Rachna Madan

The spectrum of Castleman's disease: mimics, radiologic pathologic correlation and role of imaging in patient management.

Castlemans disease (CD) is a rare benign lymphoid disorder with variable clinical course. The two principal histologic subtypes of CD are hyaline-vascular and plasma cell variants and the major clinicoradiological entities are unicentric and multicentric CD. Management of CD is tailored to clinicoradiologic subtype. In this review, we describe the CT, MR and PET/CT findings in Castlemans disease which can help suggest a diagnosis of CD as well as emphasize role of imaging in management of patients with CD.

Cardiac Masses, Part 1: Imaging Strategies and Technical Considerations

OBJECTIVE The objective of this article is to discuss optimal imaging strategies for the evaluation of cardiac masses. The advantages and disadvantages of echocardiography, cardiac MRI, gated cardiac CT, and nuclear imaging will be discussed and specific techniques presented. CONCLUSION Multimodality imaging plays a pivotal role in the diagnosis and surgical planning of cardiac masses. Clinical features, such as patient age, location, and imaging characteristics of the mass will determine the likely differential diagnosis.

Frequency and Severity of Pulmonary Hemorrhage in Patients Undergoing Percutaneous CT-guided Transthoracic Lung Biopsy: Single-Institution Experience of 1175 Cases

PURPOSE To evaluate the frequency and severity of pulmonary hemorrhage after transthoracic needle lung biopsy (TTLB) and assess possible factors associated with pulmonary hemorrhage. MATERIALS AND METHODS This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. Records from 1113 patients who underwent 1175 TTLBs between January 2008 and April 2013 were retrospectively reviewed. Primary outcomes were pulmonary hemorrhage, documented hemoptysis, and bleeding complications necessitating intervention. Pulmonary hemorrhage was graded as follows: 0, none; 1, less than or equal to 2 cm around the needle; 2, more than 2 cm and sublobar; 3, at least lobar; and 4, hemothorax. Patient, technique, and lesion-related variables were evaluated as predictors of pulmonary hemorrhage. Patient-related variables included main pulmonary artery diameter (mPAD) at computed tomography (CT), pulmonary artery pressures at echocardiography and right-sided heart catheterization, medications, chronic lung disease, bleeding diathesis, and immunodeficiency. Technique- and lesion-related variables included needle gauge, number of passes, pleura-needle angle, lesion size and morphologic characteristics, and distance to pleura. Univariate analysis was performed with χ(2), Fisher exact, and Student t tests. RESULTS Pulmonary hemorrhage occurred in 483 of the 1175 TTLBs (41.1%); hemoptysis was documented in 21 of the 1175 TTLBs (1.8%). Higher-grade hemorrhage (grade 2 or higher) occurred in 201 of the 1175 TTLBs (17.1%); five of the 1175 TTLBs (0.4%) necessitated hemorrhage-related admission. Higher-grade hemorrhage was more likely to occur with female sex (P = .001), older age (P = .003), emphysema (P = .004), coaxial technique (P = .025), nonsubpleural location (P < .001), lesion size of 3 cm or smaller (P < .001), and subsolid lesions (P = .028). Enlarged mPAD at CT (≥2.95 cm) was not significantly associated with higher-grade hemorrhage (P = .430). CONCLUSION Pulmonary hemorrhage after TTLB is common but rarely requires intervention. An enlarged mPAD at CT may not be a risk factor for higher-grade hemorrhage.

Cardiac masses, part 2: key imaging features for diagnosis and surgical planning.

OBJECTIVE The objectives of this article are to discuss key radiologic features that differentiate primary and secondary cardiac masses. Clinical scenarios are included to highlight stepwise radiologic workup of tumors of the pericardium, epicardium, myocardium, valves, and chambers. The involvement of key cardiac anatomic structures will also be emphasized to determine resectability and guide surgical planning. CONCLUSION Multimodality imaging plays a pivotal role in diagnosis and surgical planning of cardiac masses. Clinical features, such as patient age, location, and imaging characteristics of the mass will determine the likely differential diagnosis. In addition to radiologic evaluation of the mass itself, involvement of valvular apparatus, extent of myocardial involvement, or presence of associated coronary artery involvement is necessary to determine resectability and surgical technique.

PET/CT Pattern Analysis for Surgical Staple Line Recurrence in Patients With Colorectal Cancer

OBJECTIVE The purpose of our study was to determine whether (18)F-FDG PET/CT interpretation with metabolic-anatomic pattern analysis can be used to accurately assess for surgical staple line recurrence after colorectal cancer resection. MATERIALS AND METHODS Seventy-nine consecutive patients with previous surgical resection of colorectal cancer were studied retrospectively. The surgical anastomotic or Hartmanns pouch staple lines were evaluated for presence or absence of tumor recurrence with FDG PET/CT metabolic-anatomic pattern analysis. Focal, eccentric, or perianastomotic CT masses with any associated PET pattern were regarded as positive for staple line recurrence. If the perianastomotic CT abnormality was presacral in location, then FDG uptake at least as intense as normal liver was required for positive interpretation. Eccentric or perianastomotic PET patterns matched with normal or diffuse thickening CT patterns were regarded as indeterminate. Presence or absence of recurrent tumor was confirmed by pathology, surgery, colonoscopy, imaging follow-up of at least 3 months, or clinical follow-up of at least 1 year. RESULTS Nine patients (11.4%) had staple line recurrence and 70 (88.6%) did not. FDG PET/CT interpretation yielded sensitivity, specificity, positive predictive value, negative predictive value, and accuracy results of 100% (9/9), 97.1% (68/70), 81.8% (9/11), 100% (68/68), and 97.5% (77/79), respectively. All nine patients with staple line recurrence showed perianastomotic or eccentric masses on CT, eight with matching perianastomotic or eccentric FDG uptake patterns. Background, diffuse, curvilinear, or focal FDG uptake patterns, regardless of FDG uptake intensity, paired with normal findings or diffuse mural thickening on CT were seen only in patients without staple line recurrence. CONCLUSION FDG PET/CT pattern analysis enables accurate assessment for staple line recurrence in patients with previous resection of colorectal cancer. The most reliable PET/CT pattern predicting staple line recurrence is an eccentric or perianastomotic mass on CT with corresponding eccentric or perianastomotic FDG uptake on PET. Background, diffuse (on one or both sides of the staple line), curvilinear, and focal patterns of FDG uptake do not correlate with recurrence in the absence of a mass on CT.

Radiology of Chest Wall Masses

OBJECTIVE The purpose of this article is to highlight the role of radiography, CT, PET/CT, and MRI in the diagnosis and management of chest wall lesions. Chest wall masses are caused by a spectrum of clinical entities. The lesions highlighted in this selection of case scenarios include neoplastic, inflammatory, and vascular lesions. CONCLUSION Imaging evaluation with radiography, CT, MRI, and PET/CT plays an important role in the accurate diagnosis of chest wall lesions. It can also facilitate percutaneous biopsy, when it is indicated. Imaging enables accurate staging and is a key component of treatment planning for chest wall masses.

Ultra low-dose chest CT using filtered back projection: comparison of 80-, 100- and 120 kVp protocols in a prospective randomized study.

PURPOSE To assess lesion detection and diagnostic image quality of filtered back projection (FBP) reconstruction technique in ultra low-dose chest CT examinations. METHODS AND MATERIALS In this IRB-approved ongoing prospective clinical study, 116 CT-image-series at four different radiation-doses were performed for 29 patients (age, 57-87 years; F:M - 15:12; BMI 16-32 kg/m(2)). All patients provided written-informed-consent for the acquisitions of additional ultra low-dose (ULD) series on a 256-slice MDCT (iCT, Philips Healthcare). In-addition to their clinical standard-dose chest CT (SD, 120 kV mean CTDIvol, 6 ± 1 mGy), ULD-CT was subsequently performed at three-dose-levels (0.9 mGy [120 kV]; 0.5 mGy [100 kV] and 0.2 mGy [80 kV]). Images were reconstructed with FBP (2.5mm 1.25 mm) resulting into four-stacks: SD-FBP (reference-standard), FBP0.9, FBP0.5, and FBP0.2. Four thoracic-radiologists from two-teaching-hospitals independently-evaluated data for lesion-detection and visibility-of-small-structures. Friedmans-non-parametric-test with post hoc Dunns-test was used for data-analysis. RESULTS Interobserver-agreement was substantial between radiologists (k=0.6-0.8). With pooled analysis, 146-pulmonary (27-groundglass-opacities, 64-solid-lung-nodules, 7-consolidations, 27-emphysema) and 347-mediastinal/soft tissue lesions (87-mediastinal, 46-hilar, 62-axillary-lymph-nodes, and 11-mediastinal-masses) were evaluated. Compared to the SD-FBP, 100% pulmonary-lesions were seen with FBP0.9, up to 81% with FBP0.5 (missed: 4), and up to 30% with FBP0.2 images (missed:16). Compared to SD-FBP, all enlarged mediastinal-lymph-nodes were seen with FBP0.9 images. All mediastinal-masses (>2 cm, 11/11) were seen equivalent to SD-FBP images at 0.9 mGy. Across all sizes of patients, FBP0.9 images had optimal visualization for lung findings. They were optimal for mediastinal soft tissues for only non-obese patients. CONCLUSION Filtered-back-projection technique allows optimal lesion detection and acceptable image quality for chest-CT examinations at CDTIvol of 0.9 mGy for lung and mediastinal findings in selected sizes of patients.

Solitary fibrous tumors of the thorax: Nomenclature, epidemiology, radiologic and pathologic findings, differential diagnoses, and management

AJR:200, March 2013 Epidemiology It is difficult to ascertain the true incidence and prevalence of solitary fibrous tumors because the majority of patients with these masses are asymptomatic. Solitary fibrous tumors arising from the pleura, however, have been estimated to occur with a frequency of 2.8 per 100,000 individuals, with only eight hundred cases reported between 1931 and 2002 [4]. Moreover, these tumors account for less than 5% of all tumors arising from the pleura [5]. Overall, solitary fibrous tumors account for less than 2% of all softtissue tumors [6]. These tumors occur equally in both men and women, most frequently in the 6th and 7th decades of life [7]. There is no known association with tobacco, asbestos, or any other toxicant.

ITMIG Classification of Mediastinal Compartments and Multidisciplinary Approach to Mediastinal Masses

Division of the mediastinum into specific compartments is beneficial for a number of reasons, including generation of a focused differential diagnosis for mediastinal masses identified on imaging examinations, assistance in planning for biopsies and surgical procedures, and facilitation of communication between clinicians in a multidisciplinary setting. Several classification schemes for the mediastinum have been created and used to varying degrees in clinical practice. Most radiology classifications have been based on arbitrary landmarks outlined on the lateral chest radiograph. A new scheme based on cross-sectional imaging, principally multidetector computed tomography (CT), has been developed by the International Thymic Malignancy Interest Group (ITMIG) and accepted as a new standard. This clinical division scheme defines unique prevascular, visceral, and paravertebral compartments based on boundaries delineated by specific anatomic structures at multidetector CT. This new definition plays an important role in identification and characterization of mediastinal abnormalities, which, although uncommon and encompassing a wide variety of entities, can often be diagnosed with confidence based on location and imaging features alone. In other scenarios, a diagnosis may be suggested when radiologic features are combined with specific clinical information. In this article, the authors present the new multidetector CT-based classification of mediastinal compartments introduced by ITMIG and a structured approach to imaging evaluation of mediastinal abnormalities. ©RSNA, 2017.

Imaging in lung transplants: Checklist for the radiologist

Post lung transplant complications can have overlapping clinical and imaging features, and hence, the time point at which they occur is a key distinguisher. Complications of lung transplantation may occur along a continuum in the immediate or longer postoperative period, including surgical and mechanical problems due to size mismatch and vascular as well as airway anastomotic complication, injuries from ischemia and reperfusion, acute and chronic rejection, pulmonary infections, and post-transplantation lymphoproliferative disorder. Life expectancy after lung transplantation has been limited primarily by chronic rejection and infection. Multiple detector computed tomography (MDCT) is critical for evaluation and early diagnosis of complications to enable selection of effective therapy and decrease morbidity and mortality among lung transplant recipients.