Low-dose liver CT: image quality and diagnostic accuracy of deep learning image reconstruction algorithm

OBJECTIVES

To perform a comprehensive within-subject image quality analysis of abdominal CT examinations reconstructed with DLIR and to evaluate diagnostic accuracy compared to the routinely applied adaptive statistical iterative reconstruction (ASiR-V) algorithm.

MATERIALS AND METHODS

Oncologic patients were prospectively enrolled and underwent contrast-enhanced CT. Images were reconstructed with DLIR with three intensity levels of reconstruction (high, medium, and low) and ASiR-V at strength levels from 10 to 100% with a 10% interval. Three radiologists characterized the lesions and two readers assessed diagnostic accuracy and calculated signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), figure of merit (FOM), and subjective image quality, the latter with a 5-point Likert scale.

RESULTS

Fifty patients (mean age: 70 ± 10 years, 23 men) were enrolled and 130 liver lesions (105 benign lesions, 25 metastases) were identified. DLIR_H achieved the highest SNR and CNR, comparable to ASiR-V 100% (p ≥ .051). DLIR_M returned the highest subjective image quality (score: 5; IQR: 4-5; p ≤ .001) and significant median increase (29%) in FOM (p < .001). Differences in detection were identified only for lesions ≤ 0.5 cm: 32/33 lesions were detected with DLIR_M and 26 lesions were detected with ASiR-V 50% (p = .031). Lesion accuracy of was 93.8% (95% CI: 88.1, 97.3; 122 of 130 lesions) for DLIR and 87.7% (95% CI: 80.8, 92.8; 114 of 130 lesions) for ASiR-V 50%.

CONCLUSIONS

DLIR yields superior image quality and provides higher diagnostic accuracy compared to ASiR-V in the assessment of hypovascular liver lesions, in particular for lesions ≤ 0.5 cm.

CLINICAL RELEVANCE STATEMENT

Deep learning image reconstruction algorithm demonstrates higher diagnostic accuracy compared to iterative reconstruction in the identification of hypovascular liver lesions, especially for lesions ≤ 0.5 cm.

KEY POINTS

• Iterative reconstruction algorithm impacts image texture, with negative effects on diagnostic capabilities. • Medium-strength deep learning image reconstruction algorithm outperforms iterative reconstruction in the diagnostic accuracy of ≤ 0.5 cm hypovascular liver lesions (93.9% vs 78.8%), also granting higher objective and subjective image quality. • Deep learning image reconstruction algorithm can be safely implemented in routine abdominal CT protocols in place of iterative reconstruction.

Radiomics applications in cardiac imaging: a comprehensive review

Radiomics is a new emerging field that includes extraction of metrics and quantification of so-called radiomic features from medical images. The growing importance of radiomics applied to oncology in improving diagnosis, cancer staging and grading, and improved personalized treatment, has been well established; yet, this new analysis technique has still few applications in cardiovascular imaging. Several studies have shown promising results describing how radiomics principles could improve the diagnostic accuracy of coronary computed tomography angiography (CCTA) and magnetic resonance imaging (MRI) in diagnosis, risk stratification, and follow-up of patients with coronary heart disease (CAD), ischemic heart disease (IHD), hypertrophic cardiomyopathy (HCM), hypertensive heart disease (HHD), and many other cardiovascular diseases. Such quantitative approach could be useful to overcome the main limitations of CCTA and MRI in the evaluation of cardiovascular diseases, such as readers' subjectiveness and lack of repeatability. Moreover, this new discipline could potentially overcome some technical problems, namely the need of contrast administration or invasive examinations. Despite such advantages, radiomics is still not applied in clinical routine, due to lack of standardized parameters acquisition, inconsistent radiomic methods, lack of external validation, and different knowledge and experience among the readers. The purpose of this manuscript is to provide a recent update on the status of radiomics clinical applications in cardiovascular imaging.

Iterative Reconstruction: State-of-the-Art and Future Perspectives

ABSTRACT

Image reconstruction processing in computed tomography (CT) has evolved tremendously since its creation, succeeding at optimizing radiation dose while maintaining adequate image quality. Computed tomography vendors have developed and implemented various technical advances, such as automatic noise reduction filters, automatic exposure control, and refined imaging reconstruction algorithms.Focusing on imaging reconstruction, filtered back-projection has represented the standard reconstruction algorithm for over 3 decades, obtaining adequate image quality at standard radiation dose exposures. To overcome filtered back-projection reconstruction flaws in low-dose CT data sets, advanced iterative reconstruction algorithms consisting of either backward projection or both backward and forward projections have been developed, with the goal to enable low-dose CT acquisitions with high image quality. Iterative reconstruction techniques play a key role in routine workflow implementation (eg, screening protocols, vascular and pediatric applications), in quantitative CT imaging applications, and in dose exposure limitation in oncologic patients.Therefore, this review aims to provide an overview of the technical principles and the main clinical application of iterative reconstruction algorithms, focusing on the strengths and weaknesses, in addition to integrating future perspectives in the new era of artificial intelligence.

Deep learning image reconstruction algorithm: impact on image quality in coronary computed tomography angiography

PURPOSE

To perform a comprehensive intraindividual objective and subjective image quality evaluation of coronary CT angiography (CCTA) reconstructed with deep learning image reconstruction (DLIR) and to assess correlation with routinely applied hybrid iterative reconstruction algorithm (ASiR-V).

MATERIAL AND METHODS

Fifty-one patients (29 males) undergoing clinically indicated CCTA from April to December 2021 were prospectively enrolled. Fourteen datasets were reconstructed for each patient: three DLIR strength levels (DLIR_L, DLIR_M, and DLIR_H), ASiR-V from 10% to 100% in 10%-increment, and filtered back-projection (FBP). Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) determined objective image quality. Subjective image quality was assessed with a 4-point Likert scale. Concordance between reconstruction algorithms was assessed by Pearson correlation coefficient.

RESULTS

DLIR algorithm did not impact vascular attenuation (P ≥ 0.374). DLIR_H showed the lowest noise, comparable with ASiR-V 100% (P = 1) and significantly lower than other reconstructions (P ≤ 0.021). DLIR_H achieved the highest objective quality, with SNR and CNR comparable to ASiR-V 100% (P = 0.139 and 0.075, respectively). DLIR_M obtained comparable objective image quality with ASiR-V 80% and 90% (P ≥ 0.281), while achieved the highest subjective image quality (4, IQR: 4-4; P ≤ 0.001). DLIR and ASiR-V datasets returned a very strong correlation in the assessment of CAD (r = 0.874, P = 0.001).

CONCLUSION

DLIR_M significantly improves CCTA image quality and has very strong correlation with routinely applied ASiR-V 50% dataset in the diagnosis of CAD.

Adrenal Lesions: A Review of Imaging

Adrenal lesions are frequently incidentally diagnosed during investigations for other clinical conditions. Despite being usually benign, nonfunctioning, and silent, they can occasionally cause discomfort or be responsible for various clinical conditions due to hormonal dysregulation; therefore, their characterization is of paramount importance for establishing the best therapeutic strategy. Imaging techniques such as ultrasound, computed tomography, magnetic resonance, and PET-TC, providing anatomical and functional information, play a central role in the diagnostic workup, allowing clinicians and surgeons to choose the optimal lesion management. This review aims at providing an overview of the most encountered adrenal lesions, both benign and malignant, including describing their imaging characteristics.

Artificial intelligence based image quality enhancement in liver MRI: a quantitative and qualitative evaluation

Purpose

To compare liver MRI with AIR Recon Deep Learning™(ARDL) algorithm applied and turned-off (NON-DL) with conventional high-resolution acquisition (NAÏVE) sequences, in terms of quantitative and qualitative image analysis and scanning time.

Material and methods

This prospective study included fifty consecutive volunteers (31 female, mean age 55.5 ± 20 years) from September to November 2021. 1.5 T MRI was performed and included three sets of images: axial single-shot fast spin-echo (SSFSE) T2 images, diffusion-weighted images(DWI) and apparent diffusion coefficient(ADC) maps acquired with both ARDL and NAÏVE protocol; the NON-DL images, were also assessed. Two radiologists in consensus drew fixed regions of interest in liver parenchyma to calculate signal-to-noise-ratio (SNR) and contrast to-noise-ratio (CNR). Subjective image quality was assessed by two other radiologists independently with a five-point Likert scale. Acquisition time was recorded.

Results

SSFSE T2 objective analysis showed higher SNR and CNR for ARDL vs NAÏVE, ARDL vs NON-DL(all P < 0.013). Regarding DWI, no differences were found for SNR with ARDL vs NAÏVE and, ARDL vs NON-DL (all P > 0.2517).CNR was higher for ARDL vs NON-DL(P = 0.0170), whereas no differences were found between ARDL and NAÏVE(P = 1). No differences were observed for all three comparisons, in terms of SNR and CNR, for ADC maps (all P > 0.32).

Qualitative analysis for all sequences showed better overall image quality for ARDL with lower truncation artifacts, higher sharpness and contrast (all P < 0.0070) with excellent inter-rater agreement (k ≥ 0.8143). Acquisition time was lower in ARDL sequences compared to NAÏVE (SSFSE T2 = 19.08 ± 2.5 s vs. 24.1 ± 2 s and DWI = 207.3 ± 54 s vs. 513.6 ± 98.6 s, all P < 0.0001).

Conclusion

ARDL applied on upper abdomen showed overall better image quality and reduced scanning time compared with NAÏVE protocol.

Diagnostic performance of CT lung severity score and quantitative chest CT for stratification of COVID-19 patients

Purpose

Lung severity score (LSS) and quantitative chest CT (QCCT) analysis could have a relevant impact to stratify patients affected by COVID-19 pneumonia at the hospital admission. The study aims to assess LSS and QCCT performances in severity stratification of COVID-19 patients.

Materials and methods

From April 19, 2020, until May 3, 2020, patients with chest CT suggestive for interstitial pneumonia and tested positive for COVID-19 were retrospectively enrolled and stratified for hospital admission as Group 1, 2 and 3 (home isolation, low intensive care and intensive care, respectively). For LSS, lungs were divided in 20 regions and visually assessed by two radiologists who scored for each region from non-lung involvement as 0, < 50% assigned as 1 and > 50% as 2. QCCT was performed with a dedicated software that extracts pulmonary involvement expressed in liters and percentage. LSS and QCCT were analyzed with ROC curve analysis to predict the performance of both methods. P values < 0.05 were considered statistically significant.

Results

Final population enrolled included 136 patients (87 males, mean age 66 ± 16), 19 patients in Group 1, 86 in Group 2 and 31 in Group 3. Significant differences for LSS were observed in almost all comparisons, especially in Group 1 vs 3 (AUC 0.850, P < 0,0001) and Group 1 + 2 vs 3 (AUC 0.783, P < 0,0001). QCCT showed significant results in almost all comparisons, especially between Group 1 vs 3 (AUC 0.869, P < 0,0001). LSS and QCCT comparison between Group 1 and Group 2 did not show significant differences.

Conclusions

LSS and QCCT could represent promising tools to stratify COVID-19 patient severity at the admission.

Imaging of abdominal complications of COVID-19 infection

Coronavirus disease 2019 (COVID-19) is a respiratory syndrome caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first described in Wuhan, Hubei Province, China in the last months of 2019 and then declared as a pandemic. Typical symptoms are represented by fever, cough, dyspnea and fatigue, but SARS-CoV-2 infection can also cause gastrointestinal symptoms (vomiting, diarrhoea, abdominal pain, loss of appetite) or be totally asymptomatic. As reported in literature, many patients with COVID-19 pneumonia had a secondary abdominal involvement (bowel, pancreas, gallbladder, spleen, liver, kidneys), confirmed by laboratory tests and also by radiological features. Usually the diagnosis of COVID-19 is suspected and then confirmed by real-time reverse-transcription-polymerase chain reaction (RT-PCR), after the examination of the lung bases of patients, admitted to the emergency department with abdominal symptoms and signs, who underwent abdominal-CT. The aim of this review is to describe the typical and atypical abdominal imaging findings in patients with SARS-CoV-2 infection reported since now in literature.

Chest CT texture-based radiomics analysis in differentiating COVID-19 from other interstitial pneumonia

PURPOSE

To evaluate the potential role of texture-based radiomics analysis in differentiating Coronavirus Disease-19 (COVID-19) pneumonia from pneumonia of other etiology on Chest CT.

MATERIALS AND METHODS

One hundred and twenty consecutive patients admitted to Emergency Department, from March 8, 2020, to April 25, 2020, with suspicious of COVID-19 that underwent Chest CT, were retrospectively analyzed. All patients presented CT findings indicative for interstitial pneumonia. Sixty patients with positive COVID-19 real-time reverse transcription polymerase chain reaction (RT-PCR) and 60 patients with negative COVID-19 RT-PCR were enrolled. CT texture analysis (CTTA) was manually performed using dedicated software by two radiologists in consensus and textural features on filtered and unfiltered images were extracted as follows: mean intensity, standard deviation (SD), entropy, mean of positive pixels (MPP), skewness, and kurtosis. Nonparametric Mann-Whitney test assessed CTTA ability to differentiate positive from negative COVID-19 patients. Diagnostic criteria were obtained from receiver operating characteristic (ROC) curves.

RESULTS

Unfiltered CTTA showed lower values of mean intensity, MPP, and kurtosis in COVID-19 positive patients compared to negative patients (p = 0.041, 0.004, and 0.002, respectively). On filtered images, fine and medium texture scales were significant differentiators; fine texture scale being most significant where COVID-19 positive patients had lower SD (p = 0.004) and MPP (p = 0.004) compared to COVID-19 negative patients. A combination of the significant texture features could identify the patients with positive COVID-19 from negative COVID-19 with a sensitivity of 60% and specificity of 80% (p = 0.001).

CONCLUSIONS

Preliminary evaluation suggests potential role of CTTA in distinguishing COVID-19 pneumonia from other interstitial pneumonia on Chest CT.

Postacute Sequelae of COVID-19 Pneumonia: 6-month Chest CT Follow-up

Background

The long-term post acute pulmonary sequelae of COVID-19 remain unknown.

Purpose

To evaluate lung injury in patients affected by COVID-19 pneumonia at six-month follow-up compared to baseline chest CT.

Methods

From March 19th,2020 to May 24th,2020, patients with moderate to severe COVID-19 pneumonia and baseline Chest CT were prospectively enrolled at six-months follow-up. CT qualitative findings, semi-quantitative Lungs Severity Score (LSS) and well-aerated lung quantitative Chest CT (QCCT) were analyzed. Baseline LSS and QCCT performances in predicting fibrotic-like changes (reticular pattern and/or honeycombing) at six-month follow-up Chest CT were tested with receiver operating characteristic curves. Univariable and multivariable logistic regression analysis were used to test clinical and radiological features predictive of fibrotic-like changes. The multivariable analysis was performed with clinical parameters alone (clinical model), radiological parameters alone (radiological model) and the combination of clinical and radiological parameters (combined model).

Results

One-hundred-eighteen patients, with both baseline and six-month follow-up Chest CT, were included in the study (62 female, mean age 65±12 years). At follow-up Chest CT, 85/118 (72%) patients showed fibrotic-like changes and 49/118 (42%) showed GGOs. Baseline LSS (>14), QCCT (≤3.75L and ≤80%) showed an excellent performance in predicting fibrotic-like changes at Chest CT follow-up. In the multivariable analysis, AUC was .89 (95%CI .77-.96) for the clinical model, .81 (95%CI .68-.9) for the radiological model and .92 (95%CI .81-.98)for the combined model.

Conclusion

At six-month follow-up Chest CT, 72% of patients showed late sequelae, in particular fibrotic-like changes. Baseline LSS and QCCT of well-aerated lung showed an excellent performance in predicting fibrotic-like changes at six-month Chest CT (AUC>.88). Male sex, cough, lymphocytosis and QCCT well-aerated lung were significant predictors of fibrotic-like changes at six-month with an inverse correlation (AUC .92).

See also the editorial by Wells and Devaraj.

Influence of Adaptive Statistical Iterative Reconstructions on CT Radiomic Features in Oncologic Patients

Iterative reconstructions (IR) might alter radiomic features extraction. We aim to evaluate the influence of Adaptive Statistical Iterative Reconstruction-V (ASIR-V) on CT radiomic features. Patients who underwent unenhanced abdominal CT (Revolution Evo, GE Healthcare, USA) were retrospectively enrolled. Raw data of filtered-back projection (FBP) were reconstructed with 10 levels of ASIR-V (10–100%). CT texture analysis (CTTA) of liver, kidney, spleen and paravertebral muscle for all datasets was performed. Six radiomic features (mean intensity, standard deviation (SD), entropy, mean of positive pixel (MPP), skewness, kurtosis) were extracted and compared between FBP and all ASIR-V levels, with and without altering the spatial scale filter (SSF). CTTA of all organs revealed significant differences between FBP and all ASIR-V reconstructions for mean intensity, SD, entropy and MPP (all p < 0.0001), while no significant differences were observed for skewness and kurtosis between FBP and all ASIR-V reconstructions (all p > 0.05). A per-filter analysis was also performed comparing FBP with all ASIR-V reconstructions for all six SSF separately (SSF0-SSF6). Results showed significant differences between FBP and all ASIR-V reconstruction levels for mean intensity, SD, and MPP (all filters p < 0.0315). Skewness and kurtosis showed no differences for all comparisons performed (all p > 0.05). The application of incremental ASIR-V levels affects CTTA across various filters. Skewness and kurtosis are not affected by IR and may be reliable quantitative parameters for radiomic analysis.

Radiomics in Oncology, Part 2: Thoracic, Genito-Urinary, Breast, Neurological, Hematologic and Musculoskeletal Applications

Simple Summary

This Part II is an overview of the main applications of Radiomics in oncologic imaging with a focus on diagnosis, prognosis prediction and assessment of response to therapy in thoracic, genito-urinary, breast, neurologic, hematologic and musculoskeletal oncology. In this part II we describe the radiomic applications, limitations and future perspectives for each pre-eminent tumor. In the future, Radiomics could have a pivotal role in management of cancer patients as an imaging tool to support clinicians in decision making process. However, further investigations need to obtain some stable results and to standardize radiomic analysis (i.e., image acquisitions, segmentation and model building) in clinical routine.

Abstract

Radiomics has the potential to play a pivotal role in oncological translational imaging, particularly in cancer detection, prognosis prediction and response to therapy evaluation. To date, several studies established Radiomics as a useful tool in oncologic imaging, able to support clinicians in practicing evidence-based medicine, uniquely tailored to each patient and tumor. Mineable data, extracted from medical images could be combined with clinical and survival parameters to develop models useful for the clinicians in cancer patients’ assessment. As such, adding Radiomics to traditional subjective imaging may provide a quantitative and extensive cancer evaluation reflecting histologic architecture. In this Part II, we present an overview of radiomic applications in thoracic, genito-urinary, breast, neurological, hematologic and musculoskeletal oncologic applications.

Radiomics in Oncology, Part 1: Technical Principles and Gastrointestinal Application in CT and MRI

Simple Summary

Part I is an overview aimed to investigate some technical principles and the main fields of radiomic application in gastrointestinal oncologic imaging (CT and MRI) with a focus on diagnosis, prediction prognosis, and assessment of response to therapy in gastrointestinal cancers, describing mostly the results for each pre-eminent tumor. In particular, this paper provides a general description of the main radiomic drawbacks and future challenges, which limit radiomic application in clinical setting as routine. Further investigations need to standardize and validate the Radiomics as a helpful tool in management of oncologic patients. In that context, Radiomics has been playing a relevant role and could be considered as a future imaging landscape.

Abstract

Radiomics has been playing a pivotal role in oncological translational imaging, particularly in cancer diagnosis, prediction prognosis, and therapy response assessment. Recently, promising results were achieved in management of cancer patients by extracting mineable high-dimensional data from medical images, supporting clinicians in decision-making process in the new era of target therapy and personalized medicine. Radiomics could provide quantitative data, extracted from medical images, that could reflect microenvironmental tumor heterogeneity, which might be a useful information for treatment tailoring. Thus, it could be helpful to overcome the main limitations of traditional tumor biopsy, often affected by bias in tumor sampling, lack of repeatability and possible procedure complications. This quantitative approach has been widely investigated as a non-invasive and an objective imaging biomarker in cancer patients; however, it is not applied as a clinical routine due to several limitations related to lack of standardization and validation of images acquisition protocols, features segmentation, extraction, processing, and data analysis. This field is in continuous evolution in each type of cancer, and results support the idea that in the future Radiomics might be a reliable application in oncologic imaging. The first part of this review aimed to describe some radiomic technical principles and clinical applications to gastrointestinal oncologic imaging (CT and MRI) with a focus on diagnosis, prediction prognosis, and assessment of response to therapy.

Quantitative Chest CT analysis in discriminating COVID-19 from non-COVID-19 patients

INTRODUCTION

COVID-19 pneumonia is characterized by ground-glass opacities (GGOs) and consolidations on Chest CT, although these CT features cannot be considered specific, at least on a qualitative analysis. The aim is to evaluate if Quantitative Chest CT could provide reliable information in discriminating COVID-19 from non-COVID-19 patients.

MATERIALS AND METHODS

From March 31, 2020 until April 18, 2020, patients with Chest CT suggestive for interstitial pneumonia were retrospectively enrolled and divided into two groups based on positive/negative COVID-19 RT-PCR results. Patients with pulmonary resection and/or CT motion artifacts were excluded. Quantitative Chest CT analysis was performed with a dedicated software that provides total lung volume, healthy parenchyma, GGOs, consolidations and fibrotic alterations, expressed both in liters and percentage. Two radiologists in consensus revised software analysis and adjusted areas of lung impairment in case of non-adequate segmentation. Data obtained were compared between COVID-19 and non-COVID-19 patients and p < 0.05 were considered statistically significant. Performance of statistically significant parameters was tested by ROC curve analysis.

RESULTS

Final population enrolled included 190 patients: 136 COVID-19 patients (87 male, 49 female, mean age 66 ± 16) and 54 non-COVID-19 patients (25 male, 29 female, mean age 63 ± 15). Lung quantification in liters showed significant differences between COVID-19 and non-COVID-19 patients for GGOs (0.55 ± 0.26L vs 0.43 ± 0.23L, p = 0.0005) and fibrotic alterations (0.05 ± 0.03 L vs 0.04 ± 0.03 L, p < 0.0001). ROC analysis of GGOs and fibrotic alterations showed an area under the curve of 0.661 (cutoff 0.39 L, 68% sensitivity and 59% specificity, p < 0.001) and 0.698 (cutoff 0.02 L, 86% sensitivity and 44% specificity, p < 0.001), respectively.

CONCLUSIONS

Quantification of GGOs and fibrotic alterations on Chest CT could be able to identify patients with COVID-19.

Typical and atypical COVID-19 computed tomography findings

In December 2019 a novel coronavirus, named severe acute respiratory syndrome coronavirus 2 was identified and the disease associated was named coronavirus disease 2019 (COVID-19). Fever, cough, myalgia, fatigue associated to dyspnea represent most common clinical symptoms of the disease. The reference standard for diagnosis of severe acute respiratory syndrome coronavirus 2 infection is real time reverse-transcription polymerase chain reaction test applied on respiratory tract specimens. Despite of lower specificity, chest computed tomography (CT), as reported in manifold scientific studies, showed high sensitivity, therefore it may help in the early detection, management and follow-up of COVID-19 pneumonia. Patients affected by COVID-19 pneumonia usually showed on chest CT some typical features, such as: Bilateral ground glass opacities characterized by multilobe involvement with posterior and peripheral distribution; parenchymal consolidations with or without air bronchogram; interlobular septal thickening; crazy paving pattern, represented by interlobular and intralobular septal thickening surrounded by ground-glass opacities; subsegmental pulmonary vessels enlargement (> 3 mm). Halo sign, reversed halo sign, cavitation and pleural or pericardial effusion represent some of atypical findings of COVID-19 pneumonia. On the other hand lymphadenopathy's and bronchiectasis' frequency is unclear, indeed conflicting data emerged in literature. Radiologists play a key role in recognition of high suspicious findings of COVID-19 on chest CT, both typical and atypical ones. Thus, the aim of this review is to illustrate typical and atypical CT findings of COVID-19.

Chest CT Features of COVID-19 in Rome, Italy

Background The standard for diagnosis of severe acute respiratory syndrome coronavirus 2 is a reverse transcription polymerase chain reaction (RT-PCR) test, but chest CT may play a complimentary role in the early detection of Coronavirus Disease 2019 (COVID-19) pneumonia. Purpose To investigate CT features of patients with COVID-19 in Rome, Italy, and to compare the accuracy of CT with that of RT-PCR. Materials and Methods In this prospective study from March 4, 2020, until March 19, 2020, consecutive patients suspected of having COVID-19 infection and respiratory symptoms were enrolled. Exclusion criteria were contrast material-enhanced chest CT performed for vascular indications, patients who refused chest CT or hospitalization, and severe CT motion artifact. All patients underwent RT-PCR and chest CT. Diagnostic performance of CT was calculated using RT-PCR as the reference standard. Chest CT features were calculated in a subgroup of patients with positive RT-PCR and CT findings. CT features of hospitalized patients and patients in home isolation were compared using the Pearson χ2 test. Results The study population included 158 consecutive participants (83 male, 75 female; mean age, 57 years ± 17 [standard deviation]). Of the 158 participants, fever was observed in 97 (61%), cough was observed in 88 (56%), dyspnea was observed in 52 (33%), lymphocytopenia was observed in 95 (60%), increased C-reactive protein level was observed in 139 (88%), and elevated lactate dehydrogenase level was observed in 128 (81%). Sensitivity, specificity, and accuracy of CT were 97% (95% confidence interval [CI]: 88%, 99%) (60 of 62), 56% (95% CI: 45%, 66%) (54 of 96), and 72% (95% CI: 64%, 78%) (114 of 158), respectively. In the subgroup of 58 participants with positive RT-PCR and CT findings, ground-glass opacities were present in all 58 (100%), both multilobe and posterior involvement were present in 54 (93%), bilateral pneumonia was present in 53 (91%), and subsegmental vessel enlargement (>3 mm) was present in 52 (89%). Conclusion The typical pattern of COVID-19 pneumonia in Rome, Italy, was peripheral ground-glass opacities with multilobe and posterior involvement, bilateral distribution, and subsegmental vessel enlargement (>3 mm). Chest CT had high sensitivity (97%) but lower specificity (56%). © RSNA, 2020.

Angular stable plates in proximal meta-epiphyseal tibial fractures: study of joint restoration and clinical and functional evaluation

BACKGROUND

The tibial plateau fractures involve one of the main weight bearing joints of the human body. The goals of surgical treatment are anatomical reduction, articular surface reconstruction and high primary stability. The aim of this study was to evaluate the clinical and functional outcomes after internal plate fixation of this kind of fractures.

MATERIALS AND METHODS

From January 2009 to December 2012, we treated 75 cases of tibial plateau fracture with angular stable plates. We used Rasmussen Score and the Knee Society Score for the clinical and functional evaluation. Twenty-five cases that underwent hardware removal had arthroscopic and CT evaluation of the joint.

RESULTS

No complications occurred. The clinical and functional evaluation, performed by the KSS and Rasmussen Score, highlighted the high percentage of good-to-excellent results (over 90 %). In every case, the range of motion was good with flexion >90°. Arthroscopy showed the presence of chondral damage in 100 % of patients. In all the cases, we found that X-ray images seem better than the CT images.

CONCLUSIONS

Angular stable plates allow to obtain a good primary stability, permitting an early joint recovery with an excellent range of motion. Avoiding to perform a knee arthrotomy at the time of fracture reduction could prove to be an advantage in terms of functional recovery. The meniscus on the injured bone should be preserved in order to maintain good function of the joint. X-ray images remain the gold standard in checking the progression of post-traumatic osteoarthritis.

Strontium ranelate as an adjuvant for fracture healing: clinical, radiological, and ultrasound findings in a randomized controlled study on wrist fractures

This randomized and controlled study evaluated the effect of therapy with strontium ranelate on callus formation in wrist fractures and its incidence in wrist recovery. Radiographic healing, progression of clinical recovery, and callus quality with ultrasound were evaluated. No statistically significant benefit of therapy was found.

INTRODUCTION

Fracture prevention is the main goal of any therapy for osteoporosis. Various drugs used in osteoporosis treatment have the theoretical premises to promote fracture healing and osseointegration. In this study, the effect of strontium ranelate on callus formation in wrist fractures was evaluated and whether it could lead to clinically relevant modification of wrist recovery; having strontium ranelate osteoinductive properties, it could be used, if effective, as an adjunct in fracture healing for a faster and functionally better recovery and, at the same time, in starting proper therapy in osteoporotic patients with fragility fractures.

METHODS

We considered only patients older than 60 years who had suffered wrist fracture and received nonoperative treatment with manual reduction of the fracture and cast for 35 days. Forty patients were included and randomly assigned to one of two groups: group A [patients treated with calcium (1200 mg/day) and vitamin D (800 IU/day)] and group B [patients treated with calcium (1200 mg/day) and vitamin D (800 IU/day) associated with strontium ranelate 2 g daily]. Radiographic healing was evaluated through the bone callus formation, cortical continuity, and density of the callus. A clinical evaluation using Castaing's criteria was carried out 2 and 3 months following the fracture together with an ultrasound study of callus density and vessels.

RESULTS

A parametric analysis of the X-ray data, clinical evaluation, and ultrasonography results showed that there were no statistically significant differences in the two groups (p > 0.05 for all data).

CONCLUSION

In analyzing the data obtained, we concluded that strontium ranelate administered in acute phase did not improve nor accelerate wrist fracture healing in our population.

The biphasic bioresorbable scaffold (Trufit(®)) in the osteochondral knee lesions: long-term clinical and MRI assessment in 30 patients

BACKGROUND

Chondral or osteochondral defects have been reported in 60-67 % of patients in studies reporting knee arthroscopies. The surgical management of chondral and osteochondral defects (OCD's) of the articular surface of the knee joint remains a controversial topic. Osteochondral injuries can be treated with transfer cartilage procedure and with implantation of biodegradable scaffolds. For patients over 50 years old with largest osteochondral lesions, we prefer to use the biodegradable scaffold, like Trufit(®) plug (Smith & Nephew, Andover, MA). The purpose of this study is to evaluate the outcome of this series of surgical procedure with Trufit.

METHODS

In our institute, the Trufit was used for the treatment of one or more focal osteochondral lesions of the femoral condyles positive MRI with or without concomitant ligamentous or meniscal pathology. We reviewed 30 patients with mean age of 60.57 years (range 32-79 years) with a clinical and imaging control at 6, 12, 24 and 48 months of follow-up.

RESULTS

The clinical evaluation has shown the good outcome. The MRI conducted has shown the progressive partial integration of the scaffolds.

CONCLUSIONS

The results obtained indicate a clear improvement of the clinical symptoms and slowing joint degeneration. The clinical and imaging results confirm that the Trufit constitutes a valid surgical alternative in case of focal osteochondral.

Metal-on-metal hip resurfacing: correlation between clinical and radiological assessment, metal ions and ultrasound findings

PURPOSE

We report the clinical, radiological and wear analysis of 52 consecutive MoM hip resurfacings (performed on 49 younger patients) to a mean follow-up of 9.2 years.

METHODS

Every patient underwent X-ray and clinical evaluation (HHS). Ultrasonography of the hip was performed in all patients in order to identify possible cystic or solid mass in periprosthetic tissue. In case of mass >20 mm, further MRI was performed to better analyse the characteristics of lesion.

RESULTS

Five patients (five hips) had a revision. The overall survival rate was 90.38 %. The average HHS at follow-up examination was 95.5 points. No progressive radiolucent areas and no sclerosis or osteolysis around the implants were found. The US and RMI imaging showed a pseudotumour formation in two patients (correlated with high metal ion levels in blood and urine), both asymptomatic.

CONCLUSION

A significant positive correlation between inclination of the acetabular component and serum metal ion levels was found (r = 0.64 and r = 0.62 for cobalt and chromium, respectively).

Long bone nonunions treated with autologous concentrated bone marrow-derived cells combined with dried bone allograft

INTRODUCTION

Nowadays the treatment of long bone nonunion continues to be one of the most complex and debated topics due to the large number of failures. For several years, in the relevant literature three factors have been considered essential in the healing process: growth factors and hormones, osteoprogenitor cells (mesenchymal stem cells), and extracellular matrix. The mechanical stability of the fracture site is considered the fourth element of the "Diamond concept theory." The aim of our study was to evaluate the validity of biological adjuvants of mechanical synthesis allowing a faster healing process of nonunions.

MATERIALS AND METHODS

We dealt with 19 patients with long bone nonunion. All patients have been treated with concentrated mesenchymal stem cells without bone autologous transplant. We used the Extracell BMC-marrow aspirate protocol of Regen Lab. The radiographic parameters taken into account for the diagnosis of successful healing were the presence of a bridge callus, obliteration of the fracture line and bone cortical continuity. Clinically, the pain was investigated with VAS score (visual analogue scale), where zero means no pain and 10 the worst possible pain.

RESULTS

Radiographic investigation shows complete healing in 78.9 % (15 cases) with an average time to healing of 6.5 months (minimum healing time 80 days) corresponding also in complete remission of clinical symptoms.

CONCLUSION

The use of growth factors and autologous mesenchymal stem cells through the enforcement of system for tissue regeneration is a valid and innovative biotechnology technique for the treatment long bone nonunions.

Atypical femoral fractures: retrospective radiological study of 319 femoral fractures and presentation of clinical cases

SUMMARY

There is still no clarity on the etiology and epidemiology of atypical femoral fractures. The purpose is to show, after a radiological review, that the incidence of atypical fractures is higher than that reported in the literature when compared to "typical" fractures that occurred in the same anatomical site.

INTRODUCTION

At present, it is difficult to define the true incidence of atypical fractures associated with bisphosphonate. Our purpose is to show that the incidence of atypical fractures is higher than that reported in the literature when compared to "typical" fractures that occurred in the same anatomical site.

METHODS

The authors analyzed 319 femoral fracture Rxs of patients over 60 who have had access to the PS of Clinical Orthopaedics and Traumatology II of the University of Pisa from January 2011 to February 2013. The atypical fractures have been investigated from clinical point of view, biohumoral exams, densitometry and contralateral femur X-rays, and in one case using SPECT-Tc.

RESULTS

The total number of femoral fractures was 319. The medial femur fractures were 60 (46 females and 14 males), and the lateral ones were 316 (237 females and 79 males). Subtrochanteric and diaphyseal fractures were 40 (29 females and 11 males). Among these cases, two atypical fracture cases were related to female patients, one was 79 years old and the other was 77.

CONCLUSIONS

The most recent literature reports that the incidence of atypical fractures is 0.6 %. However, taking into consideration only the fracture locations suitable for the identification of atypical fractures, the percentage rises to 5 %. To date, there is still no clarity on the exact etiology of fractures even if it seems to be related to a bone mineral component alteration.

Pseudoarthrosis in atypical femoral fracture: case report

Atypical femoral fractures can be subsequent to a long-term biphosphonates treatment; they have a high frequency of delayed healing. The authors describe a femoral pseudoarthrosis of an atypical fracture treated with intramedullary nailing in a female after prolonged alendronate therapy. Atypical femoral fractures can be subsequent to a long-term biphosphonates treatment even if, in the literature, there is no clarity on the exact pathogenetic mechanism. The Task Force of the American Society for Bone and Mineral Research described the major and minor features to define atypical fractures and recommends that all the five major features must be present while minor features are not necessary. Another controversial aspect regarding the atypical femoral fractures is the higher frequency of the delayed healing that can be probably related to a suppressed bone turnover caused by a prolonged period of bisphosphonates treatment. This concept could be corroborated by the Spet Tc exam. In the case of a pseudoarthrosis, there is not a standardization of the treatment. In this report, the authors describe a femoral pseudoarthrosis of an atypical fracture treated with intramedullary nailing in a female after prolonged alendronate therapy; the patient was studied with clinical, bioumoral end SPECT-Tc exam of both femurs. Many studies show the relationship between bisphosphonates and the presence of atypical fractures. These fractures should be monitored more closely due to the risk of nonunion and they require considering an initial treatment with pharmacological augmentation to reduce the complications for the patient and the health care costs.

Elastofibroma dorsi: case series of a rare benign tumour of the back

We analyse this rare pseudotumour with few case reports in the orthopaedic literature. Elastofibroma dorsi is an uncommon benign soft tissue pseudotumour usually located at the lower pole of the scapula. This study is a clinical assessment of 5 patients. All the patients had their diagnosis based on clinical and MRI findings and had excision biopsy. The patients were followed for a mean period of 24 months. No patient had residual symptoms. We have only one recurrence. Surgical excision is recommended when it causes functional disability, compression symptoms, an asymmetric outline of the chest wall, or when it is more than 5 cm in diameter. Pre-operative tissue diagnosis is not necessary in most cases. Despite its rarity, the elastofibroma dorsi should always be suspected with the emergence of a swelling in the subscapularis, especially in females and in old age.

Treatment of pseudoarthrosis of the upper limb using expanded mesenchymal stem cells: a pilot study

BACKGROUND

In orthopedic field is growing interest in the use of stem cells: this mesenchymal multipotent line (MSCs) can lead to differentiation into osteocytes and thus the formation of bone tissue. In literature applications of this line are described in injuries of tendons and ligaments, small bony avulsions, nonunion fractures and cartilage defects.

AIM

Utilize MSCs expanded in laboratory in case of atrophic pseudoarthrosis of the upper limb.

MATERIALS AND METHODS

We obtain the amount of cell necessary for the implant by the collaboration with the UO Haematological Department. For the procedure we make a blood sample from the iliac crest bone marrow and a subsequent phase of selection and cultivation of mesenchymal line for 3 weeks, to get a sufficient amount of tissue to be used, which is presented at the time of surgery on a scaffold made by autologous plasma gel and CaCl(2). We reassessed our experience in 8 different types of upper limb fractures result in pseudarthrosis and delayed of consolidation: 4 women and 4 men, average 44 years old followed with a follow-up of 50.3 months. In all cases the site of non-union has been revitalized (by microfractures and drilling) and a synthesis was performed with a rigid plate. So we fill the bone gap with autologous bone and mesenchymal stem cells expanded in the laboratory.

RESULTS

We have a radiographic healing in 8 cases and no adverse events were highlighted.

CONCLUSIONS

Using this cells line we obtained encouraging but certainly not conclusive impressions, according to the limited number of cases and lack of adequate comparative studies. In tissue engineering are also certainly needed further investigations and developments.

Shoulder resurfacing with Durom Cup: clinical and radiological re-assessment

BACKGROUND

The purpose of this study was to analyze and report functional and radiological results obtained with the Durom™ Shoulder Cup.

METHODS

From 2004 to 2009, 42 consecutive shoulder resurfacing prostheses were implanted in a cohort of forty patients with morphologically and functionally healthy rotator cuff. Those cases were evaluated preoperatively and postoperatively after an average of 33.5 months on the basis of Constant score, ASES score, and X-rays.

RESULTS

The Constant score increased from 29.88 points preoperatively to 82.34 after a mean follow-up period of 33.5 months. The ASES score went from 30.55 points preoperatively to 76.61. Radiologically we noticed neither radiolucent lines nor any aseptic loosening of the prosthetic cup. In the post-operative X-rays evaluation we found no significant central migration of the humeral head from the first postoperative X-ray.

CONCLUSIONS

The good functional results observed with a mean follow-up of approximately 3 years doubtless resulted from the reduction in implant-placement error, as a result of the resurfacing procedure, and from the normal rotator cuff function. This technique facilitates surgical reconstruction of the anatomical and biomechanical conditions required for physiological function of the shoulder.

G-CSF alone vs cyclophosphamide plus G-CSF in PBPC mobilization of patients with lymphoma: results depend on degree of previous pretreatment

We performed a randomized study to compare 'G-CSF alone' (administered at dose of 10 mcg/kg/day) and 'cyclophosphamide plus G-CSF' (cyclophosphamide at dose of 4 g/m(2) and G-CSF at dose of 10 microg/kg/day), as PBPC mobilization schedules in 52 patients with NHL or HD. Randomization was stratified according to the amount of previous chemotherapy (< or =2 and >2 lines of previous chemotherapy). Mean CD34+ cell peak in P.B., mean 'Total CD34+ cells' harvested and percentage of patients successfully mobilized, in the group mobilized with 'G-CSF alone' vs the group mobilized with 'cyclophosphamide plus G-CSF', were: 35.3 x 10(6) vs 45.8 x 10(6)/l (P=0.3), 5.4 x 10(6) vs 6.8 x 10(6)/kg (P>0.9) and 50 vs 61% (P=0.4). No differences were observed in the stratum of less pretreated patients. However, in the stratum of patients who had previously received more than two lines of chemotherapy, CD34+cell peak (P=0.05) and percentage of successful mobilization (P=0.01) were higher when 'cyclophosphamide plus G-CSF' was used. Using logistic regression, both age and mobilization with 'G-CSF alone' were significantly associated with a low CD34+ cell peak in P.B. However, in the stratum of less pretreated patients, only age was significantly associated with this risk.

Prefrontal blood flow dysregulation in drug naive ADHD children without structural abnormalities

Recent studies suggest a role for prefrontal cortex abnormalities in the pathogenesis of attention deficit/hyperactivity disorder (ADHD). We evaluated young drug-naive ADHD outpatients without MRI structural abnormalities to detect prefrontal cortex regional cerebral blood flow (rCBF) functional dysregulation; correlation between age and rCBF; and correlation between symptoms profile and rCBF. Functional brain activities (i.e. rCBF), neuropsychological attention performance and symptom profile were evaluated respectively by single photon emission computerized tomography (SPECT) scan, Stroop Test and the Child Attention Problem Rating Scale. There was a decreased rCBF in the left dorso lateral prefrontal cortex (DLPFC) compared to the right DLPFC of the subjects. In addition, there were positive correlations between age and relative rCBFs of the dorsolateral and orbital prefrontal cortex, and negative correlations between age and absolute rCBFs of the dorsolateral and orbital prefrontal cortex. Finally, higher levels of right relative rCBF and lower levels of left relative rCBF were predictors of higher severity of clinical symptom expression and neuropsychological attention impairment. The results of this study highlight the role of the DLPFC blood flow impairment in the pathogenesis of ADHD even in young subjects without structural abnormalities.

Chronic hepatitis induced by Jin Bu Huan

BACKGROUND/AIMS

Jin Bu Huan and other Chinese herbal products are widely taken remedies. They have been developed as a natural alternative to traditional drugs in the treatment of various ailments. Their ability to induce several side effects such as acute hepatitis has already been described. We report a case of chronic hepatic damage following administration of Jin Bu Huan Anodyne tablets.

METHODS

The patient, a 49-year-old man, developed biochemical signs of liver damage 2 months after beginning Jin Bu Huan intake (3 tablets/daily) including biopsy-proven chronic hepatitis with moderate fibrosis. Virological, autoimmune, metabolic or other hepatotoxic causes were excluded. Liver function impairment was resolved by discontinuing Jin Bu Huan intake.

CONCLUSIONS

This case reinforces the already known hepatotoxicity of this product and should make us think more about the uncontrolled use of alternative products.