Role of delayed phase contrast-enhanced CT in the intra-thoracic staging of non-small cell lung cancer (NSCLC): What does it add?

PURPOSE: The aim of the study was to investigate differences in non-small cell lung cancer (NSCLC) intra-thoracic staging by using contrast-enhanced computed tomography (ce-CT) at the arterial phase (AP), at the arterial plus delayed phases (AP + DEP), and at the delayed phase (DEP), and to evaluate their potential impact on disease staging. MATERIALS AND METHODS: Two chest radiologists with different level of expertise and a general radiologist independently reviewed the chest CT exams of 150 patients with NSCLC; CT scans were performed 40 s (AP) and 60 s (DEP) after contrast material injection. Image assessment included three reading sessions: session A (AP), session B (AP + DEP) and session C (DEP). CT descriptors for the primary tumour (T), regional nodal involvement (N), and intra-thoracic metastases (M) were evaluated in each reading session. Readers had to assign a confidence level (CL) for the assessment of each descriptor and define the TNM stage. Friedman and Cochran Q test was used to compare the assessments of the 3 reading sessions; inter-reader agreement was determined (Intraclass Correlation Coefficient - ICC). RESULTS: The CL was significantly higher in sessions B and C than in session A for all descriptors, with the exception of pulmonary arterial invasion. Primary tumour inner necrosis and regional nodal involvement were detected in a significantly higher number of cases in sessions B and C as compared to session A (p ≤ 0.001). DEP significantly changed N stage determination (p < 0.001), particularly N3, and excluded chest wall invasion (p = 0.05) and venous invasion (p = 0.001). The agreement was good among the 3 readers (ICC = 0.761) and excellent between the 2 chest radiologists (ICC ≥ 0.940), regardless of the contrast phase. CONCLUSIONS: The 60-second DEP ce-CT for staging NSCLC significantly increased the readers' CL, changed the N stage determination, and helped excluding chest wall invasion and venous invasion.

COVID-19 pneumonia: current evidence of chest imaging features, evolution and prognosis.

COVID-19 pneumonia represents a global threatening disease, especially in severe cases. Chest imaging, with X-ray and high-resolution computed tomography (HRCT), plays an important role in the initial evaluation and follow-up of patients with COVID-19 pneumonia. Chest imaging can also help in assessing disease severity and in predicting patient's outcome, either as an independent factor or in combination with clinical and laboratory features. This review highlights the current knowledge of imaging features of COVID-19 pneumonia and their temporal evolution over time, and provides recent evidences on the role of chest imaging in the prognostic assessment of the disease.

Diagnosis and management of hemoptysis.

Hemoptysis is the expectoration of blood that originates from the lower respiratory tract. It is usually a self-limiting event but in fewer than 5% of cases it may be massive, representing a life-threatening condition that warrants urgent investigations and treatment. This article aims to provide a comprehensive literature review on hemoptysis, analyzing its causes and pathophysiologic mechanisms, and providing details about anatomy and imaging of systemic bronchial and nonbronchial arteries responsible for hemoptysis. Strengths and limits of chest radiography, bronchoscopy, multidetector computed tomography (MDCT), MDCT angiography and digital subtraction angiography to assess the cause and lead the treatment of hemoptysis were reported, with particular emphasis on MDCT angiography. Treatment options for recurrent or massive hemoptysis were summarized, highlighting the predominant role of bronchial artery embolization. Finally, a guide was proposed for managing massive and nonmassive hemoptysis, according to the most recent medical literature.

Effect of clinical history in focal liver lesion detection and classification on 4-detector row computed tomography and gadoxetic acid enhanced MR imaging in oncologic patients.

PURPOSE: To determine the influence of clinical data on reader diagnostic accuracy in focal liver lesion (FLL) detection and classification. MATERIALS AND METHODS: Eighty-seven oncologic patients with FLLs underwent contrast-enhanced multidetector-row computed tomography (MDCT) and gadoxetic acid-enhanced magnetic resonance imaging (MRI). Two independent readers reviewed images for FLL detection and classification as benign or malignant without knowledge and after provision of clinical information. The sensitivity, specificity, diagnostic accuracy, and Az values were calculated using intraoperative ultrasound and pathologic findings as standard of reference. RESULTS: The awareness of clinical data significantly improved the accuracy (p = 0.02 for both readers) and Az values (p = 0.03 for reader 1 and p = 0.04 for reader 2) of MDCT for the detection of lesions with a diameter of 1 cm or less. When considering MRI, the provision of clinical data produced an improvement of accuracy and Az values for both readers, although differences were not significant.For MDCT lesion classification, the awareness of clinical data produced a decrease of accuracy (p = 0.03 for both readers) and Az values (p = 0.07 for reader 1 and p = 0.06 for reader 2) because of an associated increase in false-positive findings. When considering MRI, the provision of clinical data produced an improvement of accuracy and Az values for both readers, although differences were not significant. CONCLUSIONS: For detecting and classifying FLLs in oncologic patients, the knowledge of clinical data does not significantly change diagnostic accuracy and reader performance when using MRI, whereas, when considering MDCT, it improves the detection rate but produces an increase of false-positive findings for diagnosis of malignancy.

Contrast-enhanced ultrasound versus color duplex ultrasound imaging in the follow-up of patients after endovascular abdominal aortic aneurysm repair.

PURPOSE: This study assessed the negative predictive value, sensitivity, specificity, and diagnostic accuracy of real-time contrast-enhanced ultrasound imaging (CEUS) in the detection of endoleaks in patients with abdominal aortic aneurysm (AAA) who underwent endovascular repair (EVAR) compared with unenhanced ultrasound imaging. Computed tomography angiography (CTA) was the gold standard. The secondary objective was to define the optimal dose of the second-generation contrast agent to routinely use in the CEUS examinations for endoleak detection. METHODS: The study enrolled 84 patients with unruptured AAA who were treated with EVAR and underwent CTA follow-up. In the same day, CTA (4- x 1-mm collimation, 1.25-mm slice width), unenhanced US imaging and CEUS imaging was performed in all patients. The CEUS studies were performed after an intravenous bolus injection of 1.2 mL and 2.4 mL of a second-generation contrast agent with continuous low-mechanical index (range, 0.01-0.04) real-time tissue harmonic imaging. The unenhanced US and CEUS studies were interpreted separately by two independent experienced readers to detect the presence of endoleaks by viewing recorded videotapes according to a five-point confidence scale. The standard of reference was represented by the consensus reading of CTA performed by two experienced radiologists not involved in the image analysis. Qualitative analysis as well as sensitivity, specificity, negative predictive value, and diagnostic accuracy in detecting endoleaks of each reading session were compared. RESULTS: CEUS imaging significantly improved the diagnostic performance of unenhanced US studies in the detection of endoleaks in terms of sensitivity (97.5% vs 62.5%), negative predictive value (97.3% vs 65.1%), accuracy (89.3% vs 63.1%), and specificity (81.8% vs 63.6%). The optimal dose of contrast agent to detect and characterize endoleaks was 2.4 mL. No adverse events were recorded during the study. CONCLUSIONS: The results showed CEUS imaging is a fast, noninvasive, reliable, and valid alternative to multislice CTA for endoleak detection in endovascular aortic stent graft patients, and is superior to unenhanced US imaging. Contrast-enhanced ultrasound imaging should be performed using a recommended contrast medium dose of 2.4 mL.

MDCT angiography for detection of pulmonary emboli: comparison between equi-iodine doses of iomeprol 400 mgI/mL and iodixanol 320 mgI/mL.

OBJECTIVES: To compare iomeprol 400 and iodixanol 320 in pulmonary artery MDCTA in subjects with suspected pulmonary embolism. METHODS: Eighty randomized subjects received equi-iodine intravenous doses (48 g) of iomeprol 400 (n=40) or iodixanol 320 (n=40), via power injector at 4 mL/s. Four-row (35 subjects) and 64-row (45 subjects) scanners were used. Lumen attenuation was determined on-site and by two off-site blinded readers in the main, lobar, segmental and subsegmental pulmonary arteries. Statistical comparison between groups was performed for demographics and lumen attenuation. RESULTS: There were no between-group differences (p>0.05) in demographics. Pulmonary artery attenuation was significantly (p

Four-detector row computed tomographic angiography in the evaluation of infrarenal aorta and peripheral arterial occlusive disease: influence of contrast medium concentration.

PURPOSE: To prospectively compare the diagnostic accuracy and quality of vascular enhancement of 2 contrast agents with different iodine concentrations in 4-detector row computed tomographic angiography of abdominal aorta and lower-extremity arteries. MATERIALS AND METHODS: Forty consecutive patients with peripheral arterial occlusive disease referred for conventional angiography (digital subtraction angiography [DSA]) of the lower extremity were prospectively enrolled in the study and underwent multidetector row computed tomographic angiography (CTA) receiving either 90 mL of iomeprol 400 (Iomeron 400, group A; Bracco Imaging S.p.A., Milan, Italy) or 120 mL of iomeprol 300 (Iomeron 300, group B; Bracco Imaging). Resultant images, both axial, maximum intensity projection, multiplanar reformatted, and volume-rendered 3-dimensional images, were independently evaluated by 2 clinically competent and experienced blinded radiologists for the presence of stenotic and occluded arterial segments using DSA as the standard of reference. Computed tomographic images were also evaluated quantitatively for maximum arterial and venous enhancement, and qualitatively for vascular opacification, venous overlap, and diagnostic efficacy. Quantitative and qualitative results of the 2 study agent groups were statistically compared. Both contrast media were evaluated for safety and tolerability. RESULTS: From 760 segments, 722 arterial segments were effectively evaluated in the comparative analysis of CTA and DSA. In the evaluation of significant stenoses (>70%) and occluded segments, multidetector row CTA obtained a sensitivity, specificity, and accuracy of 97.1%, 96%, and 96.3%, and 98.9%, 100%, and 99%, respectively. Iomeprol 400 demonstrated an increased arterial enhancement in aortoiliac and femoral districts in comparison to iomeprol 300 (mean increase in opacification, 37.3 Hounsfield units) and a significant better qualitative assessment in the aortoiliac segments without an increase in venous opacification or the presence of venous overlap. No significant differences were found for sensitivity and specificity for the diagnosis of significant stenoses (>70%) and occluded segments. Both agents were well tolerated, and no adverse events were recorded. CONCLUSIONS: The use of a small volume of a high-concentration contrast material yielded higher arterial enhancement from the abdominal aorta down to the femoral arteries with absent or minimal venous overlap and without significant differences in diagnostic ability.

Multidetector-row computed tomography angiography in abdominal aortic aneurysm treated with endovascular repair: evaluation of optimal timing of delayed phase imaging for the detection of low-flow endoleaks.

PURPOSE: To evaluate the optimal timing of delayed phase imaging for detecting low-flow endoleaks. MATERIALS AND METHODS: Fifty-eight patients with unruptured abdominal aortic aneurysm treated with endovascular repair underwent 1- and 6-month follow-up multidetector row computed tomography (CT) performed during unenhanced, arterial, and delayed phase. At 6-month follow-up, delayed phase imaging, focused on stent graft, was performed with a delay of 60 (early delayed enhanced phase) and 300 seconds (late delayed enhanced phase) after intravenous injection of 120 mL of iodinated nonionic contrast medium (iomeprol 300 mgI/mL, Iomeron), at a flow rate of 3 mL/s via an antecubital vein, with a detector-row configuration of 4 x 1-mm, a 1.25-mm slice width, and a pitch of 6. Six-month follow-up CT images were independently evaluated by 2 readers during 2 different reading sessions: sets A (unenhanced, arterial, and early delayed phase images) and B (unenhanced, arterial, and late delayed phase images). Sensitivity and diagnostic accuracy of both reading sessions were compared. The standard of reference was represented by the combined evaluation of 1- and 6-month CT scans. RESULTS: At standard of reference, 24 of 58 patients had an endoleak classified as type 1 in 2 cases, type 2 in 21 cases, and type 3 in the last 1 case. Seven of 21 type 2 endoleaks were classified as low-flow endoleaks. Set A reading session, including early delayed enhanced phase, allowed the detection of 19 of 24 endoleaks (5 false-negative cases represented by low-flow endoleaks), whereas all endoleaks were detected during set B reading session, including late delayed enhanced phase. Differences between sets A and B in terms of sensitivity and diagnostic accuracy were statistically significant (P < 0.05). CONCLUSIONS: For optimal multidetector CT detection of low-flow endoleaks in patients who underwent endovascular repair, delayed phase should be acquired 300 seconds after injection of contrast medium.

Multidetector-row CT angiographic imaging of the celiac trunk: anatomy and normal variants.

PURPOSE: To evaluate the ability of MDCT reformations in describing the celiac trunk vascular anatomy and variations. MATERIALS AND METHODS: A total of 555 MDCT angiographies of the abdominal aorta performed between January 2002 and July 2005 were retrospectively reviewed to assess the celiac trunk vascular anatomy and variations. All the patients with pathological condition likely to affect normal vascular anatomy as well as CT exams technically inadequate were excluded from our study. RESULTS: A total of 524 MDCT angiographies of abdominal aorta were included in our study. The classical configuration of the celiac trunk was detected in 72.1%. The hepato-splenic trunk was detected in 50.4% of cases; the hepato-gastro-splenic trunk was detected in 19.4% of cases; the gastro-splenic trunk was detected in 2.3% of cases. The hepato-spleno-gastric trunk associated with hepatic arteries variants were found in 15.4%. The hepato-splenic trunk, the hepato-gastric trunk, the hepato-splenic-mesenteric trunk, and the spleno-gastric trunk were found in 2.7, 5, 0.4, and 3.6%, respectively. In 0.6%, we found an absent celiac trunk. CONCLUSION: The knowledge of the type of anatomical variants and their subtypes is fundamental for a correct pre-operative vascular planning in surgical or radiological abdominal procedures. Multidetector-row CT (MDCT) provides high-quality 3D-reconstructed images and allows non-invasive assessment of normal anatomy and anatomic variants of celiac trunk.

Obscure gastrointestinal bleeding and small bowel pathology: comparison between wireless capsule endoscopy and multidetector-row CT enteroclysis.

Obscure gastrointestinal bleeding is defined as bleeding of unknown origin, that persists or recurs after negative conventional barium contrast studies and upper and lower tract endoscopy. The causes of such a bleeding frequently arise in the small bowel, and they are represented by mucosal vascular abnormalities, neoplasms and other conditions such as Crohn's disease, Meckel's diverticulum, and vasculitis. Conventional barium contrast studies and push enteroscopy allow only a limited small bowel examination; moreover, intraoperative endoscopy may be inconclusive, since the small bowel is difficult to evaluate given its length and tortuous course. In the same way, angiographic diagnosis is stricktly related to the activity rate of hemorrhage. Wireless capsule endoscopy and multidetector-row CT enteroclysis are two recently developed minimally invasive techniques that may provide a complete small bowel examination, the first offering a direct visualization of the mucosal aspect, the second allowing evaluation of mural and extramural pathologies. This review is an update of the technique and clinical application of capsule endoscopy and multidetector-row CT enteroclysis in patients suffering from obscure small bowel bleeding.

Idiopathic segmental infarction of the greater omentum diagnosed by unenhanced multidetector-row CT and treated successfully by laparoscopy.

Idiopathic segmental infarction of the greater omentum is a rare disorder presenting with nonspecific clinical symptoms that may mimic a variety of acute abdominal conditions. We describe the diagnosis and treatment of two patients who had idiopathic infarction of the greater omentum and presented with localized abdominal pain, mimicking acute cholecystitis and acute diverticulitis, respectively. Patients underwent unenhanced multidetector-row computed tomography (CT) examination, which demonstrated the characteristic features of omental infarction, consisting of a heterogeneous density fatty mass, containing hyperattenuating streaks, located in the greater omentum, between the anterior abdominal wall and the colon; a moderate amount of free peritoneal fluid was also present. There were no other pathological abdominal findings. Giving persisting and worsening symptoms, both patients underwent laparoscopy with resection of the necrotic portion of the omentum. Pathology confirmed the preoperative diagnosis. Unenhanced CT allows us to obtain a reliable diagnosis of omental infarction in patients with acute abdominal pain and may help in selecting the appropriate medical or surgical therapy.

Endovascular treatment of thoracic aortic diseases: Follow-up and complications with multi-detector computed tomography angiography.

Endovascular procedures with placement of stent-graft has become an accepted alternative to traditional open surgery for treatment of descending thoracic aortic aneurysms, ulcers, post-traumatic rupture, or complications of type-B dissection, due to significant reduction in perioperative mortality, rate of complications and length of hospitalization. Moreover, increasing operator experience and continuous advances in stent-graft technology are making treatment of a wider range of cases possible with redefinition of guidelines for endovascular stent-graft. The feasibility of endovascular stent-graft is mainly dependent on anatomic factors which represent the important predictors of the success of this procedure as well as on strictly follow-up in order to obtain early detection and treatment of eventual complications. Multi-detector CT-angiography is a fast, safe, and minimally invasive imaging technique that represents the standard of reference in the follow-up of patients who have undergone endovascular stent-graft, as it is effective and specific in the detection of procedure-correlated complications. The purpose of this article is to give a brief review of those techniques most commonly used for endovascular treatment of thoracic aortic diseases together with a more detailed description of post-procedural complications and their appearance on multi-detector CT-angiography.

MDCT angiography in abdominal aortic aneurysm treated with endovascular repair: diagnostic impact of slice thickness on detection of endoleaks.

OBJECTIVE: The objective of our study was to evaluate the diagnostic impact of slice thickness on the detection of endoleaks at MDCT. SUBJECTS AND METHODS: Fifty patients with abdominal aortic aneurysm treated with endovascular repair who had undergone follow-up MDCT were enrolled in this study. Contrast-enhanced images were obtained with a 4-MDCT scanner (1-mm collimation). Images were reconstructed using a 1-mm (set A), 3-mm (set B), or 5-mm (set C) slice width. Each image set was interpreted by two independent readers for the presence of endoleaks and for image quality on a dedicated workstation. Sensitivity, specificity, and positive predictive values of each reading session were compared. RESULTS: The statistical values obtained with sets A and B were significantly higher (p < 0.001) than those obtained with set C. No statistically significant differences were found between the values obtained with sets A and B. CONCLUSION: For the detection of endoleaks at MDCT, the sensitivity of 1- and 3-mm-thick images was significantly higher than that of 5-mm-thick slices. However, no statistically significant differences were found between the 1- and 3-mm image sets; moreover, the use of thinner reconstruction images (1 mm) has the disadvantage of increasing the number of images that must be interpreted and archived.

Four-section multidetector computed tomographic imaging of bowel obstruction: usefulness of axial and coronal plane combined reading.

OBJECTIVE: To compare the diagnostic performance of axial and coronal views in multidetector-row computed tomography (MDCT) of patients with small-bowel obstruction (SBO) or large-bowel obstruction (LBO). MATERIALS AND METHODS: Among 157 patients with clinical and radiographic findings of BO, 73 patients, who underwent MDCT and were found to have surgically proven SBO (49/73) or LBO (24/73), were retrospectively evaluated. Portal-enhanced MDCT was performed using 4 x 2.5-mm collimation; 3-mm-thick axial images were reconstructed with 2 mm of increment. Coronal views were reformatted using 3-mm-thick sections with 1 mm of increment. Three radiologists analyzed axial (session A), coronal (session B), and axial plus coronal images (session C) to identify the site, cause, and type of BO. To correlate surgical findings and MDCT results, the bowel was divided into duodenum, oral jejunum, aboral jejunum, oral ileum, aboral ileum, cecum/ascending colon, transverse colon, descending colon, and sigmoid colon/rectum. The mean diagnostic accuracy and the mean confidence score of each reader and each reading session were calculated. RESULTS: The diagnostic accuracy of axial images was higher than that of coronal views (P = 0.014) in SBO, whereas no significant differences were found in LBO. The definition of the SBO cause was correctly assessed in 45 of 49 patients during session A, in 40 of 49 during session B, and in 45 of 49 during session C. In patients with LBO, the cause was correctly assessed in 21 of 24 patients during session A and in 22 of 24 patients during sessions B and C. All readers interpreted axial plus coronal images with a significantly higher confidence level than axial or coronal views alone, either for the detection of the site (P = 0.002) or for the identification of the cause (P < 0.001) of SBO and LBO. CONCLUSION: The MDCT allowed accurate detection of the site and the cause of obstruction. In SBO, axial images yielded a higher diagnostic accuracy than coronal views, whereas in LBO, no differences were found between axial and coronal planes. The reading of axial plus coronal views significantly improved diagnostic confidence.

Coronary artery bypass grafts and MDCT imaging: what to know and what to look for.

Multi-detector row CT (MDCT) scanners with high spatial and temporal resolutions are now available and are increasingly used for non-invasive assessment of vascular disease, including coronary arteries and coronary artery bypass grafts (CABG). Follow-up of patients who have previously undergone surgical revascularization for coronary artery disease is nowadays one of the main applications of MDCT. Thanks to the continuous technical evolution of the CT scanners, it is now possible to scan the heart and the full anatomic extent of grafts with sub-millimeter slice-thickness within a single breath-hold. In the evaluation of these patients, it is important for the radiologist to be familiar with the different types of grafts and surgical techniques to know the main characteristics of each graft type and what to look for in the assessment of a patient who has undergone coronary artery surgical revascularization. This review summarizes some surgical aspects, the biological characteristics of conduits, and the main technical MDCT features, and describes the CABG anatomy together with some typical CT findings.

Multi-slice CT (MSCT) angiography for assessment of traumatic lesions of lower limbs peripheral arteries.

AIM: The aim of this study was to evaluate the feasibility and effectiveness of multi-slice computed tomography (MSCT) angiography for the assessment of traumatic lesions involving the arteries of the lower limbs. MATERIALS AND METHODS: Forty-seven patients with suspected arterial post-traumatic lesions of lower limbs underwent MSCT angiography (4 x 2.5-mm collimation, 3-mm slice width). The standards of reference were: digital subtraction angiography (DSA; patients with inconclusive/doubtful or positive MSCT angiography indicating a need for intravascular treatment), surgical findings (patients with positive MSCT angiography indicating a need for surgery), or clinical/investigational follow-up (patients with negative MSCT angiography and no need for further diagnostic procedures or surgery). RESULTS: All CT exams were technically adequate. Sensitivity, specificity, and overall diagnostic accuracy of MSCT angiography were 96.3, 90, and 93.6%, respectively, relative to the reference of standard findings. In 44 out of 47 patients, MSCT angiography allowed a correct continuation of the diagnostic work-up. CONCLUSION: MSCT angiography is a reliable fast tool for diagnosing traumatic vascular lesions, providing results comparable to DSA.

Multidetector-row computed tomography of focal liver lesions treated by radiofrequency ablation: spectrum of findings at long-term follow-up.

OBJECTIVE: To assess serial changes in liver tumors after percutaneous radiofrequency ablation at follow-up multidetector-row computed tomography. MATERIALS AND METHODS: Forty patients with 65 malignant lesions underwent multidetector-row computed tomography immediately, 1 month and every 3 months, up to a maximum of 15 months after radiofrequency ablation. The computed tomography (CT) appearance of the treated lesions (non-enhanced attenuation, enhancement pattern, shape and size) was assessed at each follow-up. The relationship between each CT finding and the treatment outcome was evaluated by chi2 test (P < 0.05). RESULTS: No significant differences were found in lesion shape and in non-enhanced CT attenuation between successfully and unsuccessfully treated lesions, whereas over time change of lesion size was significantly different. The no enhancement and nodular enhancement pattern prevalence was significantly (P < 0.0001) different between successfully and unsuccessfully treated lesions, whereas non-nodular enhancement pattern did not show any relationship with the treatment outcome. CONCLUSIONS: Lesion size increase and nodular enhancement pattern resulted significantly related to the treatment failure.

Bowel obstruction: comparison between multidetector-row CT axial and coronal planes.

Acute obstruction of bowel is a common reason for presentation to the emergency department. Causes of obstruction are multiple (tumorous, inflammatory, postoperative, or congenital), but the clinical presentation is usually not specific. The abdominal radiographs are sometimes inconclusive, and cause of obstruction is rarely detected. Computed tomography (CT) has been shown to be useful in revealing the site and the cause of obstruction. Although radiologists are skilled in the interpretation of CT scans in the axial plane, the development of multidetector-row CT coupled with fast reconstruction hardware and software has stimulated interest in viewing abdomen in coronal plane. In the evaluation of small bowel obstruction, coronal plane serves as a useful adjunct for the identification of the point of transition from dilated to decompressed bowel. On the other hand, in the evaluation of large bowel obstruction, coronal planes could replace axial images in the evaluation of the site and cause of obstruction, although the best values of confidence level in the diagnosis are reached when interpreting axial combined with coronal images.

Pulmonary nodule.

A pulmonary nodule is a frequent and often incidental finding, and still represents a diagnostic challenge for radiologists. Although most solitary nodules are related to benign disease, some represent stage I lung cancers. and need to be distinguished from benign nodules in a cost-effective manner. The aim of diagnostic assessment should be to allow early treatment of small malignant nodules but avoid unnecessary biopsy or surgery, with their attendant risks, in patients with benign disease. The advent of Multislice Computed Tomography (MSCT) technology has sparked new interest in the non-invasive assessment of pulmonary nodules. Thanks to its ability to scan the whole thoracic volume with thinner collimations, this technology allows a more accurate identification and characterisation of pulmonary nodules, as well as the determination of perfusion patterns and growth rates. In this paper we present an algorithm for the diagnostic workup of incidentally detected small pulmonary nodules in subjects without known malignancy.