Patients
A total of 11 patients with pericardial findings were identified, while the remaining 26 patients did not show CT evidence of pericardial findings. The general demographic and clinical characteristics of all the study patients is summarized in Table 1.
Table 1
Demographic and clinical characteristics of 37 patients with cocci subgrouped by the pericardial findings positivity on CT chest
Characteristic | Total | Pericardial findings on CT N, % |
No | Yes | P-value |
Age, mean ± SD (min-max) | | 50.9 ± 15.3 (26–80) | 49.2 ± 15.6 (26–78) | 54.2 ± 14.8 (26–80) | 0.42 |
Sex | Female | 10 | 5, 19% | 5, 45% | 0.12 |
| Male | 27 | 21, 81% | 6, 55% | |
Race | White | 21 | 15, 58% | 6, 55% | 0.31 |
| Hispanic | 11 | 7, 27% | 4, 36% | |
| Black | 1 | 0, 0% | 1, 9% | |
| Asian | 4 | 4, 15% | 0, 0% | |
Smoking history | No | 22 | 14, 54% | 8, 73% | 0.47 |
| Yes | 15 | 12, 46% | 3, 27% | |
Comorbidities | No | 12 | 9, 35% | 3, 27% | 1.00 |
| Yes | 25 | 17, 65% | 8, 73% | |
DM | No | 25 | 19, 73% | 6, 55% | 0.44 |
| Yes | 12 | 7, 27% | 5, 45% | |
Autoimmunity | No | 32 | 23, 88% | 9, 82% | 0.62 |
| Yes | 5 | 3, 12% | 2, 18% | |
Cancer | No | 33 | 23, 88% | 10, 91% | 1.00 |
| Yes | 4 | 3, 12% | 1, 9% | |
Obesity | No | 35 | 24, 92% | 11, 100% | 1.00 |
| Yes | 2 | 2, 8% | 0, 0% | |
Clinical presentation | | | | | |
Asymptomatic | No | 35 | 24, 92% | 11, 100% | 1.00 |
| Yes | 2 | 2, 8% | 0, 0% | |
Fever | No | 21 | 15, 58% | 6, 55% | 1.00 |
| Yes | 16 | 11, 42% | 5, 45% | |
Cough | No | 20 | 13, 50% | 7, 64% | 0.50 |
| Yes | 17 | 13, 50% | 4, 36% | |
Fatigue or SOB | No | 30 | 24, 92% | 6, 55% | 0.02 |
| Yes | 7 | 2, 8% | 5, 45% | |
Weight loss | No | 34 | 23, 88% | 11, 100% | 0.54 |
| Yes | 3 | 3, 12% | 0, 0% | |
Pain (chest, abd., back) | No | 27 | 20, 77% | 7, 64% | 0.44 |
| Yes | 10 | 6, 23% | 4, 36% | |
Hemoptysis | No | 34 | 23, 88% | 11, 100% | 0.54 |
| Yes | 3 | 3, 12% | 0, 0% | |
Chronicity | Acute | 15 | 9, 35% | 6, 55% | 0.30 |
| Chronic | 22 | 17, 65% | 5, 45% | |
Other organs (any) | No | 31 | 23, 88% | 8, 73% | 0.34 |
| Yes | 6 | 3, 12% | 3, 27% | |
CNS | No | 33 | 25, 96% | 8, 73% | 0.07 |
| Yes | 4 | 1, 4% | 3, 27% | |
Bone | No | 33 | 24, 92% | 9, 82% | 0.57 |
| Yes | 4 | 2, 8% | 2, 18% | |
Liver | No | 36 | 25, 96% | 11, 100% | 1.00 |
| Yes | 1 | 1, 4% | 0, 0% | |
Except for age, data shown as number and percentage within columns (N, %) |
There was no significant difference regarding the demographics (age, sex, race) and duration of infection between patients with and without pericardial findings. Also, the smoking history and potential risk factors of these two subgroups were comparable.
Medical comorbidity were noted: autoimmune disease consisted of rheumatoid arthritis (n = 2), systemic juvenile idiopathic arthritis (n = 1), celiac disease (n = 1), and ulcerative colitis (n = 1). Malignancies included renal cell carcinoma (n = 1), rectal carcinoma (n = 1), acute myeloid leukemia (n = 1), and papillary thyroid carcinoma (n = 1).
Clinical symptoms that the patients experienced were mostly cough (46%, n = 17) and fever (43%, n = 16). Shortness of breath and chest pain were the next most reported symptoms (both 19%, n = 7). Other less commonly reported symptoms included abdominal pain (3%, n = 1) and back pain (3%, n = 1). Two of the 37 patients were asymptomatic.
Duration of infection was chronic for most patients (32/49, 65%) and acute for 17 of 49 patients (35%).
Extrapulmonary or extrathoracic manifestations of infection were seen in a total of 6 patients and consisted of central nervous system in 4/37 patients (8%), musculoskeletal abnormalities in 4 patients (8%), and hepatic involvement in 1/37 patients (3%).
Chest Ct Findings
Overall CT imaging features are summarized in Table 2. Representative CT images are shown in Figs. 1, 2 and 3.
Table 2
Thoracic CT imaging features subgrouped by pericardial CT findings.
Thoracic CT chest features | Total | Pericardial findings on CT N, % |
No | Yes | P-value |
Parenchymal changes | | | | | |
Nodules | No | 4 | 2, 8% | 2, 18% | 0.57 |
| Yes | 33 | 24, 92% | 9, 82% | |
Miliary pattern | No | 30 | 22, 85% | 8, 73% | 0.40 |
| Yes | 7 | 4, 15% | 3, 27% | |
Consolidation | No | 12 | 11, 42% | 1, 9% | 0.06 |
| Yes | 25 | 15, 58% | 10, 91% | |
Cavitation | No | 24 | 18, 69% | 6, 55% | 0.46 |
| Yes | 13 | 8, 31% | 5, 45% | |
Mass(s) | No | 33 | 23, 88% | 10, 91% | 1.00 |
| Yes | 4 | 3, 12% | 1, 9% | |
Mediastinal/hilar LNs | No | 17 | 14, 54% | 3, 27% | 0.17 |
| Yes | 20 | 12, 46% | 8, 73% | |
Pleural effusion | No | 24 | 22, 85% | 2, 18% | < 0.001 |
| Yes | 13 | 4, 15% | 9, 82% | |
Laterality | Unilateral | 7 | 4, 100% | 3, 33% | 0.07 |
| Bilateral | 6 | 0, 0% | 6, 67% | |
Volume | Trace | 6 | 2, 50% | 4, 44% | 1.00 |
| Small | 6 | 2, 50% | 4, 44% | |
| Large | 1 | 0, 0% | 1, 11% | |
All patients had imaging evidence of pulmonary parenchymal abnormalities on CT. The most prevalent CT pattern of involvement was nodule formation seen in 33 out of 37 (89%) patients. This involvement was solitary in 1 patient and multiple in 32 patients. A miliary pattern of lung nodules occurred in 7 of 37 patients (19%). Cavitation within the nodules was seen in 2 patients.
Lung consolidation was the second most prevalent pattern of involvement, seen in 25 of 37 patients (68%). Consolidation was associated with cavitation in 8 patients.
Intrathoracic lymphadenopathy including mediastinal or hilar lymphadenopathy was present in 54% of patients (20/37).
Thirty five percent of patients (13/37) had pleural effusions with most of them having trace (n = 6) or small (n = 6) pleural effusions. Only one patient had large pleural effusion. Pleural effusion was on the left side (n = 1), right side (n = 6) or bilateral (n = 6).
Pericardial Findings
Twenty-six out of 37 (70%) did not have pericardial findings. Trace or small pericardial effusions were noted in 3 and 8 patients, respectively. One of 11 patients with pericardial effusions had concomitant pericardial thickening/enhancement and had previously undergone pericardiocentesis for pericardial tamponade. Pericardial culture for this patient revealed no signs of infection. None of the other patients with pericardial effusions had clinical signs of pericardial tamponade or pericarditis. Pericardial calcifications were not observed in any of the patients.
Pericardial effusion was strongly associated with the presence of pleural effusion. Nine of 13 patients (69%) with pleural effusion also demonstrated pericardial effusion; compared to 2/26 (8%) without pleural effusion (P < 0.001). Pleural effusion was bilateral in 6 out of the 9 patients with both pericardial and pleural effusions. The association was marginally significant (P = 0.07). The volume of pleural effusion was not associated with the presence or absence of pericardial effusion; however, the volumes of pleural and pericardial effusions showed positive ordinal correlation (Spearman’s Rho = 0.62; 95% confidence interval = 0.33–0.88; P < 0.001).
Pericardial effusion was slightly more frequently seen with a pulmonary consolidation pattern (10/25 with consolidative changes compared to 1/12 without consolidation) and with positive mediastinal lymph nodes (8/20 with lymphadenopathy compared to 3/17 without positive lymph nodes); however, these associations did not reach a statistically significant value.
A follow-up CT was performed in 10 patients (8 with CT-evidence of pericardial effusion and 2 without). Pericardial effusion resolved in 3, decreased in 4, and was stationary in 1 patient(s). Newly developed effusion was seen in 2 patients. However, the interval between the index CT and the follow-up study was highly variable with mean of 659 ± 785 days and range of 87 to 4054 days.
In 9 of the primary 11 patients with evidence of pericardial effusion on CT chest, an echocardiography was performed within a median of 27 days and confirmed the persistence of effusion in 5 patients. Effusion resolved in 4 patients.