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Background: Radiomics is a quantitative approach that allows the extraction of mineable data from medical images. Despite the growing clinical interest, radiomics studies are affected by variability stemming from analysis choices. We aimed to investigate the agreement between two open-source radiomics software for both contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance imaging (MRI) of lung cancers and to preliminarily evaluate the existence of radiomic features stable for both techniques., Methods: Contrast-enhanced CT and MRI images of 35 patients affected with non-small cell lung cancer (NSCLC) were manually segmented and preprocessed using three different methods. Sixty-six Image Biomarker Standardisation Initiative-compliant features common to the considered platforms, PyRadiomics and LIFEx, were extracted. The correlation among features with the same mathematical definition was analyzed by comparing PyRadiomics and LIFEx (at fixed imaging technique), and MRI with CT results (for the same software)., Results: When assessing the agreement between LIFEx and PyRadiomics across the considered resampling, the maximum statistically significant correlations were observed to be 94% for CT features and 95% for MRI ones. When examining the correlation between features extracted from contrast-enhanced CT and MRI using the same software, higher significant correspondences were identified in 11% of features for both software., Conclusions: Considering NSCLC, (i) for both imaging techniques, LIFEx and PyRadiomics agreed on average for 90% of features, with MRI being more affected by resampling and (ii) CT and MRI contained mostly non-redundant information, but there are shape features and, more importantly, texture features that can be singled out by both techniques., Relevance Statement: Identifying and selecting features that are stable cross-modalities may be one of the strategies to pave the way for radiomics clinical translation., Key Points: • More than 90% of LIFEx and PyRadiomics features contain the same information. • Ten percent of features (shape, texture) are stable among contrast-enhanced CT and MRI. • Software compliance and cross-modalities stability features are impacted by the resampling method., (© 2024. The Author(s).)

Background: Classical pulmonary thromboembolism (TE) and local pulmonary thrombosis (PT) have been suggested as mechanisms of thrombosis in COVID-19. However, robust evidence is still lacking because this was mainly based on retrospective studies, in which patients were included when TE was suspected., Methods: All patients with COVID-19 pneumonia underwent computed tomography and pulmonary angiography in a prospective study. The main objective was to determine the number and percentage of thrombi surrounded by lung opacification (TSO) in each patient, as well as their relationship with percentage of lung involvement (TLI), to distinguish classical TE (with a random location of thrombi that should correspond to a percentage of TSO equivalent to the TLI) from PT. We determined TLI by artificial intelligence. Analyses at patient level (TLI and percentage of TSO) and at thrombi level (TLI and TSO) were performed., Results: We diagnosed TE in 70 out of 184 patients. Three (2-8) thrombi/patient were detected. The percentage of TSO was 100% (75-100) per patient, and TLI was 19.9% (4.6-35.2). Sixty-five patients (92.9%) were above the random scenario with higher percentage of TSO than TLI. Most thrombi were TSO (n = 299, 75.1%). When evaluating by TLI (<10%, 10%-20%, 20%-30% and >30%), percentage of TSO was higher in most groups. Thrombi were mainly in subsegmental/segmental arteries, and percentage of TSO was higher in all locations., Conclusions: Thrombi in COVID-19 were found within lung opacities in a higher percentage than lung involvement, regardless of TLI and clot location, supporting the hypothesis of local PT rather than "classic TE"., (© 2024 The Authors. European Journal of Clinical Investigation published by John Wiley & Sons Ltd on behalf of Stichting European Society for Clinical Investigation Journal Foundation.)

Objective: The aim of the study was to retrospectively evaluate the prevalence of reported and unreported potentially important incidental findings (PIFs) in consecutive nonenhanced abdominal CTs performed specifically for renal colic in the urgent setting., Methods: One radiologist, blinded to the finalized report, retrospectively re-evaluated nonenhanced abdominal CTs performed from January to December 2017 on adult patients from the emergency department with the specific request of urgent evaluation for renal colic, searching for PIFs., Results: The CTs of 312 patients were included in the study. Thirty-eight findings were reported in 38 different CTs, whereas the re-evaluation added 47 unreported findings in 47 different CTs, adding to total of 85 findings (27%). The difference in the proportion of reported and unreported PIFs between the original report and re-evaluation was significant (p < 0.001). No significant difference was found between the age of patients with and without reported findings. The proportion of potentially important findings did not vary significantly among the 3 shifts in the original report and in re-evaluation. The most frequent findings, both reported and unreported, were pleural effusion, lymphadenopathies, and liver nodules., Conclusions: Potentially important additional findings are frequently present in urgent nonenhanced abdominal CTs performed for renal colic, and many are not described in the finalized reports. Radiologists should take care not to underreport PIFs even in the urgent setting because of the possible consequences on the patient's health and in order to avoid legal issues, while at the same time satisfying the need for timely and efficient reporting., (© 2021 The Author(s) Published by S. Karger AG, Basel.)

Objectives: Pulmonary nodules and masses are the typical presentations of lung cancer. However, a spectrum of focal opacities cannot be defined as either "pulmonary nodule" or "mass," despite representing cancer. We aimed to assess the morphology of screening-detected lung cancers at low-dose computed tomography LDTC and to evaluate inter-observer agreement in their classification., Methods: Four radiologists with different experiences in thoracic imaging retrospectively reviewed 273 screening-detected lung cancers. Readers were asked to assess if morphology at the time of diagnosis was consistent with the Fleischner Society definition of pulmonary "nodule" or "mass." Cancers not consistent were defined as "non-nodular/non-mass" (NN/NM) and sub-classified as follows: associated with cystic airspaces, stripe-like, scar-like, endobronchial, or not otherwise defined (NOD). Inter-observer agreement was evaluated using Cohen's K statistic among pairs of readers and modified Fleiss' kappa statistic for overall agreement., Results: Two hundred forty-one of the 273 (88%) lesions were defined as pulmonary nodule or mass by complete agreement, while 20/273 (7.3%) were defined as NN/NM. Six (2.2%) of 273 were sub-classified as lesions associated with cystic airspace, six (2.2%) as scar-like, five (1.8%) as endobronchial, and one (0.7%) as NOD by complete agreement. The concordance in defining morphology was excellent (261/273; 96%, 95%CI 92-98%; k 0.85, 95%CI 0.75-0.92) and also in the sub-classification (18/20; 90%, 95%CI 68-99%, k 0.93, 95%CI 0.86-1.00). There was incomplete agreement regarding lesion morphology in 4.4% (12/273) of cases., Conclusions: A non-negligible percentage of screening-detected lung cancers has a NN/NM appearance at LDCT. The concordance in defining lesion morphology was excellent. The awareness of various presentations can avoid missed or delayed diagnosis., Key Points: • A non-negligible percentage of screening-detected lung cancers have neither nodular nor mass appearance at low-dose CT. • The awareness of various LDCT presentations of lung cancer can avoid missed or delayed diagnosis. • Optimal protocol management in CT screening should take into consideration lung nodules as well as various other focal abnormalities.

Objectives: To evaluate quantification of iodine uptake in metastatic and non-metastatic lymph nodes (LNs) by dual-energy CT (DECT) and to assess if the distribution of iodine within LNs at DECT correlates with the pathological structure., Methods: Ninety LNs from 37 patients (23 with lung and 14 with gynaecological malignancies) were retrospectively selected. Information of LNs sent for statistical analysis included Hounsfield units (HU) at different energy levels; decomposition material densities fat-iodine, iodine-fat, iodine-water, water-iodine. Statistical analysis included evaluation of interobserver variability, material decomposition densities and spatial HU distribution within LNs., Results: Interobserver agreement was excellent. There was a significant difference in iodine-fat and iodine-water decompositions comparing metastatic and non-metastatic LNs (p < 0.001); fat-iodine and water-iodine did not show significant differences. HU distribution showed a significant gradient from centre to periphery within non-metastatic LNs that was significant up to 20-30% from the centre, whereas metastatic LNs showed a more homogeneous distribution of HU, with no significant gradient., Conclusions: DECT demonstrated a lower iodine uptake in metastatic compared to non-metastatic LNs. Moreover, the internal iodine distribution showed an evident gradient of iodine distribution from centre to periphery in non-metastatic LNs, and a more homogeneous distribution within metastatic LNs, which corresponded to the pathological structure., Key Points: • This study demonstrated a lower iodine uptake in metastatic than non-metastatic LNs. • Internal distribution of HU was different between metastatic and non-metastatic lymph nodes. • The intranodal iodine distribution disclosed a remarkable correlation with the histological LN structure.

Purpose: The authors assessed the adequacy and sensitivity of CT-guided bone biopsy in 308 procedures performed in 286 cancer patients with suspected bone metastases., Materials and Methods: An electronic search of our CT-guided bone biopsy database was retrospectively performed to evaluate the adequacy of samples and, in the event of negative samples, whether the patients had radiological progression at the site of biopsy (false negative). Adequacy and false-negative rate were compared with radiological features, biopsy location, specimen length and complications to assess any statistically relevant association with a multivariate logistic regression model., Results: A total of 290/308 (94.1 %) samples were adequate. Forty-five patients had normal bone marrow and were followed-up, with evidence of progression at the site of biopsy in 10 cases (false-negative cases); overall sensitivity was 96.7 %. Specimen length was significantly correlated to the probability of an adequate biopsy (p = 0.035) and inversely correlated to the probability to obtain a false-negative result (p = 0.02). We encountered 11/308 (3.5 %) minor complications and no major complications., Conclusion: CT-guided biopsy of bone lesions in cancer patients allows for a final diagnosis in 94 % of cases. A specimen longer than 1 cm may lead to a significant result in terms of adequacy and sensitivity. Negative biopsies with positive positron emission tomography or magnetic resonance imaging and specimen shorter than 1 cm should be repeated to avoid a false-negative result.

Background and Purpose: Irradiation of the Pharyngeal Superior Constrictor Muscle (PSCM) seems to play a crucial role in radiation-related swallowing dysfunctions. Purpose of our study was to quantify operator-related variability in the contouring of PSCM on Computed Tomography (CT) scans and adherence with contours derived from MR images., Materials and Methods: Three sets of treatment planning CT and their corresponding MR images were selected. Contouring of the PSCM was performed using both a literature-based method, derived from literature review, and an optimized method, derived from Magnetic Resonance (MR) images thus obtaining "literature-based" and "optimized" contours. Each operator contoured the PSCM on CT scans according to both methods for three times in three different days. Inter- and intra-operator variability and adherence to a contour obtained from MR images (named "MR-derived" contour) were analyzed., Results: Thirty-four operators participated and 612 contours were obtained. Both intra- and inter-operator variability and adherence to the "MR-derived" contour were significantly different between the two methods (p⩽0.05). The "optimized" method showed a lower intra- and inter-operator variability and a higher adherence to the "MR-derived" contour., Conclusions: The "optimized" method ameliorates both operator-related variability and adherence with MR images., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

This review aims to summarize the technique and clinical applications of CT perfusion (CTp) of head and neck cancer. The most common pathologic type (90%) of head and neck cancer is squamous cell carcinoma (HNSCC): its diagnostic workup relies on CT and MRI, as they provide an accurate staging for the disease by determining tumour volume, assessing its extension, and detecting of lymph node metastases. Compared with conventional CT and MRI, CTp allows for obtaining measures of tumour vascular physiology and functional behaviour, and it has been demonstrated to be a feasible and useful tool in predicting local outcomes in patients undergoing radiation therapy and chemotherapy and may help monitor both treatments.

Purpose: To retrospectively assess the detection rate, histologic characteristics, and clinical stage of screening-detected extrapulmonary malignancies in a population at high risk for lung cancer., Materials and Methods: In this institutional review board-approved study, 5201 asymptomatic heavy smokers aged 50 years or older underwent annual low-dose computed tomography (CT) for 5 consecutive years. The 5-year cumulative effective dose was 5 mSv. Subjects with at least one "potentially significant extrapulmonary incidental finding" (PS-IF) were extracted from the study database. An extrapulmonary finding was classified as potentially significant if it required further diagnostic and/or clinical evaluation. In retrospect all clinically relevant information, including findings from diagnostic work-up and final diagnosis of the PS-IF, was collected. On the basis of the information collected, only histologically proved screening-detected extrapulmonary malignancies were eventually included in this study. The percentages of volunteers with extrapulmonary malignancies were calculated, along with 95% confidence intervals (CIs), on the basis of a binomial distribution., Results: After 5 years of CT screening, 27 unsuspected extrapulmonary malignancies were diagnosed, representing 0.5% (27 of 5201 subjects; 95% CI: 0.34%, 0.75%) of volunteers enrolled and 6.2% (27 of 436 findings; 95% CI: 4.12%, 8.88%) of PS-IFs. Eight malignancies were diagnosed at the 1st year of screening, nine at the 2nd year, four at the 3rd year, two at the 4th year, and four at the 5th year. Twelve of the 27 extrapulmonary tumors (44%) were renal carcinomas (n = 7) or lymphomas (n = 5). Twenty-four of the 27 subjects with a malignancy were alive at the most recent follow-up., Conclusion: A considerable number of unsuspected extrapulmonary malignancies can be detected in lung cancer screening trials. A careful evaluation of extrapulmonary structures, with particular attention to the kidneys and lymph nodes, is recommended., (© RSNA, 2011.)

Purpose: This study assessed the risk factors for pneumothorax and intrapulmonary haemorrhage after computed tomography (CT)-guided lung biopsies., Materials and Methods: CT-guided lung biopsies performed between January 2007 and July 2008 were retrospectively evaluated to select the study cohort. Whenever possible, emphysema was quantified by using dedicated software. Features related to the patient, the lesion and the needle and its intrapulmonary path were recorded, along with the pathology findings and operators' experience. The occurrence of pneumothorax and parenchymal haemorrhage was recorded. Univariate and multivariate statistical analyses were performed to assess the association between risk factors and complications. P values <0.05 were considered significant., Results: In 157/222 of the procedures considered, complications were associated with small lesion size and length of the intrapulmonary needle path. Transfissural course and type of needle were associated with pneumothorax using univariate analysis, whereas transfissural course was associated with intrapulmonary haemorrhage using both univariate and multivariate analysis. Emphysema, nodule type, patient position, access site and needle diameter were not significant. Fine-needle aspirates and operator experience were significantly correlated with inadequate biopsy samples., Conclusions: The size of the lesion and the length of the intrapulmonary trajectory are risk factors for pneumothorax and parenchymal haemorrhage. The transfissural course of the needles is frequently related to pneumothorax and intrapulmonary haemorrhage, and the type of the needle is related to pneumothorax.

Background: We describe preoperative computed tomography (CT)-guided injection of radiotracer technetium (99m) macroaggregates ((99m)Tc-MAA) in challenging small lung nodules, intraoperative localization, and resection., Methods: Between November 2007 and February 2010, 44 patients with 47 lung nodules which were detected incidentally or at screening and that were (18)F-fluorodeoxyglucose positron emission tomography ((18)F FDG-PET) positive or increasing in size at subsequent CT scans were candidates for surgical biopsy. Inclusion criteria for preoperative percutaneous CT-guided (low-dose technique) (99m)Tc-MAA localization included having at least one of the following characteristics: nodule size less than 1 cm, subsolid morphology, or distance from the pleura greater than 1 cm., Results: Mean nodule size was 11 mm (range, 5 to 24 mm); 24 nodules were nonsolid, 15 nodules were partially solid, and 8 nodules had a solid morphology. Mean distance from the pleura was 11 mm (range, 0 to 35 mm). Localization complications included 13 minor asymptomatic pneumothoraces, 9 parenchymal hemorrhage suffusions, 1 mild allergic reaction to contrast medium, and 2 patients with chest pain after the procedure. Nine patients had mild extravasation of radiotracer into the pleura. In 2 cases, there was an extravasation of a significant quantity of radiotracer into the pleural cavity. Thoracoscopic biopsy was performed in 30 cases, 2 cases were converted to thoracotomy, and 12 patients underwent intentional thoracotomy., Conclusions: Asymptomatic subjects with suspicious nodules detected by screening or incidental CT are best candidates due to small lesion size and high percentage of nonsolid morphology, making thoracoscopic biopsy potentially difficult. Radiotracer localization is a safe, versatile, simple technique to help perform diagnosis with a minimally invasive approach in nonpalpable lung lesions., (Copyright © 2010 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Functional imaging is becoming increasingly important in both research and clinical diagnostic radiology. Perfusion computed tomography (CTP) is a readily available and widely used tool that allows an objective measurement of tissue perfusion through the mathematical analysis of data obtained from repeated scans performed after administration of contrast agent. Recently, CTP has been increasingly used in the oncological field, being studied as a potential marker of neoplastic angiogenesis, which is one of the main targets of new tumour therapies. The aim of this paper was to provide the theoretical background and practical guidance for accurately performing CTP and interpreting results of examinations in solid-body tumours. CTP could be a valid tool for functional imaging of tumours if the acquisition technique is robust, if image and data analysis is accurate and if interpretation of results is adequately inserted within a clinical context.

Perfusion computed tomography (CTP) has shown great potential in diagnosing tumours and evaluating and predicting treatment response and has been the subject of numerous experimental and clinical studies. Its increasing availability and simplicity allow it to be performed alongside morphological imaging to complete the evaluation of neoplastic lesions. The aim of this paper is to describe our personal experience and review the literature on the applications of CTP in tumours of different body regions, with particular regard to fields of development for new research. Increased clinical application is desirable, especially in relation to a wider use of antiangiogenic drugs. Additional and ideally multicentre studies are necessary to define the role of this technique.

Low-dose computed tomography (ld-CT) for lung cancer screening in high-risk subjects is performed within clinical trials and has started to be used in routine clinical practice. The technique is well defined, even if some methodological problems are still debated, such as the measurements of pulmonary nodules, the size to define them as clinically significant, the management of small or non-solid nodules and the best diagnostic work-up to optimize diagnostic accuracy. The data derived from an IEO observational study, started in 2000, shows a high prevalence and incidence of early stage lung cancer detected at ld-CT, demonstrating the need to prolong observation for a long period of time. The high survival rate of patients with screening-detected cancer has recently been debated in a number of papers using statistical models, but the advantage of the yearly ld-CT for the individuals is unquestionable; its benefit on the population base has still to be demonstrated by ongoing randomized trials.

Background and Purpose: CT Perfusion (CTP) has shown potential for assessing head and neck tumors. Our purposes were to assess the inter- and intraobserver agreement of CTP measurements and to investigate whether the selection of arterial input, ipsilateral versus contralateral to the tumor or left-versus-right external carotid artery (ECA), may affect CTP measurements in patients with squamous cell carcinoma (SCCA) of the upper aerodigestive tract., Materials and Methods: Twenty-six patients with SCCA were enrolled in this prospective study and underwent CTP. Data were analyzed by 2 expert readers and by an inexperienced reader for interobserver agreement and by the 2 expert readers for intraobserver agreement assessment, by using the ECA ipsilateral to tumor site as arterial input. All 3 readers repeated their analysis by using the ECA contralateral to tumor site as arterial input. Inter- and intraobserver agreement was assessed by using the Bland-Altman approach; CTP measurements by using ipsilateral-versus-contralateral or left-versus-right ECA were compared by using the Wilcoxon signed rank test., Results: The geometric mean of the ratios (95% limits of agreement) for inter- and intraobserver agreement ranged from 0.96 (0.75-1.23) to 1.00 (0.92-1.10) for blood flow (BF), from 0.88 (0.63-1.21) to 1.00 (0.88-1.14) for blood volume (BV), from 0.96 (0.64-1.44) to 0.98 (0.76-1.27) for mean transit time (MTT), and from 0.85 (0.41-1.76) to 1.14 (0.70-1.86) for permeability surface area product (PS). Significantly higher tumor PS and MTT for 2 readers and lower tumor BF for 1 of 3 readers were observed when the arterial input was placed in the left ECA., Conclusions: BF, BV, and MTT demonstrated higher inter- and intraobserver agreement than PS. The selection of arterial input, right-versus-left ECA, may determine changes in CTP measurements in patients with SCCA of the upper aerodigestive tract.

Objective: The main challenge of screening a healthy population with low-dose computed tomography is to balance the excessive use of diagnostic procedures with the risk of delayed cancer detection. We evaluated the pitfalls, difficulties, and sources of mistakes in the management of lung nodules detected in volunteers in the Cosmos single-center screening trial., Methods: A total of 5201 asymptomatic high-risk volunteers underwent screening with multidetector low-dose computed tomography. Nodules detected at baseline or new nodules at annual screening received repeat low-dose computed tomography at 1 year if less than 5 mm, repeat low-dose computed tomography 3 to 6 months later if between 5 and 8 mm, and fluorodeoxyglucose positron emission tomography if more than 8 mm. Growing nodules at the annual screening received low-dose computed tomography at 6 months and computed tomography-positron emission tomography or surgical biopsy according to doubling time, type, and size., Results: During the first year of screening, 106 patients underwent lung biopsy and 91 lung cancers were identified (70% were stage I). Diagnosis was delayed (false-negative) in 6 patients (stage IIB in 1 patient, stage IIIA in 3 patients, and stage IV in 2 patients), including 2 small cell cancers and 1 central lesion. Surgical biopsy revealed benign disease (false-positives) in 15 cases (14%). Positron emission tomography sensitivity was 88% for prevalent cancers and 70% for cancers diagnosed after first annual screening. No needle biopsy procedures were performed in this cohort of patients., Conclusion: Low-dose computed tomography screening is effective for the early detection of lung cancers, but nodule management remains a challenge. Computed tomography-positron emission tomography is useful at baseline, but its sensitivity decreases significantly the subsequent year. Multidisciplinary management and experience are crucial for minimizing misdiagnoses.

Background: Indeterminate non-calcified lung nodules are frequent when low-dose spiral computed tomography (LD-CT) is used for lung cancer screening. We assessed the diagnostic utility of a non-invasive work-up protocol for nodules detected at baseline in volunteers enrolled in our single-centre screening trial, and followed for at least 1 year., Methods: 5201 high-risk volunteers, recruited over 1 year from October 2004, underwent baseline LD-CT; 4821 (93%) returned for the first repeat LD-CT. Nodules 8mm received combined CT-positron emission tomography (CT-PET). A subset of nodules >8mm was studied by CT with contrast. Protocol failures were delayed diagnosis with disease progression beyond stage I, and negative surgical biopsy., Results: 2754 (53%) volunteers presented one or more non-calcified nodules. Ninety-two lung cancers were diagnosed: 55 at baseline and 37 at annual screening (66% stage I). Among the 37 incident cancers, 17 had a baseline nodule that remained stage I, 7 had a baseline nodule that progressed beyond stage I, and 13 presented a new malignant nodule. Baseline and annual cancers were 79 (1.5%) and 13 (0.2%), respectively. In 15 of 104 (14%) invasive diagnostic procedures, the lesion was benign. Sensitivity, and specificity were 91 and 99.7%, respectively, for the entire protocol; 88 and 93% for CT-PET; and 100 and 59% for CT with contrast., Conclusions: The protocol limits invasive diagnostic procedures while few patients have diagnosis delay, supporting the feasibility of lung cancer screening in high-risk subjects by LD-CT. Nevertheless further optimization of the clinical management of screening-detected nodules is necessary.

The purpose of this study was to register the accuracy and reproducibility of the multidetector computed tomography (MDCT) estimate of hypopharyngeal and laryngeal tumor volumes. Eighteen consecutive patients with larynx or hypopharynx squamous cell carcinoma were enrolled in this prospective trial, scheduled for surgery and examined by MDCT. A total of 72 tumor volume measurements were reported by two different operators, one of them in three different sessions, using the sum-of-areas method. The results were compared with the volume calculated by surgical sampling. The mean tumor volume measured by MDCT was 5.7 +/- 9.3 ml (range 0.1-41.6). The mean volume measured from the surgical specimens was 5.6 +/- 8.6 ml (range 0.06-33.6). The level of agreement between histological and MDCT volumes was high, with a slight tendency of MDCT to overestimation, proportional to the size. The analysis of interoperator variability showed a tendency of the more expert operator to make more accurate estimates, but the differences were not significant (P = 0.62, 0.75 and 0.63). The evaluation of the three different sessions of the less expert operator revealed a good repeatability. According to our study, MDCT estimate of tumor volume is an effective, reproducible method. MDCT tends to produce more dispersed results in case of large tumors.

Objective: To investigate the capacity of helical CT in the pre- and post-operative management of oromandibular reconstruction of patients with oropharyngeal carcinoma using microvascular composite free flaps., Materials/methods: Thirty-four patients with oropharyngeal cancer were examined by helical CT and nine (six men and three women) submitted to oromandibular reconstruction. The osteomyocutaneous flaps used for reconstruction were taken from the iliac crest in six cases and from the fibula in three cases. All patients were examined by CT 1 - 4 days postoperatively and then at 6 monthly intervals. Double helical scans were performed in all cases, with slices of 2 - 3 mm for primary lesion studies and 5 mm for lymph node staging, pitch >/=1 and RI=1. Multiplanar (MPR) and 3D reconstructions were obtained from pre- and postoperative CT examinations., Results: Preoperative CT showed massive bone infiltration in six of the nine surgical patients and marginal infiltration in three. These findings were confirmed histologically. There were no false negatives. The immediate postoperative examination showed correct flap positioning in eight of nine cases. The flap underwent ischemic necrosis in two cases; CT showed very early signs of bone ischemia in both. CT detected two cases of recurrence after about 1 year., Conclusions: Axial CT permitted adequate assessment of the extent of mandibular infiltration and detected early ischemic complications and distant recurrences. Integration with MPR and 3D reconstructions simplified the choice of flap type and size and enabled the postoperative assessment of correct flap positioning. This helped the surgeon plan subsequent rehabilitation with osseo-integrated implants.

Intra-abdominal panniculitis is a thickening of the mesentery of the small/large intestine due to infiltration of lipid-laden macrophages associated with a variable amount of fibrosis. This condition is rarely associated with malignant neoplasms. We report the computed tomography (CT) findings of a patient treated for uterine papillary serous adenocarcinoma (UPSC). She had mesenteric panniculitis where metastatic tumor nodules implanted. This was the only intraperitoneal recurrence. To our knowledge, no such finding has been reported in the gynecologic and radiologic literature to date. On CT images, the differential diagnosis is with cystic dilatations of mesenteric lymph vessels.

Introduction: Adequate radiologic assessment of the maxillofacial trauma patient is the basis for planning reparative surgery. We investigated the yield of the integration of axial CT with multiplanar (MP) and three-dimensional (3D) reconstructions with the Spiral technique., Material and Methods: Thirty-five patients (21 men and 14 women, mean age: 31.2 years) with complex maxillofacial traumas were submitted to Spiral CT. Images were acquired with 2-3-mm collimation, 1:1 to 2:1 pitch, 210 mAs, 120 kV, 15-24 s Spiral scan, RI = 1. 3D reconstructions were always obtained and used to guide MPRs targeted on the single injury. The examinations were retrospectively given a score, namely 1 if 3D and MPR yielded no more important diagnostic information than axial CT, 2 if 3D and MPR permitted better detailing of some axial CT findings and thus improved image reading, and 3 if 3D and MPR showed new injuries missed on axial images. Then, a radiologist and a maxillofacial surgeon reviewed the 3D images together only to assess in which cases they were useful to optimize surgical planning., Results: Nine cases (25.7%) scored 1, seventeen (48.6%) scored 2 and nine (25.7%) scored 3. MP and 3D reconstructions were useful or determinant (2 + 3) in over 74% of cases. 3D images made surgical planning easier in 15 of 32 surgical patients (46.8%), allowing the surgeon a better panoramic view of the complex fracture., Conclusions: The greatest advantage of multiplanar imaging is the improved depiction of skeletal injuries along a horizontal plane, paralleling that of axial scans. The depiction of fractures of cribrum and of orbital roof and floor was particularly useful from a clinical viewpoint. MPRs clearly depicted herniation and incarceration of the lower rectus muscle in blow-out fractures. MP and 3D reconstructions better defined the presence and grade of displaced bone fragments in nearly vertical structures, such as the upward branches and coronoid apophysis of the mandible. 3D images alone never showed any more fractures than those seen on axial and MP images. 3D images are especially useful to the surgeon because they permit the panoramic depiction of the fracture complex, which facilitates treatment planning. The radiologist can use 3D reconstructions to guide the acquisition of targeted MP reconstructions, for better diagnostic yield. The Spiral technique, with its pitch increases up to 2, permits to limit the radiation dose while preserving the quality of postprocessing reconstructions. Finally, decreasing the execution time is important in multiple trauma patients who are often clinically unstable or have damaged vital organs.

Subcutaneous metastases from clear cell endometrial carcinoma are an uncommon event and tumor implantations are rarely found with diagnostic imaging techniques. The nodular form is the most frequent type of subcutaneous metastasis from genital system tumors, even though plaque-like and infiltrative forms have also been reported. We report the first case of subcutaneous metastasis from clear cell endometrial carcinoma whose progression from the early nodular to the lymphangitic infiltrative form was studied with computed tomography (CT). Differential diagnostic problems are discussed.

We investigated the accuracy of spiral computed tomography angiography (CTA) in the detection and study of intracranial aneurysms by comparing CTA with selective angiograms and surgical findings. Twenty-six patients (9 men and 17 women; mean age 53.1 +/- 1.8 years) with suspected intracranial aneurysms were submitted to CTA (1- to 2-mm slices, pitch 1:1, 24 s, RI = 1) after a conventional CT examination showing subarachnoid hemorrhage (SAH) in 19 cases and during neuroradiological investigations performed for other reasons in 7 cases. One hundred twenty to 150 ml iodate contrast agent (0.3-0.4 gI/ml) were injected intravenously at 5 ml/s rate and with 12- to 25-s delay calculated with a preliminary test bolus. Three-dimensional shaded surface display (3D SSD) and maximum intensity projection (MIP) reconstructions were obtained from axial images. Then, within 48 h, all patients were submitted to digital subtraction angiography (DSA), with separate assessment of CTA and DSA findings. Twenty-two aneurysms shown by CTA were confirmed at DSA and surgery (true positives), whereas the vascular lesion was not confirmed at DSA in 2 cases (false positives). The presence of intracranial aneurysms was excluded at both CTA and subsequent DSA in 7 cases (true negatives) and there were no false negatives; sensitivity was 100 %, specificity 77.8 %, and diagnostic accuracy 93.5 %. Computed tomography angiography aneurysm location was confirmed at surgery in all cases, with very high accuracy in assessing the presence of an aneurysm neck (100 %). Computed tomography angiography accurately depicted the aneurysm shape in 20 of 22 cases, but failed to depict its multilobed nature in 2 cases. The mean aneurysm diameter calculated at CTA was 0.99 +/- 0.12 cm vs 1.09 +/- 0.11 cm at surgery (p < 0.01). The present results suggest that the high sensitivity of CTA, if confirmed by further studies, might help in avoiding having to resort to arteriography after negative CTA in SAH patients.

Objective: To compare spiral with conventional CT for multiplanar reconstruction (MPR) prior to dental implant placement., Methods: Ten patients underwent conventional and then Spiral CT at 1 mm slice thickness. In six patients (Group A) the pitch was 1:1; the other four (Group B) it was 2:1. Image quality and clinical features were evaluated separately on axial and reconstructed images by two experienced radiologists who scored each parameter from 1 (poor, non-diagnostic) to 3 (good, diagnostic)., Results: Loss of spatial resolution with spiral CT was not significant and the diagnostic yield poorer only for trabecular bone structure. The MPRs were better and depiction of the mandibular canal more reliable., Conclusions: We recommend the use of spiral CT instead of conventional CT for dental MPR because examination time is shorter and patient comfort is improved. Use of a pitch of 2:1 permits a marked reduction in X-ray dose with no loss of image quality.

Implantation subcutaneous metastases from ovarian cancer are an uncommon event in surgery, and diagnostic procedures such as laparoscopy, fine-needle biopsy, and intraperitoneal catheter access are usually used. Findings of tumor implantations are rarely reported with diagnostic imaging techniques. In this case, an infiltrative subcutaneous metastasis appeared on computed tomography 4 months after paracentesis in a patient with untreated ovarian cancer. Differential diagnostic problems are discussed.

Purpose: To compare spiral CT with conventional radiography in planning the orthodontic treatment of impacted permanent maxillary canines., Methods: Nineteen patients with 29 malpositioned permanent maxillary canines (15 palatal and 12 buccal impactions, one ectopic and one transposition) were examined with conventional panoramic and lateral cephalometric radiography and with spiral CT (at 1 mm slice thickness, and 1:1 or 2:1 pitch) using multiplanar (MPR) and 3D reconstruction., Results: Conventional radiography failed to depict root resorption especially on the buccal surfaces of the incisor teeth. CT located impacted teeth better. Contact between impacted maxillary canines and incisor roots was demonstrated in 26 cases and root resorption in eight. MPR proved to be superior for the orientation of impacted teeth, and, in two cases, confirmed the presence of minimal root lesions for which axial images had proved inconclusive. The 3D reconstructions were useful in targeting the MPR., Conclusions: CT facilitates the treatment of impacted canine especially when the teeth are very oblique to the arch. Root resorption is better demonstrated especially on the palatal and buccal surfaces of the adjacent incisors. Spiral CT reduces examination time and risk of accidental movement, thus optimizing MPR quality. Examination at 2:1 pitch enables a significant reduction in radiation exposure without loss of image quality.

This retrospective study was aimed at assessing Computed Tomography (CT) capabilities in identifying low- and high-risk groups of clinical stage I endometrial carcinoma patients. CT of the pelvis was performed on 125 endometrial carcinoma patients who were divided into two groups based on T (stage and depth of myometrial invasion) and N (lymph node status) parameters. All patients had histologic evidence of well/moderately-differentiated adenocarcinoma (G1-G2). The low-risk group consisted of stage I patients with superficial myometrial involvement and no lymphadenopathy, while the high-risk group consisted of the patients with deep myometrial invasion and/or stage II and/or positive lymph nodes. All patients were operated on-i.e., total abdominal hysterectomy with vaginal cuff, bilateral salpingo-oophorectomy and pelvic lymphadenectomy. The patients were followed-up for 36 months at least. On the basis of CT findings, 85 patients were included in the low-risk group, but 11 misstaged cases were found at surgery in which lymphadenectomy never changed the factor risk. Only four relapses (4.7%) were observed in this group. Forty patients were included in the high-risk group: CT misstaged 20 cases and 12 relapses (30%) were observed. This study demonstrates the clinical value of CT in the assessment of radiologic risk factors in stage I endometrial carcinoma; CT findings can be used as guidelines for different treatments.

Pulmonary sequestration has always been diagnosed by direct demonstration of the vessels tributary to the lesion, usually by angiography. Conventional CT can identify the arterial supply in only two thirds of cases. We report a case of pulmonary sequestration diagnosed using Spiral CT, based on the demonstration of both arterial supply and venous drainage. The capabilities of Spiral CT to detect subtle vessel abnormalities and to yield reliable multiplanar imaging enabled us to show the whole course of both the artery and the vein tributary to the lesion. Axial images were the most useful ones to diagnose pulmonary sequestration; 2D and 3D reconstructions were useful for a detailed and immediate spatial depiction of the parenchymal abnormality and of its vascular pedicle.

Three dimensional computer reconstruction of CT scans provide head and neck surgeons with an exciting interactive display of clinical anatomy. The 3D CT reconstruction of complex maxillo facial anatomic parts permits a more specific preoperative analysis and surgical planning. Its delineation of disease extension aids the surgeon in developing his own mental three-dimensional image of the regional morphology. Three-dimensional CT permits a clearer perception of the extent of fracture comminution and resulting displacement of fragments. In the case of maxillo-facial tumors, 3D images provide a very clear picture of the extent of erosion involving the adjacent critical organs. Three-dimensional imaging in first generation 3D scanners did have some limitations such as long reconstruction times and inadequate resolution. Subsequent generations, in particular the spiral 3D CT, have eliminated these drawbacks. Furthermore, costs are comparable with those of other computer reconstruction technology that might provide similar images. Representative cases demonstrating the use of 3D CT in maxillofacial surgery and its benefits in planning surgery are discussed.

One hundred male patients affected by ischaemic stroke were studied with the use of CT scans. A clinical-biohumoral pattern was traced for every patient, with particular regard to the incidence of risk factors for stroke of which systolic arterial hypertension, appear to be the most frequent. It would be useful to extend this research to female patients as well in order to discover any significant differences between sexes.