Single-photon emission computed tomography

Single-photon emission computed tomography, abbreviated SPECT or SPET, is a nuclear medicine imaging test. It is used to obtain 3-D images of many body systems, however, the one used specifically for ME/CFS is a brain scan. At present time, the use of SPECT brain scans for ME/CFS is mostly in research studies of the pathophysiology of ME/CFS. It is not needed for diagnosis nor is it used as a treatment.

SPECT studies related to ME/CFS
Nuclear Medicine Communication. 1992 Oct;13(10):767-72 (Abstract) American Journal of Roentgenology. 1994 Apr;162(4):935-41. (Abstract) Clinical and Diagnostic Laboratory Immunology. 1994 Mar;1(2):222-6. (Abstract) Quarterly Journal of Medicine. 1995 Nov;88(11):767-73. (Abstract) Nuclear Medicine Communications. 1998 Nov;19(11):1065-71. (Abstract) Psychosomatic Medicine. 2003 Jan-Feb;65(1):129-36. (Abstract) Clinical Physiology and Functional Imaging. 2006 Mar;26(2):83-6. (Abstract)
 * 1992: A study at the Department of Radiology (Division of Nuclear Medicine), University of Toronto, Canada stated: "Regional cerebral blood flow (rCBF) was assessed in 60 clinically defined CFS patients and 14 normal control (NC) subjects using 99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) single photon emission computed tomography (SPECT). Compared with the NC group, the CFS group showed significantly lower cortical/cerebellar rCBF ratios, throughout multiple brain regions (P < 0.05). Forty-eight CFS subjects (80%) showed at least one or more rCBF ratios significantly less than normal values. The major cerebral regions involved were frontal (38 cases, 63%), temporal (21 cases, 35%), parietal (32 cases, 53%) and occipital lobes (23 cases, 38%). The rCBF ratios of basal ganglia (24 cases, 40%) were also reduced. 99Tcm-HMPAO brain SPECT provided objective evidence for functional impairment of the brain in the majority of the CFS subjects."
 * 1994, A study at the Department of Radiology, Brigham and Women's Hospital, Boston, showed that "Patients with chronic fatigue syndrome had significantly more defects throughout the cerebral cortex on SPECT scans than did normal subjects (7.31 vs 0.43 defects per subject, p < .001). SPECT abnormalities were present in 13 (81%) of 16 patients, vs three (21%) of 14 control subjects (p < .01). SPECT scans showed significantly more abnormalities than did MR scans in patients with chronic fatigue syndrome (p < .025)."
 * 1994, A study done at the Department of Medicine, Hennepin County Medical Center, Minneapolis, MN concluded: "Serum TGF-beta and cerebral blood flow abnormalities, detected by single-photon emission-computed tomographic scanning, were accentuated postexercise in the CFS group. Although these findings were not significantly different from those in the control group, the effect of exercise on serum TGF-beta and cerebral blood flow appeared magnified in the CFS patients."
 * 1995, A study done at the Department of Psychiatry, UCL Medical School, London using SPET concluded: "An initial pilot study revealed widespread reduction of regional brain perfusion in 24 ME/CFS patients, compared with 24 normal volunteers." A second test was done on 67 patients with ME/CFS and that study showed: "Brain-stem hypoperfusion was confirmed in all ME/CFS patients....Patients with ME/CFS have a generalized reduction of brain perfusion, with a particular pattern of hypoperfusion of the brainstem."
 * 1998: A study done at the Department of Radiology, St. Vincent's Hospital, New York, NY used eighteen patients (14 females, 4 males), who fulfilled the diagnostic criteria of the Centers for Disease Control for chronic fatigue syndrome. They concluded that: "Thirteen patients had abnormal SPET brain perfusion scans and five had normal scans."
 * 2003, A study at the College of Health Sciences, University of Texas, El Paso, Texas on 15 subjects with CFS and 15 healthy persons was done twice, at rest and when performing the Paced Auditory Serial Addition Test (PASAT). Results showed: "No group differences were found for performance on the PASAT despite CFS subjects' perceptions of exerting more mental effort to perform the task than healthy subjects. Inspection of the aggregate scans by group and task suggested a pattern of diffuse regional cerebral blood flow among subjects with CFS in comparison with the more focal pattern of regional cerebral blood flow seen among healthy subjects. Between-group region-of-interest analysis revealed that although CFS subjects showed less perfusion in the anterior cingulate region, the change in CFS subjects' activation of the left anterior cingulate region during the PASAT was greater than that observed for healthy subjects. The differences were not attributable to lesser effort by the subjects with CFS, confounding effects of mood perturbation, or to poorer performance on the experimental task."
 * 2006, A study at the Department of Neurosciences, Fatigue Research Center, UMDNJ-New Jersey Medical School, Newark stated: "Xenon-computed tomography blood flow studies were done on 25 CFS patients and seven healthy controls. Analyses were done after stratifying the CFS patients based on the presence or absence of a current psychiatric disorder. Flow was diminished in both groups as follows: patients with no current psychiatric disorders had reduced cortical blood flow in the distribution of both right and left middle cerebral arteries (P<0.05 for both) while those with current psychiatric disorders had reduced blood flow only in the left middle cerebral artery territory (P<0.05). These data indicate that patients with CFS have reduced absolute cortical blood flow in rather broad areas when compared with data from healthy controls and that those devoid of psychopathology had the most reductions in cortical flow. These data support, in part, our earlier findings that patients devoid of psychopathology are the group most at risk of having some of the symptoms of CFS due to brain dysfunction."

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