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Missed lung cancer is a source of concern among radiologists and an important medicolegal challenge. In 90% of the cases, errors in diagnosis of lung cancer occur on chest radiographs. It may be challenging for radiologists to distinguish a lung lesion from bones, pulmonary vessels, mediastinal structures, and other complex anatomical structures on chest radiographs. Nevertheless, lung cancer can also be overlooked on computed tomography (CT) scans, regardless of the context, either if a clinical or radiologic suspect exists or for other reasons. Awareness of the possible causes of overlooking a pulmonary lesion can give radiologists a chance to reduce the occurrence of this eventuality. Various factors contribute to a misdiagnosis of lung cancer on chest radiographs and on CT, often very similar in nature to each other. Observer error is the most significant one and comprises scanning error, recognition error, decision-making error, and satisfaction of search. Tumor characteristics such as lesion size, conspicuity, and location are also crucial in this context. Even technical aspects can contribute to the probability of skipping lung cancer, including image quality and patient positioning and movement. Albeit it is hard to remove missed lung cancer completely, strategies to reduce observer error and methods to improve technique and automated detection may be valuable in reducing its likelihood. [ABSTRACT FROM AUTHOR]

Objectives: The objective was to evaluate the performances of dose-reduced dual-energy computed tomography (DECT) in decreasing metallic artifacts from orthopedic devices compared with dose-neutral DECT, dose-neutral single-energy computed tomography (SECT), and dose-reduced SECT.Materials and Methods: Thirty implants in 20 consecutive cadavers underwent both SECT and DECT at three fixed CT dose indexes (CTDI): 20.0, 10.0, and 5.0 mGy. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV, and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. In each group, the image quality of the seven monoenergetic images and of the SECT image was assessed qualitatively and quantitatively by visually rating and by measuring the maximum streak artifact respectively.Results: The comparison between SECT and OPTkeV evaluated overall within all groups showed a significant difference (p <0.001), with OPTkeV images providing better images. Comparing OPTkeV with the other DECT images, a significant difference was shown (p <0.001), with OPTkeV and 130-keV images providing the qualitatively best results. The OPTkeV images of 5.0-mGy acquisitions provided percentages of images with scores 1 and 2 of 36 % and 30 % respectively, compared with 0 % and 33.3 % of the corresponding SECT images of 10- and 20-mGy acquisitions. Moreover, DECT reconstructions at the OPTkeV of the low-dose group showed higher CT numbers than the SECT images of dose groups 1 and 2.Conclusions: This study demonstrates that low-dose DECT permits a reduction of artifacts due to metallic implants to be obtained in a similar manner to neutral-dose DECT and better than reduced or neutral-dose SECT. [ABSTRACT FROM AUTHOR]

Background: Correct alignment of prosthetic components is the most important factor for the success of total knee arthroplasty (TKA). Dual-energy computed tomography (DECT) may be a reliable method in determining implant position after TKA.Purpose: To evaluate the accuracy and reproducibility of DECT in determining implant position after TKA.Material and Methods: Institutional review board approval was obtained. Forty-five patients (age 75.2 ± 6.4 years) prospectively underwent TKA at our institution between May and December 2012. DECT was performed 1 year after surgery, using an alignment similar to a standing position and generating images at an extrapolated energy of 120 kVp, in order to reduce metal artifacts. Implant position was evaluated by two independent readers. Intra- and inter-observer agreements were calculated. DECT measurements on implant position were compared with the preoperative planning based on radiographs. Additional clinical and DECT findings were taken into account.Results: Metal artifact reduction was judged satisfactory in all cases. Regarding implant position assessed with DECT, good to excellent intra-observer (k: 0.74-0.87 and k: 0.75-0.88, respectively), and inter-observer agreement (k: 0.72-0.82) were found. In the comparison with preoperative planning, the widest limits of agreement were within 3.9° for the sagittal orientation of tibial component. A single patient with postoperative knee pain and stiffness had periprosthetic osteopenia, quadriceps femoris tendon calcifications, articular effusion, and excessive intrarotation of the femoral component.Conclusion: DECT is an accurate and reproducible tool for determining implant position after TKA. [ABSTRACT FROM AUTHOR]

Background: Computed tomography (CT) is frequently used to diagnose glenoid bone defects in anterior shoulder instability. The assessment of glenoid defects on 2-dimensional (2D) and 3-dimensional (3D) CT scans has been reported with and without a comparative study of the contralateral shoulder; however, no previous studies have analyzed if these 4 methods agree. Purpose: To estimate agreement between CT assessments of glenoid defects by examination of the affected shoulder alone and by comparison with the contralateral side on both 2D and 3D CT scans. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 200 prospectively enlisted patients affected by unilateral anterior shoulder instability underwent CT of both shoulders. The area of the missing glenoid was calculated on 4 sets of CT scans (2D and 3D CT images with and without comparison with the contralateral shoulder) by using the circle method. Agreement between the 4 measurements in quantifying the bone defect was estimated according to the Bland-Altman method. Agreement between the 4 measurements in assessing the presence and type of defect (fracture or erosion) was analyzed with κ statistics. Results: Analysis of agreement between CT measurements in quantifying glenoid bone defects showed that the mean difference between the 4 measures was less than 1% of the area of the inferior glenoid in each pairwise comparison. Limits of agreement were always below the established acceptable limit of 5%. The assessment of the presence and type of bone defect showed strong to near-complete agreement between the 4 measurement methods. Conclusion: CT assessments of glenoid bone defects with and without comparison with the contralateral shoulder showed very good agreement in identifying the size, presence, and type of defect in patients with anterior shoulder instability on both 2D and 3D CT scans. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this ex vivo study was to assess the performance of monoenergetic dual-energy CT (DECT) reconstructions to reduce metal artefacts in bodies with orthopedic devices in comparison with standard single-energy CT (SECT) examinations in forensic imaging. Forensic and clinical impacts of this study are also discussed. Materials and methods: Thirty metallic implants in 20 consecutive cadavers with metallic implants underwent both SECT and DECT with a clinically suitable scanning protocol. Extrapolated monoenergetic DECT images at 64, 69, 88, 105, 120, and 130 keV and individually adjusted monoenergy for optimized image quality (OPTkeV) were generated. Image quality of the seven monoenergetic images and of the corresponding SECT image was assessed qualitatively and quantitatively by visual rating and measurements of attenuation changes induced by streak artefact. Results: Qualitative and quantitative analyses showed statistically significant differences between monoenergetic DECT extrapolated images and SECT, with improvements in diagnostic assessment in monoenergetic DECT at higher monoenergies. The mean value of OPTkeV was 137.6 ± 4.9 with a range of 130 to 148 keV. Conclusions: This study demonstrates that monoenergetic DECT images extrapolated at high energy levels significantly reduce metallic artefacts from orthopedic implants and improve image quality compared to SECT examination in forensic imaging. [ABSTRACT FROM AUTHOR]

Lung cancer is the most frequently fatal cancer, with poor survival once the disease is advanced. Annual low-dose computed tomography has shown a survival benefit in screening individuals at high risk for lung cancer. Based on the available evidence, the European Society of Radiology and the European Respiratory Society recommend lung cancer screening in comprehensive, quality-assured, longitudinal programmes within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres. Minimum requirements include: standardised operating procedures for low-dose image acquisition, computer-assisted nodule evaluation, and positive screening results and their management; inclusion/exclusion criteria; expectation management; and smoking cessation programmes. Further refinements are recommended to increase quality, outcome and cost-effectiveness of lung cancer screening: inclusion of risk models, reduction of effective radiation dose, computer-assisted volumetric measurements and assessment of comorbidities (chronic obstructive pulmonary disease and vascular calcification). All these requirements should be adjusted to the regional infrastructure and healthcare system, in order to exactly define eligibility using a risk model, nodule management and a quality assurance plan. The establishment of a central registry, including a biobank and an image bank, and preferably on a European level, is strongly encouraged. Key points: • Lung cancer screening using low dose computed tomography reduces mortality. • Leading US medical societies recommend large scale screening for high-risk individuals. • There are no lung cancer screening recommendations or reimbursed screening programmes in Europe as of yet. • The European Society of Radiology and the European Respiratory Society recommend lung cancer screening within a clinical trial or in routine clinical practice at certified multidisciplinary medical centres. • High risk, eligible individuals should be enrolled in comprehensive, quality-controlled longitudinal programmes. [ABSTRACT FROM AUTHOR]

The article explains the concept of integrated cardiothoracic imaging. Topics discussed include the impact of the combination of thoracic and cardiac imaging into one specialty on computed tomography (CT) imaging practices, the technologies that helped advance chest imaging and the features and functions of cardiothoracic imaging.

Background: Glenoid bone defect is frequently associated with anterior shoulder instability and is considered one of the major causes of recurrence of instability after shoulder stabilization.Hypothesis: Some risk factors are significantly associated with the presence, size, and type of glenoid bone defect.Study Design: Cohort study (prognosis); Level of evidence, 2.Methods: One hundred sixty-one patients affected by anterior shoulder instability underwent morphologic evaluation of the glenoid by computed tomography scans to assess the presence, size, and type of glenoid bone defect (erosion or bony Bankart lesion). Bone loss greater than 20% of the area of the inferior glenoid was considered “critical” bone defect (at risk of recurrence). Outcomes were correlated with the following predictors: age, gender, arm dominance, frequency of dislocation, age at first dislocation, timing from first dislocation, number of dislocations, cause of first dislocation, generalized ligamentous laxity, type of sport, and manual work.Results: Glenoid bone defect was observed in 72% of the cases. Presence of the defect was significantly associated with recurrence of dislocation compared with a single episode of dislocation, increasing number of dislocations, male gender, and type of sport. Size of the defect was significantly associated with recurrent dislocation, increasing number of dislocations, timing from first dislocation, and manual work. Presence of a critical defect was significantly associated with number of dislocations and age at first dislocation. Bony Bankart lesion was significantly associated with male gender and age at first dislocation.Conclusion: The number of dislocations and age at first dislocation are the most significant predictors of glenoid bone loss in anterior shoulder instability. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the diagnostic accuracy of multidetector-CT enteroclysis (MDCT-E) versus barium enteroclysis with methylcellulose (BE) in clinically selected patients with suspected small bowel disease. We prospectively studied 52 patients who underwent unenhanced and contrast-enhanced multidetector CT (16 rows) after administration of 2-2.5 l of methylcellulose by naso-jejunal tube. BE was performed after administration of barium 60% w/v (200-250 ml) and methylcellulose (1-2 l). Patients with radiological signs of Crohn's disease were classified into the following subtypes: active, fibrostenotic, fistulising/perforating, reparative or regenerative subtypes. Twenty-eight patients also underwent endoscopy. The radiological prevalent subtype was the active subtype. The sensitivity, specificity and diagnostic accuracy of MDCT-E versus BE was 83%, 100% and 89%, respectively. BE showed five false negative CT cases due to early Crohn's disease; endoscopy confirmed positive cases of the CT and the BE, but showed one false negative case of the BE. Together, MDCT enteroclysis and BE permitted the diagnosis of Crohn's disease in 30 patients, adhesions in one patient, lymphoma in two patients and carcinoid tumours in two patients. In conclusion, MDCT-E permits good representation of pathological patterns. Early stages of Crohn's disease are better evaluated by BE. [ABSTRACT FROM AUTHOR]

Objectives: CT is nowadays an examination routinely performed in Crohn's disease (CD) patients. However, there are several ways to assess gastro-intestinal tract, in particular colonic segments. Aim of this study is to compare enterography-CT (E-CT), performed after oral administration of polyethylene-glycol solution (PEG-CT) versus enterography-CT performed also with water enema via rectum (ECT-WE) in patients with CD.Methods: We have studied 79 patients with CD undergone to enterography-CT (42 evaluated with PEG-CT and 37 with ECT-WE) who have performed a lower endoscopy within 15 days before CT. CT results concerning large bowel were compared with endoscopic findings. Intestinal distension, discomfort of the patients, sensitivity, specificity and diagnostic accuracy were evaluated. Pearson test was used for statistical analysis.Results: Degree of abdominal pain was significantly higher in patients underwent to ECT-WE compared to PEG-CT. Distension of the colon was significantly greater in patients studied with ECT-WE compared to those studied with PEG-CT. Values of sensitivity, specificity and diagnostic accuracy of PEG-CT and ECT-WE were respectively 77, 86.5 and 81%, and 89, 100 and 92% in comparison with endoscopy.Conclusions: In patients with CD, ECT-WE allows the evaluation of large bowel in addition to small bowel better than PEG-CT. [ABSTRACT FROM AUTHOR]