Pulmonary Artery CTA

EFFECTS OF TEST-BOLUS AND LOW-DOSE SCAN ON CT PULMONARY ANGIOGRAPHY IMAGE QUALITY IN PATIENTS WITH DIFFERENT BODY MASS INDEXES

This study aimed to investigate different methods of obtaining high-quality Computed Tomography pulmonary angiography (CTPA) images using low-dose scanning in patients with different body mass index (BMI) values. Sixty patients with suspected pulmonary embolism were grouped based on their BMI values (BMI < 25, designated N, and BMI ≥ 25, designated O) and were assigned to receive either test bolus (TB) or bolus tracking (BT) at conventional (C) or low (L) dose. The effective dose (ED) in the N-TB-L group was lower than in the group N-TB-C (0.56 ± 0.05 vs. 3.78 ± 1.16, p < 0.001), with similar image quality (4.90 ± 0.31 vs. 4.70 ± 0.47, p = 0.120). The ED in the O-TB-L group was lower than in the O-TB-C group (0.54 ± 0.03 vs. 5.14 ± 1.34, p < 0.001), but the group O-TB-C's image quality was higher (4.65 ± 0.59 vs. 3.95 ± 0.89, p = 0.006). Groups N-TB-L versus O-TB-L, groups N-TB-L versus N-BT-L and groups O-TB-C versus O-BT-C had similar EDs (all ps > 0.05), but the image quality was different (all ps < 0.05). In conclusion, the results showed that the image quality of low-dose CTPA scanning using TB was similar to that of the conventional-dose CTPA in patients with BMI < 25 but was lower in patients with BMI ≥ 25. TB was better than BT for all patients, regardless of BMI, when receiving the same ED.

Percutaneous Venous Interventions in The Pulmonary Vascular, Central and Peripheral Venous Systems: How to Recognize, Avoid and Treat Complications

Endovascular treatment of venous disease encompasses a broad range of interventions. Both central and peripheral venous interventions can range from the simple to the complex which increases the need for proper patient selection, procedural planning and technical proficiency. The following article will discuss the importance of avoiding, recognizing and addressing complications associated with venous interventions. Our goal is to raise awareness and educate to help the reader improve performance.

Individually tailored contrast enhancement in CT pulmonary angiography

OBJECTIVE

The purpose was to evaluate individually shaped contrast media (CM) delivery in CT pulmonary angiography (CTPA) for suspected pulmonary embolism (PE).

METHODS

100 consecutive emergency patients with clinical suspicion of PE were evaluated. High-pitch CTPA was performed on a second-generation dual-source CT using the following parameters: 100 kV, 200-250 mAsref, rotation time 0.28 s, 128 × 0.6 mm col. and image reconstruction 1.0/0.8 mm (B30f). Group 1 (n = 50) then received a fixed CM bolus (300 = mgI ml(-1), volume = 90 ml and flow rate = 6 ml s(-1)); Group 2 (n = 50) received a body weight-adapted CM bolus determined by dedicated contrast injection software. For analysis, groups were further subdivided into low-weight (40-75 kg) and high-weight (76-117 kg) groups. Technical image quality was graded using a four-point Likert scale (1 = non-diagnostic; 2 = diagnostic; 3 = good and 4 = excellent image quality) at the level of the pulmonary trunk and pulmonary arteries. Objective image quality analysis was performed by measuring contrast enhancement in Hounsfield units (HU) at the same levels. Attenuation levels > 180 HU were considered diagnostic.

RESULTS

All examinations were graded as diagnostic at each level. The individual minimum pulmonary attenuation was 184 and 270 HU for Group 1 and 2, respectively. Mean attenuation was as follows: Group 1: 475 ± 105 HU (40-75 kg) and 402 ± 115 HU (76-117 kg), p < 0.03. Group 2: 424 ± 76 HU (40-75 kg) and 418 ± 100 HU (76-117 kg), p = 0.8. For Group 2, CM volumes were: 55 ± 5 ml (40-75 kg) and 66 ± 5 ml (76-117 kg), leading to 16-51% CM reduction.

CONCLUSION

Even under emergency conditions, individualized CM protocols can provide diagnostic and robust image quality in CTPA for PE with a substantial reduction of CM volume for lower weight patients, compared with a fixed CM protocol.

ADVANCES IN KNOWLEDGE

CM volume can substantially be reduced by using individualized CM protocols in CT angiography for PE without compromising the diagnostic image quality.

A case of hepatopulmonary syndrome

This report presents the case of a 42-year-old man with liver cirrhosis who presents with breathlessness. Initial investigations are unable to explain his persistent hypoxia and a diagnosis of hepatopulmonary syndrome is considered. Saline contrast echocardiography is utilised in confirming the diagnosis. Details of this case as well as practicalities in performing and interpreting saline contrast echocardiography are reviewed.

Comparison of non-invasive diagnostic tests to multi-detector CT pulmonary angiography for the diagnosis of pulmonary embolism

CONTEXT

Acute pulmonary embolism (PE) remains a diagnostic and therapeutic challenge to physicians. There are various non-invasive diagnostic modalities been suggested to diagnose pulmonary embolism.

AIM

We tried to find the performance of various non-invasive investigations in comparison to multi-detector Computerized Tomography (MDCT pulmonary angiography for the diagnosis of PE).

SETTINGS AND DESIGN

A prospective cohort study was conducted in 80 hospitalized medical patients.

MATERIALS AND METHODS

There were 80 patients with Wells score > 2 who were included. The demographic data, non-invasive investigations, and MDCT pulmonary angiography were conducted in these patients. The sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV) were calculated for each test.

RESULTS

Out of 80 patients, 77.5% patients were with Wells score 3-6 and 22.5% patients were with Wells score more than 6. The test with highest sensitivity was d-dimer (SEN - 90%, P = 0.091) followed by PAH on TTE (SEN - 83%, PPV - 86%, P = 0.006). The most specific test was ECG showing S1Q3T3 (SPE - 100%, P = 0.421), followed by Wells score > 6 (SPE - 91%, P = 0.211). There was no test with sensitivity and specificity more than 90%

CONCLUSION

In all patients with intermediate to high-risk probability MDCT pulmonary angiography is the most accurate test to diagnose PE and should be performed at the earliest. The combination of 2-dimensional ECHO and d-dimer can be used in patients with a high clinical suspicion of PE on pre-test probability where MDCT pulmonary angiography is not possible.

Comparison of non-invasive diagnostic tests to multi-detector CT pulmonary angiography for the diagnosis of pulmonary embolism

CONTEXT

Acute pulmonary embolism (PE) remains a diagnostic and therapeutic challenge to physicians. There are various non-invasive diagnostic modalities been suggested to diagnose pulmonary embolism.

AIM

We tried to find the performance of various non-invasive investigations in comparison to multi-detector Computerized Tomography (MDCT pulmonary angiography for the diagnosis of PE).

SETTINGS AND DESIGN

A prospective cohort study was conducted in 80 hospitalized medical patients.

MATERIALS AND METHODS

There were 80 patients with Wells score > 2 who were included. The demographic data, non-invasive investigations, and MDCT pulmonary angiography were conducted in these patients. The sensitivity (SEN), specificity (SPE), positive predictive value (PPV), and negative predictive value (NPV) were calculated for each test.

RESULTS

Out of 80 patients, 77.5% patients were with Wells score 3-6 and 22.5% patients were with Wells score more than 6. The test with highest sensitivity was d-dimer (SEN - 90%, P = 0.091) followed by PAH on TTE (SEN - 83%, PPV - 86%, P = 0.006). The most specific test was ECG showing S1Q3T3 (SPE - 100%, P = 0.421), followed by Wells score > 6 (SPE - 91%, P = 0.211). There was no test with sensitivity and specificity more than 90%

CONCLUSION

In all patients with intermediate to high-risk probability MDCT pulmonary angiography is the most accurate test to diagnose PE and should be performed at the earliest. The combination of 2-dimensional ECHO and d-dimer can be used in patients with a high clinical suspicion of PE on pre-test probability where MDCT pulmonary angiography is not possible.

Parenchymal and pleural abnormalities in children with and without pulmonary embolism at MDCT pulmonary angiography

BACKGROUND

Prior studies in adults suggest that a wedge-shaped peripheral consolidation may be predictive of pulmonary embolism (PE). In contrast, a previous study in children provided no evidence of an association between this finding and PE, but it was limited by a small sample size and was not specifically designed to answer this question.

OBJECTIVE

To compare the frequencies of parenchymal and pleural abnormalities in children with and without PE at multidetector computed tomographic pulmonary angiography (CTPA).

MATERIALS AND METHODS

The study population included 22 consecutive pediatric patients (11 males, 11 females; mean age 13.2 +/- 5.8 years; range 4 months to 18 years) with PE diagnosed by CTPA from July 2004 to January 2009 and identified using our hospital database. The comparison group included 22 randomly selected pediatric patients (10 males, 12 females; mean age 15.2 +/- 3.3 years; range 5.6 to 18 years) who underwent CTPA studies without evidence of PE during the same study period. All CTPA studies were reviewed by consensus by two pediatric radiologists for the presence of parenchymal and pleural abnormalities including: wedge-shaped peripheral consolidation, other forms of consolidation, atelectasis, linear opacity, ground-glass opacity, mosaic attenuation pattern, nodule, mass, focal patchy increased attenuation, and pleural effusion. Differences in frequencies of parenchymal and pleural abnormalities between the two groups were analyzed by logistic regression to determine odds ratios for association with PE. The two groups were also compared with respect to risk factors for PE.

RESULTS

Wedge-shaped peripheral consolidation was seen in eight children (36%) with PE and in two children (9%) without PE [odds ratio = 5.7, 95% confidence interval (CI): 1.2 to 30, p = 0.03]. There were no significant differences in the frequency of other findings between the groups (all p-values > 0.10). Prior history of neoplasm was the only independent risk factor significantly associated with the presence of PE (p = 0.006).

CONCLUSION

Wedge-shaped peripheral consolidation is significantly associated with PE on CTPA studies of children. The identification of a wedge-shaped peripheral consolidation in children should alert radiologists to carefully evaluate for concurrent PE.

Dual-energy CT for the assessment of contrast material distribution in the pulmonary parenchyma

OBJECTIVE

The purpose of this study was to assess the feasibility and diagnostic value of dual-energy CT iodine mapping at pulmonary CT angiography.

SUBJECTS AND METHODS

Ninety-three patients underwent CT angiography with the dual-energy technique on a dual-source CT scanner. Postprocessing was used to map iodine in the lung parenchyma on the basis of its spectral behavior, and image quality was assessed by two readers. Iodine distribution patterns were rated as homogeneous, patchy, or circumscribed defects. Conventional CT angiographic images reconstructed from the same data sets were reviewed for the presence and localization of pulmonary embolism, whether embolic occlusion was partial or complete, and the presence of changes in the lung parenchyma. Dual-energy perfusion findings were correlated with the CT angiographic and lung-window CT findings in per-patient and per-segment analyses.

RESULTS

Iodine distribution was homogeneous in 49 patients, of whom CT angiography showed no pulmonary embolism in 46 patients and nonocclusive pulmonary emboli in three patients. Images of 29 patients showed a patchy pattern; 24 of these patients had no pulmonary embolism, and five had nonocclusive pulmonary emboli with solely nonocclusive intravascular clots. Images of 15 patients showed segmental or subsegmental defects; four of these patients had evidence of pulmonary embolism, and 11 had occlusive pulmonary emboli with at least one occlusive clot in the pulmonary vasculature.

CONCLUSION

Dual-energy CT is reliable in the detection of defects in pulmonary parenchymal iodine distribution that correspond to embolic vessel occlusion.

The role of multidetector computed tomography angiography for the diagnosis of pulmonary embolism

From a radiological point of view, computed tomography pulmonary angiography (CTPA) has effectively become the de-facto first-line imaging test for the evaluation of pulmonary embolism (PE), as patients with a high-quality negative CTPA do not require further examination or treatment for suspected PE. We are likely to see further technical developments in CT technology in the near future. These advances will most likely further improve image quality. Several questions or issues remain, including strategies for further imaging when CT is inconclusive or contraindicated, issues regarding radiation exposure, the prevalence of PE in specific populations, best tests and pathways in specific patient groups, including patients with specific comorbidities such as oncology patients or patients with chronic obstructive pulmonary disease. Also, the question whether all PE patients need anticoagulation, the clinical effect of follow-up imaging, and the accuracy of different clinical prediction rules, remains.

Dual energy CT for the assessment of lung perfusion--correlation to scintigraphy

Purpose of this study was to determine the diagnostic value of dual energy CT in the assessment of pulmonary perfusion with reference to pulmonary perfusion scintigraphy. Thirteen patients received both dual energy CT (DECT) angiography (Somatom Definition, Siemens) and ventilation/perfusion scintigraphy. Median time between scans was 3 days (range, 0-90). DECT perfusion maps were generated based on the spectral properties of iodine. Two blinded observes assessed DECT angiograms, perfusion maps and scintigrams for presence and location of perfusion defects. The results were compared by patient and by segment, and diagnostic accuracy of DECT perfusion imaging was calculated regarding scintigraphy as standard of reference. Diagnostic accuracy per patient showed 75% sensitivity, 80% specificity and a negative predictive value of 66%. Sensitivity per segment amounted to 83% with 99% specificity, with 93% negative predictive value. Peripheral parts of the lungs were not completely covered by the 80 kVp detector in 85% of patients. CTA identified corresponding emboli in 66% of patients with concordant perfusion defects in DECT and scintigraphy. Dual energy CT perfusion imaging is able to display pulmonary perfusion defects with good agreement to scintigraphic findings. DECT can provide a pulmonary CT angiogram, high-resolution morphology of the lung parenchyma and perfusion information in one single exam.