Chest radiography or computed tomography for COVID-19 pneumonia? Comparative study in a simulated triage setting.

INTRODUCTION: For the management of patients referred to respiratory triage during the early stages of the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic, either chest radiography or computed tomography (CT) were used as first-line diagnostic tools. The aim of this study was to compare the impact on the triage, diagnosis and prognosis of patients with suspected COVID-19 when clinical decisions are derived from reconstructed chest radiography or from CT. METHODS: We reconstructed chest radiographs from high-resolution CT (HRCT) scans. Five clinical observers independently reviewed clinical charts of 300 subjects with suspected COVID-19 pneumonia, integrated with either a reconstructed chest radiography or HRCT report in two consecutive blinded and randomised sessions: clinical decisions were recorded for each session. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and prognostic value were compared between reconstructed chest radiography and HRCT. The best radiological integration was also examined to develop an optimised respiratory triage algorithm. RESULTS: Interobserver agreement was fair (Kendall's W=0.365, p<0.001) by the reconstructed chest radiography-based protocol and good (Kendall's W=0.654, p<0.001) by the CT-based protocol. NPV assisted by reconstructed chest radiography (31.4%) was lower than that of HRCT (77.9%). In case of indeterminate or typical radiological appearance for COVID-19 pneumonia, extent of disease on reconstructed chest radiography or HRCT were the only two imaging variables that were similarly linked to mortality by adjusted multivariable models CONCLUSIONS: The present findings suggest that clinical triage is safely assisted by chest radiography. An integrated algorithm using first-line chest radiography and contingent use of HRCT can help optimise management and prognostication of COVID-19.

CT angiography for pulmonary embolism in the emergency department: investigation of a protocol by 20 ml of high-concentration contrast medium.

OBJECTIVES: To retrospectively compare semi-qualitative and quantitative CT pulmonary angiography (CTPAs) image metrics testing diagnostic performance between protocols performed by 20 or 40 ml of contrast medium (CM) in patients with suspected pulmonary embolism (PE). METHODS: A total of 102 CTPAs performed by 20 ml (ultra-low volume: ULV) and 74 CTPAs performed by 40 ml (low volume: LV) protocol for the diagnosis of clinically suspected PE performed between October 2012 and September 2013 were retrieved. High-concentration CM (Iomeprol 400 mgI/ml) was injected at 3 ml/s (iodine delivery rate 1.2 mgI/s). Two radiologists (blinded and independent) semi-qualitatively scored vascular enhancement and image noise according to a five-point visual scoring system. Quantitative analysis was performed by regions of interest quantifying densitometric parameters, such as central and peripheral pulmonary arteries vascular contrast enhancement (CE, threshold for diagnostic CE ≥ 250 HU), and metrics for image noise. Continuous variables were compared by the Student's t test between groups if normally distributed while categorical variables were analyzed with the Chi-squared test. Interobserver agreement was calculated by the weighted kappa test; correlation coefficients were calculated using Pearson's correlation tests. RESULTS: The semi-qualitative scores for central and peripheral pulmonary arteries vascular CE were sufficient by ULV, yet inferior than LV (p < 0.001). Semi-qualitative image noise was comparable between ULV and LV, and the interobserver agreement was only fair for quality of peripheral vessels. Agreement on nondiagnostic semi-qualitative parameters was seen in 9/102 (8.8%) ULV CTPAs, in particular associated with massive PE (2/9), pleuro-pulmonary abnormalities (5/9) or without major abnormalities (2/9). Quantitative analysis showed that mean CE was lower in ULV group (p < 0.001), though greater than the diagnostic threshold of 250 HU in both groups. CONCLUSIONS: Diagnostic vascular CE (> 250 HU) was obtained in both 20 ml and 40 ml CTPAs. CTPA by 20 ml of CM rendered diagnostic CE for the assessment of pulmonary arteries in patients with clinical suspicion of acute PE. Decreased image quality was mostly associated with massive PE or concomitant pleuro-parenchymal abnormalities.

Pre-surgical assessment of mandibular bone invasion from oral cancer: comparison between different imaging techniques and relevance of radiologist expertise.

PURPOSE: To compare diagnostic performance between computed tomography (CT) and magnetic resonance imaging (MRI) for the detection of bone infiltration from oral cancer, and to test interobserver agreement between radiologists with different expertises. MATERIALS AND METHODS: Pre-surgical CT and MRI were reviewed independently by two radiologists with different expertises in head and neck oncology. A third radiologist reviewed CT and MRI simultaneously. Interobserver agreement was calculated by Cohen test. Association between radiological evidence of bone infiltration and histological reference was tested by Fisher's exact test or Chi-squared test, as appropriate. Receiving operator curve was calculated and area under the curve (AUC) was compared between CT, MRI, and both methods together. RESULTS: Interobserver agreement was moderate: the trainee under-reported periosteal reaction on CT and inferior alveolar canal involvement on MRI. Imaging findings associated with histologic evidence of bone infiltration were: periosteal reaction and cortical erosion on CT; bone marrow involvement, contrast enhancement within bone; and inferior alveolar canal involvement on MRI. Sensitivity of MRI alone (74 %) was higher than CT (52 %). Simultaneous review of CT and MRI showed the highest specificity (91 %), with the increase of diagnostic performance in the subgroup of subjects with positive MRI (AUC = 0.689; p = 0.044). CONCLUSION: Higher expertise allows pre-surgical detection of clinically relevant signs of bone infiltration sensitivity of MRI alone is higher than CT for the detection of bone infiltration from oral cancer. In MRI positive cases, diagnostic integration with combined review of CT and MRI is suggested for optimal diagnostic performance.

Multiparametric MRI in the management of prostate cancer: an update-a narrative review.

The growing interest in multiparametric MRI is leading to important changes in the diagnostic process of prostate cancer. MRI-targeted biopsy is likely to become a standard for the diagnosis of prostate cancer in the next years. Despite it is well known that MRI has no role as a staging technique, it is clear that multiparametric MRI may be of help in active surveillance protocols. Noteworthy, MRI in active surveillance is not recommended, but a proper understanding of its potential may be of help in achieving the goals of a delayed treatment strategy. Moreover, the development of minimally invasive techniques, like laparoscopic and robotic surgery, has led to greater expectations as regard to the functional outcomes of radical prostatectomy. Multiparametric MRI may play a role in planning surgical strategies, with the aim to provide the highest oncologic outcome with a minimal impact on the quality of life. We maintain that a proper anatomic knowledge of prostate lesions may allow the surgeon to achieve a better result in planning as well as in performing surgery and help the surgeon and the patient engage in a shared decision in planning a more effective strategy for prostate cancer control and treatment. This review highlights the advantages and the limitations of multiparametric MRI in prostate cancer diagnosis, in active surveillance and in planning surgery.

High-pitch dual-source CT angiography without ECG-gating for imaging the whole aorta: intraindividual comparison with standard pitch single-source technique without ECG gating.

PURPOSE: We aimed to perform intraindividual comparison of computed tomography (CT) parameters, image quality, and radiation exposure between standard CT angiography (CTA) and high-pitch dual source (DS)-CTA, in subjects undergoing serial CTA of thoracoabdominal aorta. METHODS: Eighteen subjects with thoracoabdominal CTA by standard technique and high-pitch DS-CTA technique within 6 months of each other were retrieved for intraindividual comparison of image quality in thoracic and abdominal aorta. Quantitative analysis was performed by comparison of mean aortic attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Qualitative analysis was performed by visual assessment of motion artifacts and diagnostic confidence. Radiation exposure was quantified by effective dose. Image quality was apportioned to radiation exposure by means of figure of merit. RESULTS: Mean aortic attenuation and noise were higher in high-pitch DS-CTA of thoracoabdominal aorta, whereas SNR and CNR were similar in thoracic aorta and significantly lower in high-pitch DS-CTA of abdominal aorta (P = 0.024 and P = 0.016). High-pitch DS-CTA was significantly better in the first segment of thoracic aorta. Effective dose was reduced by 72% in high-pitch DS-CTA. CONCLUSION: High-pitch DS-CTA without electrocardiography-gating is an effective technique for imaging aorta with very low radiation exposure and with significant reduction of motion artifacts in ascending aorta; however, the overall quality of high-pitch DS-CTA in abdominal aorta is lower than standard CTA.

An uncommon cause of ascites: uroperitoneum from iatrogenic bladder fistula detected by CT urography.

We report the case of a female who underwent laparoscopic hysterectomy and was referred to the emergency department with massive ascites 10 days later. Anamnestic background and clinical presentation suggested the occurrence of a urinary lesion, which was investigated by CT urography. CT urography with ultra-late excretory phase showed the leakage of iodinated contrast agent from the bladder dome into the peritoneal cavity, as expected in uroperitoneum from iatrogenic bladder laceration. CT cystography is the reference standard for the assessment of bladder leakage; however, this technique is quite invasive, time consuming and does not provide a panoramic overview of the entire excretory system. Conversely, CT urography provides a complete overview of the entire excretory system by means of an optimized protocol with optional ultra-late acquisition to gain adequate bladder distension and depict minor urinary leakage.

Semiautomatic Analysis on Computed Tomography in Locally Advanced or Metastatic Non-Small Cell Lung Cancer: Reproducibility and Prognostic Significance of Unidimensional and 3-dimensional Measurements.

PURPOSE: The aim of the study was to compare both reproducibility and prognostic value of lesion size measurements obtained manually and semiautomatically on computed tomography in advanced non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Manual axial longest diameter, semiautomatic axial longest diameter, and volume of NSCLC lesions were independently analyzed by 4 readers at baseline and after at least 1 cycle of platinum-based chemotherapy. The prognostic value of the proportional change in lesion size between baseline and follow-up CT was evaluated using either RECIST or experimental thresholds derived from the quartiles of the changes as assessed manually or semiautomatically. RESULTS: Semiautomatic axial longest diameter (concordance correlation coefficient [CCC]: 0.980 to 0.987; variation coefficient [VC%]: 6% to 7.3%) and volume (CCC: 0.974 to 0.991; VC%: 5.6% to 9.5%) were more reproducible than manual axial longest diameter (CCC: 0.950 to 0.984; VC%: 6.4% to 11.7%). RECIST categories did not stratify patients with different survival durations. For 3/4 readers, a decrease of ≤ 70% in lesion volume was associated with shorter survival (median survival: 11 mo, P < 0.05; hazard ratio: 5 to 22.2, P < 0.05). CONCLUSIONS: In advanced NSCLC, semiautomatic measures were more reproducible than manual diameter, and volumetric measurement may better predict patient survival.

Non-small cell lung cancer after surgery and chemoradiotherapy: follow-up and response assessment.

The imaging techniques in patients treated for lung cancer may be challenging to interpret. Radiologists are often asked to evaluate computed tomography (CT) scans after surgery, and this interpretation requires an understanding of both the timing and type of the surgical procedure. However, follow-up strategies are still not well defined. The assessment of tumor response to chemoradiotherapy relies on a tight integration of CT and clinical findings. Positron emission tomography-computed tomography (PET-CT) with fluorodeoxyglucose may help to exclude tumor recurrence when the sole CT scan is equivocal. More efforts are needed to validate the tools for volumetric tumor measurement in routine practice and to demonstrate their superiority compared to the Response Evaluation Criteria in Solid Tumors (RECIST). Familiarity with the assessment of lung cancer perfusion is also important because of the increasing use of cytostatic therapy. In this review, we outlined the imaging assessment of tumor recurrence after surgery and the role of CT, magnetic resonance imaging, and PET-CT in the follow-up after chemotherapy, radiotherapy, and radiofrequency ablation.

Long-term surveillance of ground-glass nodules: evidence from the MILD trial.

INTRODUCTION: The purpose of this study was to evaluate the natural evolution of ground-glass nodules (GGNs) in the Multicentric Italian Lung Detection (MILD) trial, which adopted a nonsurgical approach to this subset of lesions. METHODS: From September 2005 to August 2007, 56 consecutive MILD participants with 76 GGNs were identified from 1866 individuals who underwent baseline low-dose computed tomography. The features of GGNs were assessed and compared with the corresponding repeat low-dose computed tomographies after a mean time of 50.26 ± 7.3 months. The GGNs were classified as pure (pGGN) or part-solid (psGGN) GGNs. The average of the maximum and the minimum diameters for both pGGNs and psGGNs and the maximum diameter of the solid portion of psGGNs were manually measured. At follow-up, GGNs were classified as follows: resolved, decreased, stable, or progressed (according to three defined growth patterns). RESULTS: A total of 15 of 48 pGGNs (31.3%) resolved, 4 of 48 (8.3%) decreased in size, 21 of 48 (43.8%) remained stable, and 8 of 48 (16.7%) progressed. Among the psGGNs with a solid component smaller than 5 mm, 3 of 26 (11.5%) resolved, 11 of 26 (42.3%) remained stable, and 12 of 26 (46.2%) progressed. One of the two psGGNs with a solid component larger than 5 mm remained stable, and the other decreased in size. Four lung cancers were detected among the GGN subjects, but only one arose from a psGGN, and was resected in stage Ia. CONCLUSIONS: The progression rate of the GGNs toward clinically relevant disease was extremely low in the MILD trial and supports an active surveillance attitude.