Ultrafast nuclear myocardial perfusion imaging on a new gamma camera with semiconductor detector technique: first clinical validation

PURPOSE: To assess the diagnostic performance of a novel ultrafast cardiac gamma camera with cadmium-zinc-telluride (CZT) solid-state semiconductor detectors for nuclear myocardial perfusion imaging (MPI). METHODS: The study group comprised 75 consecutive patients (55 men, BMI range 19-45 kg/m(2)) who underwent a 1-day (99m)Tc-tetrofosmin adenosine-stress/rest imaging protocol. Scanning was performed first on a conventional dual-detector SPECT gamma camera (Ventri, GE Healthcare) with a 15-min acquisition time each for stress and rest. All scans were immediately repeated on an ultrafast CZT camera (Discovery 530 NMc, GE Healthcare) with a 3-min scan time for stress and a 2-min scan time for rest. Clinical agreement (normal, ischaemia, scar) between CZT and SPECT was assessed for each patient and for each coronary territory using SPECT MPI as the reference standard. Segmental myocardial tracer uptake values (percent of maximum) using a 20-segment model and left ventricular ejection fraction (EF) values obtained using CZT were compared with those obtained using conventional SPECT by intraclass correlation and by calculating Bland-Altman limits of agreement. RESULTS: There was excellent clinical agreement between CZT and conventional SPECT on a per-patient basis (96.0%) and on a per-vessel territory basis (96.4%) as shown by a highly significant correlation between segmental tracer uptake values (r=0.901, p<0.001). Similarly, EF values for both scanners were highly correlated (r=0.976, p<0.001) with narrow Bland-Altman limits of agreement (-5.5-10.6%). CONCLUSION: The novel CZT camera allows a more than fivefold reduction in scan time and provides clinical information equivalent to conventional standard SPECT MPI

Comparing S-Guide® and Gliderite® Times to Assist Video laryngoscopic Intubation in Patients with Simulated Difficult Airways: A Single-Blinded Randomized Prospective Study.

Gliderite®, one of the first stylets designed specifically to assist tracheal intubation with non-channeled curved blades video laryngoscopes, can cause injury. The S-Guide® is a new, malleable, intubating guide allowing oxygenation. Its soft tip is designed to prevent trauma. We aimed to compare the duration of tracheal intubation with S-Guide compared to Gliderite using a C-MAC® D-Blade® video laryngoscope in patients with simulated difficult airways. We performed a single-blinded prospective randomized study, with 50 adult patients requiring orotracheal intubation under general anaestheesia in Lausanne University Hospital. A cervical collar was fitted around the patient's neck to simulate difficult intubation conditions. Exclusion criteria were American Society of Anesthesiologists (ASA) &gt;3, BMI &gt; 35 kg m2 , known or at risk of difficult intubation, and risk of aspiration of gastric content. We recorded T1: time of identification of the glottis; T2: time to inflate the cuff, and T3: total intubation time (capnography curve appearance). Secondary outcomes were the presence of arytenoid contact during intubation and postoperative airway discomfort. There were no significant differences between T1 and T2 (seconds) while using the S-Guide or Gliderite, respectively: 14.6 [9.6- 18.6] vs 16.5 [11.0-20.6]; P=.368 and 43.3 [33.2-49.3] vs 46.3 [35.6-61.5], P =.308. T3 was significantly shorter in the S-Guide group: 58.1 [50.2-61.8] vs 65.3 [57.6-78.7], P =.044. Fewer arytenoid contact occurred during intubation using the S-Guide (P =.032), without difference in postoperative airway discomfort. S-Guide-assisted tracheal intubation, with a C-MAC D-Blade in simulated difficult airways, allows successful and faster intubation than with the Gliderite Stylet

Improvement in Coronary Endothelial Function is Independently Associated with a Slowed Progression of Coronary Artery Calcification in Type 2 Diabetes Mellitus.

none10Valenta I; Vincenti G; Quercioli A; Nkoulou R; Zaidi H; Dewarrat S; Seimbille Y; Ratib O; Mach F; Schindler TH.Valenta, I; Vincenti, G; Quercioli, ALESSANDRA MARIA; Nkoulou, R; Zaidi, H; Dewarrat, S; Seimbille, Y; Ratib, O; Mach, F; Schindler, T. H

Validation of CT attenuation correction for high-speed myocardial perfusion imaging using a novel cadmium-zinc-telluride detector technique.

The aim of this study was to validate attenuation correction (AC) using low-dose standard CT for myocardial perfusion imaging (MPI) on a novel ultra fast γ-camera with cadmium-zinc-telluride (CZT) detector technology. METHODS: Sixty-six patients (body mass index ± SD, 27.2 ± 3.5 kg/m(2); range, 19.1-36.0 kg/m(2)) underwent a 1-d (99m)Tc-tetrofosmin adenosine stress-rest imaging protocol with 15-min acquisitions on a standard dual-head SPECT camera. All scans were repeated within minutes on the CZT camera, with 3-min acquisitions for stress (low dose) and 2-min acquisitions for rest (high dose) as recently established. We compared maximum myocardial uptake (20-segment model) from CZT versus standard SPECT MPI by intraclass correlation without and with CT AC. In addition, clinical agreement for each coronary territory for all scans from both devices was assessed, and Bland-Altmann (BA) limits of agreement for percentage uptake were calculated. RESULTS: The clinical agreement between CZT and standard SPECT cameras was 96% for noncorrected low- and high-dose images (r = 0.90 and BA = -18 to 15, and r = 0.91 and BA = -15 to 16, respectively), and agreement after AC was 96% for low- and 99% for high-dose images (r = 0.87 and BA = -16 to 14, and r = 0.88 and BA = -16 to 14, respectively). CONCLUSION: Our results support that AC of MPI on the novel CZT camera, compared with AC MPI on a conventional SPECT camera, is feasible because it provides a high correlation of segmental tracer uptake and an excellent clinical agreement

Real-time breath-hold triggering of myocardial perfusion imaging with a novel cadmium-zinc-telluride detector gamma camera

PURPOSE: The aim of this study was to assess the ability of real-time breath-hold-triggered myocardial perfusion imaging (MPI) using a novel cadmium-zinc-telluride (CZT) gamma camera to discriminate artefacts from true perfusion defects. METHODS: A group of 40 patients underwent a 1-day (99m)Tc-tetrofosmin pharmacological stress/rest imaging protocol on a conventional dual detector SPECT gamma camera with and without attenuation correction (AC), immediately followed by scanning on an ultrafast CZT camera with and without real-time breath-hold triggering (instead of AC) by intermittent scanning confined to breath-hold at deep inspiration (using list mode acquisition). We studied the use of breath-hold triggering on the CZT camera and its ability to discriminate artefacts from true perfusion defects using AC SPECT MPI as the reference standard. Myocardial tracer uptake (percent of maximum) from CZT was compared to AC SPECT MPI by intraclass correlation and by calculating Bland-Altman limits of agreement. RESULTS: AC of SPECT MPI identified 19 apparent perfusion defects as artefacts. Of these, 13 were correctly identified and 4 were partially unmasked (decrease in extent and/or severity) by breath-hold triggering of the CZT scan. All perfusion defects verified by SPECT MPI with AC were appropriately documented by CZT with and without breath-hold triggering. This was supported by the quantitative analysis, as the correlation (r) of myocardial tracer uptake between CZT and AC SPECT improved significantly from 0.81 to 0.90 (p<0.001) when applying breath-hold triggering. Similarly, Bland-Altman limits of agreement were narrower for CZT scans with breath-hold triggering. CONCLUSION: This novel CZT camera allows real-time breath-hold triggering as a potential alternative to AC to assist in the discrimination of artefacts from true perfusion defects

Lowering heart rate with an optimised breathing protocol for prospectively ECG-triggered CT coronary angiography

The breath-hold level to best reduce heart rate for CTCA should be individually assessed prior to scanning because a mean heart rate reduction of 5 bpm can be achieved