Breath-holding Method Research Articles

The effect on gastrointestinal peristalsis for magnetic resonance cholangiopancreatography during breath-holding methods.

The breath-hold (BH) 3D magnetic resonance cholangiopancreatography method has been reported to suppress "respiratory artifacts"; however, the influence of gastrointestinal peristalsis around the target organs has not been discussed. In contrast, the autonomic nervous system has been reported to affect gastrointestinal peristalsis and BH imaging has been reported to influence venous blood flow signal (BFS) through its involvement with the autonomic nervous system. We examined the impact of BH imaging on gastrointestinal peristalsis. Seven healthy volunteers participated. Three respiratory patterns-free breathing (FB), BH at maximum inspiration (Insp-BH), and BH at maximum expiration (Exp-BH)-were used. Gastrointestinal peristalsis was measured using cine MRI. Cine MRI data were analyzed using the normalized interframe difference method, focusing on the duodenum and gastric body. Hemodynamic changes resulting from BH methods were evaluated using 2D phase contrast, targeting the inferior vena cava (IVC). The BFS was examined for all phases of each respiratory pattern. Peristalsis variation in the duodenum showed no significant differences among FB, Exp-BH, and Insp-BH. In the gastric body, no significant differences were observed between FB and Exp-BH or between Exp-BH and Insp-BH. However, a significant difference emerged between FB and Insp-BH. Regarding BFS, in the IVC, significant differences were observed between Exp-BH and Insp-BH and between FB and Insp-BH (both, p < 0.01), with no significant difference between FB and Exp-BH. Insp-BH reduces venous blood flow and suppresses the influence of peristalsis variation.

The Effect on Gastrointestinal Peristalsis for MR Cholangiopancreatography During Breath-Holding Methods [Presidential Award Proceedings

The Effect on Gastrointestinal Peristalsis for MR Cholangiopancreatography During Breath-Holding Methods [Presidential Award Proceedings

Regional lung targeting with a fluticasone/salmeterol aerosol using a bolus breath hold method of the PreciseInhale® system: A first evaluation in humans

BackgroundIn development of inhaled drugs- and formulations the measured concentration in the systemic circulation is often used as a surrogate for local dosimetry in the lungs. To further elucidate regional differences in the fate of drugs in the lungs, different aerodynamic sizes of aerosols have been used to target major airway regions. An alternative approach to achieve regional targeting of aerosols, is to use a defined aerosol bolus together with a bolus breath hold strategy. A small volume of test aerosol is intercalated and stopped at different penetration depths, to achieve increased drug deposition at chosen lung locations. Drug permeation from the lung regions is then investigated by repeatedly sampling venous blood from the systemic circulation.The PreciseInhale® (PI) exposure platform was developed to allow generation of aerosols from different sources, including clinical inhalers, into a holding chamber, for subsequent use with alternative exposure modules in vitro and in vivo. In the current first-in-human study was investigated the feasibility of a new clinical exposure module added to the PI system. By extracting aerosol puffs from a medical inhaler for subsequent delivery to volunteers, it was possible to administer whole lung exposures, as well as regional targeting exposures. MethodsAerosols containing 250 µg/25 µg fluticasone propionate (FP)/salmeterol xinafoate (SMX) were automatically actuated and extracted from the pressurized Metered Dose Inhaler (pMDI) Evohaler Seretide forte into the PI system's holding chamber, then administered to the healthy volunteers using controlled flowrate and volume exposure cycles.Two main comparisons were made by measuring the systemic PK response: I. One label dose directly from the inhaler to the subject was compared to the same dose extracted from the pMDI into the PI system and then administered to the subject. II A small aerosol bolus at a penetration level in the central airways was compared to a small aerosol bolus at a penetration level in the peripheral lung. Results and ConclusionsWhen one inhaler dose was administered via the PI system, the absorbed dose, expressed as AUC24, was approximately twice as high and the CV was less than half, compared to direct inhalation from the same pMDI. Bolus breath hold targeting of drugs from the same aerosol mixture to the peripheral lung and the central airways showed a difference in their appearance in the systemic circulation. Normalized to the same deposited dose, SMX had a 57 % higher Cmax in the peripheral lung compared to the central airways. However, from 6 to 24 h after dosing the systemic concentrations of SMX from both regions were quite similar. FP had parallel concentrations curves with a 23 % higher AUC24 in the peripheral lung with no noticeable elevation around Cmax. The permeability of these two substances from similar sized aerosols was indeed higher in the thinner air/blood barriers of the peripheral lung compared to the central airways, but differences as measured on the venous side of the circulation were not dramatic. In conclusion, the PI system provided better control of actuation, aspiration, and dispensation of aerosols from the clinical inhaler and thereby delivered higher quality read outs of pharmacokinetic parameters such as tmax, Cmax, and AUC. Improved performance, using PI system, can likely also be employed for studying regional selectivity of other responses in the lungs, for use in drug development.

A short-TR single-echo spin-echo breath-hold method for assessing liver T2.

Conventional single-echo spin-echo T2 mapping used for liver iron quantification is too long for breath-holding. This study investigated a short TR (~100ms) single-echo spin-echo T2 mapping technique wherein each image (corresponding to a single TE) could be acquired in ~17s-short enough for a breath-hold. TE images were combined for T2 fitting. To avoid T1 bias, each TE acquisition incremented TR to maintain a constant TR-TE. Experiments at 1.5T validated the technique's accuracy in phantoms, 9 healthy volunteers, and 5 iron overload patients. In phantoms and healthy volunteers, the technique was compared to the conventional approach of constant TR for all TEs. Iron overload results were compared to FerriScan. In phantoms, the constant TR-TE technique provided unbiased estimates of T2, while the conventional constant TR approach underestimated it. In healthy volunteers, there was no significant discrepancy at the 95% confidence level between constant TR-TE and reference T2 values, whereas there was for constant TR scans. In iron overload patients, there was a high correlation between constant TR-TE and FerriScan T2 values (r2 = 0.95), with a discrepancy of 0.6+/-1.4ms. The short-TR single-echo breath-hold spin-echo technique provided unbiased estimates of T2 in phantoms and livers.

Detection and Mitigation of Neurovascular Uncoupling in Brain Gliomas.

Functional magnetic resonance imaging (fMRI) with blood oxygen level-dependent (BOLD) technique is useful for preoperative mapping of brain functional networks in tumor patients, providing reliable in vivo detection of eloquent cortex to help reduce the risk of postsurgical morbidity. BOLD task-based fMRI (tb-fMRI) is the most often used noninvasive method that can reliably map cortical networks, including those associated with sensorimotor, language, and visual functions. BOLD resting-state fMRI (rs-fMRI) is emerging as a promising ancillary tool for visualization of diverse functional networks. Although fMRI is a powerful tool that can be used as an adjunct for brain tumor surgery planning, it has some constraints that should be taken into consideration for proper clinical interpretation. BOLD fMRI interpretation may be limited by neurovascular uncoupling (NVU) induced by brain tumors. Cerebrovascular reactivity (CVR) mapping obtained using breath-hold methods is an effective method for evaluating NVU potential.

Impact of breath hold on regional nodal irradiation and heart volume in field in left breast cancer adjuvant irradiation.

Compared to the free-breathing technique, adjuvant left breast irradiation after breast-conserving surgery or mastectomy using the breath-hold method significantly reduces the heart mean dose, Left anterior descending artery, and ipsilateral lung doses. Movement with deep inspiration may also reduce heart volume in the field and regional node doses. Pre-radiotherapy planning CT was performed in the free-breathing, and breath-hold techniques using RPM, demographic information, clinicopathological data, heart volume in the field, heart mean dose, LAD mean dose, and regional nodal doses were calculated in both free breathing and DIBH. Fifty patients with left breast cancer receiving left breast adjuvant radiation were enrolled. There was no significant difference in axillary LN coverage between the two techniques, except for SCL maximum dose, Axilla I node maximum dose, and Axilla II minimum dose in favor of the breath hold technique. The mean age was 47.54years, 78% had GII IDC, 66% had positive LVSI results, and 74% of patients had T2. The breath hold strategy resulted in considerably decreased mean heart dose (p = 0.000), LAD dose (p = 0.000), ipsilateral lung mean dose (p = 0.012), and heart volume if the field (p = 0.013). The mean cardiac dosage and the dose of the LAD were significantly correlated (p = 0.000, R = 0.673). Heart volume in the field and heart mean dosage was not significantly correlated (p = 0.285, r = -0.108). When compared to free breathing scans, DIBH procedures result in considerably reduced dosage to the OAR and no appreciable changes in dose exposure to regional lymph node stations in patients with left-sided breast cancer.

The effect of breath-hold technique on conformal and intensity modulated radiotherapy techniques at right breast cancer radiotherapy including internal mammarian field

Background/Aim: Significantly lower heart doses can be achieved by breath-hold technique at left-sided breast cancer radiotherapy (RT). We see high doses at organs at risk such as lung, heart, and contralateral breast during right-sided breast cancer RT planning especially in the presence of RT indication for mammaria interna (MI) lymph nodes. This study compared RT-planning methods that are conformal with intensity-modulated RT (IMRT) with breath holding and free breathing for right-sided breast cancer RT including full axillary and MI lymph node fields. Methods: Computed tomography (CT) simulations were performed using free-breath (FB) and breath-hold (BH) methods in 10 patients with right-sided breast cancer. A total of 40 RT treatment plans were calculated. Right-sided breast, level 1-2-3 axillary regions, and MI regions served for the target-planning volume. Left-sided breast, heart, as well as right-sided and left lungs were contoured as critical organs according to the atlas of the "Radiation Therapy Oncology Group." We used a Varian Eclipse v.13 for treatment planning. Conformal “FieldinField” RT (FinFRT) and dynamic IMRT (dIMRT) planning were performed separately for each patient over breath-hold and free-breath images. For PTV, 50 Gy was prescribed in 25 fractions and optimized such that the planned target volume (PTV) remained between 95% and 110% of the dose. The mean and maximum doses of the heart, V5 and V20 of the lungs, as well as V95 doses for MI were recorded. Statistical analyses were performed with SPSS version 22, and a paired t-test was used for comparison. Results: Four treatment plans (FB FinFRT, BH FinFRT, FB dIMRT, BH dIMRT) were made separately for 10 patients. For comparison, common FB FinFRT plans were accepted as the baseline plan. As expected, there were no significant differences in PTV coverage. The mean dose received by 95% of the MI volume was between 42.27 Gy and 42.4 Gy. For the maximum heart dose, the breath hold technique had no significant effect on plans. The lowest average maximum heart dose was seen in the BH FinFRT group. Mean heart doses are between 1.28 Gy – 4.85 Gy. There was no significance between BH FinFRT and FB FinFRT plan (P=0.504), and there was a significant difference for heart mean dose versus dIMRT plans (P=0.001). The mean V20 of the lungs ranged from 11.9 to 17.8. There was a significant decrease in V20 with BH or FB dIMRT plans (P=0.001). There was no difference between BH FinFRT (P=0.138). On the contrary, lung V5 values were significantly higher in dIMRT plans, and the lowest mean V5 value was seen in BH FinFRT plan. Conclusion: With the BH method, lower doses (but not significantly lower doses) were obtained in critical organ doses. There was a significant decrease with FinFRT plans in terms of heart mean and maximum dose and lung V5 percentages. The dIMRT plans were significant only in lung V20 percentages. When planning RT, we recommend evaluating all treatment techniques individually for right-sided breast cancer patients to obtain lower doses in critical organs.

An Intra-individual Comparison between Free-breathing Dynamic MR Imaging of the Liver Using Stack-of-stars Acquisition and the Breath-holding Method Using Cartesian Sampling or View-sharing.

To compare the quality of dynamic imaging between stack-of-stars acquisition without breath-holding (DISCO-Star) and the breath-holding method (Cartesian LAVA and DISCO). This retrospective study was conducted between October 2019 and February 2020. Two radiologists performed visual assessments of respiratory motion or pulsation artifacts, streak artifacts, liver edge sharpness, and overall image quality using a 5-point scale for two datasets: Dataset 1 (n = 107), patients with Cartesian LAVA and DISCO-Star; Dataset 2 (n = 41), patients with DISCO and DISCO-Star at different time points. Diagnosable image quality was defined as ≥ 3 points in overall image quality. Whether the scan timing of the arterial phase (AP) was appropriate was evaluated, and results between the pulse sequences were compared. In cases of inappropriate scan timing in the DISCO-Star group, retrospective reconstruction with a high frame rate (80 phases, 3 s/phase) was added. The overall image quality of Cartesian LAVA was better than that of DISCO-Star in AP. However, noninferiority was shown in the ratio of diagnosable images between Cartesian LAVA and DISCO-Star in AP. There was no significant difference in the ratio of appropriate scan timing between DISCO-Star and Cartesian LAVA; however, the ratio of appropriate scan timing in DISCO-Star with high frame rate reconstruction was significantly higher than that in Cartesian LAVA in both readers. Overall image quality scores between DISCO and DISCO-Star were not significantly different in AP. There was no significant difference in the ratio of appropriate scan timing between DISCO-Star with high frame rate reconstruction and DISCO in both readers. The use of DISCO-Star with high frame rate reconstruction is a good solution to obtain appropriate AP scan timing compared with Cartesian LAVA. DISCO-Star showed equivalent image quality in all phases and in the ratio of appropriate AP scan timing compared with DISCO.

Development of deep-inspiration breath-hold system that monitors the position of the chest wall using infrared rangefinder.

We conducted a prospective study to quantitatively evaluate the movement of the chest wall to establish the simple and reproducible deep-inspiration breath-hold (DIBH) method. The left nipple position was monitored to confirm the inspiratory state. Planning computed tomography (CT) was performed under DIBH and free-breath. We conducted radiation plans with DIBH and free-breath CT and evaluated organ at risk (OAR) and target doses according to two different plans. The relationship between positioning errors of the chest wall and patient factors was evaluated using univariate analysis and fixed-effects models. Twenty-three patients aged ≤ 60years were enrolled during January-August 2021; 358 daily radiation treatments were evaluated. The median time of treatment room occupancy was 16minutes (interquartile range, 14-20). The area of the planning target volume (PTV) surrounded by the 95% isodose line was more extensive in DIBH than in free breathing (71.6% vs 69.5%, P < 0.01), whereas the cardiac and left anterior descending (LAD) artery doses were lower (both P < 0.01). In the fixed-effects model analysis, the occupation time of the treatment room was correlated with positioning error. The difference between the planned and irradiated dose was the largest in the LAD branch of the coronary artery (-2.5Gy), although the OAR dose decreased owing to positional error. The current DIBH method, wherein a single point on the chest wall is monitored to confirm that the patient is in an inspiratory state, allows radiation to be performed in a short time with a small dose error.

Compromised cerebrovascular reactivity in migraineurs with right-to-left shunts: a potential mechanism of white matter hyperintensities

ABSTRACT Objective Our study aims to explore the changes of cerebrovascular reactivity (CVR) in migraineurs with right-to-left shunts (RLS), and further evaluate the association between CVR and the occurrence of the white matter hyperintensities (WMHs). Methods RLS was diagnosed based on a contrast enhancement transcranial Doppler (c-TCD) examination. The breath holding index (BHI), which represents CVR, was measured from the middle cerebral artery (MCA) using a TCD with the breath-holding method. WMHs was defined as clearly hyperintense areas in 3 T magnetic resonance imaging (MRI). All migraineurs underwent a standardized questionnaire for family and personal history and detailed migraine features. Results Three hundred and ninety-seven migraineurs and 100 controls were included in our study. The BHI was significantly lower in migraineurs than controls (0.527 ± 0.709 vs. 0.674 ± 0.489, P = 0.016). Moreover, migraineurs with RLS had lower BHI than those without RLS (0.504 ± 0.671 vs. 0.674 ± 0.721, p = 0.024). Migraineurs with WMHs had lower BHI than those without (0.47 ± 0.71 vs. 0.75 ± 0.49, p = 0.035). The reduced BHI was an independent influencing factor for WMHs in our study (OR = 0.338; 95% CI = 0.142–0.806, p = 0.014). Conclusion Our results indicated that BHI was reduced in migraineurs, and the reduced BHI was associated with RLS. Moreover, the reduced CVR in migraineurs with RLS might be related to the occurrence of WMHs.

The Effect of an Olympic Distance Triathlon on Pulmonary Diffusing Capacity and its Recovery 24 Hours Later.

The Olympic distance triathlon includes maximal exercise bouts with transitions between the activities. This study investigated the effect of an Olympic distance triathlon (1.5-km swim, 40-km bike, 10-km run) on pulmonary diffusion capacity (DLCO). In nine male triathletes (age: 24 ± 4.7 years), we measured DLCO and calculated the DLCO to alveolar volume ratio (DLCO/VA) and performed spirometry testing before a triathlon (pre-T), 2 hours after the race (post-T), and the day following the race (post-T-24 h). DLCO was measured using the 9-s breath-holding method. We found that (1) DLCO decreased significantly between pre- and post-T values (38.52 ± 5.44 vs. 35.92 ± 6.63 ml∙min-1∙mmHg-1) (p < 0.01) and returned to baseline at post-T-24 h (38.52 ± 5.44 vs. 37.24 ± 6.76 ml∙min-1∙mmHg-1, p > 0.05); (2) DLCO/VA was similar at the pre-, post- and post-T-24 h DLCO comparisons; and (3) forced expiratory volume in the first second (FEV1) and mean forced expiratory flow during the middle half of vital capacity (FEF25-75%) significantly decreased between pre- and post-T and between pre- and post-T-24-h (p < 0.02). In conclusion, a significant reduction in DLCO and DLCO/VA 2 hours after the triathlon suggests the presence of pulmonary interstitial oedema. Both values returned to baseline 24 hours after the race, which reflects possible mild and transient pulmonary oedema with minimal physiological significance.

A Prospective Trial Demonstrating the Benefit of Personalized Selection Of Breath-Hold Technique for Upper-Abdominal Radiation Therapy Using the Active Breathing Coordinator

PurposeFor upper abdominal tumors, our institutional-standard motion reduction method is the expiration breath-hold (EBH) technique, using Active Breathing Coordinator (ABC). However, an individual patient's breath-hold (BH) reproducibility (RBH) may be improved in deep inspiration or inspiration breath-hold (DIBH or IBH). This trial compared the tumor position RBH, stability (SBH), and breath-hold time (TBH) of 3 BH methods, using ABC, to personalize the selection of technique, by using a preplanning screening assessment. Methods and MaterialsWe invited patients planned for upper abdominal radiation therapy (kidney, pancreas, liver, or adrenal gland) to participate in this prospective trial. We conducted ABC education with the study participants, who then attempted EBH, DIBH, and IBH in randomized order. During 5 consecutive BH's for each method, we acquire kV fluoroscopy images of the diaphragm. We personalized the BH technique selection according to a decision matrix. We analyzed the EBH and the personalized technique cohort mean RBH and SBH. ResultsBetween May 2019 and March 2020, we recruited 19 participants. Median age of participants was 68 years (range 32-81). Tumor sites included kidney (n = 1), adrenal gland (n = 5) and liver (n = 14). We excluded 1 participant due to poor BH compliance, leaving 270 images from 18 participants for analysis. Mean TBH was 22.1, 23.9, and 24.2 seconds for EBH, DIBH, and IBH respectively. Screening selected EBH for 44% (n = 8), IBH for 39% (n = 7), and DIBH for 17% (n = 3) of participants. The mean RBH was superior at 0.92 mm (0.79 mm SD) for the personalized technique, compared with EBH of 1.79 mm (1.49 mm SD) (P = .016). Preplanned subset analysis of participants whose personalized technique was not EBH showed improved mean RBH of 0.63 mm (0.29 mm SD) compared with their EBH RBH of 2.2 mm (1.7 mm SD) (P = .011). ConclusionsIn 56% of participants, DIBH or IBH demonstrated superior RBH compared with EBH. Personalised BH screening can inform selection of an ABC BH method which provides optimal RBH with improved TBH for an individual's planning and treatment course.

Evaluation of thoracic surface motion during the free breathing and deep inspiration breath hold methods.

The aim of this study was to evaluate thoracic surface motion from chest wall expansion during free breathing (FB) and deep inspiration breath hold (DIBH) methods, measured with and without 4-dimensional computed tomography (4D-CT) simulation, using equipment developed in-house. The respiratory amplitude and chest wall expansion were evaluated at 5 levels of the thorax, (the sterno-clavicular joint (SCJ), the second level, the intermammary line (IML), the fourth level and the caudal end of the xiphoid process (XP)) using radiopaque wires and potentiometers, with a CT scan simultaneously. This study included 25 examinees (10 volunteers performed FB, 10 volunteers performed DIBH and 5 patients performed FB). For low and irregular respiration, coaching was used, and its impact was evaluated for both breathing methods, FB and DIBH. The breathing amplitude performed with FB between volunteers and patients was not detectable at the SCJ; increasing to the abdomen, 3 mm vs 2 mm (p = 0.326) at the second level; 6 mm vs 4 mm (p = 0.042) at the IML; 10 mm vs 8 mm (p < 0.01) at the fourth level; and 23 mm vs 19 mm (p < 0.001) at the XP. Contrary to the DIBH, where breathing amplitude was greater at 2 first levels 18 mm (SCJ) and 20 mm (second level), decreasing to the abdomen, 14 mm (IML); 11 mm (fourth level); and 10 mm (XP). Chest wall expansion was not detected at the SCJ, while at other levels measured from 1 to 7 mm. Coaching was improve breathing amplitude, for both methods, FB (3 mm) and DIBH (5 mm). The location of amplification is different depending on the breathing method and the in-house phantom was useful to check the amplification level.

Role of DLCO in differentiation or subtyping of obstructive lung disease beyond spirometry and CT scan.

Introduction: Spirometry helps us to differentiate between obstructive and restrictive disease, body plethysmography tells about lung volumes and DLCO about diffusion defect. Determining which tests to do depends on the clinical question to be answered i.e. whether test is being done to diagnose a disease or for evaluation for lung surgery or some other reason. Material &amp; Methods: 46 patients coming to department of respiratory medicine, who were diagnosed with obstructive lung disease by PFT as per GOLD guidelineswere considered for the study. Chest X-ray and CT chest were also done.Then DLCO was performed in every patient. Single breath hold method was used in the study.The report of the DLCO was interpreted according tothe American Thoracic Society/European Respiratory Society statement on PFT interpretation. Results: Male preponderance was seen in study cases with 65.2% males to 34.8% females. Mean age of the study group was 54.39 years with most cases (18) from 31-50 years of age group. Most common diagnosis was COPD emphysema (22) followed by chronic bronchitis (12), bronchial asthma (10) and bronchiectasis (2). Among obstructive lung diseases, B. asthma had the highest mean DLCO percentage predicted of 102.20 ± 14.36 followed by COPD-Bronchitis (76.33±5.57), COPD–Emphysema (37.80±13.41) and bronchiectasis (62±4.48). Conclusion: DLCO can be helpful beyond spirometry in classification of obstructive lung diseases. DLCO values in COPD Emphysema variant are decreased, COPD bronchitis variant remains normal or slightly reduced and asthma either normal or increased. So, DLCO can help in differentiation or sub categorization of obstructive disease more than spirometry.

PERANAN MRI ABDOMEN PADA KASUS HERLYN WERNER WUNDERLICH

Background: Herlyn-Werner-Wunderlich syndrome (HWW) is a very rare genetic syndrome, a combination of anomalies between the mullerian and mesonephric ducts characterized by uterine didelphys, hemivaginal obstruction, and ipsilateral renal agenesis, also known as Obstructed Hemivaginal syndrome and Ipsilateral Renal Anomaly (OHVIRA). Magnetic Resonance Imaging (MRI) is an effective diagnostic support tool for finding out anatomical abdominal abnormalities with the right choice of protocol sequences to obtain optimal MRI images.&#x0D; Method: This study used a qualitative descriptive approach by presenting a case of a 20 year old female patient who had complaints of lower abdominal pain, no previous medical history and irregular menstruation. MRI Abdomen without contrast was performed using an MRI 1.5 Tesla signa explorer GE Healthcare at EMC Tangerang Hospital. Using the Coronal T2 SSFSE sequence, T1 fat sat LAVA, Axial T2 SSFSE, T1 fat sat LAVA breath hold method and Coronal 3D IFIR (MRA renal without contrast). Specifically for the pelvic area with the Axial T2 Propeller, Coronal T2 fat sat, and Sagittal T2 sequences.&#x0D; Result: In the Axial T2 propeller sequence, pelvic area retrieval revealed two separate uterine corpuses (uterus didelphys) accompanied by a heterogeneous oval lesion most likely originating from the left side of the vagina (hemivagina). Whereas in the Coronal T2 sequence the whole abdomen was taken and confirmed by the Coronal 3D IFIR, the right kidney was anatomically visible while the left kidney was not visible (agenesis).&#x0D; Conclusion: Abdominal MRI is a very accurate diagnostic tool to perform Herlyn-Werner-Wunderlich (HWW) syndrome without contrast agent with SSFSE T2 sequences, T2 propeller and 3D IFIR which have an important role in visualizing the quality of MRI images.

Magnetic resonance imaging of lungs using fluorinated gas

Three different pulse sequences (UTE, RARE and FISP) were optimized for 19F-MRI. Coronal slices of respiratory system of laboratory animals (rats) were obtained in 1.5 mm increments and 3D reconstruction of respiratory system of laboratory animals was constructed. For this experiment the animals for 30 minutes breathed with a mixture of fluorinated gas perfluorocyclobutane C4F8 and oxygen in a volume ratio of 70% to 30% using artificial lungs ventilation machine. We showed the possibility to obtain 19F-MRI images of lungs, trachea and bronchi without using breath-holding methods. Such an approach can be especially important for patients with pulmonology diseases (COPD, fibrosis, asthma, etc.). Experiment with a flat wireless coil has shown the possibility of increasing of the intensity of the recorded 19F-NMR signal from the lungs.

Evaluation of beam-on time and number of breath-holds using a flattening-filter-free beam with the deep inspiration breath-hold method in left-sided breast cancer

We performed a dosimetric study to evaluate the benefits of using a flattening-filter-free (FFF) beam with the deep inspiration breath-hold (DIBH) method for left-breast cancer. We used data from 30 previous patients with treatment plans that included DIBH for left-breast cancer with a flattened beam. FFF beam plans were calculated from previous treatment plan images and compared to the original plans in terms of monitor units (MU), number of segments, beam-on time, and breath-holds. Beam-on time was calculated by adding the traveling time of 1.5 second between segments to the time calculated from the MU and dose rate. Breath-holds were calculated based on the beam-on time, assuming 15 s per hold. The FFF beam had increased MU in all cases (mean ± SD: flattened beam, 122.4 ± 9.8 MU; FFF beam, 160.2 ± 17.5 MU). Furthermore, the number of segments increased with the FFF beam in all cases (median [range]: flattened beam, 2 [1 to 3]; FFF beam, 5 [3 to 7]). However, in most cases, the beam-on time was reduced using the FFF beam (mean ± SD: flattened beam, 27.8 ± 7.4 seconds; FFF beam, 13.2 ± 1.7 seconds), although when a 6 MV flattened beam was used there was not a large increase. There were fewer breath-holds in most cases with the FFF beam. Cases using a 4 MV flattened beam also had fewer breath-holds; however, the number of breath-holds was consistent or increased in cases that used a 6 MV flattened beam (median [range]: flattened beam, 3 [1 to 3]; FFF beam, 1 [1 to 2]).

Changes in power of surface electromyogram during breath-holding

Introduction/Objective. Numerous studies on surface electromyographic (sEMG) signals in response to different respiratory parameters, particularly on sternocleidomastoid (SCM) muscles and diaphragm (DIA), indicated the promising advantages of their simultaneous monitoring with possible applications in the analysis of their correlation. This motivated ? detailed statistical analysis of the average power (PAV) on sEMG signals during prolonged breath-holding, simultaneously measured in the SCM and DIA areas. Methods. The physiological breath-holding method was applied to 30 healthy volunteers, with sEMG of SCM and DIA regions measured before, during, and after the breath-holding exercise. All the subjects were sitting in an upward position, with nostrils closed by the right index finger and thumb during breath-hold. To synchronize the records, the user would press a special switch using the other hand at the beginning and at the end of breath-holding experiment. The average power of sEMG (PAV) was measured for each 500 ms signal window. Results. The PAV remains constant before and 3 seconds after the exercise. During the ending of breathholding, at least one region had the PAV afflux of a minimum of 91%. Student?s t-test between SCM signals shows a significant difference of p &lt; 0.001, while the DIA lacks it. Although the results showed that SCM is the dominant region in 76.67% of cases, the exclusive PAV afflux in the DIA region was detected in precisely five cases (16.67% of the total namber of participants). Conclusions. Our research concludes that there is the necessity of simultaneous measurement of SCM and DIA to observe dominant changes in sEMG during breath-holding. The physiological response of the respiratory center can be observed by approximately doubling PAV in one of SCM or DIA regions.

Voluntary breath-hold reduces dose to organs at risk in radiotherapy of left-sided breast cancer.

To compare the dose to organs at risk with free breathing (FB) or voluntary breath-hold (VBH) during radiotherapy of patients with left sided breast cancer. Radiotherapy reduces the risk of breast-cancer-specific mortality but the effects on other organs increase non-cancer-specific mortality. Radiation exposure to the heart, in particular in patients with left sided breast cancer, can be reduced by breath hold methods that increase the distance between the heart and the radiation field. Three-dimensional conformal radiotherapy (3D-CRT) dose plans for the left breast and organs at risk including the heart, left anterior descending coronary artery (LAD) and ipsilateral lung were compared with FB and VBH in ten patients with left sided breast cancer. The mean doses to the heart and LAD were reduced by 50.4 % (p<0.001) and 58.8 % (p=0.006), respectively, in VBH relative to FB. The mean dose to the ipsilateral lung was reduced by 13.8 % (p=0.11) in VBH relative to FB. The planning target volume (PTV) coverage was at least 95 % in both FB and VBH (p=0.78). The VBH technique significantly reduces the dose to organs at risk in 3D-CRT treatment plans of left sided breast cancer.

Assessment of concordance between diffusion of carbon monoxide through the lung using the 10 s breath-hold method, and the simultaneous NO/CO technique, in healthy participants

IntroductionThere is limited, large sample size, healthy control data comparing measurement of diffusing capacity of the lungs for carbon monoxide (DLCO) via the 10 s single-breath carbon monoxide uptake method (DLCO10) and using a DLCO-DLNO double diffusion test performed with a 5 s time of apnoea (DLCO5). ObjectivesThe primary objective was to compare DLCO5 and DLCO10 in healthy participants. The secondary objective was to evaluate the reproducibility of DLCO5. Material and methodsWe included medical students at Caen University Hospital, from 2008 to 2011. We performed a standard single-breath carbon monoxide uptake and combined DLCO and DLNO measurement for each participant. The combined test was repeated one week later. ResultsAmong the 153 study participants, there was no statistically significant difference between the mean values of DLCO10 (10.2 ± 2.2 mmol.min−1 kPa−1) and DLCO5 (10.3 ± 2.2 mmol.min−1 kPa−1; paired t-test p = 0.19). Corrected for the same FiO2, DLCO5 was calculated at 10.5 ± 2.3 mmol.min−1 kPa−1 and was significantly different from DLCO10 (paired t-test p < 0.001). DLCO5 deviates from 1,6 mmol.min−1 kPa−1 (4,6 mL.min−1. mmHg−1) or 15 % of DLCO10 (17 % above and 13% below, for 95 % of the subjects). Forty-seven participants were included in the DLCO5 reproducibility test. The 2 test sessions were carried out at 6 ± 2 day intervals. Reproducibilities for DLCO, DLNO, DmCO and Vc was respectively 1.2 (11 %), 6.8 (13%), 16.5 (32 %), 12.5 (17 %) mmol.min−1 kPa−1. ConclusionIn healthy participants, discrepancies between DLCO measured during the double diffusion and DLCO measured on an apnoea of 10 s are quite large. It may be an indication that the Roughton and Forster interpretation to describe this type of measurements is inadequate.