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Breath-hold CT attenuation correction for quantitative cardiac SPECT
Kazuhiro Koshino, Kazuhito Fukushima, Masaji Fukumoto, Kazunari Sasaki, Tetsuaki Moriguchi, Yuki Hori, Tsutomu Zeniya, Yoshihiro Nishimura, Keisuke Kiso, Hidehiro Iida
EJNMMI Research , 2012, DOI: 10.1186/2191-219x-2-33
Abstract: A series of 201Tl-emission and 99mTc-based transmission computed tomography (TCT) scans was carried out along with CT-attenuation scans on 11 young normal volunteers using a hybrid SPECT/CT scanner. The CT scans were performed at three respiratory phases: end-inspiration (INS), end-expiration (EXP), and the midpoint (MID) between these phases. Using alignment parameters between attenuation maps and SPECT images without attenuation or scatter corrections, quantitative SPECT images were reconstructed, including corrections for attenuation and scatter. Regional radioactivity concentrations normalized by the subjects’ weights were compared between CT- and TCT-based attenuation correction techniques.SPECT images with CT attenuation maps at the EXP phase showed significant differences in regional weight-normalized radioactivity concentrations relative to the images using the other attenuation maps (p?<?0.05), as well as systematic positive bias errors, compared to TCT-based images for all myocardial segments, 5.7%?±?2.7% (1.9% to 10.0%). No significant differences in regional weight-normalized radioactivity concentrations were observed between images with CT attenuation maps at MID and INS phases or between these and the TCT-based images, but regional tendencies were found: for anterior to anterolateral segment, positive bias of 5.0%?±?2.2% (1.3% to 8.1%) and 5.6%?±?1.9% (2.6% to 8.5%) and for inferior to inferoseptal segment, negative bias of ?5.3%?±?2.6% (?9.1% to ?1.7%) and ?4.6%?±?2.5% (?8.8% to ?1.5%) for the MID and INS phases, respectively.Use of breath-hold CT attenuation maps at INS and MID phases for attenuation and scatter corrections demonstrated accurate quantitative images that would prove beneficial in cardiac SPECT/CT studies.Single photon emission computed tomography (SPECT) has the unique ability to provide functional images of biological tissues in vivo. As is the case with positron emission tomography (PET), corrections for attenuation and scatter are
Comparisons of Image Quality and ADCs in Breath-Hold, Respiratory-Triggered and Free-Breathing DWI of Pancreas at 3-T  [PDF]
Chao Ma, Jian Wang, Yan-Jun Li, Chun-Shu Pan, Yong Zhang, He Wang, Shi-Yue Chen, Jian-Ping Lu
Open Journal of Radiology (OJRad) , 2014, DOI: 10.4236/ojrad.2014.44037
Abstract: Objective: To compare image quality and apparent diffusion coefficients (ADC) of the normal pancreas parenchymas in breath-hold, respiratory-triggered and free-breathing diffusion weighted imaging (DWI) at 3.0-Tesla. Methods: DWI of the pancreas was performed at 3.0-Tesla in 21 healthy volunteers with breath-hold, respiratory-triggered and free-breathing using b-values of 0 and 500 s/mm2. For all three sequences, two readers assigned an image quality score to images at b0 and b500, and two independent readers measured ADCs for the head, body and tail of pancreas. Image quality scores and ADCs of pancreas in the three DWIs were compared. Results: For b0, image quality scores was not significantly different among the three sequences (p = 0.103). For b500, image quality score was significantly lower in free-breathing DWI than breath-hold or respiratory-triggered DWI (p = 0.000), and not significantly different between breath-hold and respiratory-triggered DWI (p = 0.212). Mean ADCs differed significantly among the anatomical regions with the lowest values measured in the pancreatic tail both at breath-hold and respiratory-triggered DWIs whereas no significant difference was found at free-breathing DWI. Conclusion: Breath-hold or respiratory-triggered technique provided DW images of pancreas with acceptable quality at 3.0-Tesla. Breath-hold is the preferred DWI technique for ADC measurements of pancreas.
Magnitude of shift of tumor position as a function of moderated deep inspiration breath-hold: An analysis of pooled data of lung patients with active breath control in image-guided radiotherapy  [cached]
Muralidhar K,Murthy P,Mahadev D,Subramanyam K
Journal of Medical Physics , 2008,
Abstract: The purpose of this study was to evaluate the reproducibility and magnitude of shift of tumor position by using active breathing control and iView-GT for patients with lung cancer with moderate deep-inspiration breath-hold (mDIBH) technique. Eight patients with 10 lung tumors were studied. CT scans were performed in the breath-holding phase. Moderate deep-inspiration breath-hold under spirometer-based monitoring system was used. Few important bony anatomic details were delineated by the radiation oncologist. To evaluate the interbreath-hold reproducibility of the tumor position, we compared the digital reconstruction radiographs (DRRs) from planning system with the DRRs from the iView-GT in the machine room. We measured the shift in x, y, and z directions. The reproducibility was defined as the difference between the bony landmarks from the DRR of the planning system and those from the DRR of the iView-GT. The maximum shift of the tumor position was 3.2 mm, 3.0 mm, and 2.9 mm in the longitudinal, lateral, and vertical directions. In conclusion, the moderated deep-inspiration breath-hold method using a spirometer is feasible, with relatively good reproducibility of the tumor position for image-guided radiotherapy in lung cancers.
Improving Intra-Fractional Target Position Accuracy Using a 3D Surface Surrogate for Left Breast Irradiation Using the Respiratory-Gated Deep-Inspiration Breath-Hold Technique  [PDF]
Yi Rong, Steve Walston, Meng Xu Welliver, Arnab Chakravarti, Allison M. Quick
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0097933
Abstract: Purpose To evaluate the use of 3D optical surface imaging as a surrogate for respiratory gated deep-inspiration breath-hold (DIBH) for left breast irradiation. Material and Methods Patients with left-sided breast cancer treated with lumpectomy or mastectomy were selected as candidates for DIBH treatment for their external beam radiation therapy. Treatment plans were created on both free breathing (FB) and DIBH computed tomography (CT) simulation scans to determine dosimetric benefits from DIBH. The Real-time Position Management (RPM) system was used to acquire patient's breathing trace during DIBH CT acquisition and treatment delivery. The reference 3D surface models from FB and DIBH CT scans were generated and transferred to the “AlignRT” system for patient positioning and real-time treatment monitoring. MV Cine images were acquired during treatment for each beam as quality assurance for intra-fractional position verification. The chest wall excursions measured on these images were used to define the actual target position during treatment, and to investigate the accuracy and reproducibility of RPM and AlignRT. Results Reduction in heart dose can be achieved using DIBH for left breast/chest wall radiation. RPM was shown to have inferior correlation with the actual target position, as determined by the MV Cine imaging. Therefore, RPM alone may not be an adequate surrogate in defining the breath-hold level. Alternatively, the AlignRT surface imaging demonstrated a superior correlation with the actual target positioning during DIBH. Both the vertical and magnitude real-time deltas (RTDs) reported by AlignRT can be used as the gating parameter, with a recommended threshold of ±3 mm and 5 mm, respectively. Conclusion The RPM system alone may not be sufficient for the required level of accuracy in left-sided breast/CW DIBH treatments. The 3D surface imaging can be used to ensure patient setup and monitor inter- and intra- fractional motions. Furthermore, the target position accuracy during DIBH treatment can be improved by AlignRT as a superior surrogate, in addition to the RPM system.
Impact of different breathing conditions on the dose to surrounding normal structures in tangential field breast radiotherapy
Prabhakar Ramachandran,Tharmar Ganesh,Julka Pramod,Rath Goura
Journal of Medical Physics , 2007,
Abstract: Cardiac toxicity is an important concern in tangential field breast radiotherapy. In this study, the impact of three different breathing conditions on the dose to surrounding normal structures such as heart, ipsilateral lung, liver and contralateral breast has been assessed. Thirteen patients with early breast cancer who underwent conservative surgery (nine left-sided and four right-sided breast cancer patients) were selected in this study. Spiral CT scans were performed for all the three breathing conditions, viz., deep inspiration breath-hold (DIBH), normal breathing phase (NB) and deep expiration breath-hold (DEBH). Conventional tangential fields were placed on the 3D-CT dataset, and the parameters such as V30 (volume covered by dose> 30 Gy) for heart, V20 (volume covered by dose> 20 Gy) for ipsilateral lung and V50 (volume receiving> 50% of the prescription dose) for heart and liver were studied. The average reduction in cardiac dose due to DIBH was 64% (range: 26.5-100%) and 74% (range: 37-100%) as compared to NB and DEBH respectively. For right breast cancer, DIBH resulted in excellent liver sparing. Our results indicate that in patients with breast cancer, delivering radiation in deep inspiration breath-hold condition can considerably reduce the dose to the surrounding normal structures, particularly heart and liver.
Energy cost and optimisation in breath-hold diving  [PDF]
Martino Trassinelli
Quantitative Biology , 2015,
Abstract: We present a theoretical model for calculating the locomotion cost of breath-hold divers. Starting from basic principles of mechanics, we calculate the work that the diver has to provide with propulsion for counterbalance the action of the drag, the buoyant force and the weight during the immersion. The basal metabolic rate and the efficiency to transform chemical energy in propulsion are also considered for the calculation of the total energy cost of a dive. The dependency on the diver and dive characteristics and possible optimisations are analysed and discussed. Our results are compared to observation on different breath-hold diving animals. The model confirms the good adaptation of dolphin for deep dives, and it gives some insights for a possible explanation of the exhalation of air before diving observed in seals. A comparison between predicted and observed swim velocities of different breath-hold mammals confirms the importance of the role of the diving reflex.
Accuracy of Dose Delivery in Multiple Breath-Hold Segmented Volumetric Modulated Arc Therapy: A Static Phantom Study  [PDF]
Kimiya Noto,Shinichi Ueda,Hironori Kojima,Naoki Isomura,Akihiro Takemura,Shigeyuki Takamatsu,Tomoyasu Kumano,Tsuyoshi Takanaka
Journal of Radiotherapy , 2014, DOI: 10.1155/2014/743150
Abstract: Purpose. Accuracy of dose delivery in multiple breath-hold segmented volumetric modulated arc therapy (VMAT) was evaluated in comparison to noninterrupted VMAT using a static phantom. Material and Methods. Five VMAT plans were evaluated. A Synergy linear accelerator (Elekta AB, Stockholm, Sweden) was employed. A VMAT delivery sequence was divided into multiple segments according to each of the predefined breath-hold periods (10, 15, 20, 30, and 40 seconds). The segmented VMAT delivery was compared to noninterrupted VMAT delivery in terms of the isocenter dose and pass rates of a dose difference of 1% with a dose threshold of 10% of the maximum dose on a central coronal plane using a two-dimensional dosimeter, MatriXX Evolution (IBA Dosimetry, Schwarzenbruck, Germany). Results. Means of the isocenter dose differences were 0.5%, 0.2%, 0.2%, 0.0%, and 0.0% for the beam-on-times between interrupts of 10, 15, 20, 30, and 40 seconds, respectively. Means of the pass rates were 85%, 99.9%, 100%, 100%, and 100% in the same order as the above. Conclusion. Our static phantom study indicated that the multiple breath-hold segmented VMAT maintains stable and accurate dose delivery when the beam-on-time between interrupts is 15 seconds or greater. 1. Introduction Although radiotherapy has been successfully applied to lung, liver, and pancreas tumors [1–3], breathing motion needs to be considered for the tumors located in proximity to the diaphragm [4–9]. A traditional approach is an enlarged internal margin that was added to a gross tumor volume (GTV) or a clinical target volume (CTV), resulting in possible higher complication to neighboring organs at risk (OARs) [10]. To minimize the internal margin, breath-hold with active breathing control (ABC) or patient voluntary breath-hold was used for intensity modulated radiation therapy (IMRT) [4, 10–12] among other techniques such as gating. IMRT provides more conformal dose for the target and more reduced dose for OARs compared to 3D conformal radiotherapy (3D-CRT). A disadvantage of IMRT is increased monitor units and thus beam-on-time, thereby possibly causing larger intrafractional tumor localization error [13, 14]. Volumetric modulated arc therapy (VMAT) allows a faster dose delivery while gantry and multileaf collimator (MLC) are dynamically controlled [15–19]. A combination of breath-hold and VMAT may lead to a quick and accurate treatment option for a moving tumor close to diaphragm. Nevertheless, the beam-on-time for a VMAT delivery is typically two to four minutes, thereby preventing a single breath-hold
Optimization of single shot 3D breath-hold non-enhanced MR angiography of the renal arteries
Huan Tan, Ioannis Koktzoglou, Christopher Glielmi, Mauricio Galizia, Robert R Edelman
Journal of Cardiovascular Magnetic Resonance , 2012, DOI: 10.1186/1532-429x-14-30
Abstract: Technical optimization of the breath-hold technique was performed with fourteen healthy volunteers. An alternative magnetization preparation scheme was tested to maximize inflow signal. Quantitative and qualitative comparisons were made between the breath-hold technique and the clinically accepted navigator-gated technique in both volunteers and patients on a 1.5?T scanner.The breath-hold technique provided an average of seven fold reduction in imaging time, without significant loss of image quality. Comparable single-to-noise and contrast-to-noise ratios of intra- and extra-renal arteries were found between the breath-hold and the navigator-gated techniques in volunteers. Furthermore, the breath-hold technique demonstrated good image quality for diagnostic purposes in a small number of patients in a pilot study.The single-shot, breath-hold technique offers an alternative to navigator-gated methods for non-enhanced renal magnetic resonance angiography. The initial results suggest a potential supplementary clinical role for the breath-hold technique in the evaluation of suspected renal artery diseases.
Comparison of Two Devices and Two Breathing Patterns for Exhaled Breath Condensate Sampling  [PDF]
Eva-Maria Hüttmann, Timm Greulich, Akira Hattesohl, Severin Schmid, Sarah Noeske, Christian Herr, Gerrit John, Rudolf A. J?rres, Bernd Müller, Claus Vogelmeier, Andreas Rembert Koczulla
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0027467
Abstract: Introduction Analysis of exhaled breath condensate (EBC) is a noninvasive method to access the epithelial lining fluid of the lungs. Due to standardization problems the method has not entered clinical practice. The aim of the study was to assess the comparability for two commercially available devices in healthy controls. In addition, we assessed different breathing patterns in healthy controls with protein markers to analyze the source of the EBC. Methods EBC was collected from ten subjects using the RTube and ECoScreen Turbo in a randomized crossover design, twice with every device - once in tidal breathing and once in hyperventilation. EBC conductivity, pH, surfactant protein A, Clara cell secretory protein and total protein were assessed. Bland-Altman plots were constructed to display the influence of different devices or breathing patterns and the intra-class correlation coefficient (ICC) was calculated. The volatile organic compound profile was measured using the electronic nose Cyranose 320. For the analysis of these data, the linear discriminant analysis, the Mahalanobis distances and the cross-validation values (CVV) were calculated. Results Neither the device nor the breathing pattern significantly altered EBC pH or conductivity. ICCs ranged from 0.61 to 0.92 demonstrating moderate to very good agreement. Protein measurements were greatly influenced by breathing pattern, the device used, and the way in which the results were reported. The electronic nose could distinguish between different breathing patterns and devices, resulting in Mahalanobis distances greater than 2 and CVVs ranging from 64% to 87%. Conclusion EBC pH and (to a lesser extent) EBC conductivity are stable parameters that are not influenced by either the device or the breathing patterns. Protein measurements remain uncertain due to problems of standardization. We conclude that the influence of the breathing maneuver translates into the necessity to keep the volume of ventilated air constant in further studies.
Comparison of 16 slice multi-detector computed tomography and breath hold 3D magnetic resonance angiography in the detection of coronary stenosis
Xin LIU,Zulong CAI,Youquan CAI,Shaohong ZHAO,Ningyu AN,Yuangui GAO,
,Zulong CAI,Youquan CAI,Shaohong ZHAO,Ningyu AN,Yuangui GAO

老年心脏病学杂志(英文版) , 2006,
Abstract: Objective To compare 16-slice multi-detector spiral computed tomography (MDCT) and breathhold 3D magnetic resonance (MR) coronary angiography in the visualization of coronary arteries and the accuracy of detecting significant (> 50%) coronary stenoses in patients with suspected coronary artery disease. Methods Forty patients were examined by 16-slice CT (GE, Lightspecdl6) and MR (GE.Twinspeed) within 3 days: 31 of them underwent conventional coronary angiography (CAG) within 2 weeks after CT and MR scan. CT was performed with 16x 1.25 mm detector collimation, 0.5 s rotation time and images were reconstructed at 60%-75% of the cardiac cycle. MR was performed with breath hold 3D FIESTA (TR4.0 ms, TE1.7 ms, flip angle 65, slice thickness 3 mm, FOV 280 mm, matrix 256x 192) . Mean heart rate was 63 ± 5.8 bpm and (3-blocker was used in 24 patients. MR and CT image quality was evaluated in 9 coronary segments (RCA1. RCA2. RCA3, LM, LAD1, LAD2, LAD3, LCX1. LCX2) using a four-point grading scale. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated for detection of significant stenosis using CAG as the gold standard. Results 16-slice CT showed higher image quality in most coronary segments except RCA2. Forty-three segments were diagnosed as significant stenosis by CAG, 36 and 27 of these were correctly detected by CT and MR respectively. Sensitivity, specificity, positive predictive value, and negative predictive value of 16-slice CT and MR for detecting significant stenosis were 83%, 84%, 49%, 97% and 63%, 90%, 55%, 93%, respectively. Conclusion Sixteen-slice CT showed higher image quality in most coronary segments cxccpted for middle RCA. 16-slice CT had higher sensitivity than MR for detection of coronary significant stenosis, whereas MR had higher specificity than CT. Both CT and MR showed high negative predictive value, which is useful for excluding coronary stenosis in symptomatic patients.
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