T1 mapping in the rat myocardium at 7 tesla using a modified CINE inversion recovery sequence.

PURPOSE: To evaluate the reproducibility and sensitivity of the modified CINE inversion recovery (mCINE-IR) acquisition on rats for measuring the myocardial T1 at 7 Tesla. MATERIALS AND METHODS: The recently published mCINE-IR acquisition on humans was applied on rats for the first time, enabling the possibility of translational studies with an identical sequence. Simulations were used to study signal evolution and heart rate dependency. Gadolinium phantoms, a heart specimen and a healthy rat were used to study reproducibility. Two cryo-infarcted rats were scanned to measure late gadolinium enhancement (LGE). RESULTS: In the phantom reproducibility studies the T1 measurements had a maximum coefficient of variation (COV) of 1.3%. For the in vivo reproducibility the COV was below 5% in the anterior cardiac segments. In simulations with phantoms and specimens, a heart rate dependency of approximately 0.5 ms/bpm was present. The T1 maps of the cryo-infarcted rats showed a clear lowering of T1 in de LGE region. CONCLUSION: The results show that mCINE-IR is highly reproducible and that the sensitivity allows detecting T1 changes in the rat myocardium.

Image registration improves human knee cartilage T1 mapping with delayed gadolinium-enhanced MRI of cartilage (dGEMRIC).

OBJECTIVES: To evaluate the effect of automated registration in delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) of the knee on the occurrence of movement artefacts on the T1 map and the reproducibility of region-of-interest (ROI)-based measurements. METHODS: Eleven patients with early-stage knee osteoarthritis and ten healthy controls underwent dGEMRIC twice at 3 T. Controls underwent unenhanced imaging. ROIs were manually drawn on the femoral and tibial cartilage. T1 calculation was performed with and without registration of the T1-weighted images. Automated three-dimensional rigid registration was performed on the femur and tibia cartilage separately. Registration quality was evaluated using the square root Cramér-Rao lower bound (CRLB(σ)). Additionally, the reproducibility of dGEMRIC was assessed by comparing automated registration with manual slice-matching. RESULTS: Automated registration of the T1-weighted images improved the T1 maps as the 90% percentile of the CRLB(σ) was significantly (P < 0.05) reduced with a median reduction of 55.8 ms (patients) and 112.9 ms (controls). Manual matching and automated registration of the re-imaged T1 map gave comparable intraclass correlation coefficients of respectively 0.89/0.90 (patients) and 0.85/0.85 (controls). CONCLUSIONS: Registration in dGEMRIC reduces movement artefacts on T1 maps and provides a good alternative to manual slice-matching in longitudinal studies.

Chocolate, lifestyle, and health.

Interest in the biological activities of cocoa polyphenols is increasing steadily. In fact, the high polyphenol content of cocoa, coupled with its widespread presence in many food items, render this food of particular interest from the nutritional and "pharmacological" viewpoints. This paper summarizes the new findings and developments regarding the effects of cocoa and chocolate consumption on human health as presented at the International Conference "Chocolate, Lifestyle, and Health" (Milan, Italy, March 2, 2007) regarding the effects of cocoa and chocolate consumption on human health.

Effect of medication reconciliation with and without patient counseling on the number of pharmaceutical interventions among patients discharged from the hospital.

BACKGROUND: Hospital admissions are a risk factor for the occurrence of unintended medication discrepancies between drugs used before admission and after discharge. To diminish such discrepancies and improve quality of care, medication reconciliation has been developed. The exact contribution of patient counseling to the medication reconciliation process is unknown, especially not when compared with community pharmacy medication records, which are considered reliable in the Netherlands. OBJECTIVE: To examine the effect of medication reconciliation with and without patient counseling among patients at the time of hospital discharge on the number and type of interventions aimed at preventing drug-related problems. METHODS: A prospective observational study in a general teaching hospital was performed. Patients discharged from the pulmonology department were included. A pharmacy team assessed the interventions with and without patient counseling on discharge medications for each patient. RESULTS: Two hundred sixty-two patients were included. Medication reconciliation without patient counseling was responsible for at least one intervention in 87% of patients (mean 2.7 interventions/patient). After patient counseling, at least one intervention (mean 5.3 interventions/patient) was performed in 97% of patients. After patient counseling, discharge prescriptions were frequently adjusted due to discrepancies in use or need of drug therapy. Most interventions led to the start of medication due to omission and dose changes due to incorrect dosages being prescribed. Patients also addressed their problems/concerns with use of the drug, which were discussed before discharge. CONCLUSIONS: Significantly more interventions were identified after patient counseling. Therefore, patient information is essential in medication reconciliation.

Pulmonary vascular responses to hypoxia and hyperoxia in healthy volunteers and COPD patients measured by electrical impedance tomography.

BACKGROUND: Electrical impedance tomography (EIT) is a noninvasive imaging technique using impedance to visualize and measure blood volume changes. STUDY OBJECTIVE: To examine the validity of EIT in the measurement of hypoxic pulmonary vasoconstriction (HPV) and hyperoxic pulmonary vasodilation in healthy volunteers and COPD patients. PARTICIPANTS: Group 1 consisted of seven healthy volunteers (mean age, 46 years; age range, 36 to 53 years). Group 2 comprised six clinically stable COPD patients (mean age, 65 years; age range, 50 to 74 years). INTERVENTIONS: EIT measurements were performed in healthy subjects while they were breathing room air, 14% oxygen (ie, hypoxia), and 100% oxygen (ie, hyperoxia) through a mouthpiece. Maximal impedance change during systole (DeltaZsys) was used as a measure of pulmonary perfusion-related impedance changes. Stroke volume (SV) was measured by means of MRI. In the COPD group, EIT and SV also were determined, but only in room air and under hyperoxic conditions. RESULTS: The data were statistically compared to data for the room air baseline condition. In the volunteers, the mean (+/- SD) DeltaZsys for the group was 352 +/- 53 arbitrary units (AU) while breathing room air, 309 +/- 75 AU in hypoxia (p < 0.05), and 341 +/- 69 AU in hyperoxia (not significant [NS]). The mean MRI-measured SV was 83 +/- 21 mL while breathing room air, 90 +/- 29) mL in hypoxia (NS), and 94 +/- 19 mL in hyperoxia (p < 0.05). In the COPD patients, the mean DeltaZsys for this group was 222 +/- 84 AU while breathing room air and 255 +/- 83 AU in hyperoxia (p < 0.05). In this group, the SV was 59 +/- 16 mL while breathing room air and 61 +/- 13 mL in hyperoxia (NS). Thus, the volunteer EIT response to hypoxia is not caused by decreased SV, because SV did not show a significant decrease. Similarly, in COPD patients the EIT response to hyperoxia is not caused by increased SV, because SV showed only a minor change. CONCLUSION: EIT can detect blood volume changes due to HPV noninvasively in healthy subjects and hyperoxic vasodilation in COPD patients.

Assessment of elastin deficit in a Marfan mouse aneurysm model using an elastin-specific magnetic resonance imaging contrast agent.

BACKGROUND: Ascending aortic dissection and rupture remain a life-threatening complication in patients with Marfan syndrome. The extracellular matrix provides strength and elastic recoil to the aortic wall, thereby preventing radial expansion. We have previously shown that ascending aortic aneurysm formation in Marfan mice (Fbn1(C1039G/+)) is associated with decreased aortic wall elastogenesis and increased elastin breakdown. In this study, we test the feasibility of quantifying aortic wall elastin content using MRI with a gadolinium-based elastin-specific magnetic resonance contrast agent in Fbn1(C1039G/+) mice. METHODS AND RESULTS: Ascending aorta elastin content was measured in 32-week-old Fbn1(C1039G/+) mice and wild-type (n=9 and n=10, respectively) using 7-T MRI with a T1 mapping sequence. Significantly lower enhancement (ie, lower R1 values, where R1=1/T1) was detected post-elastin-specific magnetic resonance contrast agent in Fbn1(C1039G/+) compared with wild-type ascending aortas (1.15±0.07 versus 1.36±0.05; P<0.05). Post-elastin-specific magnetic resonance contrast agent R1 values correlated with ascending aortic wall gadolinium content directly measured by inductively coupled mass spectroscopy (P=0.006). CONCLUSIONS: Herein, we demonstrate that MRI with elastin-specific magnetic resonance contrast agent accurately measures elastin bound gadolinium within the aortic wall and detects a decrease in aortic wall elastin in Marfan mice compared with wild-type controls. This approach has translational potential for noninvasively assessing aneurysm tissue changes and risk, as well as monitoring elastin content in response to therapeutic interventions.

Prolonged sampling of spontaneous sputum improves sensitivity of hypermethylation analysis for lung cancer.

AIMS: The adequacy of lung cancer diagnosis with sputum cytology depends on duration of sputum sampling. The aim of this methodological study was to determine whether the hypermethylation detection rate of RASSF1A, adenomatous polyposis coli (APC) and cytoglobin (CYGB) is influenced by the duration of sputum collection. METHODS: Prospective sputum samples were collected from 53 lung cancer patients and 47 chronic obstructive pulmonary disease patients as controls. Subjects collected spontaneous sputum at home during nine consecutive days in three canisters I, II and III (ie, days 1-3, days 4-6, days 7-9, respectively). Quantitative methylation-specific PCR was performed to assess gene promoter methylation status of RASSF1A, APC and CYGB. RESULTS: Analysis of each canister separately showed hypermethylation of RASSF1A, APC and/or CYGB in samples I, II and III, in 43%, 40% and 47% of cases, respectively. In control samples, these numbers were 4%, 2% and 4%, respectively. Cumulative analysis for days 1-6 and days 1-9 revealed an increase in sensitivity to 53% and 64%, and specificity of 94% and 91%, respectively. CONCLUSION: Sputum collected over multiple successive days results in a gain in sensitivity for the detection of lung cancer, at the expense of a small loss in specificity. Condensed abstract Assessment of hypermethylation sensitivity of biomarkers in sputum collected over a prolonged period for the detection of lung cancer resulted in a promising gain in sensitivity, at the expense of a small loss in specificity.

Assessment of the pulmonary volume pulse in idiopathic pulmonary arterial hypertension by means of electrical impedance tomography.

BACKGROUND: Electrical impedance tomography (EIT) is a non-invasive imaging technique which can be used to measure the blood volume changes in the pulmonary vascular bed during the cardiac cycle. STUDY OBJECTIVES: This study was performed to evaluate the differences in the EIT signal of the pulmonary vascular bed between healthy subjects and patients with idiopathic pulmonary arterial hypertension (IPAH), who are known to have a remodelled pulmonary vascular bed. PATIENTS AND METHODS: Twenty-one patients (17 females, 4 males) with IPAH and 30 healthy controls (5 females, 25 males) were measured. EIT measurements were performed in duplicate, on the same day as right heart catheterization to obtain haemodynamic data. The maximal impedance change during systole (Delta Z(sys)) was used as a measure of the pulmonary volume pulse and expressed in arbitrary units (AU). Total lung capacity, spirometric values and diffusion capacity for carbon monoxide were measured as well. RESULTS: Mean Delta Z(sys) was 215 +/- 58 x 10(-2) AU (95% CI 193 x 10(-2) to 236 x 10(-2)) in the healthy subjects and 78 +/- 27 x 10(-2) AU (95% CI 66 x 10(-2) to 91 x 10(-2)) in the IPAH patient group (p < 0.0001). No significant correlation was found between Delta Z(sys) and any of the haemodynamic or lung function data. CONCLUSION: The impedance pulsation of the pulmonary vascular bed is reduced in IPAH in comparison with controls, indicating a reduced volume pulse. This might represent the reduced cross section area, as well as the reduced compliance and number of the pulmonary vessels in these patients.

Determinants of pulmonary perfusion measured by electrical impedance tomography.

Electrical impedance tomography (EIT) is a non-invasive imaging technique for detecting blood volume changes that can visualize pulmonary perfusion. The two studies reported here tested the hypothesis that the size of the pulmonary microvascular bed, rather than stroke volume (SV), determines the EIT signal. In the first study, the impedance changes relating to the maximal pulmonary pulsatile blood volume during systole (Delta Z(sys)) were measured in ten healthy subjects, ten patients diagnosed with chronic obstructive pulmonary disease, who were considered to have a reduced pulmonary vascular bed, and ten heart failure patients with an assumed low cardiac output but with a normal lung parenchyma. Mean Delta Z(sys) (SD) in these groups was 261 (34)x10(-5), 196 (39)x10(-5) ( P<0.001) and 233 (61)x10(-5) arbitrary units (AU) (P=NS), respectively. In the second study, including seven healthy volunteers, Delta Z(sys) was measured at rest and during exercise on a recumbent bicycle while SV was measured by means of magnetic resonance imaging. The Delta Z(sys) at rest was 352 (53)x10(-5 ) and 345 (112)x10(-5 )AU during exercise (P=NS), whereas SV increased from 83 (21) to 105 (34) ml (P<0.05). The EIT signal likely reflects the size of the pulmonary microvascular bed, since neither a low cardiac output nor a change in SV of the heart appear to influence EIT.