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OBJECTIVE MRI volumetry could be used as an alternative to invasive tests of shunt function. In this study, the authors aimed to assess the difference in ventricular volume (VV) before and after surgery and at different performance levels (PLs) of the shunt. METHODS This study was a randomized, double-blind trial with a crossover design. The study sample consisted of 36 patients (25 men, 11 women) with a median age of 76 years. All patients had idiopathic normal pressure hydrocephalus (iNPH) and received a Strata shunt at the regional hospital in & Ouml;stersund, Sweden, with an initial PL of 1.5. Participants underwent MRI with volumetric sequences before surgery and four times postoperatively: at 1 month before randomization to either PL 1.0 (n = 15) or 2.5 (n = 17); at 2 months before crossover to PL 2.5 or 1.0; at 3 months before lowering the PL to 0.5; and finally, at 3 months and 1 day after surgery before resetting the PL to 1.5. VV was measured semiautomatically using quantitative MRI. Both the patient and the examiner of clinical tests and volumetry were blinded to the PL. RESULTS VV changed significantly between the presurgical level (median 129 ml) and the different shunt settings, i.e., PL 1.0 (median 115 ml), 1.5 (median 120 ml), and 2.5 (median 128 ml; p < 0.001). A unidirectional change in VV was observed for all participants between PL 1.0 and PL 2.5 (median 12 ml, range 2.1-40.7 ml, p < 0.001). No significant change was noted in VV after 24 hours at PL 0.5. Eight participants had asymptomatic subdural effusions at PL 1.0. CONCLUSIONS The consistent decrease in VV after shunt surgery and between PL 2.5 and 1.0 supports the idea that MRI volumetry could be a noninvasive method for evaluating shunt function in iNPH, preventing unnecessary shunt revisions. However, further studies on retest variability of VV as well as verification against advanced testing of shunt function are needed before a clinical implementation of this method can be perf

Background: Levels of the biomarkers amyloid-beta 1-42 (A beta 42), tau and phosphorylated tau (p-tau) are decreased in the cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). The mechanism behind this is unknown, but one potential explanation is dilution by excessive CSF volumes. The aim of this study was to investigate the presence of a dilution effect, by studying the relationship between ventricular volume (VV) and the levels of the CSF biomarkers. Methods: In this cross-sectional observational study, preoperative magnetic resonance imaging (MRI) and lumbar CSF was acquired from 136 patients with a median age of 76 years, 89 men and 47 females, selected for surgical treat-ment for iNPH. The CSF volume of the lateral and third ventricles was segmented on MRI and related to preoperative concentrations of A beta 42, tau and p-tau. Results: In the total sample W (Median 140.7 mL) correlated weakly (r(s) = - 0.17) with A beta 42 (Median 534 pg/mL), but not with tau (Median 216 pg/mL) nor p-tau (Median 31 pg/mL). In a subgroup analysis, the correlation between W and A beta 42 was only present in the male group (r(s) = - 0.22, p= 0.038). Further, A beta 42 correlated positively with tau (r(s) =0.30, p= 0.004) and p-tau (r(s) = 0.26, p = 0.012) in males but not in females. Conclusions: The findings did not support a major dilution effect in iNPH, at least not in females. The only result in favor for dilution was a weak negative correlation between VV and A beta 42 but not with the other lumbar CSF biomarkers. The different results between males and females suggest that future investigations of the CSF pattern in iNPH would gain from sex-based subgroup analysis.

Background: Levels of the biomarkers amyloid-beta 1-42 (A beta 42), tau and phosphorylated tau (p-tau) are decreased in the cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). The mechanism behind this is unknown, but one potential explanation is dilution by excessive CSF volumes. The aim of this study was to investigate the presence of a dilution effect, by studying the relationship between ventricular volume (VV) and the levels of the CSF biomarkers. Methods: In this cross-sectional observational study, preoperative magnetic resonance imaging (MRI) and lumbar CSF was acquired from 136 patients with a median age of 76 years, 89 men and 47 females, selected for surgical treat-ment for iNPH. The CSF volume of the lateral and third ventricles was segmented on MRI and related to preoperative concentrations of A beta 42, tau and p-tau. Results: In the total sample W (Median 140.7 mL) correlated weakly (r(s) = - 0.17) with A beta 42 (Median 534 pg/mL), but not with tau (Median 216 pg/mL) nor p-tau (Median 31 pg/mL). In a subgroup analysis, the correlation between W and A beta 42 was only present in the male group (r(s) = - 0.22, p= 0.038). Further, A beta 42 correlated positively with tau (r(s) =0.30, p= 0.004) and p-tau (r(s) = 0.26, p = 0.012) in males but not in females. Conclusions: The findings did not support a major dilution effect in iNPH, at least not in females. The only result in favor for dilution was a weak negative correlation between VV and A beta 42 but not with the other lumbar CSF biomarkers. The different results between males and females suggest that future investigations of the CSF pattern in iNPH would gain from sex-based subgroup analysis.

Background: Levels of the biomarkers amyloid-beta 1-42 (A beta 42), tau and phosphorylated tau (p-tau) are decreased in the cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). The mechanism behind this is unknown, but one potential explanation is dilution by excessive CSF volumes. The aim of this study was to investigate the presence of a dilution effect, by studying the relationship between ventricular volume (VV) and the levels of the CSF biomarkers. Methods: In this cross-sectional observational study, preoperative magnetic resonance imaging (MRI) and lumbar CSF was acquired from 136 patients with a median age of 76 years, 89 men and 47 females, selected for surgical treat-ment for iNPH. The CSF volume of the lateral and third ventricles was segmented on MRI and related to preoperative concentrations of A beta 42, tau and p-tau. Results: In the total sample W (Median 140.7 mL) correlated weakly (r(s) = - 0.17) with A beta 42 (Median 534 pg/mL), but not with tau (Median 216 pg/mL) nor p-tau (Median 31 pg/mL). In a subgroup analysis, the correlation between W and A beta 42 was only present in the male group (r(s) = - 0.22, p= 0.038). Further, A beta 42 correlated positively with tau (r(s) =0.30, p= 0.004) and p-tau (r(s) = 0.26, p = 0.012) in males but not in females. Conclusions: The findings did not support a major dilution effect in iNPH, at least not in females. The only result in favor for dilution was a weak negative correlation between VV and A beta 42 but not with the other lumbar CSF biomarkers. The different results between males and females suggest that future investigations of the CSF pattern in iNPH would gain from sex-based subgroup analysis.

Background: Levels of the biomarkers amyloid-beta 1-42 (A beta 42), tau and phosphorylated tau (p-tau) are decreased in the cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). The mechanism behind this is unknown, but one potential explanation is dilution by excessive CSF volumes. The aim of this study was to investigate the presence of a dilution effect, by studying the relationship between ventricular volume (VV) and the levels of the CSF biomarkers. Methods: In this cross-sectional observational study, preoperative magnetic resonance imaging (MRI) and lumbar CSF was acquired from 136 patients with a median age of 76 years, 89 men and 47 females, selected for surgical treat-ment for iNPH. The CSF volume of the lateral and third ventricles was segmented on MRI and related to preoperative concentrations of A beta 42, tau and p-tau. Results: In the total sample W (Median 140.7 mL) correlated weakly (r(s) = - 0.17) with A beta 42 (Median 534 pg/mL), but not with tau (Median 216 pg/mL) nor p-tau (Median 31 pg/mL). In a subgroup analysis, the correlation between W and A beta 42 was only present in the male group (r(s) = - 0.22, p= 0.038). Further, A beta 42 correlated positively with tau (r(s) =0.30, p= 0.004) and p-tau (r(s) = 0.26, p = 0.012) in males but not in females. Conclusions: The findings did not support a major dilution effect in iNPH, at least not in females. The only result in favor for dilution was a weak negative correlation between VV and A beta 42 but not with the other lumbar CSF biomarkers. The different results between males and females suggest that future investigations of the CSF pattern in iNPH would gain from sex-based subgroup analysis.

Background: Levels of the biomarkers amyloid-beta 1-42 (A beta 42), tau and phosphorylated tau (p-tau) are decreased in the cerebrospinal fluid (CSF) of patients with idiopathic normal pressure hydrocephalus (iNPH). The mechanism behind this is unknown, but one potential explanation is dilution by excessive CSF volumes. The aim of this study was to investigate the presence of a dilution effect, by studying the relationship between ventricular volume (VV) and the levels of the CSF biomarkers. Methods: In this cross-sectional observational study, preoperative magnetic resonance imaging (MRI) and lumbar CSF was acquired from 136 patients with a median age of 76 years, 89 men and 47 females, selected for surgical treat-ment for iNPH. The CSF volume of the lateral and third ventricles was segmented on MRI and related to preoperative concentrations of A beta 42, tau and p-tau. Results: In the total sample W (Median 140.7 mL) correlated weakly (r(s) = - 0.17) with A beta 42 (Median 534 pg/mL), but not with tau (Median 216 pg/mL) nor p-tau (Median 31 pg/mL). In a subgroup analysis, the correlation between W and A beta 42 was only present in the male group (r(s) = - 0.22, p= 0.038). Further, A beta 42 correlated positively with tau (r(s) =0.30, p= 0.004) and p-tau (r(s) = 0.26, p = 0.012) in males but not in females. Conclusions: The findings did not support a major dilution effect in iNPH, at least not in females. The only result in favor for dilution was a weak negative correlation between VV and A beta 42 but not with the other lumbar CSF biomarkers. The different results between males and females suggest that future investigations of the CSF pattern in iNPH would gain from sex-based subgroup analysis.

Purpose: We calculated the brain volumes of preterm infants using two-dimensional cranial ultrasonography and explored the relationships thereof with neurodevelopment. Methods: Cranial measurements were derived using routine ultrasonographic scanning. The brain was considered to be an ellipsoid and estimated absolute brain volumes (EABVs) were calculated by substracting the volumes of the two lateral ventricles from the total brain volumes. Results: We enrolled preterm infants of mean gestational age 28 ± 2 weeks and mean birthweight 973 ± 187 g. Twenty-one exhibited dilated ventricles; their EABVs were lower than normal (206 ± 11 cm3 vs. 275 ± 17 cm3, p 0.001). The mental development indices were similar (74 ± 5 vs. 78 ± 14, p = 0.069), but the psychomotor development indices (PDIs) differed significantly (77 ± 7 vs. 86 ± 17, p = 0.001). We found a slight positive correlation between the PDI and EABV (r = + 0.258, p = 0.012). Conclusion: The EABV can be calculated using two-dimensional measurements and low EABV found to be associated with poor neurological outcomes.

Purpose: We calculated the brain volumes of preterm infants using two-dimensional cranial ultrasonography and explored the relationships thereof with neurodevelopment. Methods: Cranial measurements were derived using routine ultrasonographic scanning. The brain was considered to be an ellipsoid and estimated absolute brain volumes (EABVs) were calculated by substracting the volumes of the two lateral ventricles from the total brain volumes. Results: We enrolled preterm infants of mean gestational age 28 ± 2 weeks and mean birthweight 973 ± 187 g. Twenty-one exhibited dilated ventricles; their EABVs were lower than normal (206 ± 11 cm3 vs. 275 ± 17 cm3, p 0.001). The mental development indices were similar (74 ± 5 vs. 78 ± 14, p = 0.069), but the psychomotor development indices (PDIs) differed significantly (77 ± 7 vs. 86 ± 17, p = 0.001). We found a slight positive correlation between the PDI and EABV (r = + 0.258, p = 0.012). Conclusion: The EABV can be calculated using two-dimensional measurements and low EABV found to be associated with poor neurological outcomes.

Purpose: Brain abnormalities in patients with syndromic craniosynostosis can either be a direct result of the genetic defect or develop secondary to compression due to craniosynostosis, raised ICP or hydrocephalus. Today it is unknown whether children with syndromic craniosynostosis have normal brain volumes. The purpose of this study was to evaluate brain and ventricular volume measurements in patients with syndromic and complex craniosynostosis. This knowledge will improve our understanding of brain development and the origin of raised intracranial pressure in syndromic craniosynostosis. Methods: Brain and ventricular volumes were calculated from MRI scans of patients with craniosynostosis, 0.3 to 18.3 years of age. Brain volume was compared to age matched controls from the literature. All patient charts were reviewed to look for possible predictors of brain and ventricular volume. Results: Total brain volume in syndromic craniosynostosis equals that of normal controls, in the age range of 1 to 12 years. Brain growth occurred particularly in the first 5 years of age, after which it stabilized. Within the studied population, ventricular volume was significantly larger in Apert syndrome compared to all other syndromes and in patients with a Chiari I malformation. Conclusions: Patients with syndromic craniosynostosis have a normal total brain volume compared to normal controls. Increased ventricular volume is associated with Apert syndrome and Chiari I malformations, which is most commonly found in Crouzon syndrome. We advice screening of all patients with Apert and Crouzon syndrome for the development of enlarged ventricle volume and the presence of a Chiari I malformation.

Background: Some implantable cardioverter defibrillators (ICD) are able to monitor intrathoracic impedance to detect pulmonary fluid overload. This is achieved by measuring impedance between the ICD case and the right ventricular (RV) lead. We hypothesized that the measured impedance would rise with improvement in left ventricular (LV) volumes during cardiac resynchronization therapy (CRT), and that such impedance changes would be more apparent when measured with an alternative pacing vector. Methods: We analyzed echocardiographic and impedance data from heart failure patients implanted with a CRT-ICD capable of intrathoracic impedance measurement for fluid accumulation diagnosis, and LV pacing impedance recording for lead integrity monitoring. Results: In 127 out of 170 patients that received de novo CRT implantation, the LV end-systolic volume (LVESV) decreased at 6-month follow-up (LVESV at 6 month - LVESV at baseline <0: group A). For the remaining 43 patients (group B) the change was ≥0. Despite comparable values at baseline (P = 0.262), the impedances of groups A and B gradually diverged soon after the implant, resulting in significant difference between the two groups at the 6-month visit (P = 0.001). The changes in LV dimensions produced larger differences between groups in the impedance measured between the LV and the RV leads (P < 0.001). The regression analysis demonstrated an inverse correlation between paired changes of volume and intrathoracic impedance. Higher correlation coefficient was obtained using the LV-to-RV measurement vector (r = -0.635, P < 0.001). Conclusions: The changes in ICD-measured impedance seem associated with the LV volume changes induced by CRT. Specifically, the LV-to-RV impedance estimations seem to better correlate with paired changes of ventricular volumes. (PACE 2010; 64-73)

When performing equilibrium radionuclide angiocardiography with two successive acquisition views, absolute left-ventricular volumes can be calculated using an 'internal standard' generated by a computer in the left-ventricular cavity. The method is based on the computed ratio of maximum to global activity in the 40°-left-anterior-oblique view after background correction and on the measured depth of the left ventricle in almost-orthogonal, 30°-left-posterior-oblique Fourier first-harmonic images. The method does not require blood sampling or correction for self attenuation. The intra- and interobserver reproducibility is excellent, even in patients with severe impairment of the ventricular-contractility pattern. When compared with a classical method requiring venous-blood counting and an attenuation correction factor, the accuracy of the internalstandard method was fairly good, with a regression coefficient of 0.90. © 1985 Springer-Verlag., SCOPUS: ar.j, info:eu-repo/semantics/published

When performing equilibrium radionuclide angiocardiography with two successive acquisition views, absolute left-ventricular volumes can be calculated using an 'internal standard' generated by a computer in the left-ventricular cavity. The method is based on the computed ratio of maximum to global activity in the 40°-left-anterior-oblique view after background correction and on the measured depth of the left ventricle in almost-orthogonal, 30°-left-posterior-oblique Fourier first-harmonic images. The method does not require blood sampling or correction for self attenuation. The intra- and interobserver reproducibility is excellent, even in patients with severe impairment of the ventricular-contractility pattern. When compared with a classical method requiring venous-blood counting and an attenuation correction factor, the accuracy of the internalstandard method was fairly good, with a regression coefficient of 0.90. © 1985 Springer-Verlag., SCOPUS: ar.j, info:eu-repo/semantics/published