Diagnostic yield of CT pulmonary angiography for pulmonary embolism in clinically suspected patients

Diagnostic Yield of CT Pulmonary Angiogram in the Diagnosis of Pulmonary Embolism and Its Predictive Factors

Introduction Computed tomography pulmonary angiography (CTPA) is the reference investigation of choice to diagnose pulmonary embolism (PE). Nevertheless, the use of CTPA should be weighed against its risks, such as radiation and contrast-induced nephropathy. We aim to assess the yield of CTPA in diagnosing PE at a tertiary centre in Malaysia. We also identify predictive factors associated with the yield of CTPA in this cohort. Methods This was a cross-sectional study involving all patients who had had CTPA done at Hospital Tengku Ampuan Afzan, Kuantan, Malaysia, from January 1, 2021, to November 30, 2021. All patients' records were retrieved and reviewed. CTPA images were retrieved from the Radiology Information System (RIS) and Picture Archiving and Communication System (PACS). They were double-reviewed by the authors, with the initial reports redacted from reporting radiologists to prevent reporting bias. The predictive factors were determined using simple logistic regression and multiple logistic regression. Results A total of 351 CTPAs were reviewed, of which 93 were found to be positive for PE, giving rise to an overall CTPA yield of 26.5%. Upon simple logistic regression, factors such as gender, discipline, history of trauma, presence of COVID-19 infection, and pneumonia were found to be associated with positive CTPA. Upon multiple logistic regression, male patients were found to have a higher chance of positive CTPA results. On the other hand, patients with COVID-19 infection and pneumonia have a lower chance of positive results in CTPA. Conclusion The yield of CTPA in diagnosing PE at our institution was acceptable at 26.5%. Upon multiple logistic regression, patients with COVID-19 infection and pneumonia were more likely to have a negative CTPA result, highlighting the need for clinicians to be more prudent in requesting CTPAs in these patients.

Positive rate and quality assessment of CT pulmonary angiography in sickle cell disease: a case‒control study

BACKGROUND

Pulmonary complications are common in sickle cell disease (SCD) and can mimic pulmonary embolisms (PEs), leading to potential overuse of computed tomography pulmonary angiography (CTPA). Maximizing the quality of CTPA is essential for its diagnostic accuracy. However, little is known about the positive rate and quality of CTPA in SCD.

METHODS

This retrospective case‒control study aimed to determine the positive rate and quality of CTPA studies performed to rule out PE in SCD (HbSS genotype) patients compared to a control group. Logistic regression analysis was used to identify independent factors associated with suboptimal CTPA studies, defined as a mean enhancement of < 210 HU in the pulmonary artery.

RESULTS

The study included 480 patients, consisting of 240 SCD patients and 240 controls. The positive rate of PE was 4.0%, with a similar rate in both SCD patients and the control group (4.2% vs. 3.8%, p = 0.08). However, SCD patients had significantly lower contrast enhancement of the pulmonary artery than the control group (266.1 ± 90.5 HU vs. 342.2 ± 116.1 HU, p < 0.01). Notably, 25.4% of SCD patients had suboptimal scans. The logistic regression model demonstrated that SCD was significantly associated with suboptimal pulmonary arterial contrast enhancement compared to the control group (OR = 4.4; 95% CI: 2.4-8.3).

CONCLUSIONS

This study revealed a relatively low positive rate of CTPA in both SCD patients and the control group. However, SCD was significantly associated with suboptimal image quality due to inadequate contrast enhancement of the pulmonary artery. Further research is needed to identify measures that can enhance the quality of CTPA studies in SCD patients and to establish a specific imaging protocol for this patient population.

The relationship between pulmonary artery obstruction index and troponin in thorax computed tomography in pulmonary embolism

Aim: To study the relation between troponin and pulmonary artery obstruction index in thoracic computerized tomography in patients diagnosed with acute pulmonary embolism. Material and Method: Data obtained from patients hospitalized in the ward and intensive care units with a pulmonary embolism diagnosis between January 2016 and February 2022 were scanned retrospectively. The full blood count, D-dimer, C-reactive protein, procalcitonin, troponin I, thoracic computerized tomography (CT), angiography, and bilateral lower extremity venous Doppler ultrasonography data were extracted. Patients with left heart failure, renal failure, gastrointestinal hemorrhage, sepsis, respiratory system disease, burns, ischemic stroke, or subarachnoid hemorrhage were excluded. The obstruction indices were calculated according to storage defects in the main, right, left, lobar, and segmental pulmonary artery branches in CT angiography. Results: While 57.0% of the 69 patients included in the study were female, 42.1% were male. The obstruction index in the high troponin-I group was significantly higher than that in the normal troponin-I group (p=0.006). In addition, the obstruction index was significantly higher in patients with bilateral pulmonary embolism than in those with unilateral pulmonary embolism (

Clinical value and feasibility of CT pulmonary angiography with personalized injection of contrast agent in pulmonary embolism

OBJECTIVE

To determine the clinical value and feasibility of CT pulmonary angiography (CTPA) with personalized injection of contrast agent in pulmonary embolism (PE).

METHODS

In the present retrospective study, 130 patients who underwent CTPA examination in our hospital from June 2019 to May 2020 were evaluated. Among them, 67 cases were detected by CTPA with personalized injection of contrast agent as the observation group (Obs group), and 63 cases were detected by CTPA with bolus-tracking (BT) as the control group (Con group). The specificity, sensitivity and accuracy of the detection in the two groups were compared. The image quality score and superior vena cava artifact score of the two diagnostic methods were compared. Additionally, the volumetric CT dose index (CTDIvol) and dose length product (DLP) of the two groups were compared.

RESULTS

The Obs group yielded a significantly higher specificity in diagnosing PE than the Con group (P<0.05), but there were no significant differences between the two groups in the sensitivity and accuracy (P>0.05). The image quality score and superior vena cava artifact score of the two groups were not significantly different (P>0.05), and the Obs group showed significantly lower CTDIvol and DLP than the Con group (P<0.05).

CONCLUSION

CTPA with personalized injection of contrast agent has good diagnostic value for PE, with good imaging effect and safe profile, and has a lower radiation dose requirement.