Table 1 Study Characteristics
Author ID | Study design | Location | Participants’ characteristics | Reference tests | POCUS | Chest x-ray | Main Outcomes | ||
|---|---|---|---|---|---|---|---|---|---|
Machine | Position | Machine | Position | ||||||
Elmahalawy et al. 2016 [12] | A prospective randomized single-group observational study | Egypt | 130 patients (84 males and 46 females; mean age: 43.23 ± 12.62 years) | CT scans | Micro convex 5–9 MHz transducer | Supine | Portable x-ray machine | Upright | CXR was 70% sensitive and 90% specific in diagnosing pleural effusion, while POCUS was 94% sensitive and 96% specific |
Graven et al. 2015 [13] | Prospective single-center observational study | Norway | 59 patients (20 females and 39 males; mean age: 67 (35–86) years) | Echocardiography performed by 4 cardiologists | PSID Vscan (version 1.2) with an adjustable bandwidth of 1.7–3.8 MHz | Lateral decubitus | NR | Upright and lateral | The US exam detected pleural effusion with a 98% sensitivity and 70% specificity, while CXR had a 40% sensitivity and 78% specificity |
Rocco et al. 2008 [14] | Prospective clinical study | Italy | 15 patients (10 males and 5 females; mean age: 42 ± 14 years) | CT scans | Aloka SSD 1700 with a 3.5 MHz convex probe | Supine | Portable radiograph Siemens Mobilett II with a high voltage (80–90 kV) | Supine | CXR was less sensitive than the US in diagnosing PE (42 vs. 94%); however, the specificity was relatively similar (97 vs. 99%, respectively) |
Mohamed.,2018 [15] | Comparative cross-sectional study | Egypt | 60 patients (38 male and 22 females; mean age: 53.83 ± 14.63 years) | CT scans | YD-9000 A and Fukuda denshi (UF-400AX) with 3.5–5 MHz and 5–8 MHz probes | Supine | Siemens portable X-ray machine | Supine | CXR had a poor diagnostic accuracy for pleural effusion than chest US (76.2 vs. 100% sensitivity and 70.6 vs. 100% specificity, respectively.) |
Rozycki et al. 2001 [16] | Observational study | United States | 47 patients (41 males and 6 females; mean age: 44.4 ± 17.9 years) | CXR and CT scans | B&K Panther 2002 US scanner and a 3.5MHz transducer | Supine | NR | NR | The US exams yielded an 83.6% sensitivity, 100% specificity, and 94% accuracy for detecting pleural effusion |
Xirouchaki et al. 2011 [17] | Prospective Study | Greece | 42 patients (34 male and 8 females; mean age: 57.1 ± 21.5 years) | CT scans | Micro-convex 5–9 MHz transducer | Supine | Portable X-ray machine (Siemens Polymobile, Erlangen, Germany) | Supine | The sensitivity and specificity of CXR to diagnose pleural effusion were poor compared to POCUS (65 vs. 100% and 81 vs. 100%, respectively) |
Walsh et al. 2021 [18] | A prospective multicenter study | Canada and the United States | 34 patients (16 male and 18 female) | Chest radiography by radiologists | Low-frequency transducer (2–5 MHz in Canada and 1–5 MHz in the United States) | Upright and supine | NR | NR | US exams carried out in upright and supine positions had very high accuracies in diagnosing pleural effusion (92% and 98% sensitivity and 94.4% specificity, respectively) |
Schieder et al. 2012 [19] | Observational study | Germany | 24 patients (14 male and 10 females; median age: 65 (42–91) years) | High-end US | VScan with a plane 1.7–3.8 MHz transducer for 2D imaging and a 3.5-inch color LCD | Supine | Portable X-ray device (Mobilett XP ECO, Siemens Healthcare, Erlangen, Germany) | Supine | HCU had a higher accuracy for diagnosing pleural effusion than CXR (91 vs. 74% sensitivity and 100 vs. 31% specificity, respectively) |
Ahmed et al. 2022 [20] | Cross-sectional Study | Egypt | 40 patients (22 male and 18 females; mean age: 50.5 ± 17.1 years) | CT scans | A curved array probe operating at 5 MHz frequency | Supine and upright | NR | NR | Chest US was 100% sensitive and specific in diagnosing pleural effusion |
Kocijancic et al. 2002 [21] | Case controlled Study | Slovenia | 69 patients (51 men and 18 women; mean age: 57.1 years) | US or thoracentesis | NR | NR | 140-kV Sire graph D3 unit (Siemens, Erlangen, Germany) | lateral decubitus | 48 of the 52 patients showed positive results for pleural effusion on lateral decubitus radiographs (92% PPV) |
Moller.,1984 [22] | Observational study | Sweden | 100 patients (47 men and 53 women aged 17–94 years) | Oblique semi-supine CXR | NR | NR | NR | Lateral decubitus | 38 true positives, 1 false positive, 5 false negatives, and 68 true negatives were recorded on the lateral decubitus views |
Ruskin et al. 1987 [8] | Prospective study | United States | 34 patients | Lateral decubitus CXR | NR | NR | 40-inch target film | Supine | The sensitivity and specificity of supine CXR for detecting pleural effusion were 67% and 70%, respectively |
Emamian et al. 1997 [10] | Comparative Study | Denmark | 59 patients (28 men and 31 women; median age: 66 (16–93) years) | US | NR | NR | High kilovoltage (110–150) and portable grid with a 1/10 grid ratio | Supine | Supine CXR had an overall accuracy of 82% for detecting pleural effusion (82% sensitivity and 82% specificity) |
Danish et al. 2019 [23] | Cross-sectional observational study | India | 90 patients (67 males and 23 females; mean age: 47.66 ± 16.21 years) | CT scan | 2–5 MHz curvilinear probe with SonoSite M-turbo portable USG machine | Supine | A portable device MobileArt eco MUX 10 | supine | Compared to POCUS, CXR had a poor accuracy for detecting pleural effusion (47.5 vs. 92.9% and 71.8 vs. 100%, sensitivity, and specificity, respectively) |
Mumtaz et al. 2017 [24] | Descriptive validation study | Pakistan | 80 patients (57 males and 23 females) | CT scan | NR | Supine | NR | Supine | The overall diagnostic accuracy of US for detecting pleural effusion was higher than that of CXR (90 vs. 81.25%, respectively) |
Kitazono et al. 2010 [9] | Retrospective study | United States | 100 patients (60 male and 40 females; mean age 54.3 (14–91) years) | CT scan | NR | NR | Mobile x-ray unit (AMX-4 + , GE Healthcare) | Supine | CXR had an overall sensitivity and specificity of 66% and 89% for detecting pleural effusion |
Lichtenstein et al. 2004 [25] | Prospective study | France | 32 patients (mean age: 58 ± 15 years) | CT scan | Hitachi-405 and a micro convex 5MHz probe | Supine and lateral | AMX4 with high voltage (120–130kV) | Supine | POCUS exam had a higher diagnostic accuracy for detecting pleural effusion than CXR (92 vs. 39%, and 93 vs. 85%, sensitivity, and specificity, respectively) |
Brixey et al. 2011 [7] | Retrospective study | United States | 61 patients (34 males and 27 females; mean age: 56.8 ± 20.1 years) | CT scan | NR | NR | NR | Upright and lateral | The Upright PA CXR detected effusions with sensitivity and specificity of 82.1% and 81.3% The sensitivity and specificity of lateral CXR to identify effusions were 85.7% and 87.5%, respectively) |