Non-invasive determination of pulmonary hypertension with dynamic contrast-enhanced computed tomography: a pilot study

Objectives

In this pilot study we explored whether contrast-material bolus propagation time and speed in the pulmonary arteries (PAs) determined by dynamic contrast-enhanced computed tomography (DCE-CT) can distinguish between patients with and without pulmonary hypertension (PH).

Methods

Twenty-three patients (18 with and 5 without PH) were examined with a DCE-CT sequence following their diagnostic or follow-up right-sided heart catheterisation (RHC). X-ray attenuation over time curves were recorded for regions of interest in the main, right and left PA and fitted with a spline fit. Contrast material bolus propagation speeds and time differences between the peak concentrations were compared with haemodynamic parameters from RHC.

Results

Bolus speed correlated (ρ?=??0.55) with mean pulmonary arterial pressure (mPAP) and showed a good discriminative power between patients with and without PH (cut-off speed 317 mm/s; sensitivity 100 %/specificity 100 %). Additionally, time differences between peaks correlated with mPAP (ρ?=?0.64 and 0.49 for right and left PA, respectively) and discrimination was achieved with sensitivity 100 %/specificity 100 % (cut-off time 0.15 s) and sensitivity 93 %/specificity 80 % (cut-off time 0.45 s), respectively.

Conclusions

Bolus propagation speed and time differences between contrast material peaks in the PA can identify PH. This method could be used to confirm the indication for RHC in patients screened for pulmonary hypertension.

Key Points

? Dynamic contrast-enhanced computed tomography (CT) can identify patients with pulmonary hypertension. ? Bolus propagation speed in the pulmonary artery is reduced in pulmonary hypertension. ? Peak-contrast propagation times provide a practical surrogate for speed. ? This non-invasive technique could serve as a screening method for pulmonary hypertension. ? Invasive right-sided heart catheterisations might be restricted to a smaller group of patients.     

ECG-gated computed tomography to assess pulmonary capillary wedge pressure in pulmonary hypertension

Objective

We propose a non-invasive method for diagnosing post-capillary pulmonary hypertension (PH group 2). We evaluated pulmonary capillary wedge pressure (PCWP) by studying the left atrium (LA) on thoracic ECG-gated CT compared with right heart catheterisation (RHC).

Methods

We retrospectively studied 54 patients with suspected PH or followed for PH who underwent thoracic ECG-gated CT and RHC within 15 days. The diagnostic accuracy of CT morphological and functional data of the LA for the detection of PCWP >15 mmHg, evaluated by two independent readers, was assessed using correlation and receiver-operating characteristic (ROC) analysis.

Results

Interobserver agreement was high (r?=?0.97–0.99). Correlations were found between PCWP and the morphological criteria of the LA such as anteroposterior diameter at 0 % of the R-R interval (r?=?0.70, P?≤?0.001) as well as at 40 % (r?=?0.69, P?≤?0.001). ROC curves constructed with a threshold value of PCWP?>?15 mmHg showed an area under the curve between 0.88 and 0.91. Significant correlations were found between PCWP and functional criteria of the LA, including distensibility (r?=??0.49, P?≤?0.001) and ejection fraction (r?=??0.58, P?≤?0.001).

Conclusion

Thoracic ECG-gated CT in a PH workup helps distinguish between pre- and post-capillary PH.

Key Points

? Computed tomography may help differentiate the various types of pulmonary hypertension (PH). ? Post-capillary PH group 2 is due to left heart disease. ? Right heart catheterisation is used to separate pre- and post-capillary PH. ? Left atrium anteroposterior diameter measured on CT is of value. ? ECG-gated CT helps clinicians to assess patients with PH non-invasively.     

Magnetic resonance imaging to assess the effect of exercise training on pulmonary perfusion and blood flow in patients with pulmonary hypertension

Objectives

To evaluate whether careful exercise training improves pulmonary perfusion and blood flow in patients with pulmonary hypertension (PH), as assessed by magnetic resonance imaging (MR).

Methods

Twenty patients with pulmonary arterial hypertension or inoperable chronic thromboembolic PH on stable medication were randomly assigned to control (n?=?10) or training groups (n?=?10). Training group patients received in-hospital exercise training; patients of the sedentary control group received conventional rehabilitation. Medication remained unchanged during the study period. Changes of 6-min walking distance (6MWD), MR pulmonary flow (peak velocity) and MR perfusion (pulmonary blood volume) were assessed from baseline to week 3.

Results

After 3 weeks of training, increases in mean 6MWD (P?=?0.004) and mean MR flow peak velocity (P?=?0.012) were significantly greater in the training group. Training group patients had significantly improved 6MWD (P?=?0.008), MR flow (peak velocity ?9.7?±?8.6 cm/s, P?=?0.007) and MR perfusion (pulmonary blood volume +2.2?±?2.7 mL/100 mL, P?=?0.017), whereas the control group showed no significant changes.

Conclusion

The study indicates that respiratory and physical exercise may improve pulmonary perfusion in patients with PH. Measurement of MR parameters of pulmonary perfusion might be an interesting new method to assess therapy effects in PH. The results of this initial study should be confirmed in a larger study group.

Key Points

? Quantification of magnetic resonance perfusion is feasible in patients with pulmonary hypertension. ? Quantified magnetic resonance perfusion may become useful for non-invasive monitoring of treatment. ? Quantification of lung perfusion allows new insights into lung (patho-)physiology of PH. ? Careful exercise training improves pulmonary perfusion and blood flow in patients with PH.     

Portopulmonary hypertension: Improved detection using CT and echocardiography in combination

Objectives

To establish the relationship between CT signs of pulmonary hypertension and mean pulmonary artery pressure (mPAP) in patients with liver disease, and to determine the additive value of CT in the detection of portopulmonary hypertension in combination with transthoracic echocardiography.

Methods

Forty-nine patients referred for liver transplantation were retrospectively reviewed. Measured CT signs included the main pulmonary artery/ascending aorta diameter ratio (PA/AA_meas) and the mean left and right main PA diameter (RLPA_meas). Enlargement of the pulmonary artery compared to the ascending aorta was also assessed visually (PA/AA_vis). CT measurements were correlated with right-sided heart catheter-derived mPAP. The ability of PA/AA_vis combined with echocardiogram-derived right ventricular systolic pressure (RVSP) to detect portopulmonary hypertension was tested with ROC analysis.

Results

There were moderate correlations between mPAP and both PA/AA_meas and RLPA_meas (r_s?=?0.41 and r_s?=?0.42, respectively; p?p?=?0.23), a diagnostic algorithm incorporating PA/AA_vis and transthoracic echocardiography-derived RVSP improved the detection of portopulmonary hypertension (AUC?=?0.8, p?Conclusions CT contributes to the non-invasive detection of portopulmonary hypertension when used in a diagnostic algorithm with transthoracic echocardiography. CT may have a role in the pre-liver transplantation triage of patients with portopulmonary hypertension for right-sided heart catheterisation.

Key Points

? CT signs correlate with right-sided heart catheter data in portopulmonary hypertension ? CT adds to the transthoracic echocardiography detection of portopulmonary hypertension ? CT may have a complementary role in pre-liver transplantation triage     

Potential of right to left ventricular volume ratio measured on chest CT for the prediction of pulmonary hypertension: correlation with pulmonary arterial systolic pressure estimated by echocardiography

Objectives

To investigate the correlation of right ventricular (RV) to left ventricular (LV) volume ratio measured by chest CT with pulmonary arterial systolic pressure (PASP) estimated by echocardiography.

Methods

104 patients (72.47?±?13.64?years; 39 male) who had undergone chest CT and echocardiography were divided into two groups (hypertensive and normotensive) based upon an echocardiography-derived PASP of 25?mmHg. RV to LV volume ratios (RV_V/LV_V) were calculated. RV_V/LV_V was then correlated with PASP using regression analysis. The Area Under the Curve (AUC) for predicting pulmonary hypertension on chest CT was calculated.

Results

In the hypertensive group, the mean PASP was 46.29?±?14.42?mmHg (29-98?mmHg) and there was strong correlation between the RV_V/LV_V and PASP (R?=?0.82, p?V/LV_V were 0.990 and 0.892. RV_V/LV_V was 1.01?±?0.44 (0.51-2.77) in the hypertensive and 0.72?±?0.14 (0.52-1.11) in the normotensive group (P <0.05). With 0.9 as the cutoff for RV_V/LV_V, sensitivity and specificity for predicting pulmonary hypertension over 40?mmHg were 79.5?% and 90?%, respectively. The AUC for predicting pulmonary hypertension was 0.87

Conclusion

RV/LV volume ratios on chest CT correlate well with PASP estimated by echocardiography and can be used to predict pulmonary hypertension over 40?mmHg with high sensitivity and specificity.

Key Points

? Chest CT is widely used in patients who may have pulmonary hypertension. ? Cardiac ventricular volume ratios on chest CT correlate with pulmonary arterial systolic pressure. ? A R/L ventricular volume ratio >0.9 usually indicates pulmonary hypertension >40?mmHg. ? Information available on routine chest CT may help predict pulmonary hypertension.     

Pulmonary hypertension due to left heart disease: diagnostic and prognostic value of CT in chronic systolic heart failure

Objectives

To evaluate the ability of chest computed tomography (CT) to predict pulmonary hypertension (PH) and outcome in chronic heart failure with reduced ejection fraction (HFrEF).

Methods

We reviewed 119 consecutive patients with HFrEF by CT, transthoracic echocardiography (TTE) and right heart catheterization (RHC). CT-derived pulmonary artery (PA) diameter and PA to ascending aorta diameter ratio (PA:A ratio), left atrial, right atrial, right ventricular (RV) and left ventricular volumes were correlated with RHC mean pulmonary arterial pressure (mPAP) . Diagnostic accuracy to predict PH and ability to predict primary composite endpoint of all-cause mortality and HF events were evaluated.

Results

RV volume was significantly higher in 81 patients with PH compared to 38 patients without PH (133 ml/m² vs. 79 ml/m², p < 0.001) and was moderately correlated with mPAP (r=0.55, p < 0.001). Also, RV volume had higher ability to predict PH (area under the curve: 0.88) than PA diameter (0.79), PA:A ratio (0.76) by CT and tricuspid regurgitation gradient (0.83) and RV basal diameter by TTE (0.84, all p < 0.001). During the follow-up period (median: 3.4 years), 51 patients (43%) had HF events or died. After correction for important clinical, TTE and RHC parameters, RV volume (adjusted hazard ratio [HR]: 1.71, 95% CI 1.31–2.23, p < 0.001) and PA diameter (HR: 1.61, 95% CI 1.18–2.22, p = 0.003) were independent predictors of the primary endpoint.

Conclusion

In patients with HFrEF, measurement of RV volume and PA diameter on ungated CT are non-invasive markers of PH and may help to predict the patient outcome.

Key Points

? Right ventricular (RV) volume measured by chest CT has good ability to identify pulmonary hypertension (PH) in patients with chronic heart failure (HF) and reduced ejection fraction (HFrEF). ? The accuracy of pulmonary artery (PA) diameter and PA to ascending aorta diameter ratio (PA:A ratio) to predict PH was similar to previous studies, however, with lower cut-offs (28.1 mm and 0.92, respectively). ? Chest CT-derived PA diameter and RV volume independently predict all-cause mortality and HF events and improve outcome prediction in patients with advanced HFrEF.

     

Attenuated right ventricular energetics evaluated using 11C-acetate PET in patients with pulmonary hypertension

Purpose

The right ventricle (RV) has a high capacity to adapt to pressure or volume overload before failing. However, the mechanisms of RV adaptation, in particular RV energetics, in patients with pulmonary hypertension (PH) are still not well understood. We aimed to evaluate RV energetics including RV oxidative metabolism, power and efficiency to adapt to increasing pressure overload in patients with PH using ¹¹C-acetate PET.

Methods

In this prospective study, 27 patients with WHO functional class II/III PH (mean pulmonary arterial pressure 39.8?±?13.5 mmHg) and 9 healthy individuals underwent ¹¹C-acetate PET. ¹¹C-acetate PET was used to simultaneously measure oxidative metabolism (k _mono) for the left ventricle (LV) and RV. LV and RV efficiency were also calculated.

Results

The RV ejection fraction in PH patients was lower than in controls (p?=?0.0054). There was no statistically significant difference in LV k _mono (p?=?0.09). In contrast, PH patients showed higher RV k _mono than did controls (0.050?±?0.009 min^?1 vs. 0.030?±?0.006 min^?1, p?<?0.0001). PH patients exhibited significantly increased RV power (p?<?0.001) and hence increased RV efficiency compared to controls (0.40?±?0.14 vs. 0.017?±?0.12 mmHg·mL·min/g, p?=?0.001).

Conclusion

The RV oxidative metabolic rate was increased in patients with PH. Patients with WHO functional class II/III PH also had increased RV power and efficiency. These findings may indicate a myocardial energetics adaptation response to increasing pulmonary arterial pressure.     

特发性肺动脉高压与先天性心脏病相关肺动脉高压患者右心室心肌葡萄糖代谢的比较研究

目的:比较分析特发性肺动脉高压（IPAH）与先天性心脏病相关肺动脉高压（PAH-CHD）患者右心室心肌葡萄糖代谢的差异。方法:选取2016年11月至2018年12月在中国医学科学院北京协和医学院阜外医院确诊的26例IPAH患者（IPAH组）[女性17例、男性9例,年龄（28.23±8.92）岁]和16例PAH-CHD患...     

Native myocardial T1 mapping in pulmonary hypertension: correlations with cardiac function and hemodynamics

Objectives

To analyze alterations in left ventricular (LV) myocardial T1 times in patients with pulmonary hypertension (PH) and to investigate their associations with ventricular function, mass, geometry and hemodynamics.

Methods

Fifty-eight patients with suspected PH underwent right heart catheterization (RHC) and 3T cardiac magnetic resonance imaging. Ventricular function, geometry and mass were derived from cine real-time short-axis images. Myocardial T1 maps were acquired by a prototype modified Look-Locker inversion-recovery sequence in short-axis orientations. LV global, segmental and ventricular insertion point (VIP) T1 times were evaluated manually and corrected for blood T1.

Results

Septal, lateral, global and VIP T1 times were significantly higher in PH than in non-PH subjects (septal, 1249?±?58 ms vs. 1186?±?33 ms, p?<?0.0001; lateral, 1190?±?45 ms vs. 1150?±?33 ms, p?=?0.0003; global, 1220?±?52 ms vs. 1171?±?29 ms, p?<?0.0001; VIP, 1298?±?78 ms vs. 1193?±?31 ms, p?<?0.0001). In PH, LV eccentricity index was the strongest linear predictor of VIP T1 (r?=?0.72). Septal, lateral and global T1 showed strong correlations with VIP T1 (r?=?0.81, r?=?0.59 and r?=?0.75, respectively).

Conclusions

In patients with PH, T1 times in VIPs and in the entire LV myocardium are elevated. LV eccentricity strongly correlates with VIP T1 time, which in turn is strongly associated with T1 time changes in the entire LV myocardium.

Key Points

? Native T1 mapping detects left ventricular myocardial alterations in pulmonary hypertension ? In pulmonary hypertension, native T1 times at ventricular insertion points are increased ? These T1 times correlate strongly with left ventricular eccentricity ? In pulmonary hypertension, global and segmental myocardial T1 times are increased ? Global, segmental and ventricular insertion point T1 times are strongly correlated

     

Diagnostic accuracy of contrast-enhanced MR angiography and unenhanced proton MR imaging compared with CT pulmonary angiography in chronic thromboembolic pulmonary hypertension

Objective

To evaluate the diagnostic accuracy of contrast-enhanced MR angiography (CE-MRA) and the added benefit of unenhanced proton MR angiography compared with CT pulmonary angiography (CTPA) in patients with chronic thromboembolic disease (CTE).

Methods

A 2?year retrospective study of 53 patients with chronic thromboembolic pulmonary hypertension who underwent CTPA and MRI for suspected pulmonary hypertension and a control group of 36 patients with no CT evidence of pulmonary embolism. The MRI was evaluated for CTE and the combined diagnostic accuracy of ce-MRA and unenhanced proton MRA was determined. CE-MRA generated lung perfusion maps were also assessed.

Results

The overall sensitivity and specificity of CE-MRA in diagnosing proximal and distal CTE were 98% and 94%, respectively. The sensitivity improved from 50% to 88% for central vessel disease when CE-MRA images were analysed with unenhanced proton MRA. The CE-MRA identified more stenoses (29/18), post-stenosis dilatation (23/7) and occlusions (37/29) compared with CTPA. The CE-MRA perfusion images showed a sensitivity of 92% for diagnosing CTE.

Conclusion

CE-MRA has high sensitivity and specificity for diagnosing CTE. The sensitivity of CE-MRA for visualisation of adherent central and lobar thrombus significantly improves with the addition of unenhanced proton MRA which delineates the vessel wall.     

Capability of differentiating smokers with normal pulmonary function from COPD patients: a comparison of CT pulmonary volume analysis and MR perfusion imaging

Objective

To compare CT volume analysis with MR perfusion imaging in differentiating smokers with normal pulmonary function (controls) from COPD patients.

Methods

Sixty-two COPD patients and 17 controls were included. The total lung volume (TLV), total emphysema volume (TEV) and emphysema index (EI) were quantified by CT. MR perfusion evaluated positive enhancement integral (PEI), maximum slope of increase (MSI), maximum slope of decrease (MSD), signal enhancement ratio (SER) and signal intensity ratio (R_SI) of perfusion defects to normal lung.

Results

There were 19 class I, 17 class II, 14 class III and 12 class IV COPD patients. No differences were observed in TLV, TEV and EI between control and class I COPD. The control was different from class II, III and IV COPD in TEV and EI. The control was different from each class of COPD in R_SI, MSI, PEI and MSD. Differences were found in R_SI between class I and III, I and IV, and II and IV COPD. Amongst controls, MR detected perfusion defects more frequently than CT detected emphysema.

Conclusions

Compared with CT, MR perfusion imaging shows higher potential to distinguish controls from mild COPD and appears more sensitive in identifying abnormalities amongst smokers with normal pulmonary function (controls).

Key Points

? Detailed information is needed to diagnose chronic obstructive pulmonary disease. ? High-resolution CT provides detailed anatomical and quantitative information. ? Magnetic resonance imaging is demonstrating increasing potential in pulmonary function imaging. ? MR perfusion can distinguish mild COPD patients from controls. ? MRI appears more sensitive than CT in identifying early abnormalities amongst controls.     

Dual-energy CT perfusion and angiography in chronic thromboembolic pulmonary hypertension: diagnostic accuracy and concordance with radionuclide scintigraphy

Objectives

To evaluate the diagnostic accuracy of dual-energy computed tomography (DECT) perfusion and angiography versus ventilation/perfusion (V/Q) scintigraphy in chronic thromboembolic pulmonary hypertension (CTEPH), and to assess the per-segment concordance rate of DECT and scintigraphy.

Methods

Forty consecutive patients with proven pulmonary hypertension underwent V/Q scintigraphy and DECT perfusion and angiography. Each imaging technique was assessed for the location of segmental defects. Diagnosis of CTEPH was established when at least one segmental perfusion defect was detected by scintigraphy. Diagnostic accuracy of DECT perfusion and angiography was assessed and compared with scintigraphy. In CTEPH patients, the per-segment concordance between scintigraphy and DECT perfusion/angiography was calculated.

Results

Fourteen patients were diagnosed with CTEPH and 26 with other aetiologies. DECT perfusion and angiography correctly identified all CTEPH patients with sensitivity/specificity values of 1/0.92 and 1/0.93, respectively. At a segmental level, DECT perfusion showed moderate agreement (κ?=?0.44) with scintigraphy. Agreement between CT angiography and scintigraphy ranged from fair (κ?=?0.31) to slight (κ?=?0.09) depending on whether completely or partially occlusive patterns were considered, respectively.

Conclusions

Both DECT perfusion and angiography show satisfactory performance for the diagnosis of CTEPH. DECT perfusion is more accurate than angiography at identifying the segmental location of abnormalities.

Key Points

? Chronic thromboembolic pulmonary hypertension (CTEPH) is potentially treatable by surgery. ? Dual-energy computed tomography (DECT) allows angiography and perfusion using a single acquisition. ? Both DECT perfusion and angiography showed satisfactory diagnostic performance in CTEPH. ? DECT perfusion was more accurate than angiography in identifying segmental abnormalities.     

Bronchial artery embolization for the treatment of haemoptysis in pulmonary hypertension

Purpose

To test the efficacy of bronchial artery embolization (BAE) to treat haemoptysis in pulmonary hypertension (PH).

Methods

33 patients were treated by BAE for haemoptysis associated with PH (PH group = 21) or non-associated with PH (control group = 12). The details of procedure, outcome, and rate of relapse were compared between the two groups. Within the PH group, the comparison was operated between subjects with congenital heart disease-associated pulmonary artery hypertension (CHD-APAH subgroup = 12) and non-CHD (non-CHD-APAH subgroup = 9).

Results

The rate of relapse at 30 and 90-days was similar between the PH group and control group. BAE in the PH group was more challenging (median 2 arteries embolized per procedure) compared to the control group (median 1 artery embolized per procedure; p = 0.001). Bleeding arteries were more heterogeneous in the PH group, while a single right bronchial artery was the only clinical finding in 66.7% of controls (p = 0.001). Within the PH group, the CHD subgroup showed higher survival rate compared to the non-CHD-APAH group (p = 0.007).

Conclusion

BAE is effective and safe for the treatment of haemoptysis in PH, yet more challenging than other conditions. In PH-associated haemoptysis, BAE provides higher survival rate for subjects with PH associated with CHD.

     

Significance of pulmonary nodules in patients with colorectal cancer

Objectives

Radiographically small pulmonary nodules (PNs) in patients with colorectal cancer are troublesome because their discovery raises concern about metastases. This study sought to establish the appropriate timing of radiological follow-up for PNs detected at initial staging evaluation of colorectal carcinoma patients.

Methods

The medical records of 376 consecutive colorectal cancer patients who underwent curative surgery and had baseline and follow-up chest X-rays (CXR) and computed tomography (CT) were reviewed.

Results

The study included 92 patients who had all CXR and chest CT available for review, at least one PN found on baseline imaging, and no synchronous neoplasms. On baseline chest CT, these 92 patients had 170 PNs altogether and 77 (45.2?%) of them were greater than 5?mm in size. Baseline CXR detected 13 PNs in 12 patients and all but 2 were larger than 5?mm. Nodule size greater than 5?mm and irregular margins were predictors of nodule growth. The mean doubling time of 24/170 (14.1?%) growing PNs was about 4?months.

Conclusions

Our findings suggest that baseline and follow-up CXR are pointless, and short-interval CT follow-up is warranted when PNs larger than 5?mm with irregular margins are detected on preoperative chest CT.

Key Points

? Pulmonary nodules in colorectal cancer patients raise concern about metastasis. ? Baseline and follow-up chest X-ray in colorectal cancer can be abandoned. ? CT is the best technique for assessing PNs in colorectal cancer. ? Short-interval CT follow-up advisable for PNs larger than 5?mm with irregular margins.     

Analysis of the impact of digital tomosynthesis on the radiological investigation of patients with suspected pulmonary lesions on chest radiography

Objective

To assess the impact of digital tomosynthesis (DTS) on the radiological investigation of patients with suspected pulmonary lesions on chest radiography (CXR).

Methods

Three hundred thirty-nine patients (200 male; age, 71.19?±?11.9?years) with suspected pulmonary lesion(s) on CXR underwent DTS. Two readers prospectively analysed CXR and DTS images, and recorded their diagnostic confidence: 1 or 2?=?definite or probable benign lesion or pseudolesion deserving no further diagnostic workup; 3?=?indeterminate; 4 or 5?=?probable or definite pulmonary lesion deserving further diagnostic workup by computed tomography (CT). Imaging follow-up by CT (n?=?76 patients), CXR (n?=?256) or histology (n?=?7) was the reference standard.

Results

DTS resolved doubtful CXR findings in 256/339 (76?%) patients, while 83/339 (24?%) patients proceeded to CT. The mean interpretation time for DTS (mean?±?SD, 220?±?40?s) was higher (P?Conclusions DTS avoided the need for CT in about three-quarters of patients with a slight increase in the interpretation time and effective dose compared to CXR.

Key Points

? Digital tomosynthesis (DTS) improves the diagnostic confidence of chest radiography (CXR) ? DTS reduces the need for CT for a suspected pulmonary lesion ? DTS only imparts a radiation dose of around two CXRs ? DTS takes longer to interpret than conventional chest radiography     

Comparison of image quality and radiation dose of different pulmonary CTA protocols on a 128-slice CT: high-pitch dual source CT, dual energy CT and conventional spiral CT

Objectives

To compare image quality and radiation dose of high-pitch dual-source computed tomography (DSCT), dual energy CT (DECT) and conventional single-source spiral CT (SCT) for pulmonary CT angiography (CTA) on a 128-slice CT system.

Methods

Pulmonary CTA was performed with five protocols: high-pitch DSCT (100?kV), high-pitch DSCT (120?kV), DECT (100/140?kV), SCT (100?kV), and SCT (120?kV). For each protocol, 30 sex, age, and body-mass-index (mean 25.3?kg/m²) matched patients were identified. Retrospectively, two observers subjectively assessed image quality, measured CT attenuation (HU±SD) at seven central and peripheral levels, and calculated signal-to-noise-ratio (SNR) and contrast-to-noise-ratio (CNR). Radiation exposure parameters (CTDIvol and DLP) were compared.

Results

Subjective image quality was rated good to excellent in >92% (>138/150) with an interobserver agreement of 91.4%. The five protocols did not significantly differ in image quality, neither by subjective, nor by objective measures (SNR, CNR). By contrast, radiation exposure differed between protocols: significant lower radiation was achieved by using high-pitch DSCT at 100?kV (p?Conclusions SCT, high-pitch DSCT, and DECT protocols techniques result in similar subjective and objective image quality, but radiation exposure was significantly lower with high-pitch DSCT at 100?kV.

Key Points

• New CT protocols show promising results in pulmonary embolism assessment.
• High-pitch dual-source CT (DSCT) at 100?kV provides radiation dose savings for pulmonary CTA.
• High-pitch DSCT at 100?kV maintains diagnostic image quality for pulmonary CTA.
• Dual energy CT uses more radiation but also provides lung perfusion evaluation.
• Whether the additional perfusion data is worth the extra radiation remains undetermined.

     

Morphological measurements in computed tomography correlate with airflow obstruction in chronic obstructive pulmonary disease: systematic review and meta-analysis

Objectives

To determine the correlation between CT measurements of emphysema or peripheral airways and airflow obstruction in chronic obstructive pulmonary disease (COPD).

Methods

PubMed, Embase and Web of Knowledge were searched from 1976 to 2011. Two reviewers independently screened 1,763 citations to identify articles that correlated CT measurements to airflow obstruction parameters of the pulmonary function test in COPD patients, rated study quality and extracted information. Three CT measurements were accessed: lung attenuation area percentage?1 %pred) and FEV₁ divided by the forced volume vital capacity.

Results

Seventy-nine articles (9,559 participants) were included in the systematic review, demonstrating different methodologies, measurements and CT airflow obstruction correlations. There were 15 high-quality articles (2,095 participants) in the meta-analysis. The absolute pooled correlation coefficients ranged from 0.48 (95?% CI, 0.40 to 0.54) to 0.65 (0.58 to 0.71) for inspiratory CT and 0.64 (0.53 to 0.72) to 0.73 (0.63 to 0.80) for expiratory CT.

Conclusions

CT measurements of emphysema or peripheral airways are significantly related to airflow obstruction in COPD patients. CT provides a morphological method to investigate airway obstruction in COPD.

Key Points

? Computed tomography is widely performed in patients with chronic obstructive pulmonary disease (COPD) ? CT provides quantitative morphological methods to investigate airflow obstruction in COPD ? CT measurements correlate significantly with the degree of airflow obstruction in COPD ? Expiratory CT measurements correlate more strongly with airflow obstruction than inspiratory CT ? Low-dose CT decreases the radiation dose for diagnosis and quantitative emphysema evaluation     

CT halo sign as an imaging marker for response to adoptive cell therapy in metastatic melanoma with pulmonary metastases

Objectives

The halo sign refers to a zone of ground-glass attenuation surrounding a pulmonary nodule. Pulmonary metastatic nodules exhibiting a halo sign are seen mainly in hypervascular tumours. We describe the appearance of a halo sign following treatment of adoptive transfer of autologous tumour-infiltrating lymphocytes (TIL) to melanoma patients with lung metastases.

Methods

The study included 29 melanoma patients with pulmonary metastases who received TIL therapy. Pre- and post-treatment chest CTs were retrospectively reviewed for the presence of a halo sign and its correlation with therapeutic response.

Results

A pulmonary halo sign was not seen in any pre-treatment CT. It was observed in four of 12 patients who responded to the therapy but not in those who failed to respond. Significant differences were found between response ratio in patients in whom post-TIL halo sign appeared compared with those without the halo sign (p?=?0.02).

Conclusions

The appearance of a CT halo sign in melanoma with lung metastases following TIL therapy may indicate antitumoral effect and a good response to therapy. Our findings emphasize the importance of applying new assessment criteria for immunological anticancer therapies.

Key Points

? Tumour-infiltrating lymphocytes (TIL) in melanoma patients is a promising novel immunotherapy ? Post-therapy pulmonary halo sign appeared in one-third of TIL responders ? Pulmonary halo sign may serve as an imaging marker for antitumoral activity     

Cardiac MR-assessed hemodynamic changes in pulmonary arterial hypertension and their relation to pulmonary artery pressure

Purpose

To demonstrate the hemodynamic changes of pulmonary arterial hypertension using cardiac MRI and to determine which parameters are best representative of the pulmonary artery pressure.