Ultrasonographic Demonstration of the Tissue Microvasculature in Children: Microvascular Ultrasonography Versus Conventional Color Doppler Ultrasonography

Microvascular ultrasonographic imaging is the most recent and unique Doppler ultrasound technique. It uses an advanced clutter filter that can remove clutter artifacts and preserve the low-velocity microvascular flow signal. The potential advantages of microvascular ultrasonography are its superiority in detection and visualization of the small blood vessels in tissues, providing radiologists with more information on the vascular structures. Therefore, it has shown particular value in the clinical fields. The aim of this study was to provide microvascular ultrasonographic images for the tissue microvasculature, including the brain, thyroid gland, kidney, urinary bladder, small bowel, ovary, testis, lymph node, and hemangiomas in children, focusing on the comparison with conventional color Doppler ultrasonographic images.

Diagnostic Accuracy of Percutaneous Transthoracic Needle Lung Biopsies: A Multicenter Study

Objective

To measure the diagnostic accuracy of percutaneous transthoracic needle lung biopsies (PTNBs) on the basis of the intention-to-diagnose principle and identify risk factors for diagnostic failure of PTNBs in a multi-institutional setting.

Materials and Methods

A total of 9384 initial PTNBs performed in 9239 patients (mean patient age, 65 years [range, 20–99 years]) from January 2010 to December 2014 were included. The accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of PTNBs for diagnosis of malignancy were measured. The proportion of diagnostic failures was measured, and their risk factors were identified.

Results

The overall accuracy, sensitivity, specificity, PPV, and NPV were 91.1% (95% confidence interval [CI], 90.6–91.7%), 92.5% (95% CI, 91.9–93.1%), 86.5% (95% CI, 85.0–87.9%), 99.2% (95% CI, 99.0–99.4%), and 84.3% (95% CI, 82.7–85.8%), respectively. The proportion of diagnostic failures was 8.9% (831 of 9384; 95% CI, 8.3–9.4%). The independent risk factors for diagnostic failures were lesions ≤ 1 cm in size (adjusted odds ratio [AOR], 1.86; 95% CI, 1.23–2.81), lesion size 1.1–2 cm (1.75; 1.45–2.11), subsolid lesions (1.81; 1.32–2.49), use of fine needle aspiration only (2.43; 1.80–3.28), final diagnosis of benign lesions (2.18; 1.84–2.58), and final diagnosis of lymphomas (10.66; 6.21–18.30). Use of cone-beam CT (AOR, 0.31; 95% CI, 0.13–0.75) and conventional CT-guidance (0.55; 0.32–0.94) reduced diagnostic failures.

Conclusion

The accuracy of PTNB for diagnosis of malignancy was fairly high in our large-scale multi-institutional cohort. The identified risk factors for diagnostic failure may help reduce diagnostic failure and interpret the biopsy results.

Analysis of Complications of Percutaneous Transthoracic Needle Biopsy Using CT-Guidance Modalities In a Multicenter Cohort of 10568 Biopsies

Objective

To analyze the complications of percutaneous transthoracic needle biopsy using CT-based imaging modalities for needle guidance in comparison with fluoroscopy in a large retrospective cohort.

Materials and Methods

This study was approved by multiple Institutional Review Boards and the requirement for informed consent was waived. We retrospectively included 10568 biopsies from eight referral hospitals from 2010 through 2014. In univariate and multivariate logistic analyses, 3 CT-based guidance modalities (CT, CT fluoroscopy, and cone-beam CT) were compared with fluoroscopy in terms of the risk of pneumothorax, pneumothorax requiring chest tube insertion, and hemoptysis, with adjustment for other risk factors.

Results

Pneumothorax occurred in 2298 of the 10568 biopsies (21.7%). Tube insertion was required after 316 biopsies (3.0%), and hemoptysis occurred in 550 cases (5.2%). In the multivariate analysis, pneumothorax was more frequently detected with CT {odds ratio (OR), 2.752 (95% confidence interval [CI], 2.325–3.258), p < 0.001}, CT fluoroscopy (OR, 1.440 [95% CI, 1.176–1.762], p < 0.001), and cone-beam CT (OR, 2.906 [95% CI, 2.235–3.779], p < 0.001), but no significant relationship was found for pneumothorax requiring chest tube insertion (p = 0.497, p = 0.222, and p = 0.216, respectively). The incidence of hemoptysis was significantly lower under CT (OR, 0.348 [95% CI, 0.247–0.491], p < 0.001), CT fluoroscopy (OR, 0.594 [95% CI, 0.419–0.843], p = 0.004), and cone-beam CT (OR, 0.479 [95% CI, 0.317–0.724], p < 0.001) guidance.

Conclusion

Hemoptysis occurred less frequently with CT-based guidance modalities in comparison with fluoroscopy. Although pneumothorax requiring chest tube insertion showed a similar incidence, pneumothorax was more frequently detected using CT-based guidance modalities.

Nondiagnostic Percutaneous Transthoracic Needle Biopsy of Lung Lesions: A Multicenter Study of Malignancy Risk

Purpose To evaluate the malignancy risk of lung lesions that show nondiagnostic results at transthoracic needle biopsy (PTNB) of the lung and to identify any malignancy-associated risk factors in each nondiagnostic category. Materials and Methods In this retrospective study, 9384 initial PTNBs (9239 patients [mean age, 65 years; age range, 20-99 years] consisting of 5729 men [mean age, 66 years; age range, 20-99 years] and 3510 women [mean age, 63 years; age range, 20-94 years]) were performed in eight institutions between January 2010 and December 2014. PTNB results were categorized as diagnostic (malignant or specifically benign) or nondiagnostic (nonspecific benign pathologic findings, atypical cells, or insufficient specimen), and the proportion of final malignant diagnoses per nondiagnostic category was obtained. Malignancy-associated factors were determined by using multivariable analyses. Results Nondiagnostic results were present in 27.6% (2590 of 9384) of PTNBs. Proportions of final malignant diagnoses were 21.3% (339 of 1592) for nonspecific benignities, 90.1% (503 of 558) for atypical cells, and 46.6% (205 of 440) for insufficient specimens. In the nonspecific benign category, granulomatous inflammation (odds ratio [OR], 0.04; 95% confidence interval [CI]: 0.02, 0.12; P < .001), abscess (OR, 0.04; 95% CI: 0.01, 0.28; P = .001), and organizing pneumonia (OR, 0.05; 95% CI: 0.01, 0.23; P < .001) were demonstrated to be important factors negating malignancy. Atypical cells suspicious for malignancy were more associated with malignancy (OR, 6.3; 95% CI: 1.9, 21.0; P = .003) than were atypical cells of indeterminate malignancy. All 130 lesions with atypical cells suggestive of malignancy were finally malignant. Conclusion After nondiagnostic lung biopsies, lesions categorized as atypical cell lesions have a high likelihood of malignancy, with somewhat lower likelihood for lesions with insufficient specimens and nonspecific benign categories. © RSNA, 2018 Online supplemental material is available for this article. See also the editorial by Elicker in this issue.

Bronchopulmonary foregut malformation presenting as extralobar pulmonary sequestration associated with a bronchogenic cyst: an unusual clinical and radiological feature in an adolescent patient

We present a case of symptomatic complex bronchopulmonary foregut malformation (BPFM), including extralobar pulmonary sequestration and a bronchogenic cyst, in the left anterior mediastinum of a 15-year-old boy. Preoperative computed tomography showed a cystic mass with heterogeneous enhancement of adjacent soft tissue components and pleural effusion. We suggested the infected bronchogenic cyst as the first impression. However, pathological examination after surgical resection revealed extralobar pulmonary sequestration and a bronchogenic cyst with unusual manifestation, which was located in the left upper hemithorax and supplied by the pulmonary artery. In patients presenting with a cystic mass with features of inflammation or infection and collateral vasculature, the possibility of a complex bronchopulmonary foregut malformation should be considered in the differential diagnosis.

Predictive Factors of Atelectasis Following Endoscopic Resection

BACKGROUND AND AIM

Atelectasis is one of the pulmonary complications associated with anesthesia. Little is known about atelectasis following endoscopic procedures under deep sedation. This study evaluated the frequency, risk factors, and clinical course of atelectasis after endoscopic resection.

METHODS

A total of 349 patients who underwent endoscopic resection of the upper gastrointestinal tract at a single academic tertiary referral center from March 2010 to October 2013 were enrolled. Baseline characteristics and clinical data were retrospectively reviewed from medical records. To identify atelectasis, we compared the chest radiography taken before and after the endoscopic procedure.

RESULTS

Among the 349 patients, 68 (19.5 %) had newly developed atelectasis following endoscopic resection. In univariate logistic regression analysis, atelectasis correlated significantly with high body mass index, smoking, diabetes mellitus, procedure duration, size of lesion, and total amount of propofol. In multiple logistic regression analysis, body mass index, procedure duration, and total propofol amount were risk factors for atelectasis following endoscopic procedures. Of the 68 patients with atelectasis, nine patients developed fever, and six patients displayed pneumonic infiltration. The others had no symptoms related to atelectasis.

CONCLUSIONS

The incidence of radiographic atelectasis following endoscopic resection was nearly 20 %. Obesity, procedural time, and amount of propofol were the significant risk factors for atelectasis following endoscopic procedure. Most cases of the atelectasis resolved spontaneously with no sequelae.

Sequential morphological changes in follow-up CT of pulmonary mucormycosis

PURPOSE

We aimed to describe the computed tomography (CT) features of pulmonary mucormycosis including sequential changes between follow-ups.

MATERIALS AND METHODS

Between June 2001 and May 2011, five patients (three males and two females; median age, 43 years; age range, 13-73 years) who had been pathologically diagnosed with pulmonary mucormycosis constituted our study population. Their clinical and CT features including sequential changes over follow-ups were evaluated retrospectively.

RESULTS

All patients were immunocompromised due to either hematologic diseases (n=3), diabetes mellitus (n=1), or steroid administration for autoimmune hepatitis (n=1). All patients had symptoms such as fever (n=5), tachycardia (n=1), or pleuritic chest pain (n=1) on admission. Regarding the clinical outcome after treatment, one patient died, and the remaining four recovered from the disease. In terms of initial CT features, the morphologies of pulmonary mucormycosis included a single mass (n=3), consolidation (n=1), or multiple masses (n=1). There were seven pulmonary lesions in total, 3-7 cm in size, which showed a CT halo sign (n=3), reversed-halo sign (n=2), or air-fluid levels (n=2). On follow-up CTs, the lesions of all patients contained necrosis. All three patients with a mass or masses with a CT halo sign on initial CT had a decreased surrounding halo followed by central necrosis, and the lesions gradually decreased in size on recovery.

CONCLUSION

Pulmonary mucormycosis usually manifests as a mass or masses with a halo or reversed-halo sign on the initial CT scan followed by a decreased extent of surrounding ground-glass opacities with the development of internal necrosis during follow-up.

A case of a migrating pleural lipoma: the beginning of a thoracolith?

Lipomas can be encountered almost anywhere in the body, yet they are rare in the pleural space of the thorax. However, they have been typically described as pleural-based fatty masses. We present a rare case of a pleural lipoma that changed its location on follow-up images. Migration and rotation of the lesion were investigated using chest computed tomography. A pathologic examination demonstrated extensive calcification and fat necrosis. The findings in this case support a mechanism of development of thoracolith.

Usefulness of Digital Tomosynthesis for the Detection of Airway Obstruction: A Case Report of Bronchial Carcinosarcoma

Bronchial carcinosarcoma is a very rare malignant tumor that is composed of carcinomatous and sarcomatous elements. We describe the first case in which digital tomosynthesis was useful for the evaluation of airway obstruction by bronchial carcinosarcoma that was overlooked on initial chest radiography.

Localized pulmonary alveolar proteinosis: two case reports

BACKGROUND

Pulmonary alveolar proteinosis (PAP) is a relatively rare disease characterized by abnormal accumulation of surfactant-like material in the alveolar spaces. The classic radiologic findings of PAP include bilateral, symmetric, diffuse ground-glass opacity (GGO) or consolidation. The most common computed tomography (CT) feature of PAP is widespread GGO with thickened interlobular septa, the so-called crazy-paving pattern, which strongly suggests the diagnosis.

CASE REPORT

Here, we report the cases of two young male patients with unusual presentations of PAP. One patient showed localized PAP in the left lower lobe on CT images and the other patient presented with unilateral PAP involving the right lower lung field and recurrence in the same area with the same pattern as the initial manifestation.

CONCLUSION

In conclusion, it is important for radiologists to be aware of potential atypical imaging findings of PAP in order to provide a correct diagnosis. Along these lines, PAP can present as a solitary nodular lesion or unilateral focal lesion, and can recur in the same pattern and location.

Computer-aided classification of visual ventilation patterns in patients with chronic obstructive pulmonary disease at two-phase xenon-enhanced CT

Objective

To evaluate the technical feasibility, performance, and interobserver agreement of a computer-aided classification (CAC) system for regional ventilation at two-phase xenon-enhanced CT in patients with chronic obstructive pulmonary disease (COPD).

Materials and Methods

Thirty-eight patients with COPD underwent two-phase xenon ventilation CT with resulting wash-in (WI) and wash-out (WO) xenon images. The regional ventilation in structural abnormalities was visually categorized into four patterns by consensus of two experienced radiologists who compared the xenon attenuation of structural abnormalities with that of adjacent normal parenchyma in the WI and WO images, and it served as the reference. Two series of image datasets of structural abnormalities were randomly extracted for optimization and validation. The proportion of agreement on a per-lesion basis and receiver operating characteristics on a per-pixel basis between CAC and reference were analyzed for optimization. Thereafter, six readers independently categorized the regional ventilation in structural abnormalities in the validation set without and with a CAC map. Interobserver agreement was also compared between assessments without and with CAC maps using multirater κ statistics.

Results

Computer-aided classification maps were successfully generated in 31 patients (81.5%). The proportion of agreement and the average area under the curve of optimized CAC maps were 94% (75/80) and 0.994, respectively. Multirater κ value was improved from moderate (κ = 0.59; 95% confidence interval [CI], 0.56-0.62) at the initial assessment to excellent (κ = 0.82; 95% CI, 0.79-0.85) with the CAC map.

Conclusion

Our proposed CAC system demonstrated the potential for regional ventilation pattern analysis and enhanced interobserver agreement on visual classification of regional ventilation.

Endometrial stromal sarcoma presented as an incidental lung mass with multiple pulmonary nodules

Low-grade endometrial stromal sarcoma (ESS) is an uncommon gynecologic malignancy of mesodermal origin. Pulmonary metastasis of low-grade ESS can occur years and decades after the treatment of the primary disease. Low-grade ESS is frequently mistaken as benign uterine neoplasm like uterine leiomyoma, which can potentially lead to a misdiagnosis. We present a case of a 42-year-old woman with low-grade ESS, that initially presented as an incidental lung mass with multiple pulmonary nodules, seven years after an uterine myomectomy. A 6.9×5.8 cm-sized intrapelvic mass suspected of uterine origin was discovered while searching for potential extrathoracic primary origin. A pelviscopy and simultaneous thoracoscopic lung biopsy were conducted for pathologic diagnosis. Finally, the diagnosis was confirmed as low-grade ESS with lung metastasis based on the histopathologic examination with immunohistochemical stain, which was showed positive for CD10 and hormone receptor markers (estrogen and progesterone receptors) in both pelvic and lung specimens.

Quantitative analysis of emphysema and airway measurements according to iterative reconstruction algorithms: comparison of filtered back projection, adaptive statistical iterative reconstruction and model-based iterative reconstruction

OBJECTIVES

To evaluate filtered back projection (FBP) and two iterative reconstruction (IR) algorithms and their effects on the quantitative analysis of lung parenchyma and airway measurements on computed tomography (CT) images.

METHODS

Low-dose chest CT obtained in 281 adult patients were reconstructed using three algorithms: FBP, adaptive statistical IR (ASIR) and model-based IR (MBIR). Measurements of each dataset were compared: total lung volume, emphysema index (EI), airway measurements of the lumen and wall area as well as average wall thickness. Accuracy of airway measurements of each algorithm was also evaluated using an airway phantom.

RESULTS

EI using a threshold of -950 HU was significantly different among the three algorithms in decreasing order of FBP (2.30 %), ASIR (1.49 %) and MBIR (1.20 %) (P < 0.01). Wall thickness was also significantly different among the three algorithms with FBP (2.09 mm) demonstrating thicker walls than ASIR (2.00 mm) and MBIR (1.88 mm) (P < 0.01). Airway phantom analysis revealed that MBIR showed the most accurate value for airway measurements.

CONCLUSION

The three algorithms presented different EIs and wall thicknesses, decreasing in the order of FBP, ASIR and MBIR. Thus, care should be taken in selecting the appropriate IR algorithm on quantitative analysis of the lung.

KEY POINTS

• Computed tomography is increasingly used to provide objective measurements of intra-thoracic structures. • Iterative reconstruction algorithms can affect quantitative measurements of lung and airways. • Care should be taken in selecting reconstruction algorithms in longitudinal analysis. • Model-based iterative reconstruction seems to provide the most accurate airway measurements.

Tracheal metastasis from rectal cancer: a case report and review of the literature

The trachea is an uncommon site of metastasis from colorectal carcinoma. A few cases have been reported in the literature, but these focused mostly on the clinical aspects without detailing radiologic and histologic findings. The authors describe a 70-year-old woman who was diagnosed with tracheal metastasis from a primary rectal cancer. We present the contrast-enhanced chest computed temography (CT), including volume-rendered image, as well as bronchoscopic findings.

Azygos vein aneurysm mimicking paratracheal mass: dynamic magnetic resonance imaging findings

Aneurysms of the azygos vein are rare and can sometimes mimic a paratracheal or posterior mediastinal mass. It is important to confirm the diagnosis with radiologic tools before performing invasive procedures, which carry the risk of hemorrhage. Here, we present a case in a 79-year-old asymptomatic patient of an increasing azygos vein aneurysm that mimicked a growing paratracheal mass. Review of images obtained using various modalities, including dynamic magnetic resonance image (MRI), revealed that the image findings were suggestive of azygos vein aneurysm. Using this method, an exact diagnosis can be reached without resorting to invasive procedures.

Computer-aided nodule detection and volumetry to reduce variability between radiologists in the interpretation of lung nodules at low-dose screening computed tomography

OBJECTIVE

The aim of this study was to evaluate whether a computer-aided diagnosis (CAD) system improves interobserver agreement in the interpretation of lung nodules at low-dose computed tomography (CT) screening for lung cancer.

MATERIALS AND METHODS

Baseline low-dose screening CT examinations from 134 participants enrolled in the National Lung Screening Trial were reviewed by 7 chest radiologists. All participants consented to the use of their deidentified images for research purposes. Screening results were classified as positive when noncalcified nodules larger than 4 mm in diameter were present. Follow-up evaluation was recommended according to the nodule diameter: 4 mm or smaller, more than 4 to 8 mm, and larger than 8 mm. When multiple nodules were present, recommendations were based on the largest nodule. Readers initially assessed the nodule presence visually and measured the average nodule diameter manually. Revision of their decisions after reviewing the CAD marks and size measurement was allowed. Interobserver agreement evaluated using multirater κ statistics was compared between initial assessment and that with CAD.

RESULTS

Multirater κ values for the positivity of the screening results and follow-up recommendations were improved from moderate (κ = 0.53-0.54) at initial assessment to good (κ = 0.66-0.67) after reviewing CAD results. The average percentage of agreement between reader pairs on the positivity of screening results and follow-up recommendations per case was also increased from 77% and 72% at initial assessment to 84% and 80% with CAD, respectively.

CONCLUSION

Computer-aided diagnosis may improve the reader agreement on the positivity of screening results and follow-up recommendations in the assessment of low-dose screening CT.

CT-guided percutaneous transthoracic localization of pulmonary nodules prior to video-assisted thoracoscopic surgery using barium suspension

Objective

To describe our initial experience with CT-guided percutaneous barium marking for the localization of small pulmonary nodules prior to video-assisted thoracoscopic surgery (VATS).

Materials and Methods

From October 2010 to April 2011, 10 consecutive patients (4 men and 6 women; mean age, 60 years) underwent CT-guided percutaneous barium marking for the localization of 10 small pulmonary nodules (mean size, 7.6 mm; range, 3-14 mm): 6 pure ground-glass nodules, 3 part-solid nodules, and 1 solid nodule. A 140% barium sulfate suspension (mean amount, 0.2 mL; range, 0.15-0.25 mL) was injected around the nodules with a 21-gauge needle. The technical details, surgical findings and pathologic features associated with barium localizations were evaluated.

Results

All nodules were marked within 3 mm (mean distance, 1.1 mm; range, 0-3 mm) from the barium ball (mean diameter, 9.6 mm; range, 8-16 mm) formed by the injected barium suspension. Pneumothorax occurred in two cases, for which one needed aspiration. However, there were no other complications. All barium balls were palpable during VATS and visible on intraoperative fluoroscopy, and were completely resected. Both the whitish barium balls and target nodules were identifiable in the frozen specimens. Pathology revealed one invasive adenocarcinoma, five adenocarcinoma-in-situ, two atypical adenomatous hyperplasias, and two benign lesions. In all cases, there were acute inflammations around the barium balls which did not hamper the histological diagnosis of the nodules.

Conclusion

CT-guided percutaneous barium marking can be an effective, convenient and safe pre-operative localization procedure prior to VATS, enabling accurate resection and diagnosis of small or faint pulmonary nodules.

Percutaneous transthoracic needle biopsy of small (≤ 1 cm) lung nodules under C-arm cone-beam CT virtual navigation guidance

OBJECTIVES

To describe our initial experience with percutaneous transthoracic needle biopsy (PCNB) of small (≤1 cm) lung nodules using a cone-beam computed tomography (CBCT) virtual navigation guidance system in 105 consecutive patients.

METHODS

One hundred and five consecutive patients (55 male, 50 female; mean age, 62 years) with 107 small (≤1 cm) lung nodules (mean size, 0.85 cm ± 0.14) underwent PCNBs under CBCT virtual-navigation guidance system and constituted our study population. Procedural details-including radiation dose, sensitivity, specificity, diagnostic accuracy and complication rates of CBCT virtual navigation guided PCNBs-were described.

RESULTS

The mean number of pleural passages with the coaxial needle, biopsies, CT acquisitions, total procedure time, coaxial introducer dwelling time, and estimated radiation exposure during PCNBs were 1.03 ± 0.21, 3.1 ± 0.7, 3.4 ± 1.3, 10.5 min ± 3.2 and 7.2 min ± 2.5, and 5.72 mSv ± 4.19, respectively. Sixty nodules (56.1 %) were diagnosed as malignant, 38 (35.5 %) as benign and nine (8.4 %) as indeterminate. The sensitivity, specificity, and diagnostic accuracy of CBCT virtual-navigation-guided PCNB for small (≤1 cm) nodules were 96.7 % (58/60), 100 % (38/38) and 98.0 % (96/98), respectively. Complications occurred in 13 (12.1 %) cases; pneumothorax in seven (6.5 %) and haemoptysis in six (5.6 %).

CONCLUSION

CBCT virtual-navigation-guided PCNB is a highly accurate and safe diagnostic method for small (≤1 cm) nodules.