Improvement in Follow-up Imaging With a Patient Tracking System and Computerized Registry for Lung Nodule Management

PurposeDespite established guidelines, radiologists’ recommendations and timely follow-up of incidental lung nodules remain variable. To improve follow-up of nodules, a system using standardized language (tracker phrases) recommending time-based follow-up in chest CT reports, coupled with a computerized registry, was created.Materials and MethodsData were obtained from the electronic health record and a facility-built electronic lung nodule registry. We evaluated two randomly selected patient cohorts with incidental nodules on chest CT reports: before intervention (September 2008 to March 2011) and after intervention (August 2011 to December 2016). Multivariable logistic regression was used to compare the cohorts for the main outcome of timely follow-up, defined as a subsequent report within 13 months of the initial report.ResultsIn all, 410 patients were included in the pretracker cohort versus 626 in the tracker cohort. Before system inception, 30% of CT reports lacked an explicit time-based recommendation for nodule follow-up. The proportion of patients with timely follow-up increased from 46% to 55%, and the proportion of those with no documented follow-up or follow-up beyond 24 months decreased from 48% to 31%. The likelihood of timely follow-up increased 41%, adjusted for high risk for lung cancer and age 65 years or older. After system inception, reports missing a tracker phrase for nodule recommendation averaged 6%, without significant interyear variation.ConclusionsStandardized language added to CT reports combined with a computerized registry designed to identify and track patients with incidental lung nodules was associated with improved likelihood of follow-up imaging.     

Safety and diagnostic accuracy of percutaneous CT-guided transthoracic biopsy of small lung nodules (≤20 mm) adjacent to the pericardium or great vessels

PURPOSEWe aimed to evaluate the safety and diagnostic accuracy of computed tomography (CT)-guided transthoracic biopsy of small lung nodules (≤20 mm) adjacent to the pericardium or great vessels.METHODSThis retrospective study examined the safety and diagnostic accuracy of percutaneous CT-guided biopsy for small lung nodules (≤20 mm) located within 10 mm of the pericardium or great vessels. Technical aspects and factors influencing complications were assessed, and diagnostic accuracy was calculated.RESULTSA total of 168 biopsies were performed in 168 patients. The complications were mainly pneumothorax (34.5%; 58 of 168 patients), chest tube insertion (5.3%; 9 of 168 patients), and pulmonary hemorrhage (61.3%; 103 of 168 procedures), with no patient mortality. One patient (0.6%) was admitted because of hemorrhage complications. Significant independent risk factors for pneumothorax were nodules resided in upper or middle lobes and lateral patient position, and for hemorrhage, longer distance from structures and longer needle trajectory through the lung parenchyma. Overall, the sensitivity, accuracy, and specificity were 91.0%, 92.2%, and 100%, respectively.CONCLUSIONPercutaneous CT-guided transthoracic biopsy was highly accurate in small lung nodules (≤20 mm) adjacent to the pericardium or great vessels. Complications are common, but most were minor and self-limited.

In recent years, with wide availability of computed tomography (CT) and the development of low-dose CT screening techniques, more small lung nodules (≤20 mm) have been detected (1–3). Lee et al. (4) reported that small lung nodules were detected at a rate of 44.5%, and that 39.7% of lung cancers were found in small nodules. Accurate histopathological diagnosis is of great importance in management of these nodules, but biopsy via fluoroscopy or ultrasound guidance is technically more difficult, and CT guidance is usually required (5).Percutaneous CT-guided transthoracic lung biopsy is a reasonably safe and accurate approach to the histological diagnosis of primary and secondary lung nodules (4, 6, 7). However, nodule size is the major determinant of diagnostic accuracy, which reached 96.9% for larger nodules (7), but ranged from 52% to 78.8% for small nodules (8, 9).Biopsy of small lung nodules close to proximity to the pericardium or great vessels is particularly challenging, and precise needle placement is essential to avoid complications resulting from non-target tissue injury near vital mediastinal or vascular structures. Hsu et al. (10) suggested that CT-guided lung biopsy should be avoided if the adjacent nodule is within 10 mm of the pericardium.The authors know of no related studies of biopsy of small lung nodules close to the pericardium or great vessels. This study, therefore, was conducted to examine the safety and diagnostic accuracy of CT-guided transthoracic biopsy of small lung nodules (≤20 mm) within 10 mm of the pericardium or great vessels.     

Clinical Impact and Generalizability of a Computer-Assisted Diagnostic Tool to Risk-Stratify Lung Nodules With CT

ObjectiveTo evaluate whether an imaging classifier for radiology practice can improve lung nodule classification and follow-up.MethodsA machine learning classifier was developed and trained using imaging data from the National Lung Screening Trial (NSLT) to produce a malignancy risk score (malignancy Similarity Index [mSI]) for individual lung nodules. In addition to NLST cohorts, external cohorts were developed from a tertiary referral lung cancer screening program data set and an external nonscreening data set of all nodules detected on CT. Performance of the mSI combined with Lung-RADS was compared with Lung-RADS alone and the Mayo and Brock risk calculators.ResultsWe analyzed 963 subjects and 1,331 nodules across these cohorts. The mSI was comparable in accuracy (area under the curve = 0.89) to existing clinical risk models (area under the curve = 0.86-0.88) and independently predictive in the NLST cohort of 704 nodules. When compared with Lung-RADS, the mSI significantly increased sensitivity across all cohorts (25%-117%), with significant increases in specificity in the screening cohorts (17%-33%). When used in conjunction with Lung-RADS, use of mSI would result in earlier diagnoses and reduced follow-up across cohorts, including the potential for early diagnosis in 42% of malignant NLST nodules from prior-year CT scans.ConclusionA computer-assisted diagnosis software improved risk classification from chest CTs of screening and incidentally detected lung nodules compared with Lung-RADS. mSI added predictive value independent of existing radiological and clinical variables. These results suggest the generalizability and potential clinical impact of a tool that is straightforward to implement in practice.     

Methylene Blue/Collagen Mixture for CT-Guided Presurgical Lung Nodule Marking: High Efficacy and Safety

PurposeTo assess outcomes of computed tomography (CT)-guided methylene blue/collagen marking of preoperative lung nodules before video-assisted thoracoscopic surgery (VATS) and robotic-assisted thoracic surgery (RATS).Materials and MethodsA retrospective cohort study assessing 25 methylene blue/collagen solution CT-guided lung nodule localization procedures on 26 nodules in 25 patients was performed. The procedures were performed by a fellowship-trained radiologist 1–2 hours before scheduled surgery under local anesthesia. Approximately 4–6 ml of methylene blue/collagen solution was injected in a perinodular location under CT guidance with a 19-gauge trocar needle and along the track to the visceral pleural surface. Post-procedural CT images confirmed appropriate lung nodule location marking.ResultsPerinodular CT-guided trocar needle placement was achieved in all marking procedures (n = 26/26). Increased consolidation near the target nodule was also demonstrated in all patients on the post-procedural localized CT scans. One patient with moderate emphysema developed a small to moderate-sized pneumothorax (∼20%–30%), and an 8-Fr thoracentesis catheter was placed under CT guidance before surgery. There was no bleeding or hemoptysis in any patient. Methylene blue/collagen solution was readily visible by the thoracic surgeon in association with all target nodules. One patient required conversion to open procedure due to the proximal portion of the right lower lobe pulmonary artery segmental branch. Of the 26 identified nodules, pathology specimens confirmed the adequacy of nodule resection in all cases.ConclusionsPreoperative CT-guided methylene blue/collagen solution injection offers a safe and highly effective technique for marking subpleural lung nodules undergoing VATS or RATS.     

Diagnostic yield of CT-guided lung biopsies: how can we limit negative sampling?

Objectives:To investigate whether lesion imaging features may condition the outcome of CT-guided lung biopsy (CTLB) and to develop a scoring system of biopsy outcome prediction.Methods:This is a single center retrospective study on 319 CTLBs that were performed in 319 patients (167 males/152 females, mean age 68 ± 12.2). Uni- and multivariate analysis were performed aiming to assess the imaging features that are likely to be correlated to a negative biopsy outcome and patients were stratified in groups accordingly.Results:Technical success was 100%. 78% of the biopsies (250/319) led to a concrete histology report (218 malignant/32 benign). The remaining lesions led to concrete histology at a second attempt that occurred on a later time. Multivariate analysis revealed increased risk of inconclusive result for nodules with low fludeoxyglucose uptake [odds ration (OR) = 2.64, 95% confidence interval (CI) 1.4–4.97; p = 0.003], for nodules with diameter smaller than 18 mm (OR = 2.03, 95% CI 1.14–3.62; p = 0.017) and for nodules that are located in one of the lung bases (OR = 1.96, 95% CI 1.06–3.62; p = 0.033). Three different groups of patients were identified accordingly with low (<30%), medium (30–50%) and high (>50%) probability of obtaining an inconclusive biopsy sample.Conclusion:This study confirms that percutaneous CT-guided biopsy in nodules that are either small in diameter or present low positron emission tomography-fludeoxyglucose uptake or are in one of the lung bases may lead to inconclusive histology. This information should be factored when planning percutaneous biopsies of such nodules in terms of patient informed consent and biopsy strategy.Advances in knowledge:Inconclusive histology after lung biopsy may be subject to factors irrelevant to technical success. Lung biopsy histology outcomes may be predicted and avoided after adequate planning.     

Management of Lung Nodules and Lung Cancer Screening During the COVID-19 Pandemic: CHEST Expert Panel Report

BackgroundThe risks from potential exposure to coronavirus disease 2019 (COVID-19), and resource reallocation that has occurred to combat the pandemic, have altered the balance of benefits and harms that informed current (pre-COVID-19) guideline recommendations for lung cancer screening and lung nodule evaluation. Consensus statements were developed to guide clinicians managing lung cancer screening programs and patients with lung nodules during the COVID-19 pandemic.MethodsAn expert panel of 24 members, including pulmonologists (n = 17), thoracic radiologists (n = 5), and thoracic surgeons (n = 2), was formed. The panel was provided with an overview of current evidence, summarized by recent guidelines related to lung cancer screening and lung nodule evaluation. The panel was convened by video teleconference to discuss and then vote on statements related to 12 common clinical scenarios. A predefined threshold of 70% of panel members voting agree or strongly agree was used to determine if there was a consensus for each statement. Items that may influence decisions were listed as notes to be considered for each scenario.ResultsTwelve statements related to baseline and annual lung cancer screening (n = 2), surveillance of a previously detected lung nodule (n = 5), evaluation of intermediate and high-risk lung nodules (n = 4), and management of clinical stage I non–small-cell lung cancer (n = 1) were developed and modified. All 12 statements were confirmed as consensus statements according to the voting results. The consensus statements provide guidance about situations in which it was believed to be appropriate to delay screening, defer surveillance imaging of lung nodules, and minimize nonurgent interventions during the evaluation of lung nodules and stage I non–small-cell lung cancer.ConclusionsThere was consensus that during the COVID-19 pandemic, it is appropriate to defer enrollment in lung cancer screening and modify the evaluation of lung nodules due to the added risks from potential exposure and the need for resource reallocation. There are multiple local, regional, and patient-related factors that should be considered when applying these statements to individual patient care.     

多排螺旋 CT 对早期周围型小肺癌的诊断价值分析

目的：探讨多排螺旋 CT 对早期周围型小肺癌的诊断价值。方法收集近4年我院经穿刺活检或手术切除病理证实,同时具有完整多排螺旋 CT 检查资料的43例周围型小肺癌患者,对该疾病影像学特点（分叶征、毛刺征、支气管充气征、血管集束征、空泡征、胸膜凹陷征）进行系统的分析。结果本组43例病变均为直径≤20 mm 的孤立性结节,均行胸部多排螺旋 CT 扫描、横断面高分辨 CT（HRCT）扫描、动态 CT 增强扫描及胸部容积多平面重建（MPR）,所有患者病变至少具有该疾病影像学特点中的2-3个征象,可作为该病影像及临床诊断的可靠依据。结论多排螺旋 CT 对周围型小肺癌能够准确定位,具有较高的检出率和应用价值,能够为临床诊断及治疗提供客观的参考及依据。     

Initial experience of percutaneous transthoracic needle biopsy of lung nodules using C-arm cone-beam CT systems

Objective

To describe our initial experience with percutaneous transthoracic biopsy (PCNB) of lung nodules using C-arm cone-beam CT (CBCT).

Materials

Seventy-one consecutive patients with lung nodules of 30 mm or smaller underwent CBCT-guided PCNB using a coaxial cutting needle. We evaluated the procedure time, coaxial introducer dwell time, the numbers of pleural passages, coaxial introducer repositionings and CT acquisitions, as well as the technical success rate and radiation doses. Diagnostic accuracy, sensitivity, specificity and incidence of complications were also evaluated.

Results

PCNB was performed for 71 nodules: 63 solid, 6 part-solid and 2 ground-glass nodules. The procedure time, coaxial introducer dwell time, numbers of pleural passages, coaxial introducer repositionings and CT acquisitions were 17.9?±?5.9 min, 8.7?±?3.8 min, 1.1?±?0.4, 0.2?±?0.5 and 2.9?±?0.7, respectively. The technical success rate was 100% and the radiation dose was 272?±?116 mGy. Thirty-six nodules (50.7%) were diagnosed as malignant, 25 (35.2%) as benign and 10 (14.1%) as indeterminate. Diagnostic accuracy, sensitivity, specificity and incidence of complications were 98.4%, 97%, 100% and 38%, respectively. Complications included pneumothorax in 18 patients (25.4%), haemoptysis in 10 (14.1%) and chest pain in one (1.4%).

Conclusion

Under CBCT guidance, PCNB of lung nodules can be performed accurately, providing both real-time fluoroscopic guidance and CT imaging capabilities.     

Imaging findings in epithelioid hemangioendothelioma

Purpose-objectiveEpithelioid hemangioendothelioma (EHE) is a rare vascular malignancy with varying biologic behavior. The purpose of this study was to identify imaging findings most characteristic of EHE.MethodsRetrospective review of clinical and imaging records in patients referred to our Vascular Anomalies Center over a 17 year period with biopsy proven EHE.ResultsWe evaluated 29 patients (17 F) with median age of 16 years (range 2–76 y). The most common presenting symptoms were pain (n = 13) and palpable mass (n = 7). 22 (70%) had multifocal disease. Most common sites of involvement were lung (n = 25), liver (n = 16), bone (n = 12), soft tissue (n = 3) and lymph nodes (n = 1). Of patients with single site disease, 3 had lung, 3 liver, and 1 had bone lesions. In 18/25 with lung disease, there were multiple nodules of varying sizes and characteristics. In 14/16 with hepatic disease there were multiple nodules with predominantly peripheral distribution. Subcapsular retraction was seen in 10/16 and a “lollipop” sign (hepatic or portal vein tapering at the edge of a well-defined hypoenhancing lesion) identified in 5/16. Of 12 osseous lesions, 11 were lytic, 8 involved vertebrae and 9 involved the axial skeleton.ConclusionEHE has varied imaging findings. The most common sites are lungs, liver, and bone, with multi-organ involvement seen in most. Lung disease is most commonly characterized by multiple nodules. Hepatic lesions demonstrate the most distinctive findings, with peripheral distribution, lack of early enhancement, subcapsular retraction and “lollipop” sign. Osseous lesions are commonly lytic and more prevalent in the axial skeleton.     

An Exponential Growth in Incidence of Thyroid Cancer: Trends and Impact of CT Imaging

BACKGROUND AND PURPOSE:Workup of incidental thyroid nodules detected on CT imaging could be contributing to the increased diagnosis of small thyroid cancers. The purpose of this study was to evaluate recent trends in the incidence of thyroid cancer, and to determine the relationship between annual CT imaging volume and rate of thyroid cancer diagnosis.MATERIALS AND METHODS:This retrospective cohort study used data bases for thyroid cancer and CT imaging volume. Thyroid cancer data from 1983–2009 were obtained from the Surveillance, Epidemiology, and End Results data base. National Council of Radiation Protection and Measurements Report No. 160 provided data on hospital and nonhospital CT imaging volume for 1993–2006. Trends in thyroid cancer were modeled for overall incidence on the basis of patient age, tumor histologic features, and tumor size and stage. Linear regression analysis was performed to evaluate the strength of the relationship between annual CT scan volume and the incidence of thyroid cancer by tumor size and histologic type.RESULTS:In 2009, the incidence of thyroid cancer was 14 per 100,000, which represented a 1.9-fold increase compared with 2000. The growth in incidence was exponential compared with a minimal linear increase in thyroid cancer mortality rate. The subgroup with the greatest change was subcentimeter papillary carcinoma, with doubling in incidence approximately every 6.2 years. The linear relationship between annual CT scan volume and the incidence of subcentimeter papillary carcinoma was very strong (R² = 0.98; P < .0001).CONCLUSIONS:The incidence of subcentimeter papillary carcinoma is growing at an exponential rate without significant change in mortality rate. The strong linear relationship between new cases of subcentimeter papillary carcinomas and the number of CT scans per year suggests that an increase in CT scans may increase the detection of incidental thyroid cancers.

The incidence of thyroid cancer is increasing in the United States. A study published by Davies and Welch¹ found that from 1973–2002, the incidence of thyroid carcinoma more than doubled. They reported that 87% of the increase in discovered cancers was attributable to tumors that were 2 cm or smaller, and despite earlier diagnosis, there was no change in mortality. These results provided compelling evidence for an “apparent” increase in cancer derived from increased use of diagnostic imaging tests, rather than a true increase in the biologic occurrence of thyroid cancer. This pattern of increased diagnosis of a silent reservoir of disease with an indolent natural history is similar to the epidemiologic changes in prostate cancer that occurred with prostatic-specific antigen and digital rectal examination–based screening.² Davies and Welch¹ and McLeod et al³ proposed that advances in sonography and fine-needle aspiration were leading to an increased diagnosis of subclinical (ie, small, impalpable) thyroid cancers that would otherwise remain asymptomatic during a patient''s lifetime and not increase mortality rates. Epidemiologists have labeled this situation “overdiagnosis.”^1,4In recent years, 2 factors may have strongly influenced the work-up of subclinical thyroid nodules and, thus, the incidence of thyroid cancer. First, several societies, including the Society of Radiologists in Ultrasound and American Thyroid Association, published sonographic guidelines for biopsy of thyroid nodules on the basis of best available evidence and expert opinion.^5,6 These societies raised concern that their recommendations could increase the biopsy rate of thyroid nodules and the incidence of thyroid cancer.⁵ Second, the use of diagnostic imaging has changed substantially in recent years. In particular, the use of CT has increased rapidly in the United States, at a rate greater than sonography imaging.^7–9 A study of nationwide emergency department imaging use from 2000–2008 found that the use of sonography increased by 95%, whereas CT increased by 227%. In addition, CT made up 29% of emergency department imaging, but sonography comprised only 4%. CT scans of the neck, cervical spine, and/or chest can include the thyroid gland and may be a source for the detection of incidental thyroid nodules that subsequently receive work-up and biopsy.The aim of our study was to evaluate the recent trends in the incidence of thyroid cancer, and to determine the relationship between annual CT imaging volume and thyroid cancer incidence. Our hypothesis was that the incidence of subclinical thyroid cancers has continued to increase, and that the increase in thyroid cancers correlates strongly with the volume of CT imaging.     

Presence of local pleural adhesion in CT screening-detected small nodule in the lung periphery suggests noncancerous, inflammatory nature of the lesion

PURPOSE: Differential diagnosis of small nodules in the lung periphery detected by low-dose chest CT screening is important before surgery. The aim of the study was to discriminate between benign and malignant lesions, identified in our preoperative imaging work-up examinations and confirmed during surgery, for nodules detected on CT screening. MATERIALS AND METHODS: This study is based on 106 patients (46 men and 60 women, median age: 61.5 years) with 123 CT screening-detected and histologically confirmed nodules smaller than 30 mm in the lung periphery identified between 2002 and 2005 at Azumi General Hospital, Japan. Lesions were classified into three groups according to histological findings: adenocarcinoma, atypical adenomatous hyperplasia (AAH) and inflammatory focal lesions. We examined the visceral pleura during surgery at a location close to lung nodules. RESULTS: The median diameter of resected lung nodules on high-resolution CT (HRCT) was 9.0 mm. Nodules were nonsolid in 42, partly solid in 51 and solid in 30. Histopathological diagnosis was lung cancer in 69, AAH in 21, other noninflammatory tumours in 6 and inflammatory lesions in 27. Fifty-four lesions were located in the subpleural zone. Eight of 123 nodules showed local pleural adhesions (LPA), while 2 were buried in extensive pleural adhesion. LPA was noted more frequently in inflammatory nodules than in cancer nodules (P<.01). CONCLUSION: The presence of LPA in close proximity to a small nodule is indicative of noncancerous lesion. This feature allows the discrimination of pulmonary peripheral inflammatory lesion from peripheral small cancer on chest low-dose CT screening.     

Yttrium-90 Activity Quantification in PET/CT–Guided Biopsy Specimens from Colorectal Hepatic Metastases Immediately after Transarterial Radioembolization Using Micro–CT and Autoradiography

PurposeTo evaluate the yttrium-90 (⁹⁰Y) activity distribution in biopsy tissue samples of the treated liver to quantify the dose with higher spatial resolution than positron emission tomography (PET) for accurate investigation of correlations with microscopic biological effects and to evaluate the radiation safety of this procedure.Materials and MethodsEighty-six core biopsy specimens were obtained from 18 colorectal liver metastases (CLMs) immediately after ⁹⁰Y transarterial radioembolization (TARE) with either resin or glass microspheres using real-time ⁹⁰Y PET/CT guidance in 17 patients. A high-resolution micro–computed tomography (micro-CT) scanner was used to image the microspheres in part of the specimens and allow quantification of ⁹⁰Y activity directly or by calibrating autoradiography (ARG) images. The mean doses to the specimens were derived from the measured specimens’ activity concentrations and from the PET/CT scan at the location of the biopsy needle tip for all cases. Staff exposures were monitored.ResultsThe mean measured ⁹⁰Y activity concentration in the CLM specimens at time of infusion was 2.4 ± 4.0 MBq/mL. The biopsies revealed higher activity heterogeneity than PET. Radiation exposure to the interventional radiologists during post-TARE biopsy procedures was minimal.ConclusionsCounting the microspheres and measuring the activity in biopsy specimens obtained after TARE are safe and feasible and can be used to determine the administered activity and its distribution in the treated and biopsied liver tissue with high spatial resolution. Complementing ⁹⁰Y PET/CT imaging with this approach promises to yield more accurate direct correlation of histopathological changes and absorbed dose in the examined specimens.     

Fleischner Society Guideline Recommendations for Incidentally Detected Pulmonary Nodules and the Probability of Lung Cancer

PurposeThe Fleischner Society aims to limit further evaluations of incidentally detected pulmonary nodules when the probability of lung cancer is <1% and to pursue further evaluations when the probability of lung cancer is ≥1%. To evaluate the internal consistency of guideline goals and recommendations, the authors evaluated stratum-specific recommendations and 2-year probabilities of lung cancer.MethodsA retrospective cohort study (2005-2015) was conducted of individuals enrolled in one of two integrated health systems with solid nodules incidentally detected on CT. The 2017 Fleischner Society guidelines were used to define strata on the basis of smoking status and nodule size and number. Lung cancer diagnoses within 2 years of nodule detection were ascertained using cancer registry data. Confidence interval (CI) inspection was used to determine if stratum-specific probabilities of lung cancer were different than 1%.ResultsAmong 5,444 individuals with incidentally detected lung nodules (median age, 66 years; 54% women; 57% smoked; median nodule size, 5.5 mm; 55% with multiple nodules), 214 (3.9%; 95% CI, 3.4%-4.5%) were diagnosed with lung cancer within 2 years. For 7 of 12 strata (58%), 2,765 patients (51%), and 194 lung cancer cases (91%), there was alignment between Fleischner Society goals and recommendations. Alignment was indeterminate for 5 strata (42%), 2,679 patients (49%), and 20 lung cancer cases (9%) because CIs for the probability of lung cancer spanned 1%.ConclusionsFleischner Society guideline goals and recommendations align at least half the time. It is uncertain whether alignment of guideline goals and recommendations occurs more often.     

Lung cancer associated with cystic airspaces: Characteristic morphological features on CT in a series of 11 cases

PurposeTo familiarize the reader with the entity ‘lung cancer associated with cystic airspaces’ (LC-CAS) and create an awareness about the potential for slow progressive development of cancer within these nonaggressive appearing cystic airspaces (CAS) encountered in routine radiology practice.Material and methodsMorphological appearances of (n = 11) LC-CAS detected during routine radiological reporting of chest CT scans were studied. Patient demographics, clinical history, characteristics of LC-CAS including location, size, wall thickening, diffuse nodularity, eccentric nodule, ground glass change, emphysema and pathology results were collected from the hospital's internal database.ResultsPatients with LC-CAS (9F/2M) were between 49 and 77 years (mean 63.18 years). All patients (n = 11) had a history of smoking. LC-CAS had a characteristic multicystic bubbly appearance. Average size of CAS at initial detection of LC was 2.52 cm (range 1.3–4 cm). Lesions were located in the RLL (n = 4), RML (n = 2), RUL (n = 1), LLL (n = 1) and LUL (n = 3) with no lobar predilection and were more commonly peripheral (n = 7) than central (n = 4). Ground glass change (n = 2), extrinsic nodules (n = 4), diffuse wall nodularity (n = 3) and intrinsic nodules (n = 2) were observed and prompted biopsy. Lesions ranged between T1a to T4. Most cancers were T1a N0 (n = 5). Adenocarcinomas formed the majority of cases (n = 9).ConclusionLC-CAS present as new development of diffuse nodularity, eccentric nodules or ground glass change associated with CAS. These are more commonly adenocarcinomas on histology. Recognition of CAS and appropriate malignancy workup when suspicious features are observed is essential to enable early detection of lung cancer.     

Contemporary image-guided cervical cancer brachytherapy: Consensus imaging recommendations from the Society of Abdominal Radiology and the American Brachytherapy Society

PURPOSETo present recommendations for the use of imaging for evaluation and procedural guidance of brachytherapy for cervical cancer patients.METHODSAn expert panel comprised of members of the Society of Abdominal Radiology Uterine and Ovarian Cancer Disease Focused Panel and the American Brachytherapy Society jointly assessed the existing literature and provide data-driven guidance on imaging protocol development, interpretation, and reporting.RESULTSImage-guidance during applicator implantation reduces rates of uterine perforation by the tandem. Postimplant images may be acquired with radiography, computed tomography (CT), or magnetic resonance imaging (MRI), and CT or MRI are preferred due to a decrease in severe complications. Pre-brachytherapy T2-weighted MRI may be used as a reference for contouring the high-risk clinical target volume (HR-CTV) when CT is used for treatment planning. Reference CT and MRI protocols are provided for reference.CONCLUSIONSImage-guided brachytherapy in locally advanced cervical cancer is essential for optimal patient management. Various imaging modalities, including orthogonal radiographs, ultrasound, computed tomography, and magnetic resonance imaging, remain integral to the successful execution of image-guided brachytherapy.     

Imaging Features of Pulmonary Leukemic Infiltration With Comparison of Lymphoid and Myeloid Leukemias

PurposeTo describe the imaging findings of lung infiltration by leukemia and differential findings of lymphoid and myeloid leukemias.Materials and MethodsThrough a search of electronic medical records from 2005 to 2017, we identified 21 patients with pathologically proven lung involvement by leukemia. Concurrent CT findings were analyzed by 2 chest radiologists in consensus for ground glass or consolidative opacities, septal thickening, bronchovascular bundle thickening, pulmonary nodules, pulmonary masses, and hilar and mediastinal lymphadenopathy.ResultsThere were 13 cases of lymphoid leukemias and 8 of myeloid leukemias. Nodules and masses were the most common imaging feature (n = 13, 62%). Bronchovascular bundle thickening and hilar lymphadenopathy were exclusively seen in lymphoid leukemias (P = 0.01 and P = 0.006). Centrilobular nodules were also exclusively seen in 3 patients with chronic lymphocytic leukemia.ConclusionLung infiltration by leukemia presents most commonly with nodules or masses, but interstitial abnormalities such as bronchovascular bundle thickening were seen as well. Radiologists should consider leukemic infiltration in the differential diagnosis for nodules, including centrilobular nodules, in these patients.     

High Variability in Radiologists' Reporting Practices for Incidental Thyroid Nodules Detected on CT and MRI

BACKGROUND AND PURPOSE:There are no guidelines for reporting incidental thyroid nodules seen on CT and MR imaging. We evaluated radiologists'' current reporting practices for incidental thyroid nodules detected on these imaging modalities.MATERIALS AND METHODS:Radiologists were surveyed regarding their reporting practices by using 14 scenarios of incidental thyroid nodules differing in size, patient demographics, and clinical history. Scenarios were evaluated for the following: 1) radiologists'' most commonly selected response, and 2) the proportion of radiologists selecting that response (degree of agreement). These measures were used to determine how the patient scenario and characteristics of the radiologists affected variability in practice.RESULTS:One hundred fifty-three radiologists participated. In 8/14 scenarios, the most common response was to “recommend sonography.” For the other scenarios, the most common response was to “report in only body of report.” The overall mean agreement for the 14 scenarios was 53%, and agreement ranged from 36% to 75%. Smaller nodules had lower agreement: 43%–51% for 8-mm nodules compared with 64%–75% for 15-mm nodules. Agreement was poorest for the 10-mm nodule in a 60-year-old woman (36%) and for scenarios with additional history of lung cancer (39%) and multiple nodules (36%). There was no significant difference in reporting practices and agreement when radiologists were categorized by years of practice, practice type, and subspecialty (P > .55).CONCLUSIONS:The reporting practice for incidental thyroid nodules on CT or MR imaging is highly variable among radiologists, especially for patients with smaller nodules (≤10 mm) and patients with multiple nodules and a history of cancer. This variability highlights the need for practice guidelines.

Incidental thyroid nodules are seen in 16%–18% of CT and MR imaging studies that include the thyroid.^1,2 Although the prevalence of malignancy in incidental thyroid nodules (ITNs) is low and small thyroid cancers have an excellent prognosis, concern for missing malignancy may nevertheless lead to further evaluation for small nonspecific thyroid nodules. Initiating a work-up of an ITN seen on CT or MR imaging with diagnostic sonography can lead to further costly procedures, including fine-needle aspiration, follow-up sonography examinations, or even diagnostic thyroid lobectomy.The Society of Radiologists in Sonography and other societies have published recommendations for biopsy of nodules seen on sonography,³ but no medical organizations have specific published recommendations for the work-up of thyroid nodules seen on CT and MR imaging.⁴ The Society of Radiologists in Sonography recommendations cannot be simply extrapolated to CT- and MR imaging–detected nodules because the sonographic signs of microcalcifications and solid composition cannot be reliably appreciated on CT and MR imaging.⁵ Furthermore, CT and MR imaging allow a more comprehensive evaluation of neck nodes than is possible with the limited number of images captured during a thyroid sonography examination.Without technique-specific guidelines, the reporting of ITNs seen on CT and MR imaging is likely to be nonuniform and influenced by radiologists'' practice types or personal opinions. This variation leads to inconsistent practices and the potential for confusion among clinicians who receive the radiology reports. In a retrospective study, Yousem et al² found that 61% of ITNs seen on CT and MR imaging of the neck were not reported by the radiologist issuing the clinical report, and they proposed that either the nodule was not seen or it was regarded as unimportant. A prior survey on incidental findings queried radiologists about the ITN, but the survey was limited to 1 scenario and was sent only to academic body imaging radiologists.⁶The aim of this study was to survey radiologists'' self-described reporting practices of hypothetic scenarios of ITNs detected on CT and MR imaging. We hypothesized that reporting practices for ITNs are highly variable and may depend on the radiologist''s experience, practice type, and training.     

Primary lung cancers <1 cm found with MR screening appeared larger with half-Fourier sequences than with three-dimensional acquisition techniques

PurposeThe purpose was to objectively evaluate image quality characteristics of half-Fourier single-shot turbo spin-echo (HASTE) and three-dimensional volumetric interpolated breath-hold examination (3D-VIBE) for small (<1 cm) lung cancers found by magnetic resonance imaging (MRI) screening.MethodsFrom 2000 to 2009, 19,000 normal subjects were screened by MRI, and 15 cases were found to have lung cancers <1 cm. Those nodules were analyzed by image quality indices such as the signal to noise ratio, signal difference to noise ratio, percent contrast, percent contrast to noise ratio, and signal ratio of tumor to normal lung parenchyma. The area of the tumors measured by the two MR sequences and the computed tomography (CT) was compared.ResultsThe lung cancers showed significantly higher percent contrast, percent contrast to noise, and the signal ratio of tumor to normal lung parenchyma by 3D-VIBE as compared to HASTE. Tumor area estimated by HASTE was significantly larger than that estimated by VIBE. There was no significant difference in the signal to noise ratio and signal difference to noise ratio between the two MR sequences.ConclusionsThe 3D acquisition technique offers high contrast and contrast to noise ratios, while HASTE is associated with closer approximation of area estimation as compared to CT. Both sequences have similar signal to noise ratios and signal difference to noise ratios. The HASTE sequence is considered to be an essential part of imaging protocol in MR screening of lung especially for small nodules.     

Quantitative Dual-Energy CT Image Guidance for Thermochemical Ablation: In Vivo Results in the Rabbit VX2 Model

PurposeTo evaluate the feasibility of using dual-energy computed tomography (CT) and theranostic cesium hydroxide (CsOH) for image guidance of thermochemical ablation (TCA) in a rabbit VX2 tumor model.Materials and MethodsIn vivo experiments were performed on New Zealand white rabbits, where VX2 tumor fragments (0.3 mL) were inoculated into the right and left flanks (n = 16 rabbits, 32 tumors). Catheters were placed in the approximate center of 1- to 2-cm diameter tumors under ultrasound guidance. TCA was delivered in 1 of 3 treatment groups: untreated control, 5-M TCA, or 10-M TCA. The TCA base reagent was doped with 250-mM CsOH. Dual-energy CT was performed before and after TCA. Cesium (CS)-specific images were postprocessed on the basis of previous phantom calibrations to determine Cs concentration. Line profiles were drawn through the ablation center. Twenty-four hours after TCA, subjects were euthanized, and the resulting damage was evaluated with histopathology.ResultsCs was detected in 100% of treated tumors (n = 21). Line profiles indicated highest concentrations at the injection site and decreased concentrations at the tumor margins, with no Cs detected beyond the ablation zone. The maximum detected Cs concentration ranged from 14.39 to 137.33 mM. A dose-dependent trend in tissue necrosis was demonstrated between the 10-M TCA and 5-M TCA treatment groups (P = .0005) and untreated controls (P = .0089).ConclusionsDual-energy CT provided image guidance for delivery, localization, and quantification of TCA in the rabbit VX2 model.     

肺炎型肺癌与局灶性肺炎的多层螺旋CT鉴别诊断价值及病理对照分析

目的通过多层螺旋CT（MSCT）的后处理技术、肺结节分析功能深入分析肺炎型肺癌与局灶性肺炎的各种征象,结合cT导引下穿刺活检的病理结果进行对比回顾性研究,探讨肺炎型肺癌的MSCT诊断与鉴别诊断价值。方法45例肺炎型肺癌和50例局灶性肺炎患者均行MSCT全肺容积扫描,再经高分辨率cT（HRCT）、多平面重建（MPR）及LungCare软件结节分析,最终根据取得的病理结果加以回顾性研究并做r检验进行统计学分析。结果孤立肺炎型肺癌在短细毛刺、血管集束征、胸膜凹陷征、支气管充气征以及LungCare软件结节分析瘤体显示方面明显高于局灶性肺炎（P〈O．01）。结论通过MSCT的后处理技术、肺结节分析功能能对病理基础不同的肺炎型肺癌与局灶性肺炎提供较明确的诊断与鉴别诊断依据,为临床及早准确治疗提供依据。