The portal vein wall typically is hyperechoic over a wide range of beam-vessel angles, whereas the hepatic vein wall is hyperechoic only when the inci· dent beam and the vessel are perpendicular. This has been attributed to marked discrepancies in mural thickness, collagen content, or perivascular fat between portal and hepatic veins. We evaluated histologically the walls of portal and hepatic veins using three cadaveric livers. For vessels with lumi· nal diameter above 2 to 3 mm, hepatic vein and portal vein wall thicknesses were similar such that portal vein walls were not more than 50% thicker than those of hepatic veins of comparable size. Hepatic vein walls were mostly composed of parallel, tightly packed collagen fibers. In contrast, portal vein walls were composed of loosely arrayed, non parallel connective tissue fibers which were separated by multiple intervening spaces and only a minority of which were collagenous. Perivascular fat was not identified adjacent to intrahepatic vessels beyond the liver hilus. The marked differences in echogenicity between portal vein and hepatic vein walls typically observed at ultrasonography thus cannot be attributed to differences in mural thickness, collagen content, or perivascular fat between these vessels. Rather, the distinct composition of the hepatic vein wall renders it a specular reflector, which is hyperechoic only when the angle between the ultrasound beam and the vessel wall is dose to 90 degrees, whereas the composition of the portal vein wall enables it to appear hyperechoic at a wide range of beam-vessel angles. KEY WORDS: Liver, ultrasonography; Abdomen, ultrasonography; Hepatic vein; Portal vein. I t has long been known that echoes reflected from HV walls typically are less bright than those reflected by PV walls. Chafetz and Filly noted that HV walls were hyperechoic when HVs were aligned perpendicular to the ultrasonographic beam, in contrast to PV walls, which were hyperechoic over a wide range of beam-vessel angles.l They suggested that this phenomenon was due to more abundant connective tissue in PV walls than in HV walls,l an extrapolation based on the wellknown marked discrepancy in thickness between HV and PV walls at the level of the microscopic hepatic lobule.z They also suggested that differences between PVs and HVs in the quantity of perivascular fat might contribute to observed differences in echogenicity.l The imaging literature has supported the idea that the discrepancy between PV and HV 0 1997 by the American Institute of Ultrasound in Medicine • J Ultrasound Med 16:807-810, 1997 • 0278-4297/ 97/ $3.50
Purpose The aim of this study was to analyze the effect of obstructive sleep apnea (OSA) on the ultrasound (US) features of the diaphragm and to determine if diaphragmatic US may be a useful screening tool for patients with possible OSA. Methods Patients complaining of snoring were prospectively enrolled for overnight polygraphy using the ApneaLink Air device. Thickness and motion of the diaphragm during tidal and deep inspiration were measured. Logistic regression was used to assess parameters of the diaphragm associated with OSA. Results Of 100 patients, 64 were defined as having OSA. Thicknesses of the left and right hemidiaphragms were significantly different between OSA and control groups. Using a combination of diaphragmatic dimensions, diaphragm dilation, age, sex, and BMI, we developed an algorithm that predicted the presence of OSA with 91% sensitivity and 81% specificity. Conclusion A combination of anthropometric measurements, demographic factors, and US imaging may be useful for screening patients for possible OSA. These findings need to be confirmed in larger sample sizes in different clinical settings.
Összefoglaló. Bevezetés és célkitűzés: Az obstruktív alvási apnoe az intermittáló hypoxia által cardiovascularis, cerebrovascularis és metabolikus betegségek kialakulását okozhatja. Kutatásunkban célunk volt a betegség főbb jellemzőinek vizsgálata, az obstruktív alvási apnoe és a kontrollcsoport általános, antropometriai, laboratóriumi paramétereinek összehasonlító elemzése által. Anyag és módszer: A prospektív vizsgálatba 100 beteget (74 férfi, 26 nő, átlagéletkor ± SD, 42,15 ± 12,7 év) vontunk be, akiket az elvégzett poliszomnográfia eredménye alapján kontroll- (36 fő) és obstruktív alvási apnoe (64 fő) csoportra osztottunk. A betegeknél részletes anamnézisfelvételt, antropometriai méréseket, laborvizsgálatot és alváskérdőív-kitöltést végeztünk. Eredmények: Az obstruktív alvási apnoe csoportban szignifikánsan nagyobb nyak- (p = 0,015), csípő- és haskörfogat (p<0,000), továbbá BMI-érték (p<0,000) volt megfigyelhető. A férfiak szignifikánsan nagyobb számban voltak képviselve az obstruktív alvási apnoe csoportban (p<0,000). Míg az antropometriai paraméterek közül a kontrollcsoportban a nyakkörfogat különbözött szignifikánsan a nemek között (p<0,000), addig az obstruktív alvási apnoe csoportban a nyak- (p = 0,001) mellett a haskörfogat (p = 0,028) esetében volt megfigyelhető szignifikáns különbség. A társbetegségek jelenléte a kontroll- és az obstruktív alvási apnoe csoportban a hypertonia esetében 21%-nak és 64%-nak, a gastrooesophagealis refluxbetegség 5,42%-nak és 4,71%-nak, a szív-ér rendszeri betegség 2,7%-nak és 1%-nak, míg a 2-es típusú diabetes mellitus 0%-nak és 6,4%-nak adódott. A BMI az obstruktív alvási apnoe és a kontrollcsoportban egyaránt szignifikáns pozitív korrelációt mutatott a nyak-, a has- és a csípőkörfogattal, továbbá a kontrollcsoportban szignifikáns negatív korrelációt találtunk a HDL-koleszterin értéke és a BMI, valamint a nyak- és haskörfogat között. Következtetés: Az elhízás mint az obstruktív alvási apnoe legfőbb rizikófaktora és az obstruktív alvási apnoéban jellemző intermittáló hypoxia hozzájárulnak a komorbid állapotok nagyobb arányban történő megjelenéséhez, melyek mihamarabbi diagnosztikája és kezelésük megkezdése kiemelkedő fontosságú a betegek életminőségére gyakorolt hatásuk miatt. Orv Hetil. 2022; 163(15): 586–592. Summary. Introduction and objective: Obstructive sleep apnoea results in metabolic and cardiovascular disorders due to intermittent hypoxia. The main aim of the present study was to analyze the most important features of obstructive sleep apnoea, using anthropometric measurements and blood tests. Material and method: In this prospective investigation, 100 patients (74 male and 26 female patients, mean age ± SD years, 42.15 ± 12.7) were enrolled. These patients were divided into control (n = 36) and obstructive sleep apnoea (n = 64) groups regarding the results of polysomnography. The examination of the patients consisted of detailed anamnestic data, anthropometric measurements, laboratory test and the use of apnoea questionnaires. Results: In the obstructive sleep apnoea group, significantly higher neck (p<0.015), hip and abdomen circumferences and BMI values (p<0.000) were observed. Significantly higher ratio of male patients in the case of obstructive sleep apnoea was detected (p<0.000). In the control group, only the neck circumferences differed significantly between the two genders (p<0.000), but in the obstructive sleep apnoea group the neck (p = 0.001) and abdominal circumferences (p = 0.028) have also differed. Hypertension (64% and 21%) and type 2 diabetes mellitus (6.4% and 0%) were more frequent in the obstructive sleep apnoea group, while cardiovascular disorders (1% and 2.7 %) and gastroesophageal reflux disease (4.71% and 5.42%) in the control group. BMI values were significantly positively correlated with the neck, abdominal and hip circumferences, both in the control and obstructive sleep apnoea groups. Moreover, in the control group, a significant negative correlation between HDL-cholesterol and BMI, neck and abdominal circumferences was observed. Conclusion: Obesity, as one of the most important risk factors for obstructive sleep apnoea and the intermittent hypoxia contribute to the development of comorbidities. The diagnosis and therapy of the comorbidities is of great importance due to their effects on the patients’ quality of life. Orv Hetil. 2022; 163(15): 586–592.
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