close

Вход

Забыли?

вход по аккаунту

?

Technetium counting in rheumatoid arthritis evaluation in the small joints of the hand.

код для вставкиСкачать
Technetium Counting in Rheumatoid Arthritis
Evaluation in the Small Joints of the Hand
R. D. Sturrock, Rosemary Nicholson and J. A. Wojtulewski
An apparatus is described for external directional technetium counting
of the proximal interphalangeal joints of the hand. In 11 normal and 14
rheumatoid subjects a significantly higher count rate was reached in
the rheumatoid group (t = 3.79 P < 0.005). There was a good correlation
between the rate of uptake and total count rate of technetium over an
inflamed joint and this was taken to demonstrate the importance of the
effect of vascularity on technetium kinetics. Clinical improvement following gold and penicillamine therapy was reflected in a fall in count
rates which closely paralleled a reduction in ring sizes.
Radioactive technetium, g g m Thas
~ , found
application in rheumatology as an objective parameter for the detection of joint
inflammation (1,2) and as a useful adjunct
for monitoring the antiinflammatory efiects
of drugs (1). The purpose of this present
study is to describe an apparatus for measuring technetium uptake over the proximal
interphalangeal joints of the hand and to
assess the value of technetium as a measure
of joint inflammation and as a means of
monitoring the antiinflammatory effects of
drugs.
MATERIALS AND METHODS
Fourteen patients with classic or definite rheumatoid arthritis (3) and 11 normal healthy volunFrom the Departments of Rheumatology and
Physics, Westminster Hospital, London, SW 1, England.
R D STURROCK, MB, MRCP: Registrar, Centre for
Rheumatic Diseases, Baird Street, Glasgow, Scotland; ROSEMARY NICHOLSON. BSc: Physicist, Westminster Hospital, London, England; J A W o w LEWSKI, MB, MRCP: Senior Registrar, Westminster
Hospital, London, England.
Address reprint requests to: Dr R D Sturrock,
Centre for Rheumatic Diseases, Baird Street, Glasgow, G4 OEH,Scotland.
Submitted for publication July 24, 1973: accepted
December 4, 1973.
teers were subjected to kinetic studies. Three patients participating in a gold/penicillamine trial
were monitored over a period of 3 months. The
degree of joint swelling was measured using a
Geigy ring meter and a three-point pain scale was
recorded for each proximal interphalangeal joint.
T h e counting apparatus consisted of a sodium
iodite crystal and photomultiplier assembly connected to a scaler and channel analyser. This was
set to record energies within the BomTcpeak. T h e
apparatus was designed to satisfy the following
criteria:
1. Good screening of the crystal from external
sources of radiation, particularly the patient.
2. Sharp definition of the region of interest, enabling uptakes in adjacent fingers and, if necessary, different joints of the same finger, to be
measured independently.
3. Reasonable comfort for the patient who may
need to maintain his position for periods of up
to 30 minutes for kinetic studies.
4. A method of standardizing the readings, so that
comparisons of the results over the course of
treatment may be made.
T h e first of these conditions is relatively easily
satisfied for the low energy OemTcspectrum. T h e
entire crystal-photomultiplier system was encased in
lead 4 to 8 mm thick depending on its proximity
to the crystal. The background count rate with the
patient in position was thus reduced to the order
of 5% of that recorded with the finger joint in
place.
Good definition of the joint involved could only
Arthritis and Rheumatism, Vol. 17, No. 4 (July-August 1974)
417
STURROCK ET AL
<7-y
.
---Lateral
Technetium
ionfor
Collimator
Fig 1. Diagram illustrating collimator (left) and photomultiplier apparatus (right).
be achieved at the expense of sensitivity in the
system. The reduction in sensitivity was minimized
by resting the finger on the surface of a parallel,
focused collimator mounted over the crystal. The
collimator produced a sharp cut off at either end of
the response curve along the length of the finger,
while radiation incident laterally was absorbed by
two lateral septa (Figure 1, left). The experimental
arrangement is shown in (Figure 1). The open
collimator (left) aids the initial positioning of the
finger and allows detection of any movement of
the finger.
T h e technetium for injection was made up to
2 ml with normal saline in a 5-ml syringe. This
was fixed over the crystal by an attachment to the
collimator (Figure 1, right) and the count rate
immediately prior to injection was recorded with
the scaler set up for the experiment. Subsequent
readings were compared with this initial injected
activity. Reproducibility of results was tested using
a “finger phantom.” This consisted of a 2-ml
syringe containing technetium (whose activity had
been measured as described above) diluted to a
volume of 1 liter. T h e discrepancy in readings
Observed
from
to day by this method was of
the order of 1% and was negligible compared to
the variations in technetium measured in the joint.
Approximately 500 pci of 08mTC was injected
into a vein in the antecubital fossa. Counts per
418
100 seconds were recorded continuously over the
PIP joint of the right index finger for the first 15
minutes and then over each joint for 40 seconds.
T h e results were analysed by an IBM computer
which calculated the rate of uptake over the right
PIP joint and produced a histogram of the mean
technetium count (as a percentage of the standard)
over the PIP joints of each hand. Repeat observations on individual patients were performed at the
same time of day and at a constant environmental
temperature.
RESULTS
Figure 2 shows the effects of temperature
on the uptake over a normal joint. An increase in the rate of uptake and count rate
reached after 15 minutes was noted in the
heated joint, although ring s i z e s p a i n e d
unchanged. The mean count rat& reached
by the rheumatoid joints were significantly
higher than those of normal joints, t = 3.79,
P < 0.005. A good correlation ( r = +0.52,
P < 0.01) (SE = 0.16) was found between
the count rate reached and the rate of u p
take of technetium during the first 15 min-
Arthritis and Rheumatism, Vol. 17, No. 4 (July-August 1974)
TECHNETIUM COUNTING IN RA
o Normal
0
R A
0
.
0
0
0
0
0
0
0
0
s
0
0.
0 0
0
t't
0
r
=
+0.52
0
0
7
1
-
-
-
I
Time after Injection (hr
)
Fig 2. Rate of uptake of technetium over a normal joint and one immersed in water at 40°C.
Utes following injection (Figure 3). The effects of a 3-month course of gold therapy
(total dose 560 mg) in 1 patient on the
technetium count rate and ring sizes is
shown in Figure 4.A significant fall in the
technetium count rate parallels the reduction in mean ring sizes observed during
this period and similar changes were noted
in 2 other patients treated with gold and
penicillamine. Table 1 shows a significant
difference in technetium count rate and
ring sizes between paired joints with and
without a pain score.
I
I
I
I
Rate of Uptake
I
I
Fig 3. Technetium count rate reached after 15
minutes plotted against the rate of uptake during
the same period.
TcM Count Rate
QOLD
I
DISCUSSION
The present study confirms that technetium uptake over rheumatoid joints correlates with disease activity and can monitor the response to antiinflammatory therapy. The relatively good correlation between the total count rate reached and the
rate of uptake over a joint would seem to
verify the hypothesis that the initial rapid
uptake of technetium over an inflamed
I
3 Months
Fig 4. Fall in mean ring sizes and technetium
count rate over a 3-month period of gold therapy
in 1 patient.
joint is a reflection of its increased vascularity. The increased uptake in response to a
rise in joint temperature also emphasizes
the importance of the effect of blood flow
on joint scanning. The procedure used was
well tolerated by the patients and the bulk
Arthritis and Rheumatism, Vol. 17, No. 4 (July-Augurt 1974)
419
STURROCK ET AL
Table 1. Technetium Counts and Ring Size in Paired Joints
Ring Sizes (mm)
Pain score
Technetium Counts
No pain score
No pain score
56
65
62
59
72
71
59
62
60
57
67
66
57
56
56
64
60
68
68
58
62
59
54
61
64
52
1182
1133
1246
1421
1209
1372
949
1192
1201
977
64 1
843
514
894
636
1082
1271
1275
1200
788
1124
1064
901
501
655
732
X = 62.5
X = 60.15
X = 1067
X = 932
t = 2.801
Y
t = 2.924
P < 0.01
P < 0.01
of the apparatus was such that it could
easily be used in a side room of an outpatient clinic. In the initial studies, sodium
perchlorate was administered to each patient to block uptake of technetium by the
thyroid but this did not have any effect on
the uptake over joints when omitted, an
observation made by McCarty et al (5). The
possible effect of displacement of technetium from its binding sites by highly protein bound drugs was considered in this
study but no changes attributable to this
phenomenon could be detected.
ACKNOWLEDGMENTS
We wish to thank Dr. F. Dudley Hart for allowing us to study patients under his care and Dr.
Nicholson for provision of facilities for scanning.
This work would not have been possible without
support from the Arthritis and Rheumatism Council.
420
Pain score
REFERENCES
1. Carson DW, Newfeld RR, Prentice AG, et
al: Measurement of joint inflammation-A
radioisotopic method. Ann Rheum Dis 29:
135, 1970
2. Whaley K, Pack AI, Boyle JA, et al: The
articular scan in patients with rheumatoid
arthritis. A possible method of quantitating
joint inflammation using radiotechnetium.
Clin Sci 35:547, 1968
3. Ropes MW, Bennett GA, Cobb S, et al:
Diagnostic criteria for rheumatoid arthritis,
1958 revision. Ann Rheum Dis 18:49, 1959
4. Hayes MT, Green FA: The pertechnetatic
joint scan. I. Timing. Ann Rheum Dis 31:
272, 1972
5. McCarty DJ, Polcyn RE, Collins PA: B9M
Technetium scintiphotography in arthritis:
Its nonspeci ficity and clinical and roentgenocraphic correlations in rheumatoid arthritis.
Arthritis Rheum 13:21, 1970
Arthritis and Rheumatism, Voi. 17, No. 4 (July-August 1974)
Документ
Категория
Без категории
Просмотров
2
Размер файла
219 Кб
Теги
hands, evaluation, joint, small, arthritis, technetium, rheumatoid, counting
1/--страниц
Пожаловаться на содержимое документа