Yang [16] | Aloka SSD 630, SSD 650, Aloka, Tokyo, Japan; Toshiba 1OOA, Toshiba, Tokyo, Japan | 3.5-, 5.0- and 7.5-MHz linear and convex transducers | One of three sonographers performed the ultrasound. The images were recorded on Polaroid film (Polaroid, Cambridge, MA, USA) and were interpreted by the other two sonographers | Sitting or supine |
Lomas [11] | An Aloka SSD-650 or Siemens Sonoline | 3.5 MHz transducers | One of the three radiologists performed the ultrasound | Sitting |
Marcun [12] | ATL HDI 5000CV | Phase array P4-2 convex transducer | An experienced pulmonologist conducted ultrasound and the images were stored on hard disc for further evaluation | Sitting or supine |
Qureshi [13] | A single Esaote Technos MPX 25 | A 3–5-MHz curvilinear probe ± 8–15 MHz linear probe (to visualise the pleura and chest wall in greater detail) | An experienced radiologist performed the ultrasound and the images were stored as anonymised data. Consultant radiologists separately reviewed them | Upright or lateral decubitus |
Bugalho [9] | ACUSON X300 (Siemens, Germany) | A 2- to 5-MHz convex-array probe ± a 5–10-MHz linear-array transducer (to see details of the thoracic wall and parietal pleura) | Pulmonologists with at least 5 years of thoracic ultrasound experience (average of 450 exams per year) conducted ultrasound and the images were stored as 10–20-s digital video clips. At least three other ultrasound operators reviewed them | Sitting or supine (or lateral decubitus) |
Asciak [8] | Hitachi Avius | The abdomen pre-set | The ultrasound reporters held a minimum of Royal College of Radiologists level 1 accreditation, and at least two sonographers performed the pre-procedure ultrasound scan and agreed on the described echogenic qualities of the fluid | Not described |
Faheem [10] | GE logiq P6 pro | Convex array (3–5 MHz) and linear array (4–11 MHz) | Not described | Supine, prone, lateral or sitting |