CT Appearance Research Articles

Temporal Bone Trauma: Typical CT and MRI Appearances and Important Points for Evaluation.

Temporal bone trauma is frequently encountered in the emergency department. Technologic advances have enabled timely acquisition of thin-section images and multiplanar reconstructions such that temporal bone anatomy can be evaluated in great detail, with excellent delineation of fractures. The temporal bone is composed of a myriad of tiny structures, including many fissures and canals, that must be distinguished from true fractures. In addition, injury to important structures may result in serious complications such as hearing loss, dizziness, imbalance, perilymphatic fistula, cerebrospinal fluid leakage, facial nerve paralysis, and vascular injury. Structures that should be examined include the tympanic cavity and tegmen, the ossicular chain, the bony labyrinth, the facial canal, the internal carotid artery, the jugular foramen and venous sinuses, and the intracranial contents. Radiologists should be familiar with the anatomy of the temporal bone and be able to describe any pathologic findings and make suggestions to referring clinicians to guide management and determine the prognosis. The authors describe the typical CT and MRI appearances of temporal bone trauma, entities that mimic this injury and thus must be differentiated, and compulsory points for evaluating clinically relevant associated complications. Instruction is provided for acquiring the diagnostic skills necessary to report suggested injury status, complications, and likely sequelae to clinicians.©RSNA, 2020.

Intraductal papillary neoplasm of the bile duct (IPNB): CT and MRI appearance with radiology-pathology correlation

PurposeIntraductal papillary neoplasm of the bile duct (IPNB) is a precursor to invasive carcinoma and is a distinct pathologic diagnosis. The purpose of this study was to evaluate imaging features of IPNB on cross-sectional imaging studies with histopathologic correlation. Materials and methodsIn this IRB approved, HIPAA compliant retrospective observational analysis of 23 pathology proven IPNB tumors 22 imaging studies were reviewed, 14 CT and 8 MRI scans. Features evaluated in consensus by two subspecialty-trained abdominal radiologists included: presence of specific lesion/mass within the bile duct, location within the biliary tree, size, morphology, enhancement characteristics, and bile duct caliber. ResultsMajority of the subjects (16/18, 90%) had definite intraluminal mass, of which 7 (39%) had a polypoid mass with upstream diffuse biliary ductal dilation and 5 (28%) had a plaque-like mass with focal stricture and upstream biliary ductal dilatation. 6/18 (33%) subjects had low grade dysplasia, most commonly intestinal subtype, 7/18 (39%) subjects presented with invasive component, commonly pancreaticobiliary subtype, and 5/18 (28%) presented with high grade dysplasia. ConclusionIPNB has increased predilection for extrahepatic bile ducts, commonly presenting as either an intraluminal polypoidal mass with associated upstream biliary ductal dilation or a focal plaque like mass with associated ductal stricture at the site of the tumor.

CT appearances and short-term changes of COVID-19 in subclinical period

Objective To explore the characteristics and short-term changes of high resolution CT (HRCT) in subclinical stage of COVID-19. Methods The HRCT images of 17 COVID-19 patients in subclinical stage were analyzed retrospectively in Union Hospital, Tongji Medical College, Huazhong University of Science and Technology and Wuhan Jinyintan Hospital from January 15 to 31, 2020. There were 4 males and 13 females, age ranged from 25.0 to 51.0 (39.8±7.5) years, who were closely contacted with other COVID-19 patients. The follow-up CT examination was performed within 3 to 6 days after the initial CT examination in all patients. Six patients were treated using anti-virus, anti-inflammation and symptomatic therapy, while the other 11 patients were untreated. The subclinical CT findings and short-term follow-up were analyzed, and the CT changes of short-term follow-up were summarized. Results The lesions of 17 COVID-19 patients were mainly located at the lower lobes of bilateral lungs (at the left lower lobe in 9 cases and at the right lower lobe in 10 cases in the subclinical stage, at the left lower lobe in 9 cases and at the right lower lobe in 11 cases in the short-term follow-up). The number of involved lung segments increased from 46 in the subclinical stage to 90 in the short-term follow-up. In the subclinical stage, the multiple lesions were found in 13 cases, while in the short-term follow-up, the number of cases with multiple lesions decreased by 7, however the cases with focal lesions increased by 6 and diffuse lesions by 4. The lesions were mainly distributed under the pleura (13 cases) or along the bronchovascular bundle(10 cases). In the short-term follow-up, the lesion in 1 case expanded from the subpleural area to neighbouring bronchovascular bundle. There were 3 main types of the lesions, including ground glass nodule, ground glass opacity and crazy-paving pattern. In the subclinical stage and short-term follow-up, the ground glass opacities were seen in all the 17 cases. In the short-term follow-up, the number of cases with ground glass nodules decreased by 4 and crazy-paving pattern increased by 4. In 6 patients after treatment, the multiple ground glass nodules became single one in 3 cases, and in other 3 cases the multiple ground glass opacities were getting smaller. However, the scope of lesions in 11 patients without treatment enlarged. Conclusion The HRCT features of the COVID-19 in subcilincal stage have some charicteristics, such as small ground glass nodule, ground glass opacity along the subpleural area or along the bronchovascular bundle, and the great changes can be seen in the short-term follow-up. Key words: COVID-19; Tomography, X-ray computed

CT Features and Short-term Prognosis of COVID-19 Pneumonia: A Single-Center Study from Kashan, Iran.

PurposeTo assess whether certain CT chest features of patients with confirmed coronavirus disease 2019 (COVID-19) may have short-term prognostic value.Materials and MethodsOne hundred-twenty consecutive symptomatic patients with COVID-19 infection who had undergone chest CT were enrolled in this retrospective study. Patients were categorized into three groups: routine inward hospitalization, intensive care unit admission, and deceased based on a short-term follow-up. Detailed initial CT features and distributional evaluation were recorded.ResultsThe mean age in the deceased group was 70.7 years, significantly higher than the other two groups (P < .05). Ninety-four percent (113/120) of the patients had ground-glass opacities (GGO). Peripheral and lower zone predilection was present in most patients. Subpleural sparing and pleural effusion were seen in approximately 23% (28/120) and 17% (20/120) of the patients, respectively. The combined intensive care unit group and deceased patients had significantly more consolidation, air bronchograms, crazy paving, and central involvement of the lungs compared with routinely hospitalized patients (all P < .05).ConclusionThis study supports the previously described typical CT appearance of COVID-19 pneumonia with bilateral GGO, in peripheral distribution and lower lung zone predilection. Subpleural sparing and pleural effusion were seen approximately in one-fifth and one-sixth of the patients with COVID-19, respectively. Consolidation, air bronchograms, central lung involvement, crazy paving and pleural effusion on initial CT chest have potential prognostic values, the features more commonly observed in critically ill patients.© RSNA, 2020

Comparison of outcomes following segmentectomy or lobectomy for patients with clinical N0 invasive lung adenocarcinoma of 2cm or less in diameter.

Previous studies have reported similar survival between segmentectomy and lobectomy for patients with small-sized non-small cell lung cancer. However, part of those patients were with adenocarcinoma in situ or minimally invasive adenocarcinoma, which were considered to have a favorable prognosis. We compared survival outcomes of patients with clinical N0 invasive lung adenocarcinomas of no more than 2cm who underwent segmentectomy or lobectomy. Between June 1, 2008, and May 31, 2018, 1018 patients with clinical N0 invasive lung adenocarcinomas of no more than 2cm in diameter on thin-section chest CT scans were retrospectively included in this study. Of them, 214 underwent segmentectomy and 804 underwent lobectomy. Propensity-score matching of preoperative factors, such as gender, age, smoking status, forced expiratory volume in 1 s predicted%, tumor's CT appearance, tumor size on CT scan and tumor location was used to compare survival outcomes of those patients receiving different surgical treatments. Cox proportional hazard regression model was used to identify independent prognostic factors. This study was approved by the Committee for Ethical Review of Research (Fudan University Shanghai Cancer Center IRB# 090977-1). Informed consent was waived because of the retrospective nature of this study. Average follow-up time was 42.5months. Before matching, the lobectomy group had a shorter recurrence-free survival (P = 0.02), but similar overall survival (P = 0.60). After matching, no significant difference of overall survival or recurrence-free survival was found between the two groups (P = 0.70 and P = 0.40, respectively). Our results suggest that segmentectomy achieved similar recurrence-free and overall survival compared with lobectomy for patients with clinical N0 invasive lung adenocarcinomas of no more than 2cm. Therefore, segmentectomy could be an alternative approach. These results need to be further validated by randomized trials.

Performance of Radiologists in Differentiating COVID-19 from Non-COVID-19 Viral Pneumonia at Chest CT.

BackgroundDespite its high sensitivity in diagnosing COVID-19 in a screening population, chest CT appearances of COVID 19 pneumonia are thought to be non-specific.PurposeTo assess the performance of United States (U.S.) and Chinese radiologists in differentiating COVID-19 from viral pneumonia on chest CT.MethodsA total of 219 patients with both positive COVID-19 by RT-PCR and abnormal chest CT findings were retrospectively identified from 7 Chinese hospitals in Hunan Providence, China from January 6 to February 20, 2020. A total of 205 patients with positive Respiratory Pathogen Panel for viral pneumonia and CT findings consistent with or highly suspicious for pneumonia by original radiology interpretation within 7 days of each other were identified from Rhode Island Hospital in Providence, RI. Three Chinese radiologists blindly reviewed all chest CTs (n=424) to differentiate COVID-19 from viral pneumonia. A sample of 58 age-matched cases was randomly selected and evaluated by 4 U.S. radiologists in a similar fashion. Different CT features were recorded and compared between the two groups.ResultsFor all chest CTs, three Chinese radiologists correctly differentiated COVID-19 from non-COVID-19 pneumonia 83% (350/424), 80% (338/424), and 60% (255/424) of the time, respectively. The seven radiologists had sensitivities of 80%, 67%, 97%, 93%, 83%, 73% and 70% and specificities of 100%, 93%, 7%, 100%, 93%, 93%, 100%. Compared to non-COVID-19 pneumonia, COVID-19 pneumonia was more likely to have a peripheral distribution (80% vs. 57%, p<0.001), ground-glass opacity (91% vs. 68%, p<0.001), fine reticular opacity (56% vs. 22%, p<0.001), and vascular thickening (59% vs. 22%, p<0.001), but less likely to have a central+peripheral distribution (14.% vs. 35%, p<0.001), pleural effusion (4.1 vs. 39%, p<0.001) and lymphadenopathy (2.7% vs. 10.2%, p<0.001).ConclusionRadiologists in China and the United States distinguished COVID-19 from viral pneumonia on chest CT with high specificity but moderate sensitivity.A translation of this abstract in Farsi is available in the supplement. - ترجمه چکیده این مقاله به فارسی، در ضمیمه موجود است.

Role of CT Angiography in the Evaluation of Tumour Vascular Relationship in Patients with Pancreatic Tumours

Abstract Background: Pancreatic cancer is the fourth leading cause of cancer related deaths worldwide. It has poor prognosis especially in locally advanced tumours. Treatment of pancreatic tumours remains a challenge regarding their growth into the adjacent anatomical and vascular structures. Multidetector computed tomography (MDCT) plays an important role in diagnosing of patients with resectable and borderline resectable tumours. Evaluation of borderline resectable tumours should involve the accurate identification of the relationship between the tumour and the surrounding vessels and other vital struc-tures. Aim of Study: Evaluation of the role of CT angiography in the assessment of tumor vascular relationship in patients with pancreatic tumors in order to choose the proper treatment decision. Material and Methods: This study is a prospective study which was conducted in the Radiology Department of Man-soura University Hospital over the period from August 2016 to September 2019. This study included 79 patients, their ages ranged from 45 to 74 years old with mean age 58.3 years old. All patients were referred from oncology Center of Mansoura University and outpatient surgery clinics. The study was approved by our institution's ethics committee, and all patients gave their informed consent before inclusion in the study. CT scans were obtained with a MDCT scanner (Aquilion 64, Toshiba Medical Systems). CT protocols for pancreatic imaging vary at different institutions but typically include a multiphasic technique with a very thin section imaging and multiplanar reconstruction. Contrast enhanced images include: A late arterial or pancreatic phase and a portal or venous phase after injection of 100-120mL of intravenous non-ionic water soluble contrast material usually at rate of 4-5mL/sec. Results: This study included 79 patients, their ages ranged from 45 to 74 years old with mean age was 58.3 years. The most common affected site in the pancreas was the pancreatic head (47 lesions). All the lesions in our study were histopatho-logical proven malignant. The most common histopathological type in our study was pancreatic adenocarcinoma representing 61 lesions (77.21%). As regards the CT appearance of the pancreatic masses, most of the lesions were hypodense (71lesions). Detailed evaluation by CT angiography showed that the hepatic artery was involved in 35 cases, the SMA in 49 cases, the celiac trunk in 29 cases and the gartroduodenal artery in 47 cases. There was no arterial vascular involvement in 25 cases. Finally as regards the anatomical variations; accessory right hepatic artery was detected in 11 cases, Accessory left hepatic artery in 12 cases, replaced left hepatic artery in 14 cases, replaced right hepatic artery in 10 cases, replaced common hepatic artery in 9 cases and 23 cases showed no anatomical variants. Conclusion: Multidetector CT with CT angiography plays a major role in the diagnosis and staging of pancreatic carci-noma. The use of standardized technique and radiologic reporting method can improve the evaluation of the tumor-vessel relationship and precisely evaluate the arterial anatom-ical variants.

CT appearance of new coronavirus pneumonia in subclinical period and short-term changes

Objective To explore the characteristics and short-term changes of high resolutionCT (HRCT) in subclinical stage of new coronavirus pneumonia (NCP). Methods TheHRCT images of 17 NCP patients in subclinical stage were analyzed retrospectively in Union Hospital of Tongji Medical College, Huazhong University of science and technology and Wuhan JinyintanHospital from January 15 to January 31, 2020. There were 4 males and 13 females, aged from 25.0 to 51.0 (39.8±7.5) years, who were closely contacted with NCP patients. The follow-up CT examination was performed 3 to 6 days after the initial CT examination in all patients. Six patients were treated using anti-virus, anti-inflammation andsymptomatic therapy, while the orther 11 patients were untreated. The CT imaging signs of subclinical and short-term follow-up were analyzed, and the CT image changes of short-term follow-up was summarized. Results Thelesions of 17 NCP patients were mainly located at the lower lobes of both lungs (9 cases at the left lower lobe and 10 cases at the right lower lobe in the subclinical stage, 9 casesat the left lower lobe and 11casesat the right lower lobe in the short-term follow-up). The number of lung segments involved increased from 46 in the subclinical stage to 90 in the short-term follow-up. In the subclinical stage, most of the lesions were multiple (13 cases), while in the short-term follow-up, the number of multiple cases decreased (7 cases), focal (6 cases) and diffuse distribution(4 cases) increased. The lesions were mainly distributed under the pleura (13 cases) or along the bronchovascular bundle (10 cases). In the short-term follow-up, 1 case progressed from subpleural to subpleural and along the bronchovascular bundle. There were 3 main types of lesions, including ground glass nodule, ground glass opacity and crazy-paving pattern. In the subclinical stage and short-term follow-up, ground glass nodules were seen in all the 17 cases. In the short-termfollow-up, ground glass nodules decreased in 4 cases and crazy-paving pattern increased in 4 cases. In 6 patients after treatment, 3 cases were changed from multiple to single ground glass nodule, 3 cases showed multiple ground glass opacity reduced. Therange of lesions in 11 patients without treatment enlarged. Conclusion TheHRCT features of the NCP patients in subcilincal stagehave some charicteristics, such as small ground glass nodule, ground glass opacity along the subpleural or along the bronchovascular bundle, and the great changescan be seen in the short-term follow-up. Key words: Coronaviridae infections; New coronavirus; Pneumonia; Tomography, X-ray computed

A typical chest CT appearance of A case with Coronavirus Disease 2019 (COVID-19)

A typical chest CT appearance of A case with Coronavirus Disease 2019 (COVID-19)

The hypoattenuating ocular lens on CT is not always due to cataract formation.

Hypoattenuating ocular lenses on CT have been described with cataract formation in humans, however published studies are currently lacking regarding this finding in veterinary patients. The purpose of this retrospective and prospective study was to describe the varying CT appearances of the ocular lens in vivo, and investigate the causes for CT density variations in a population of cats and dogs. A total of 102 canine and feline patients with CT of the head acquired at the authors' hospital between May 2011 and March 2019 were included. A bilateral hypoattenuating halo surrounding an isoattenuating to mildly hypoattenuating core was described in the ocular lens center of every cat in which a Philips brand proprietary image construction filter was used. A similar but more varied hypoattenuating region was noted in the lenses of 45.8% of dogs where the same filter was applied, as well as 43.8% of dogs with a second, similar filter. Ophthalmic examination of three live cats and one dog with hypoattenuating lenses demonstrated normal lens translucency, excluding the presence of cataract. The effect of different proprietary filters on lens appearance was also described in three fresh cadavers with normal lenses identified on ophthalmic, macroscopic, and microscopic examination. Etiology of the hypoattenuating areas within the ocular lens was not conclusively determined. Recognition that such a variant may be seen in the absence of cataract is important, in order to prevent misdiagnosis.

Association of immune-related pneumonitis with the presence of preexisting interstitial lung disease in patients with non-small lung cancer receiving anti-programmed cell death 1 antibody.

The safety of anti-programmed cell death 1 (PD-1) antibody for patients with preexisting interstitial lung disease (ILD) remains unknown. The aim of this study was to evaluate the dependence of preexisting ILD on anti-PD-1 antibody-induced pneumonitis in non-small cell lung cancer (NSCLC) patients. We retrospectively reviewed the association of preexisting ILD with the incidence, radiographic pattern, and outcome of pneumonitis in NSCLC patients receiving anti-PD-1 antibody. A total of 331 patients were included in this study. Of these patients, 17 had preexisting ILD. The incidence of pneumonitis was higher among the patients with preexisting ILD than among those without preexisting ILD (29% vs. 10%, P = 0.027). The distributions of the CT appearances at the onset of anti-PD-1 antibody-induced pneumonitis were as follows: for the patients with preexisting ILD, two patients (40%) had diffuse alveolar damage (DAD), one patient each with organizing pneumonia-like (OP), hypersensitivity pneumonitis (HP), and other patterns (20% each); for the patients without preexisting ILD, 19 patients (61%) had OP, 8 (26%) had HP, 3 (10%) had DAD, and 1 (3.2%) had other patterns. The median onset time from the initiation of anti-PD-1 antibody treatment until the development of pneumonitis was 1.3months (range 0.3-2.1months) for the patients with preexisting ILD and 2.3months (range 0.2-14.6months) for the patients without preexisting ILD. Careful attention to the development of pneumonitis is needed, especially within the first 3 months after the start of anti-PD-1 antibody treatment, when using anti-PD-1 antibody to treat patients with preexisting ILD.

Osteochondral lesions of the lateral trochlear ridge: a rare, subtle but important finding on advanced imaging in patients with elbow pain.

To characterize the radiographic, CT, and MRI appearance of clinically and/or surgically proven osteochondral lesions of the lateral trochlear ridge. Ten years of medical charts with elbow radiographic, CT, and MRI studies were retrospectively reviewed. Patients with pathology isolated to the lateral trochlear ridge were included. Studies were reviewed by two radiologists. Identifiable pathology on each type of study was noted and characterized. Ten elbow studies were included, all from males aged 15 to 58 years (mean 29 years). Five elbow radiographs were normal, one showed mixed lucency and sclerosis of the lateral trochlear ridge, and four demonstrated small osseous fragments adjacent to the ridge. In all cases, CT demonstrated focal lucency at the cortical surface of the lateral trochlear ridge; 8 contained small osseous fragments, axial plane maximum width ranged from 5 to11 mm, depth from 1 to 2 mm. Focal bone marrow edema in the subchondral lateral trochlear ridge was found in the 6 cases with MR images. Two demonstrated linear high signal underlying the in situ osseous fragment, faintly visible on MRI. In 9 cases, arthroscopy was performed within 3 months of imaging. The remaining patient was treated conservatively with casting. Osteochondral lesions of the lateral trochlear ridge are rare but important, as these patients go on to arthroscopy at a high rate. If an abnormality of the lateral trochlear ridge is seen or suspected, we recommend CT as the best imaging study to define these lesions.

CT appearance of presumptively normal intrathoracic lymph nodes in cats.

Thoracic CT is commonly performed in cats and has been shown to be more sensitive than radiography for the detection of lymphadenopathy. However, no studies to date have reported the normal CT appearance of feline intrathoracic lymph nodes. The aim of this study was to describe the distribution, number, size and attenuation of presumed normal intrathoracic lymph nodes in cats. Retrospective analysis of the imaging archive in a teaching hospital identified cats that had undergone thoracic CT and were deemed to have no evidence of either intra- or extrathoracic disease that would influence the size of the intrathoracic lymph nodes. Lymph nodes were classified into lymph centres based on anatomical references. Descriptions of the position of each node, number of nodes in each centre, size of each node and attenuation pre- and post-contrast were recorded. Statistical analysis aimed to assess for correlations between these factors and the age, weight and sex of the subjects. Twenty cats were included in the study. One or more lymph nodes were identified in the sternal (n = 19/20), cranial mediastinal (n = 14/20) and tracheobronchial (n = 15/20) centres, while none were identified in other locations. Size varied between lymph centres and within lymph centres where more than one lymph node was identified. Tracheobronchial and sternal nodes were consistent in location, while mediastinal nodes were variable. All nodes were round to ellipsoid in shape and showed moderate enhancement post-contrast. No significant correlations were found with age, weight or sex. This study describes the CT characteristics of presumed normal intrathoracic lymph nodes in cats, and only identified nodes in the sternal, cranial mediastinal and tracheobronchial locations. This study serves as a reference point for CT analysis of feline thoracic lymph nodes.

Complex Stenoses and CT Features of the Nasolacrimal Canal in Congenital Nasolacrimal Duct Obstruction.

To study the CT appearance of the nasolacrimal canal (NLC) in cases of congenital nasolacrimal duct obstruction (CNLDO) where there is a tactile sensation of a hard contact (HC) stop in the duct preventing stent intubation. The authors retrospectively reviewed all consecutive cases of chronic CNLDO observed between 2003 and 2018 in which an apparent HC obstruction prevented nasolacrimal intubation. CT scans were reviewed to determine the cause of probing failure: distal stenosis, loss of parallelism of the NLC walls, abnormal angulations or an adjacent obstacle blocking tear outflow. Nine patients (12 sides) met the following criteria: CNLDO + HC + probing failure. The mean age at the time of the first HC was 3.9 years (range: 0.8-8.1 years) and at the time of a second confirmation of HC with subsequent dacryocystorhinostomy was 7.8 years (range: 4.1-9.2 years). Nasolacrimal duct opacification was noted in 33% of cases (4/12). Abnormalities of the NLC occurred in 8 of the 12 cases of CNLDO (8/12 = 66.6%) and on the asymptomatic side in 1 case (1/6 = 16.6%). A canine tooth bud situated in the same plane as the NLC was observed in 9 cases of CNLDO (9/12 = 75%) and on the asymptomatic side in 2 cases (2/6 = 33.3%). HC noted during probing is a sensitive but relatively nonspecific sign which, nevertheless, does indicate either a complex obstruction or at least potential intubation difficulties. As confirmed by CT imaging, a significant anatomical variant is not necessarily predictive of epiphora, but nevertheless may complicate the intubation procedure.The authors describe hard contact palpation during probing for CLNDO and its relationship to anatomic location and etiologies of obstruction in the nasolacrimal canal by CT imaging.

Incidental fetal imaging with CT: a pictorial essay.

Although CT is not the first choice for abdominal imaging of pregnant patients, it can be indicated for pregnant patients with emergent life-threatening conditions. It is prudent in these cases for the radiologist to be familiar with the normal appearance of the pregnant uterus on CT and to evaluate the female pelvis for potential maternal and fetal abnormalities. We aim to provide examples of the normal CT appearance of the female pelvis related to different gestational ages and to demonstrate variant and abnormal conditions of pregnancy which may be identified by CT.

Prevalence and outcome of central airway obstruction in patients with lung cancer

IntroductionCentral airway obstruction (CAO) is a life-threatening complication of lung cancer. The prevalence of CAO in lung cancer patients is unknown. We audited CAO burden to inform our local cancer...

Computed tomography imaging characteristics of canine nasal chondrosarcoma.

To describe the CT appearance of canine nasal chondrosarcoma and compare calcification patterns with those described in humans. CT examinations of dogs with biopsy-confirmed nasal chondrosarcoma were retrospectively reviewed and evaluated, including description of calcification patterns. Major findings are consistent with the previously described CT appearance of canine nasal tumours. Additionally, calcification patterns described as features of human nasal chondrosarcomas were also identified. Findings may help prioritise differential lists of destructive nasal masses seen on CT in dogs.

Visceral Pleural Invasion in Pulmonary Adenocarcinoma: Differences in CT Patterns between Solid and Subsolid Cancers.

To analyze the incidence and CT patterns of visceral pleural invasion (VPI) in adenocarcinomas on the basis of their CT presentation as solid or subsolid nodules. A total of 286 adenocarcinomas in direct contact with a pleural surface, resected at an institution between 2005 and 2016, were included in this retrospective, institutional review board-approved study. CT size and longest contact length with a pleural surface were measured and their ratios computed. Pleural deviation, pleural thickening, spiculations, different pleural tag types, pleural effusion, and the CT appearance of transgression into an adjacent lobe or infiltration of surrounding tissue were evaluated. Fisher exact tests and simple and multiple logistic regression models were used. Of the 286 nodules, 179 of 286 (62.6%) were solid and 107 of 286 (37.4%) were subsolid. VPI was present in 49 of 286 (17.1%) nodules and was significantly more frequent in solid (44 of 179; 24.6%) than in subsolid nodules (five of 107; 4.7%; P < .001). In solid nodules, multiple regression analysis showed an association of higher contact length-to-size ratio (adjusted odds ratio [OR], 1.02; P = .007) and the presence of multiple pleural tag types (adjusted OR, 5.88; P = .002) with VPI. In subsolid nodules, longer pleural contact length of the solid nodular component (adjusted OR, 1.27; P = .017) and the CT appearance of transgression or infiltration (adjusted OR, 10.75; P = .037) were associated with VPI. During preoperative evaluation of adenocarcinomas for the likelihood of VPI, whether a tumor manifests as a solid or a subsolid nodule is important to consider because the incidence of VPI is significantly higher in solid than in subsolid nodules. In addition, this study showed that the CT patterns associated with VPI differ between solid and subsolid nodules.© RSNA, 2019Supplemental material is available for this article.See also the commentary by Elicker in this issue.

Imaging Cystic Lung Disease

Cystic lung disease is characterized by multiple air-filled spaces in the lung. Pulmonary cysts occur in a variety of diseases, including infectious, inhalational, genetic, and neoplastic conditions. The purpose of this report is to review the CT imaging patterns and appearances of the most common cystic lung diseases, and to highlight the differences between different cystic lung diseases and the unique qualities related to each condition. Common cystic lung diseases include lymphangioleiomyomatosis, pulmonary Langerhans cell histiocytosis, lymphocytic interstitial pneumonia, desquamative interstitial pneumonia, Birt-Hogg-Dube syndrome, and light chain deposition disease/amyloidosis. Infections or age-related change may also result in cystic lung disease. Cystic lung disease has multiple etiologies. CT imaging allows for characterization of lung cyst morphology, pattern, and distribution; familiarity with the imaging appearance of the most common cystic lung diseases allows for earlier identification, diagnosis, and disease management.

CT appearance of acute pancreatitis using multiphase Multidetector Computed Tomography and correlation between CT Severity Index and clinical outcomes

CT appearance of acute pancreatitis using multiphase Multidetector Computed Tomography and correlation between CT Severity Index and clinical outcomes