Higher agreement between readers with deep learning CAD software for reporting pulmonary nodules on CT

Purpose

The aim was to evaluate the impact of CAD software on the pulmonary nodule management recommendations of radiologists in a cohort of patients with incidentally detected nodules on CT.

Methods

For this retrospective study, two radiologists independently assessed 50 chest CT cases for pulmonary nodules to determine the appropriate management recommendation, twice, unaided and aided by CAD with a 6-month washout period. Management recommendations were given in a 4-point grade based on the BTS guidelines. Both reading sessions were recorded to determine the reading times per case. A reduction in reading times per session was tested with a one-tailed paired t-test, and a linear weighted kappa was calculated to assess interobserver agreement.

Results

The mean age of the included patients was 65.0 ± 10.9. Twenty patients were male (40 %). For both readers 1 and 2, a significant reduction of reading time was observed of 33.4 % and 42.6 % (p < 0.001, p < 0.001). The linear weighted kappa between readers unaided was 0.61. Readers showed a better agreement with the aid of CAD, namely by a kappa of 0.84. The mean reading time per case was 226.4 ± 113.2 and 320.8 ± 164.2 s unaided and 150.8 ± 74.2 and 184.2 ± 125.3 s aided by CAD software for readers 1 and 2, respectively.

Conclusion

A dedicated CAD system for aiding in pulmonary nodule reporting may help improve the uniformity of management recommendations in clinical practice.

Is Fatty Liver Associated with Increased Mortality and Morbidity in Coronavirus Disease 2019 (COVID-19) Pneumonia?

BACKGROUND

Fatty liver has been shown to be associated with severe COVID-19 disease without any impact on mortality. This is based on heterogenous criteria for defining both fatty liver as well as the severity parameters. This study aimed to study the impact of fatty liver on the mortality and severity of disease in patients with COVID-19 pneumonia.

METHODS

In a case control study design, patients with COVID-19 pneumonia (COVID-19 computed tomography severity index [CTSI] on high-resolution computed tomography chest of ≥1) with fatty liver (defined as liver to spleen attenuation index ≤5 on noncontrast computed tomography cuts of upper abdomen) were compared with those without fatty liver. The primary outcome measure was in-hospital mortality, and the secondary outcome measures were CTSI score, need for intensive care unit (ICU) care, need for ventilatory support, duration of ICU stay, and duration of hospital stay.

RESULTS

Of 446 patients with COVID-19 pneumonia, 289 (64.7%)admitted to Max Hospital, Saket, India, between January 1, 2021, and October 30, 2021, had fatty liver. Fifty-nine of 446 patients died during the index admission. In-hospital mortality was not different between patients with fatty liver (38 [13.24%]) or without fatty liver (21 [13.81%]). COVID-19 CTSI score was found to be significantly higher among patients who had fatty liver (13.40 [5.16] vs 11.81 [5.50]; P = 0.003). There was no difference in the requirement of ICU (94 [32%] vs 62 [39.49%]; P = 0.752), requirement of ventilatory support (27 [9.34%] vs 14 [8.91%]; P = 0.385), duration of ICU stay (8.29 [6.87] vs 7.07 [5.71] days; P = 0.208), and duration of hospital stay (10.10 [7.14] vs 10.69 [8.13] days; P = 0.430) between the groups with fatty liver or no fatty liver. Similarly, no difference was found in primary or secondary outcomes measure between the group with severe fatty liver vs mild/moderate or no fatty liver. High total leucocyte count and Fibrosis-4 (FIB-4) index were independently associated with mortality.

CONCLUSIONS

Fatty liver may not be associated with increased mortality or clinical morbidity in patients who have COVID-19 pneumonia.

Dual energy imaging in cardiothoracic pathologies: A primer for radiologists and clinicians

Recent advances in dual-energy imaging techniques, dual-energy subtraction radiography (DESR) and dual-energy CT (DECT), offer new and useful additional information to conventional imaging, thus improving assessment of cardiothoracic abnormalities. DESR facilitates detection and characterization of pulmonary nodules. Other advantages of DESR include better depiction of pleural, lung parenchymal, airway and chest wall abnormalities, detection of foreign bodies and indwelling devices, improved visualization of cardiac and coronary artery calcifications helping in risk stratification of coronary artery disease, and diagnosing conditions like constrictive pericarditis and valvular stenosis. Commercially available DECT approaches are classified into emission based (dual rotation/spin, dual source, rapid kilovoltage switching and split beam) and detector-based (dual layer) systems. DECT provide several specialized image reconstructions. Virtual non-contrast images (VNC) allow for radiation dose reduction by obviating need for true non contrast images, low energy virtual mono-energetic images (VMI) boost contrast enhancement and help in salvaging otherwise non-diagnostic vascular studies, high energy VMI reduce beam hardening artifacts from metallic hardware or dense contrast material, and iodine density images allow quantitative and qualitative assessment of enhancement/iodine distribution. The large amount of data generated by DECT can affect interpreting physician efficiency but also limit clinical adoption of the technology. Optimization of the existing workflow and streamlining the integration between post-processing software and picture archiving and communication system (PACS) is therefore warranted.

Risk of in-hospital death associated with Covid-19 lung consolidations on chest computed tomography - A novel translational approach using a radiation oncology contour software

•

Each unit percent of lung involved resulted in a 3.6 % increase in the chance of in-hospital mortality (OR 1.036, P = 0.007).

•

The quantitative lung consolidation was also associated with ocurrence of major adverse hospital events (OR 1.025. P = 0.002).

•

These associations between lung involvement and outcomes were statistically significant after adjusting for relevant clinical parameters.

Purpose

To determine whether the percentage of lung involvement at the initial chest computed tomography (CT) is related to the subsequent risk of in-hospital death in patients with coronavirus disease-2019 (Covid-19).

Materials and methods

Using a cohort of 154 laboratory-confirmed Covid-19 pneumonia cases that underwent chest CT between February and April 2020, we performed a volumetric analysis of the lung opacities. The impact of relative lung involvement on outcomes was evaluated using multivariate logistic regression. The primary endpoint was the in-hospital mortality rate. The secondary endpoint was major adverse hospitalization events (intensive care unit admission, use of mechanical ventilation, or death).

Results

The median age of the patients was 65 years: 50.6 % were male, and 36.4 % had a history of smoking. The median relative lung involvement was 28.8 % (interquartile range 9.5–50.3). The overall in-hospital mortality rate was 16.2 %. Thirty-six (26.3 %) patients were intubated. After adjusting for significant clinical factors, there was a 3.6 % increase in the chance of in-hospital mortality (OR 1.036; 95 % confidence interval, 1.010–1.063; P = 0.007) and a 2.5 % increase in major adverse hospital events (OR 1.025; 95 % confidence interval, 1.009–1.042; P = 0.002) per percentage unit of lung involvement. Advanced age (P = 0.013), DNR/DNI status at admission (P < 0.001) and smoking (P = 0.008) also increased in-hospital mortality. Older (P = 0.032) and male patients (P = 0.026) had an increased probability of major adverse hospitalization events.

Conclusions

Among patients hospitalized with Covid-19, more lung consolidation on chest CT increases the risk of in-hospital death, independently of confounding clinical factors.

Towards establishment of diagnostic reference levels based on clinical indication in the state of Qatar

OBJECTIVES

The objectives of this study were to: 1) evaluate patient radiation exposure in CT and 2) establish CT Diagnostic Reference Levels (DRL)s based on clinical indication (CI) in Qatar.

MATERIALS AND METHODS

Patient data for 13 CIs were collected using specially designed collection forms from the dose management software (DMS) of Hamad Medical Corporation (HMC), the main Qatar healthcare provider. The methodology described in the International Commission on Radiological Protection (ICRP) Report 135 was followed to establish national clinical DRLs in terms of Volumetric Computed Tomography Dose Index (CTDIvol) and total Dose Length Product (DLPt). Effective dose (Ef) was estimated by DMS using DLPt and appropriate conversion factors and was analyzed for comparison purposes.

RESULTS

Data were retrospectively collected for 896 adult patients undergoing CT examinations in 4 hospitals and 7 CT scanners. CT for Diffuse infiltrative lung disease imparted the lowest radiation in terms of CTDIvol (5 mGy), DLPt (181 mGy.cm) and Ef (3.6 mSv). Total body CT for severe trauma imparted the highest DLPt (3137 mGy.cm) and Ef (38.6 mSv) of all CIs with a CTDIvol of 15 mGy. Rounded Third quartile CTDIvol and DLPt values were defined as the Qatar CT clinical DRLs. Comparison was limited due to sparse international literature. When this was possible data were lower or comparable with other studies.

CONCLUSIONS

This is the first study reporting national clinical DRLs in Asia and second one internationally after UK. For accurate comparison between studies, systemized CI nomenclature must be followed by researchers.

Intracranial migration of intraocular silicone oil following repetitive head trauma

Intraocular injection of silicone oil as a tamponade agent is a commonly used technique for the treatment of retinal detachment. An incompletely understood phenomenon which can occur after injection is the migration of silicone oil from the vitreous chamber to the intracranial space. Because the appearance of silicone oil can mimic hemorrhage or other pathologies on CT and MRI, careful comparison with prior studies is necessary to avoid unnecessary follow-up studies. We report a case of intracranial migration of intraocular silicone oil following repetitive head trauma.

Digital subtract angiography and lipiodol deposits following embolization in cirrhotic nodules of LIRADS category ≥3

PURPOSE

To assess the correlation between Liver Imaging Reporting and Data System (LIRADS) and digital substract angiography (DSA) and lipiodol deposits in cirrhotic nodules of LIRADS category ≥3 receiving interventional treatment.

METHODS

From June 2014 to June 2016, patients with cirrhotic nodules were identified retrospectively and MR images were reviewed by sub-specialty radiologists according to modified LIRADS v2014. Correlation between nodules of LIRADS category ≥3 and DSA findings and lipiodol deposits were analyzed.

RESULTS

71 cirrhotic nodules were evaluated in 33 patients. 39/71 nodules were classified as LR-3, 9/71 nodules were categorized as LR-4, 23/71 nodules were grouped into LR-5. 43 nodules presented positive DSA, 37 nodules showed presence of lipiodol deposits during follow up. With the upgrade of LIRADS category of cirrhotic nodules, DSA and lipiodol deposits became more conspicuous. Spearman analysis demonstrated positive correlations between LIRADS and DSA (r = 0.567, P = 0.000) as well as LIRADS and lipiodol deposits (r = 0.616, P = 0.000). ROC analysis revealed a cut-off value of LR ≥ 4 resulted in a sensitivity of 67.4% and specificity of 89.3% in predicting positive DSA (RUC = 0.799, P ＜ 0.0001), and a sensitivity of 75.7% and specificity of 88.2% in predicting lipiodol deposits (RUC = 0.818, P ＜ 0.0001). Of 39 lesions of LR-3, 64.1% (25/39) showed negative DSA, and 76.9% (30/39) showed absence of lipiodol deposits during follow up. Logistic regression analysis identified arterial enhancement (OR = 26.837, P = 0.002) and lesion size (OR = 1.325, P = 0.022) were independently associated with positive DSA in nodule of LIRADS category ≥3, while no factors were associated with lipiodol deposits.

CONCLUSION

The LIRADS can be used to predict DSA findings and lipiodol deposits in nodules with LIRADS score 3 and above. LIRADS 3 nodules tend to be DSA-negative and have less lipiodol deposits. DSA and lipiodol deposits become more conspicuous in nodules from LIRADS 3 to 5.

Filter tilting and retrievability of the Celect and Denali inferior vena cava filters using propensity score-matching analysis

Purpose

To assess the filter tilting and outcomes of the Celect and Denali inferior vena cava (IVC) filters by using a propensity score-matching analysis.

Materials and methods

From January 2009 to November 2017, 181 Celect and 58 Denali filters were inserted in our institution. To assess filter tilt, filter tip abutment or penetration of the IVC wall, and retrieval outcome, independent variables, including age, sex, IVC long diameter, IVC angulation, and proximity of the filter to renal vein insertion, were entered in the propensity model. Comparative analyses were performed before and after propensity score-matching analysis.

Results

Thirty-one patients were enrolled in each group for the final propensity score-matching analysis. The mean filter indwelling time was not significantly different between the groups (26 ± 22 days in Celect and 27 ± 23 days in Denali). After propensity score adjustment, the mean degree of filter tilt was higher in the Celect group (9.5° ± 7.4° vs 5.6° ± 6.7°). Filter tip abutment or penetration of the IVC wall was more common in the Celect group (39% [12/31, abutment: 12, penetration: 0] vs 13% [4/31, abutment: 3, penetration: 1]). The retrieval outcomes were not significantly different before and after propensity score adjustment in both filters.

Conclusion

The Denali IVC filter showed less tilt and low rate of filter tip abutment to the IVC wall after propensity score-matching analysis. The retrieval rate was not significantly different in the short-term filter indwelling setting. More large-scale, long-term follow-up studies are needed to verify these results.

Is external compression on the IVC a risk factor for IVC filter abutment? A single center experience of 141 infrarenal celect filter insertions

•

Tilt of the IVC filter is the major problem for the filter retrieval rate.

•

External compression on the IVC wall can cause filter tilting.

•

Identifying external compression factors are necessary before insertion of IVC filter.

Objectives

To investigate risk factors for inferior vena cava (IVC) filter abutment, including external compression on the IVC wall, using venous phase computed tomography (CT).

Methods

One-hundred-forty-one cases of Celect IVC filter insertion between January 2009 and April 2017 were retrospectively reviewed. On pre-procedural CT, IVC diameter and morphological classifications were measured. Filter tilt angle, IVC angle, vertical position, and filter tip abutment to the IVC wall were analyzed on post-procedural CT. IVC compression was examined by pre- and post-procedural CT analysis. Multiple logistic regression analysis was conducted to find factors related to IVC filter abutment.

Results

Of 141 IVC filter insertion cases, 52 were classified in the filter tip abutment group and 89 in the non-abutting group. IVC tilt angle (11.7 ± 5.5° vs. 6.4 ± 5.4°), presence of external compression (14/52, 27% vs. 9/89, 9%), and IVC morphology were different between the groups (p < 0.05). In multiple logistic regression analysis, filter-tilt angle over 9.25° and external compression on the IVC were found to be independent predictors of filter abutment (odds ratios: 4.56, 10.18, respectively).

Conclusion

IVC filter tilt, external compression on IVC wall, and IVC morphology were significantly different between the filter tip abutment and non-abutment groups. External compression and filter tilt over 9.25° were risk factors for filter tip abutment in multiple logistic regression analysis. By identifying these factors, we may be able to reduce filter tilting by preventing the filter from being deployed in a dangerous area.