Comparative Analysis of (99m)Tc-MDP Three-Phase Bone Scan with SPECT/CT and (99m)Tc-HMPAO-Labeled WBC SPECT/CT in the Differential Diagnosis of Clinically Suspicious Post-traumatic Osteomyelitis / 대한핵의학회잡지

PURPOSE: To identify differences between three-phase bone scan and SPECT/CT (TBS) and WBC SPECT/CT (WS) and compare diagnostic accuracies of each modality in patients with suspicious post-traumatic osteomyelitis (OM).METHODS: Twenty-one patients with suspicious post-traumatic OM were enrolled. All patients performed TBS and WS within 1 week. Foci ofMDP andWBC accumulation were divided into three categories: bone (OM), soft tissue (soft tissue inflammation; STI), negative for inflammation (NI). Confirmative diagnosis was made upon operative pathology or long-term clinical follow-up.RESULTS: Of 21 patients, four OM, eight STI, nine NI were finally diagnosed. TBS diagnosis was correct in three of four positive cases and nine of 17 negative cases. Sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV) of TBS were 75 %, 52.9 %, 57.1 %, 27.3 %, 90 %. WS diagnosis was correct in two of four positive cases and 17 of 17 negative cases. Sensitivity, specificity, accuracy, PPV, NPV were 50 %, 100 %, 81.0 %, 100 %, 89.5 %. Twelve of 21 cases showed agreement between TBS and WS. TBS misdiagnosed nine cases (six STI and two NI as eight OM; one OM as one STI), while WS misdiagnosed four cases (two OM as two STI; two STI as two NI). Combining results from TBS and WS led to better diagnostic accuracy (91.7 %) than either TBS or WS alone.CONCLUSION: TBS and WS showed moderate agreement in assessment of clinically suspected post-traumatic OM. WS better evaluated inflammation than TBS. WS tended to underestimate inflammation whereas TBS tended to overestimate inflammation. Combining TBS and WS enhanced diagnostic accuracy.

Changes in Cerebral Vascular Reserve Capacity after Carotid Artery Stenting: A 6-Month Follow-up Study

BACKGROUND: Assessment of cerebral vascular reserve capacity prior to carotid artery stenting is used for predicting hyperperfusion syndrome. However, the changes in vascular reserve capacity after carotid stenting are not fully understood. In this study we investigated the effects of carotid artery stenting on the restoration of vascular reserve capacity using (99m)TC-hexamethylpropylene amine oxime (HMPAO) single-photon-emission computed tomography (SPECT). METHODS: The study population comprised 29 patients who underwent carotid artery stenting. Patients were divided into groups according to occlusion of the contralateral internal carotid artery (unilateral group vs bilateral group) and according to the presence or absence of symptoms related to carotid stenosis (symptomatic group vs asymptomatic group). Pre- and postacetazolamide-activated (99m)TC-HMPAO SPECT were performed prior to stent insertion and at 1 and 6 months postoperatively. Vascular reserve capacity was assessed based on pre-, and 1- and 6-month postacetazolamide gamma count ratio (Post0, Post1, and Post6, respectively) and cerebrovascular reactivity (CVR0, CRV1, and CRV6, respectively). RESULTS: The postacetazolamide gamma count ratio and cerebrovascular reactivity tended to improve at 1 month after stenting, but tended to deteriorate at 6 months after stenting in the unilateral group compared with the bilateral group [Post0-Post1=0.045+/-0.078 (mean+/-SD), p=0.014; Post0-Post6=0.025+/-0.063, p=0.042; Post1-Post6=-0.020+/-0.047, p=0.102; CVR0-CVR1=0.043+/-0.071, p=0.008, CVR0-CVR6=0.019+/-0.063, p=0.097; CVR1-CVR6=-0.024+/-0.047, p=0.008] and in the symptomatic group compared with the asymptomatic group (Post0-Post1=0.058+/-0.106, p=0.038; Post0-Post6=0.048+/-0.103, p=0.061; Post1-Post6=-0.010+/-0.048, p=0.700; CVR0-CVR1=0.037+/-0.083, p=0.074; CVR0-CVR6=0.014+/-0.073, p=0.344; CVR1-CVR6=-0.023+/-0.054, p=0.055). CONCLUSIONS: The observed increases in postacetazolamide gamma count ratio and cerebrovascular reactivity at 1 month followed by decreases at 6 months may reflect the restoration of vascular reserve capacity. Carotid artery stenting can improve vascular reserve capacity, especially in patients with unilateral stenosis and with symptomatic stenosis.

Characteristics of Brain Perfusion in Patients of Parkinson's Disease / 핵의학분자영상

PURPOSE: It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. METHODS AND MATERIALS: Two hundred nineteen patients (M: 70, F: 149, mean age: 62.9+/-6.9 y/o) who were diagnosed as PD without dementia clinically and 55 patients (M: 15, F: 40, mean age: 61.4+/-9.2 y/o) as normal controls who had no past illness history were performed (99m)Tc-HMPAO brain perfusion SPECT and neuropsychological test. RESULTS: At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood perfusion in 32 (14.7%) of 219 patients with PD, decreased perfusion on the frontal lobe in 45 patients (20.6%), the temporal lobe in 38 patients (17.4%), the parietal lobe in 39 patients (17.9%), the occipital lobe in 40 patients (18.3%), diffuse area in 14 patients (6.4%) and unclassified in 10 patients (4.6%). Fifthly, we compared the results of the neuropsychological test and cerebral perfusion pattern. There was no correlation between two tests except visuospatial function. CONCLUSION: Various perfusion state were found in patients with PD according to the age and sex. Also we were able to classify perfusion state into several groups and compare the neuropsychological test with cerebral perfusion.

The Value of (99m)Tc-HMPAO-WBC Scan in the Diagnosis of Infection after Total Knee Arthroplasty

PURPOSE: The early diagnosis and detection of prosthetic infection after TKA is very important and difficult for deter- mination of the plan in management and reduction of complications. In these reasons, this study was performed to evaluate the usefulness and limitation of (99m)Tc-HMPAO(Technetium (99m)-hexamethyl- propylene amine oxime)-labeled WBC scan in the patients with clinically suspicious prosthetic infection. MATERIALS AND METHODS: The study subjects were 25 patients(3 men and 19 women, mean age: 66.5 years) performed (99m)Tc-HMPAO WBC scan in the patients with clinically suspicious prosthesis infection after TKA from January, 2005 to May, 2007. And in 6 patients who had undergone bilateral arthroplasty, we regarded one patient as two cases. Thus, total 31 prostheses were included in this study. Final diagnosis of infection was based on bacteriological result by intrao- perative cultures, surgical findings, and histological evidence intraoperatively obtained in the suspicious site and clinical follow-up. RESULTS: In the final diagnosis, we confirmed that total 16 prosthetic joints were infected. Of these infected prostheses, increased (99m)Tc-HMPAO WBC scan uptake waspositive in 15, negative in 1. Finally, 15 cases were confirmed as nonin- fected prosthesis, 6 showed positive by (99m)Tc-HMPAO WBC scan uptake, 9 showed negative. Over all sensitivity, speci- ficity, and positive predictive value for diagnosisof infected TKA were 93.75, 60%, and 71.43%. CONCLUSION: (99m)Tc-HMPAO WBC scan was a highly sensitive method for the diagnosis of prosthetic infection after TKA. But low specificity and high false positive of (99m)Tc-HMPAO WBC scan demand more clinical follow-up for confirmed diagnosis. To increase specificity, additionally scan will be needed.

Neurological Improvement after Cranioplasty in Patients with Surgical Bony Defects : The Usefulness of Acetazolamide Activated (99m)Tc-HMPAO SPECT

OBJECTIVE: The purpose of this study is to examine the influence of cranioplasty on dynamics of cerebral blood flow(CBF) and cerebrovascular reserve capacity(CVRC), and to investigate the usefulness of single photon emission computed tomography (SPECT) as a prognostic factor for neurological improvement after cranioplasty. METHODS: Between March 2003 and December 2005, a prospective study was performed on 24 patients who had undergone total 25 cranioplasty operations. Cerebral blood flow velocities in the middle cerebral artery(MCA) and internal carotid artery (ICA) were obtained by transcranial Doppler ultrasonography(TCD). The CVRC was assessed by SPECT in the natural state and after stimulation with 1g of acetazolamide. Neurological improvement after cranioplasty was compared between patients who showed hyperactivity to acetazolamide-activated SPECT (Group 1, n=7) and hypoactivity to acetazolamide-activated SPECT (Group 2, n=17). These measurements were obtained two weeks prior to and two weeks after cranioplasty. RESULTS: The blood flow velocities at the opposite site to the cranioplasty as well as at the cranioplasty site were significantly increased (P<0.05). Compared with Group 2, there was significant increase in CBF and neurological imrovement after cranioplasty in Group 1. CONCLUSION: Among patients with surgical bony defects, the patients who had normal reactivity of the CVRC showed a significant increase in CBF and neurological improvement after cranioplasty. The authors suggest that CVRC measurement prior to surgery may be an important prognostic factor for neurological improvement after cranioplasty.

The Clinical Significance of SPECT in Head Trauma

SPECT(single photon emission computed tomography) using 99m-Tc-HMPAO is a current method of identifying the relative condition of cerebral blood perfusion in pathologic conditions of the brain such as TIA, complete cerebral infarction, dementia, and psychologically ill states. The purpose of this article is to evaluate the significance of SPECT in head injuries. According to the other previous reports, there are several drawbacks in SPECT to evaluate the victims of head injury such as uncooperability of the patient, long scanning time. poor patient monitoring during the scanning time. poor availability, ete. The authors analyzed 54 cases of head injury patients, studying SPECT and CT in regard to the comparison of CT and SPECT, the relation of SPECT and the severity of the head injury, the duration of admission and the SPECT findings. The results were as follows: 1) In focal lesion, CT was more available for the quick evaluation of the location, size, and rapid decision making, and SPECT was available for the adjuvant method of postoperative follow-up. 2) In diffuse brain lesion, CT showed only the diffuse brain swelling and SPECT was available for more fine localization of the lesion. 3) In mild head injury, CT could not identify the location of the lesion and SPECT showed focal perfusion defects(55%).