Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 182, July 1978

This bibliography lists 165 reports, articles, and other documents introduced into the NASA scientific and technical information system in June 1978

Studies of the effects of gravitational and inertial forces on cardiovascular and respiratory dynamics

The current status and application are described of the biplane video roentgen densitometry, videometry and video digitization systems. These techniques were developed, and continue to be developed for studies of the effects of gravitational and inertial forces on cardiovascular and respiratory dynamics in intact animals and man. Progress is reported in the field of lung dynamics and three-dimensional reconstruction of the dynamic thoracic contents from roentgen video images. It is anticipated that these data will provide added insight into the role of shape and internal spatial relationships (which is altered particularly by acceleration and position of the body) of these organs as an indication of their functional status

Aerospace Medicine and Biology: A continuing bibliography (supplement 221)

This bibliography lists 127 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1981

The foramen magnum and its contents : a magnetic resonance imaging study of the normal spatial relationships

The well-known neurological disturbances associated with caudal displacement of the cerebellar tonsils through the fora men magnum (Chiari malformation) have lead to many radiological studies of the region. With MRI, routine sagittal and parasagittal views of the craniovertebral junction have shown that the position of the cerebellar tonsils is variable, and in many otherwise healthy individuals, the inferior tonsillar margins lie within the fora men magnum itself. In some cases, this topography is associated with little signal from the surrounding cerebra-spinal fluid (CSF), indicating reduction of the cerebellomedullary cistern and, therefore, crowding of neural structures within the confines of the fora men. The objective of this study has been to examine the spatial relationship between the contents of the foramen magnum ie. the medulla and cerebellar tonsils, using a normal sample comprising 120 volunteers. Instead of the conventional measurements of distance, a ratio, the Foramen Magnum Index (FMI), has been determined, derived from the relative surface areas (pixels) of neural parenchyma and CSF, over axially and sagittaly-defined boundaries of the fora men. The FMI, with a 95th centile of 0.77, exhibits appropriate statistical correlation with tonsillar position below the level of the foramen, and is therefore considered specific. As a quantitative means of assessing the cerebellomedullary cistern, the FMI also identifies certain subjects whose tonsils are at the foramen, in whom the cistern is small with resultant neural crowding

USSR Space Life Sciences Digest, volume 1, no. 4

An overview of the developments and direction of the USSR Space Life Sciences Program is given. Highlights of launches, program development, and mission planning are given. Results of ground-based research and space flight studies are summarized. Topics covered include: space medicine and physiology; space biology, and life sciences and technology

The Safety and Clinical Applications of Intrathecal Gadolinium-Enhanced MRI : A Systematic Review and Case Report

Gadoliniumpohjaisia kontrastiaineita käytetään magneettikuvauksessa lisäämään kuvien kontrastia ja parantamaan kudosten erottelukykyä. Intravaskulaarisessa käytössä niitä on pidetty erittäin turvallisina ja hyvin siedettyinä, mutta viime vuosina on havaittu, että gadoliniumia voi kertyä aivokudokseen. Vaikka gadoliniumpohjaisten kontrastiaineiden intratekaalinen käyttö ei ole virallisesti hyväksyttyä, menetelmän turvallisuus on osoitettu alustavasti useissa kliinisissä tutkimuksissa. Mahdollisia käyttöaiheita intratekaalisella gadoliniumilla tehostetulle magneettikuvaukselle (GdMK) ovat muun muassa likvorivuotojen ja likvorikierron häiriöiden diagnostiikka. Tämän katsauksen tavoite oli selvittää GdMK:n turvallisuutta ja hyödyllisyyttä aivojen ja selkäydinkanavan poikkeavuuksien diagnostiikassa. Kirjallisuushaussa Medline- ja Scopus-tietokannoista etsittiin alkuperäisartikkeleita ja tapausselostuksia, joissa 1) arvioitiin GdMK:n turvallisuutta ja/tai hyötyä kliinisessä käytössä, ja 2) kuvattiin toimenpiteen suoritus yksityiskohtaisesti. Täydentävää hakua tehtiin aihetta käsittelevien artikkelien kirjallisuusluetteloista. Katsaukseen otettiin mukaan 28 alkuperäisartikkelia ja 8 tapausselostusta. Neljässä tutkimuksessa GdMK:ta verrattiin suoraan yhteen tai useampaan muuhun kuvantamismenetelmään ja raportoitiin menetelmille diagnostisten testien tunnuslukuja (herkkyys, tarkkuus, PPV, NPV). Näiden neljän tutkimuksen laatua arvioitiin soveltaen QUADAS-2-kriteereitä. Meta-analyysiä ei tehty, koska aineisto oli heterogeeninen. Yhteensä 790 tutkimushenkilöä kuvannettiin GdMK:lla. Vakavia haittatapahtumia ei raportoitu. Yleisin haitta oli toimenpiteen jälkeinen päänsärky, jota esiintyi 83 potilaalla (11 %). Yhdelle potilaalle nousi toimenpiteen jälkeen kuume, yksi kärsi ohimenevästä täydellisestä muistin-menetyksestä (TGA) ja yksi sairastui bakteerimeningiittiin. GdMK:n herkkyys kallonpohjan likvorivuotojen diagnostiikassa oli 89-98 %. Kolme tutkimusta raportoi GdMK:n olevan varjoaine-TT:tä herkempi selkäydinkanavan likvorivuotojen diagnostiikassa. Lisäksi GdMK todettiin hyödylliseksi araknoidaalikystien, hydrokefaluksen ja neurokystiserkoosin diagnostiikassa. Gadoliniumpohjaisten kontrastiaineiden intratekaalinen käyttö vaikuttaa olevan turvallista ja hyvin siedettyä. Intravaskulaariseen käyttöön liittyvät haitat tulee kuitenkin huomioida myös intratekaalisessa käytössä, ja gadoliniumpohjaisia kontrastiaineita tulisi käyttää varoen potilailla, joilla on munuaisten vajaatoiminta. Vaikka intratekaaliset annokset ovat intravaskulaarisiin annoksiin nähden pieniä, intratekaaliseen käyttöön voi liittyä vaikeasti ennakoitavia haittoja, sillä annostelureitti vaikuttaa kontrastiaineen kinetiikkaan. GdMK:n etuja ovat säteilyrasituksen puuttuminen ja TT:tä parempi herkkyys muun muassa likvorivuotojen diagnostiikassa, mutta pitkäaikaishaittojen riski on huomioitava gadoliniumin intratekaalista käyttöä harkittaessa. Abstract Background: The intravenous use of gadolinium-based contrast agents (GBCAs) in MR imaging is well-established in clinical practice. GBCAs were long considered to be extremely safe, but in recent years some concerns have been raised over possible long-term adverse effects, including deposition of gadolinium in neural tissue. The intrathecal use of GBCAs is not approved by the EMA or FDA, but its relative safety and tolerability has been reported in several clinical studies. When administered intrathecally, GBCAs provide enhancement of CSF and good contrast between CSF and parenchyma. Therefore, potential clinical applications include evaluation of the subarachnoid space, CSF fistulas, and CSF flow dynamics. The objective of this review was to assess the safety and diagnostic value of intrathecal gadolinium-enhanced MRI (GdMRI) in clinical practice. Materials and methods: A search was carried out in the Medline and Scopus databases up to 30 November 2016. Original articles and case reports that 1) evaluated the safety and/or the diagnostic performance of GdMRI and 2) provided detailed information on the procedure were included. Data was collected on study design, sample size, patient demographics, GBCA type and dose, administration procedure, follow-up, adverse events, and diagnostic performance. Modified QUADAS-2 criteria were used to assess the methodological quality of four studies that compared GdMRI to other imaging modalities and reported diagnostic performance characteristics for GdMRI. Meta-analysis was not attempted due to the heterogeneity of the included studies. Results: A total of 36 studies with 790 subjects were included. There were no reports of serious adverse events associated with GdMRI. The most frequent adverse effect was mild to moderate postprocedural headache, which was reported in 83 patients (11 %). One patient developed a fever, one had an episode of TGA, and one developed pneumococcal meningitis after the procedure. In detection and localization of skull-base CSF leaks, four studies reported a sensitivity of 89-96 % for GdMRI. Three studies reported improved detection and localization of spinal CSF leaks by GdMRI compared to CECT. The diagnostic value of GdMRI for the evaluation of arachnoid cysts, hydrocephalus, and neurocysticercosis was also reported in small patient series. Conclusion: The intrathecal use of GBCAs appears to be safe and well-tolerated in the short term. Careful consideration is called for when performing GdMRI in patients with renal insufficiency, and the use of high-risk compounds should be avoided in all patients regardless of renal function. Although intrathecal doses of GBCAs are significantly lower than intravenous doses, no direct comparison can be made between the two due to differences in clearance kinetics. Because the experience on the intrathecal use of GBCAs is limited, the long-term safety of GdMRI remains unclear. In the diagnosis of CSF fistulas, GdMRI appears to have a higher sensitivity than CECT, and several small studies have shown the potential value of GdMRI in various other clinical situations. The benefits of improved diagnostics and lack of radiation exposure need to be weighed against the potential risk of long-term adverse effects when considering the intrathecal use of GBCAs, especially in young patients. More research is needed on the long-term safety of GdMRI before its widespread clinical use can be recommended

Cerebrospinal fluid dynamics

The classical cerebrospinal fluid (CSF) circulation theory has been accepted as an established theory of CSF physiology. It describes bulk CSF flow from production site to absorption site. However, much controversy remains regarding the basic CSF physiology and the mechanisms behind the development of hydrocephalus. In the recent observations made using advanced magnetic resonance imaging (MRI) technique, namely, the time spatial inversion pulse (Time-SLIP) method, CSF was used as internal CSF tracer to trace true CSF movement. Observation of the CSF dynamics using this method reveals aspects of CSF dynamics that are different from those of classical CSF circulation theory. Cerebrospinal fluid shows pulsation but does not show bulk flow from production site to absorption site, a theory that was built upon externally injected tracer studies. Observation of the exogeneous tracer studies were true but misinterpreted. Causes of misinterpretations are the differences between results obtained using the true CSF tracer and exogenous tracers. A better understanding of the real CSF physiology can be significant for the advancement of medical sciences in the future. Revisiting CSF flow physiology is a necessary step toward this goal

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 136, January 1975

This special bibliography lists 238 reports, articles, and other documents introduced into the NASA scientific and technical information system in December 1974

Aerospace Medicine and Biology: A continuing bibliography with indexes (supplement 290)

This bibliography lists 125 reports, articles and other documents introduced into the NASA scientific and technical information system in October 1986