. If the fluoroscopic unit has an over table x-ray tube/under table imaging chain, place the copper sheets directly beneath the collimator and Test Plate A on the table top or on the image intensifier. In either geometry the copper sheets and Test Plate should be centered in the fluoroscopic field-of-view (FOV).

2. If the image intensifier has different FOVs, select the 22 cm (9") FOV or the FOV that is closest to

22 cm.

3. Note the fluoroscopic kVp. Scan the image and note the number of targets that can be seen in each

row.

4. Replace Test Plate A with Test Plate B and repeat step 3. In general the fluoroscopic kVp will

remain the same.

5. The target contrast visibility threshold or low contrast resolution can be ascertained by determining

the lowest contrast target that is seen in the two plates. The contrast of targets on Plate B are slightly less (≅0.5%) than the targets in Plate A and, if the same number of targets are seen on each plate, the contrast resolution is the lowest contrast target seen in the image of Plate B. If more targets are seen in the image of Plate A, the contrast resolution is the lowest contrast target seen in Plate A. The contrast of the targets for a beam hardened by 2.0 mm of copper are given in Table 1 as a function of fluoroscopic x-ray tube potential.

1-1

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