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Annals of Nuclear Medicine (v.21, #8)
Relationships among regional diastolic impairment, elongation of global time to peak filling rate, and global diastolic function using ECG-gated myocardial perfusion SPECT in heart failure by Akira Yamamoto; Naoto Takahashi; Kazuo Munakata; Kazuya Abe; Yuuko Kobayashi; Jin Tamai; Masato Shiiba; Takao Okuyama; Tadashi Kaneshiro; Haruko Tsuruta; Toshi Takama; Masashi Satou (pp. 419-427).
The relationships among regional diastolic impairment, the elongation of global time to peak filling rate (g-TPF), and global diastolic function were examined by a novel program using electrocardiography-gated myocardial perfusion single-photon emission computed tomography (SPECT) (GMPS) in heart failure (HF).Fifteen control subjects and 70 HF patients, New York Heart Association functional classification I (N-1) 41 cases, classification II (N-II) 15 cases, and classification III (N-III) 14 cases, were examined by GMPS. Using the reference mean +2 SD (standard deviation) of g-TPF derived from control group (CG), HF patients were divided into a normal g-TPF group (NG) and elongated g-TPF group (EG). The distributions of g-TPF and regional (r-) TPF were estimated by histograms. The extension of regional diastolic impairment was estimated by the number of r-TPF elongated segments (NES).g-TPF and r-TPF mainly distributed from 100 ms to 220 ms and demonstrated a peak around 150 ms in CG and NG. g-TPF distributed from 240 ms to 560 ms, but r-TPF distributed from 90 ms to 690 ms and demonstrated two peaks around 150 ms and 350 ms in EG. NES significantly correlated with g-TPF (r = 0.79, P = 6 × 10−10 in N-I; r = 0.69 and P < 0.005 in N-II; r = 0.89, P = 2 × 10−5 in N-III). NES negatively correlated with first third filling fraction (1/3FF) (r = −0.83, P = 3 × 10−11 in N-I; r = −0.72, P < 0.0005 in N-II) and first third filling rate (1/3FR) (r = −0.49, P = 0.002 in N-I; r = −0.52, P = 0.002 in N-II; r = −0.81, P < 0.0005 in N-III). g-TPF significantly correlated with 1/3FF (r = −0.67, P = 1.5 × 10−6 in N-I; r = −0.69, P < 0.005 in N-II) and 1/3FR (r = −0.41, P < 0.01 in N-I; r = −0.69, P < 0.01 in N-III).The development of regional early diastolic impairment makes g-TPF elongation and induces global dysfunction in early diastole.
Keywords: Heart failure; Diastolic function; Peak filling rate; Gated myocardial perfusion SPECT; Regional quantitative analysis
Predictive value of bone marrow accumulation of Tc-99m tetrofosmin for subsequent development of distant metastases in breast cancer by Shigetoshi Wakasugi; Hideaki Tsukuma; Hideo Inaji; Terumi Hashizume; Atsushi Noguchi; Takeshi Ohnishi (pp. 429-437).
We evaluated the predictive value of bone marrow accumulation of technetium (Tc)-99m tetrofosmin in patients with breast cancer for distant metastases in comparison with conventional prognostic factors such as clinical stage, tumor size, axillary lymph node (Node) status, and estrogen receptor (ER) status.Bone marrow scans with Tc-99m tetrofosmin were performed on 64 patients with breast cancer who had no clinical evidence of distant metastases. Accumulation in the femoral marrow was classified into four patterns, no detectable, lower, higher, and intensively higher. Higher or intensively higher pattern was interpreted as abnormal. Thirty-six patients with abnormal accumulation (marrow-positive group) and 28 patients without abnormal accumulation (marrow-negative group) were enrolled in the follow-up study. The mean length of observation after scans was approximately 3 years. The predictive value of femoral marrow status and conventional prognostic factors for distant metastases was evaluated by statistical analysis.Univariate analysis showed a significantly higher incidence of subsequent bone metastases (36% > 4%; P < 0.005), and distant metastases (69% > 18%; P < 0.001) in the marrow-positive group when compared with the marrow-negative group. Conventional prognostic factors except tumor size were also significantly associated with the development of distant metastases; 77% in clinical stage 3 > 39% in clinical stages 1, 2, P < 0.05; 64% in Node-positive >29% in Node-negative, P < 0.01; and 70% in ER negative >27% in ER positive, P < 0.005. These conventional factors were not significantly associated with bone metastases. The Cox proportional hazard ratio for bone metastases was markedly higher in femoral marrow status (hazard ratio = 11.07). The distant metastases-free survival was significantly reduced in ER negative (P < 0.0005), Node-positive (P = 0.0215), and clinical stage 3 patients (P = 0.0163). On the other hand, a more marked difference was observed in the femoral marrow status (P < 0.0001). The hazard ratio for distant metastases was 2.44 in clinical stage, 2.74 in tumor size, 2.74 in Node, and 3.68 in ER, which were each independent prognostic factors associated with distant metastases. However, femoral marrow status was markedly associated with distant metastases (hazard ratio = 5.27).Bone marrow accumulation of Tc-99m tetrofosmin can be a promising prognostic factor independent of conventional prognostic factors for predicting development of not only bone metastases but also distant metastases in breast cancer.
Keywords: Breast cancer; Prediction of distant metastases; Occult metastases in femoral marrow; Tc-99m tetrofosmin
Regional cerebral blood flow in patients with sickle cell disease: study with single photon emission computed tomography by Fareeda A. Al-Kandari; Azu Owunwanne; Ghulam M. Syed; Rajaa Ar Marouf; Abdelhamid H. Elgazzar; Mehraj Shiekh; Ali M. Rizui; Jawaher A. Al-Ajmi; Ahmed M. Mohammed (pp. 439-445).
Neurological complications have been reported in patients with sickle-cell disease (SCD) using positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT), but not with single photon emission computed tomography (SPECT). The objective of this study was to investigate brain perfusion in the patients with SCD using SPECT after technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO), was administered and compare the findings with those of demography, physical examination, MRI and hematological profile.The study involved 21 patients (12 males, 9 females, age at study 8–45 years) who were known to be having SCD for a duration of at least 5 years. The patients were not in acute crisis and had normal neurological assessments with no known history of stroke or transient ischemic episode or previous abnormal CT or MRI brain scan, and were right-handed. The brain SPECT was performed after intravenous injection of 740 MBq (20 mCi) 99mTc-HMPAO in adults or an appropriate dose in pediatric patients. The scans were visually interpreted by two nuclear medicine physicians and a decision was reached by consensus. An MRI done 3 months later was interpreted by a radiologist. The demographic data and hematological profile were obtained from the medical records of the patients.Of the 21 patients, 7 (age 11–22 years) had brain perfusion deficit mostly in the frontal lobe either alone or in combination with temporal and/or parietal lobe. The MRI was abnormal in 2 patients. The brain perfusion deficit was not associated with the demographic data of the patients or hematological profiles.The findings show that SPECT was useful in detecting brain perfusion deficit in SCD patients, and such an early detection may be clinically useful in the subsequent follow-up of such patients, since it is known that cerebral perfusion deficit can lead to silent infarct and/or overt stroke, and affect cognitive skills.
Keywords: SPECT; Regional cerebral blood flow; Sickle cell disease; Tc99mHMPAO; MRI
Stimulation of adenosine A1 receptors decreases in vivo dopamine D1 receptor binding of [11C]SCH23390 in the cat striatum revealed by positron emission tomography by Yojiro Sakiyama; Kentaro Hatano; Takashi Kato; Toshihisa Tajima; Yasuihiro Kawasumi; Kengo Ito (pp. 447-453).
It has been previously suggested that activation of adenosine A1 receptor modulates dopamine D1 receptor binding in vitro, although the direct mechanism of this interaction in vivo has not yet been demonstrated. Here, we conducted a positron emission tomography (PET) study to demonstrate in vivo the interaction between these receptors. The specific adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) was acutely administered to cats under anesthetized condition. Cats underwent repeated measurement of striatal and cerebellar radioactivity following intravenous injection of dopamine D1 receptor-specific [11C]SCH23390. The pretreatment with CPA decreased the striatum/cerebellum ratio of the uptake of [11C]SCH23390. Using the cerebellar radioactivity as an input function, kinetic analysis was performed and demonstrated that CPA caused about 40% decrease in the association rate constant. These results suggest that stimulation of adenosine A1 receptors modulates dopamine D1 receptor binding in vivo.
Keywords: PET; N6-cyclopentyladenosine; SCH23390; Receptor; Cat
An atlas-based image registration method for dopamine receptor imaging with PET in rats by Yojiro Sakiyama; Kentaro Hatano; Toshihisa Tajima; Takashi Kato; Yasuhiro Kawasumi; Mitsuru Suzuki; Kengo Ito (pp. 455-462).
For analysis of in vivo dopamine receptor binding in the rat brain by positron emission tomography (PET), a convenient method to obtain precise anatomical registration for striatum and cerebellum on the PET image was developed. On the PET measurements, a control, an anesthetized rat was positioned in a stereotaxic holder so that the horizontal plane of the PET image would be parallel to the horizontal plane of the brain atlas. After the positioning, [11C]raclopride was intravenously injected into the rats and scanned to obtain PET images of dopamine D2 receptor in the brain. The striatum was bilaterally identified in the obtained PET image. The atlas-based regions of interest (ROIs) of the whole brain were preliminarily created according to the atlas, and were superimposed on an early phase PET image. The early phase PET image was compatible to the whole brain ROI in the atlas, which enabled determination of striatal and cerebellar ROI difficult to determine by the PET image alone. Using the cerebellar radioactivity as a reference input function, rate constants between the free/nonspecific compartment and the receptor bound compartment (k 3 and k 4) were calculated by a two-parameter compartment model, and the binding potential (k 3/k 4) was estimated. The binding potential and its coefficients of variation were 1.56 ± 0.30, 19.3% in Wistar rats, 1.05 ± 0.14, 13.4% in Sprague–Dawley (SD) rats, and 1.29 ± 0.07, 5.2% in Fischer F344 rats, in which binding potential in Wistar rats was significantly higher than that in SD rats. This method is objective and convenient in routine use for PET studies in rats, regardless of differences in the rat strains.
Keywords: PET; Atlas; Raclopride; Receptor; Rat
SPECT evaluation of cerebral blood flow during arm exercise in patients with subclavian steal by Koichiro Kaneko; Shigeru Fujimoto; Yasushi Okada; Takashi Yoshiura; Kotaro Yasumori; Toru Muranaka; Masayuki Sasaki; Hirofumi Koga; Koichiro Abe; Hirofumi Sawamoto; Hiroshi Honda (pp. 463-470).
To explore the cerebral hemodynamics in subclavian steal syndrome, we examined the cerebral perfusion of seven patients with subclavian steal (one symptomatic and six asymptomatic) using single-photon emission computed tomography (SPECT) during resting, arm exercise, and acetazolamide-activated conditions.The regional CBF (rCBF) was measured with SPECT under all conditions, and region of interest (ROI) analysis was performed using a three-dimensional stereotaxic ROI template (3DSRT). We evaluated the relationship between arm exercise-induced rCBF change and (1) presence of subclavian artery stenosis, (2) vertebral reverse flow severity, (3) presence of vertebro-basilar insufficiency (VBI) symptoms, and (4) cerebrovascular reactivity (CVR) to acetazolamide.Overall, no arm exercise-induced rCBF reduction was observed on either the affected or the unaffected side, even in patients with severe vertebral reverse flow. One patient with VBI symptoms showed an arm exercise-induced global rCBF reduction in the cerebrum and cerebellum, whereas the other asymptomatic patients did not. The %rCBF changes in segments with severely impaired CVR (−8.6%± 10.7%, mean ± SD) were significantly lower than those in other segments with less impaired CVR (P < 0.01).Our results suggest that subclavian steal is a benign condition in asymptomatic patients. On the other hand, arm exercise-induced rCBF reduction can occur in the cerebrum and cerebellum in patients with VBI symptoms possibly related to low CVR.
Keywords: Cerebral blood flow; Arm exercise; Subclavian steal
A possible method using baseline hormonal levels to prescribe the appropriate oral therapeutic radioiodine dosage for Graves' disease by Masayuki Nakajo; Shinsaku Tsuchimochi; Megumi Jinguji; Hiroaki Tanabe; Tomoichi Umanodan; Yoshiaki Nakabeppu (pp. 471-476).
The purpose of this study was to retrospectively examine the correlations of hormonal ratios with radioiodine I-131 therapeutic parameters and the potentiality of prescribing the therapeutic I-131 target dosage for an individual patient with Graves' disease using baseline serum levels of thyroid hormones.Serum T3, T4, and FT4 levels 6 and 12 months after I-131 therapy/baseline levels (hormonal ratios) were calculated for a total of 68 therapeutic courses in 57 patients with Graves' disease. The therapeutic parameters were absorbed dose (Gy), dose concentration (µCi/g) and oral dose (mCi). Linear regression analysis was performed for correlating hormonal ratios (X) and therapeutic parameters (Y).Significant (P < 0.05) negative correlations of the hormonal ratios were observed with absorbed dose (R −0.50 for T3, −0.61 for T4, and −0.46 for FT4 at 6 months, and −0.29 for T3, −0.44 for T4 at 12 months) and dose concentration (R −0.57 for T3, −0.58 for T4, and −0.49 for FT4 at 6 months and −0.27 for T3, −0.27 for T4 at 12 months), but not with oral dose at 6 months and 12 months or the absorbed dose and dose concentration for FT4 at 12 months. The correlations were higher at 6 months than at 12 months and in serum T4 than in serum T3 and FT4. The formulae for serum T4 at 6 months were as follows: Y (Gy) = 109 − 53X and Y (µCi/g) = 109 − 52X.These results suggest that the hormonal ratios are significantly correlated with the absorbed dose and dose concentration. The formulae for serum T4 at 6 months may serve to prescribe the individual oral dosage for Graves' disease, although the correlation coefficients are about −0.6.
Keywords: Thyroid; Graves' disease; Radioiodine; Thyroid hormone; Therapy
Diagnosing active inflammation in the SAPHO syndrome using 18FDG-PET/CT in suspected metastatic vertebral bone tumors by Kentaro Inoue; Tatsuo Yamaguchi; Hiroshi Ozawa; Ken Okada; Yasuyuki Taki; Ryoi Goto; Shigeo Kinomura; Tomohiro Kaneta; Hiroshi Fukuda (pp. 477-480).
The vertebral spine is frequently affected by the SAPHO (synovitis, acne, pustulosis, hyperostosis, and osteitis) syndrome. We report the collective imaging findings of hybrid F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (18FDG-PET/CT), as well as bone scans and magnetic resonance imaging, in a patient who had suspected metastatic vertebral bone tumors. 18FDG-PET/CT can be utilized to exclude metastatic vertebral tumors, as well as identifying stable lesions, by demonstrating active inflammatory lesions with accurate anatomic localization through the convergence of the functional information from 18FDG uptake with the anatomic information of CT.
Keywords: SAPHO syndrome; PET/CT; F-18 fluorodeoxyglucose