No abstract

Spontaneous intracranial hypotension (SIH) is an orthostatic headache syndrome with typical MRI findings among which engorgement of the venous sinuses, pachymeningeal enhancement, and effacement of the suprasellar cistern have the highest diagnostic sensitivity. SIH is in almost all cases caused by spinal CSF leaks. Spinal MRI scans showing so-called spinal longitudinal extradural fluid (SLEC) are suggestive of ventral dural tears (type 1 leak) which are located with prone dynamic (digital subtraction) myelography. As around half of the ventral dural tears are located in the upper thoracic spine, additional prone dynamic CT myelography is often needed. Leaking nerve root sleeves typically associated with meningeal diverticulae (type 2 leaks) and CSF-venous fistulas (type 3 leaks) are proven via lateral decubitus dynamic digital subtraction or CT myelography: type 2 leaks are SLEC-positive if the tear is proximal and SLEC-negative if it is distal, and type 3 leaks are always SLEC-negative. Although 30–70% of SIH patients show marked improvement following epidural blood patches applied via various techniques definite cure mostly requires surgical closure of ventral dural tears and surgical ligations of leaking nerve root sleeves associated with meningeal diverticulae or CSF-venous fistulas. For the latter, transvenous embolization with liquid embolic agents via the azygos vein system is a novel and valuable therapeutic alternative.

EvA (Emphysema versus Airway disease) is a multicentre project to study mechanisms and identify biomarkers of emphysema and airway disease in chronic obstructive pulmonary disease (COPD). The objective of this study was to delineate objectively imaging-based emphysema-dominant and airway disease-dominant phenotypes using quantitative computed tomography (QCT) indices, standardised with a novel phantom-based approach.441 subjects with COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages 1–3) were assessed in terms of clinical and physiological measurements, laboratory testing and standardised QCT indices of emphysema and airway wall geometry.QCT indices were influenced by scanner non-conformity, but standardisation significantly reduced variability (p<0.001) and led to more robust phenotypes. Four imaging-derived phenotypes were identified, reflecting “emphysema-dominant”, “airway disease-dominant”, “mixed” disease and “mild” disease. The emphysema-dominant group had significantly higher lung volumes, lower gas transfer coefficient, lower oxygen (PO2) and carbon dioxide (PCO2) tensions, higher haemoglobin and higher blood leukocyte numbers than the airway disease-dominant group.The utility of QCT for phenotyping in the setting of an international multicentre study is improved by standardisation. QCT indices of emphysema and airway disease can delineate within a population of patients with COPD, phenotypic groups that have typical clinical features known to be associated with emphysema-dominant and airway-dominant disease.

Background& Objectives: Spontaneous intracranial hypotension (SIH) is characterized by loss of CSF-volume. We hypothesize that in this situation of low volume, a larger CSF-flow and spinal cord motion at the upper spine can be measured by non-invasive phase-contrast MRI.Methods:A prospective, age-, gender- and BMI- matched controlled cohort study on SIH patients presenting with spinal longitudinal extradural fluid collection (SLEC) was conducted November 2021 to February 2022. Adapted cardiac-gated 2D phase-contrast MRI sequences were acquired at segment C2/C3, and C5/C6 for CSF-flow, and spinal cord motion analysis. Data processing was fully automated. CSF-flow and spinal cord motion were analyzed by peak-to-peak-amplitude and total displacement per segment and heartbeat, respectively. Clinical data included: age, height, body mass index, duration of symptoms, Bern score according to Dobrocky et al. 2019, and type of the spinal CSF leak according to Schievink et al. 2016. Groups were compared via Mann-Whitney U-test; multiple linear regression analysis was performed to address possible relations.Results:20 SIH patients and 40 healthy controls were analyzed; each group consisted of 70% women. 11 SIH patients presented with Type 1 leak, eight with Type 2, and one was indeterminate. CSF flow per heartbeat was increased at C2/C3 (peak-to-peak-amplitude 65.68 ± 18.3 mm/s vs. 42.50 ± 9.8 mm/s, total displacement 14.32 ± 3.5 mm vs. 9.75 ± 2.7 mm, p<0.001, respectively). Craniocaudal spinal cord motion per heartbeat was larger at segment C2/C3 (peak-to-peak-amplitude 7.30 ± 2.4 mm/s vs. 5.82 ± 2.0 mm/s, total displacement 1.01 ± 0.4 mm vs. 0.74 ± 0.4 mm, p=0.006, respectively) and at segment C5/C6 (total displacement 1.41 ± 0.7 mm vs. 0.97 ± 0.4 mm, p=0.021).Discussion:SLEC-positive SIH patients show higher CSF-flow and higher spinal cord motion at the upper cervical spine. This increased craniocaudal motion of the spinal cord per heartbeat might produce increased mechanic strain on neural tissue and adherent structures which may be a mechanism leading to cranial nerve dysfunction, neck pain and stiffness in SIH. Non-invasive phase-contrast MRI of CSF-flow and spinal cord motion is a promising diagnostic tool in SIH.German Clinical Trials Register, identification number:DRKS00017351Classification of Evidence:This study provides Class III evidence that non-invasive phase-contrast MRI of the upper spine identifies differences in CSF-flow and spinal cord motion in SIH patients compared to healthy controls.