Feasibility of simultaneous 99mTc-tetrofosmin and 123I-BMIPP dual-tracer imaging with cadmium-zinc-telluride detectors in patients undergoing primary coronary intervention for acute myocardial infarction.

BACKGROUND: Simultaneous dual-tracer imaging using isotopes with close photo-peaks may benefit from improved properties of cadmium-zinc-telluride (CZT)-based scanners. METHODS: Thirty patients having undergone primary percutaneous coronary intervention for acute myocardial infarction underwent single-(99mTc-tetrofosmin (TF) or 123I-BMIPP first) followed by simultaneous 99mTc-TF /123I-BMIPP dual-tracer imaging using a Discovery NM/CT 670 CZT. The values for the quantitative gated-SPECT (QGS) and the quantitative perfusion SPECT (QPS) were assessed. RESULTS: The intra-class correlation (ICC) coefficients between the single- and dual-tracer imaging were high in all the QGS and QPS data (Summed motion score: 0.95, summed thickening score: 0.94, ejection fraction: 0.98, SRS for 99mTc-TF: 0.97/ for 123I-BMIPP: 0.95). Wall motion, wall thickening and rest scores per coronary-territory-based regions were also comparable between the single- and dual imaging (ICC coefficient > 0.91). The interrater concordance in the visual analysis for the infarction and perfusion-metabolism mismatch was significant for the global and regional left ventricle (P < 0.001). CONCLUSION: The quantitative/semi-quantitative values for global and regional left-ventricular function, perfusion, and fatty acid metabolism were closely comparable between the dual-tracer imaging and the single-tracer mode. These data suggests the feasibility of the novel CZT-based scanner for the simultaneous 99mTc-TF /123I-BMIPP dual-tracer acquisitions in clinical settings.

Shortened acquisition time in simultaneous 99mTc-tetrofosmin and 123I-ß-methyl-p-iodophenyl pentadecanoic acid dual-tracer imaging with cadmium-zinc-telluride detectors in patients undergoing primary coronary intervention for acute myocardial infarction.

OBJECTIVE: The use of cadmium-zinc-telluride-based scanners may increase the clinical feasibility of simultaneous dual-isotope imaging. In the current study, we sought to investigate a potential acquisition time in simultaneous Tc-tetrofosmin/I-ß-methyl-p-iodophenyl pentadecanoic acid dual-isotope imaging using a Discovery NM/CT 670 cadmium-zinc-telluride. METHODS: Simultaneous Tc-tetrofosmin/I-ß-methyl-p-iodophenyl pentadecanoic acid dual-isotope imaging was performed in 29 patients who had undergone primary percutaneous coronary intervention for acute myocardial infarction. Referenced images with an acquisition time of 65 s/view (16.25 min) were reframed to produce images with acquisition times of 33, 16, and 8 s/view. The values for the quantitative-gated single-photon emission computed tomography (SPECT) and the quantitative perfusion SPECT were compared. RESULTS: The quantitative-gated SPECT values for images with 33, 16, and 8 s/views showed good consistency with those for 65 s/view (the lower 95% confidence intervals for the intraclass correlation were ≥0.80). The quantitative perfusion SPECT values for Tc-tetrofosmin images with 33, 16, and 8 s/views also showed good consistency with those for 65 s/view; however, the quantitative perfusion SPECT values for I-ß-methyl-p-iodophenyl pentadecanoic acid images with an acquisition time of 8 s/view were not consistent with the reference acquisition time of 65 s/view. CONCLUSIONS: The quantitative-gated SPECT and quantitative perfusion SPECT values obtained from images with shorter acquisition times correlated with the values obtained from images with a reference acquisition time of 65 s/view; however, tracer-specific predisposition should be considered. These findings suggest that it is possible to reduce acquisition time when performing simultaneous Tc-tetrofosmin/I-ß-methyl-p-iodophenyl pentadecanoic acid dual-tracer imaging with the novel cadmium-zinc-telluride scanner.

High-speed scanning of planar images showing 123I-MIBG uptake using a whole-body CZT camera: a phantom and clinical study.

BACKGROUND: The heart-to-mediastinum ratio (HMR) obtained in myocardial sympathetic innervation imaging using 123I-metaiodobenzylguanidine (MIBG) is used for heart failure or Lewy body diseases (LBD). Discovery NM/CT 670 CZT, a novel whole-body scanner, enables direct HMR measurements in planar images, in contrast to cardiac-dedicated CZT-based cameras which require specific post-processing reconstruction. We sought to investigate the clinical utility of the Discovery NM/CT 670 CZT for myocardial innervation imaging and the potential time reduction. RESULTS: Following preliminary phantom examinations, 123I-MIBG planar imaging was performed in 36 patients with suspected or known LBD to measure HMRs with a collection time of 300 s. Images for different collection times were subsequently reframed using already acquired data, and changes in HMRs were evaluated. The HMRs for patients with versus without clinically diagnosed LBD were 1.63 ± 0.08 versus 2.21 ± 0.08 at early phase (p < 0.001) and 1.54 ± 0.09 versus 2.08 ± 0.09 at delayed phase (p < 0.001). The difference of HMRs (300 s - other collection time) became greater as the collection time became shorter. There was good consistency in HMRs between the 300-s images (reference) and the 200-s (intra-class correlation (ICC) coefficients > 0.99), 100-s (ICC coefficients > 0.97), and 50-s (ICC coefficients > 0.89) images. CONCLUSIONS: In planar images with a whole-body CZT-based camera, the HMRs of patients with LBD were significantly lower than those without. HMRs with the collection time of 50 s and longer showed good consistency with those of 300 s in the ICC analysis. These findings indicate a clinical utility of this novel scanner for HMR measurements and potential time reductions.

Comparison of Dopamine Transporter SPECT and 123I-MIBG Myocardial Scintigraphy to Assess Clinical Severity in Patients With Parkinson Disease.

PURPOSE: The aim of our study was to evaluate the use of dopamine transporter (DAT) SPECT and I-MIBG myocardial scintigraphy to determine the clinical severity of Parkinson disease (PD), with a focus on motor impairments affecting activities of daily living (ADLs). METHODS: Data for 65 consecutive PD patients who underwent both DAT and MIBG imaging were reviewed. Associations between imaging variables and Hoehn and Yahr (H&Y) staging or self-supportive care ratings were investigated. Univariate and multivariate regression analyses were performed to determine the factors associated with ADLs. RESULTS: After applying the exclusion criteria, 45 patients were analyzed (age, 73.1 ± 9.3 years; 23 males; H&Y stage 1: n = 12, stage 2: n = 14, stage 3: n = 10, stage 4: n = 5, and stage 5: n = 4; self-supportive care rating-dependent ADLs: n = 29). Dopamine transporter variables were significantly associated with the clinical severity of PD as assessed by H&Y staging, whereas MIBG variables were not. Dopamine transporter variables gradually decreased throughout progressive stages, whereas the MIBG variables changed only in the advanced stages. In a multivariate analysis including clinical and imaging variables, both lower DAT and MIBG uptakes were significantly associated with dependent ADL status (P = 0.028 and 0.034, respectively). CONCLUSIONS: In patients with PD, DAT SPECT and MIBG myocardial scintigraphy were associated with ADL status; DAT SPECT was a stronger indicator of severity than MIBG myocardial scintigraphy in the early and middle stages.

Variations of the posterior cerebral artery diagnosed by MR angiography at 3 tesla.

INTRODUCTION: Fenestration, early bifurcation, and duplication of the posterior cerebral artery (PCA) and the so-called hyperplastic anterior choroidal artery (AChA), considered a variation of the PCA, are rare. We evaluated the prevalence and characteristic features of these PCA variations on magnetic resonance (MR) angiography. METHODS: We reviewed intracranial MR angiographic images of 2402 patients examined using a 3-tesla scanner. Images from the skull base to the intracranial region were obtained using the standard time-of-flight technique. We excluded images of 52 patients with insufficient image quality or occlusion of the PCA(s) and retrospectively evaluated the images of 2350 patients using a picture archiving and communication system. RESULTS: We observed PCA fenestration in eight (0.34%) patients, most at the P1 segment and P1-P2 junction and all small in size, early bifurcation at the P1-P2 junction or proximal P2A segment in eight (0.34%) patients, complete duplication in one patient, and hyperplastic AChA in 13 (0.55%) patients. Eleven of the 13 hyperplastic AChAs supplied only the territory of the temporal branch of the PCA, and the remaining two supplied the entire territory of the PCA. CONCLUSION: We observed PCA variations in 30 (1.28%) patients. We believe the name "hyperplastic AChA" inaccurately describes variations of the PCA in which the AChA supplies part of or all of the territory of the PCA and propose "accessory PCA" to describe an AChA that supplies part of the territory of the PCA or "replaced PCA" to describe that vessel that supplies the territory all branches of the PCA.

Aberrant internal carotid artery associated with occipital artery arising from the internal carotid artery.

We present an extremely rare case of an aberrant course of the petrous internal carotid artery (ICA) associated with the ipsilateral occipital artery arising from the cervical ICA, a combination not previously reported by magnetic resonance (MR) angiography. The patient was a 53-year-old woman with no symptoms related to the anomalous ICA. Source images and partial maximum-intensity-projection images of MR angiography are useful in diagnosing these variations. Source images and curved multiplanar reconstruction images of computed tomography angiography are important for the accurate evaluation of reduced arterial diameter and the relationship between the anomalous artery and petrous bone.

Left carotid-anterior cerebral artery anastomosis diagnosed by MR angiography: a case report.

Anastomosis of the carotid-anterior cerebral artery (ACA) is a rare anomalous vessel that arises from the internal carotid artery (ICA) at the level of the ophthalmic artery and takes an infraoptic and prechiasmatic path to anastomose with the ACA. It has known right-sided predominance. We report the case of an 83-year-old man with a left carotid-ACA anastomosis that was diagnosed by magnetic resonance (MR) angiography from the neck to the head during investigation of transient left hemiplegia. The right ICA was occluded at its origin. Our literature search revealed only six reported cases of left carotid-ACA anastomoses. We believe ours is the first case diagnosed by MR angiography.

Persistent dorsal ophthalmic artery and ophthalmic artery arising from the middle meningeal artery diagnosed by MR angiography at 3 T.

INTRODUCTION: A persistent dorsal ophthalmic artery (OA) is a rare variation that originates from the cavernous segment of the internal carotid artery (ICA) and enters the orbit via the superior orbital fissure (SOF). Occasionally, the OA also arises from the middle meningeal artery (MMA) and enters the orbit via the SOF. These two major variations of the OA have not been well described by magnetic resonance (MR) angiography. We evaluated their prevalence on MR angiography at 3 T. METHODS: We retrospectively reviewed our database of MR angiographic images obtained using a 3 T imager. Of images of 846 patients, we evaluated those of 826 patients (1,652 OAs) with special attention to OA origin and its course into the orbit. We excluded images of the 20 because quality was insufficient to assess. RESULTS: We found 7 (0.42%) persistent dorsal OAs among 1,652 OAs (right/left, 6/1; male/female, 3/4). Twenty-four (1.45%) OAs arose from the MMA (right/left/bilateral, 11/5/4; male/female, 10/10), three of which also demonstrated a small normally branching OA. In one patient, we observed both right persistent dorsal OA and left OA arising from the MMA. CONCLUSIONS: Per OA, the prevalence of persistent dorsal OA was 0.42% and of OA arising from the MMA, 1.45%, with a tendency toward right-side predominance. OA arising from the MMA can be seen bilaterally; preprocedural knowledge of this variation is important because of the danger associated with endovascular procedures of the external carotid system when the OA arises from the MMA.