Diagnostic accuracy of diffusion-weighted imaging- magnetic resonance imaging compared to positron emission tomography/computed tomography in evaluating and assessing pathological response to treatment in adult patients with lymphoma: A systematic review.

The use of Positron emission tomography/computerised tomography (PET/CT) is well established in the staging and assessment of treatment response of lymphoma. Recent studies have suggested that whole body diffusion-weighted imaging -magnetic resonance imaging (WB-DW-MRI) may be an alternative to PET/CT in both staging and assessment of treatment response. A systematic review was performed to assess the ability of DW-MRI in the assessment of treatment response in lymphoma. Pubmed, Medline, Web of Science and Embase databases were queried for studies examining whole body DW-MRI compared to PET/CT in adult patients using a protocol of search terms. We carried out an extensive assessment of titles, abstracts and full texts of relevant paper as well as quality assessment with the Quality Assessment of Diagnostic Accuracy (QUADAS-2) tool. Eight studies were found to meet the criteria and were included in our review and analysis. Overall, the quality of studies was found to be moderate, with good inter-rater agreement (K = 0.74). Data analysis showed that lesion-based assessment in 5 studies with pooled results had a sensitivity and specificity of 94.7% and 99.3%. Assessment with Cohen's Kappa coefficient showed agreement to be excellent (K = 0.88). Three studies were included for qualitative analysis, two of which showed good equivalence between PET/CT and DW-MRI. WB-DWI-MRI can be considered a sensitive and specific method for assessing treatment response in Lymphoma without the use of ionising radiation or administration of F-18 Flurodeoxyglucose. Further studies are needed to evaluate the optimum b-values in assessing treatment response.

Overdiagnosis of Pulmonary Embolism by Pulmonary CT Angiography.

OBJECTIVE: The purpose of this study is to evaluate the rate of overdiagnosis of pulmonary embolism (PE) by pulmonary CT angiography (CTA) in a tertiary-care university hospital. MATERIALS AND METHODS: This study is a retrospective review of all pulmonary CTA examinations performed in a tertiary-care university hospital over a 12-month period. Studies originally reported as positive for PE were retrospectively reinterpreted by three subspecialty chest radiologists with more than 10 years' experience. A pulmonary CTA was considered negative for PE when all three chest radiologists were in agreement that the pulmonary CTA study was negative for PE. The location and potential causes for PE overdiagnosis were recorded. RESULTS: A total of 937 pulmonary CTA studies were performed over the study period. PE was diagnosed in the initial report in 174 of these cases (18.6%). There was discordance between the chest radiologists and the original radiologist in 45 of 174 (25.9%) cases. Discordance occurred more often where the original reported PE was solitary (46.2% of reported solitary PEs were considered negative on retrospective review) and located in a segmental or subsegmental pulmonary artery (26.8% of segmental and 59.4% of subsegmental PE diagnoses were considered negative on retrospective review). The most common cause of diagnostic difficulty was breathing motion artifact, followed by beam-hardening artifact. CONCLUSION: In routine clinical practice, PEs diagnosed by pulmonary CTA are frequently overdiagnosed, when compared with the consensus opinion of a panel of expert chest radiologists. Improvements in the quality of pulmonary CTA examination and increased familiarity with potential diagnostic pitfalls in pulmonary CTA are recommended to minimize misdiagnosis of PE.

Update in the evaluation of the solitary pulmonary nodule.

A solitary pulmonary nodule (SPN) is defined as a round opacity that is smaller than 3 cm. It may be solid or subsolid in attenuation. Semisolid nodules may have purely ground-glass attenuation or be partly solid (mixed solid and ground-glass attenuation). The widespread use of multidetector computed tomography (CT) has increased the detection of SPNs. Although clinical assessment of patients' risk factors for malignancy--such as age, smoking history, and history of malignancy--is important to determine appropriate treatment, in the recently published Fleischner guidelines for subsolid nodules, smoking history does not factor into their recommendations for management because there is an increasing incidence of lung adenocarcinoma in younger and nonsmoking patients. At imaging evaluation, obtaining prior chest radiographs or CT images is useful to assess nodule growth. Further imaging evaluation, including CT enhancement studies and positron emission tomography (PET), helps determine the malignant potential of solid SPNs. For subsolid nodules, initial follow-up CT is performed at 3 months to determine persistence, because lesions with an infectious or inflammatory cause can resolve in the interval. CT enhancement studies are not applicable for subsolid nodules, and PET is of limited utility because of the low metabolic activity of these lesions. Because of the likelihood that persistent subsolid nodules represent adenocarcinoma with indolent growth, serial imaging reassessment for a minimum of 3 years and/or obtaining tissue samples for histologic analysis are recommended. In the follow-up of subsolid SPNs, imaging features that indicate an increased risk for malignancy include an increase in size, an increase in attenuation, and development of a solid component.

Multimodality imaging evaluation of esophageal cancer: staging, therapy assessment, and complications.

Esophageal cancer is among the leading causes of cancer-related deaths worldwide. The management of patients with esophageal cancer is determined to a large extent by patient performance status, location of the primary cancer, and stage of disease at presentation. Multimodality regimens combining neoadjuvant chemotherapy and/or radiotherapy followed by surgery have been increasingly used in suitable candidates with locally advanced cancer. There is substantial morbidity and mortality associated with this treatment strategy, which makes appropriate patient selection important. Endoscopic esophageal ultrasound is the optimal modality to evaluate the local extent of the primary tumor and diagnose locoregional nodal metastasis. Computed tomography is more useful in detecting distant nodal and systemic metastasis. Positron emission tomography/CT is increasingly being used in patient management and improves the accuracy of staging, particularly in the detection of distant nodal and systemic metastatic disease. In this article, we review the role of imaging in the staging, assessment of therapeutic response, and detection of recurrent disease, as well as the evaluation of therapeutic complications in patients with esophageal cancer.

Unsuspected pulmonary emboli in oncology patients undergoing routine computed tomography imaging.

INTRODUCTION: Clinically unsuspected pulmonary embolism (PE) can be detected in oncology patients undergoing computed tomography (CT) imaging for reasons other than for PE diagnosis, but there is little prospective data on its true prevalence, clinical importance, or on methods to improve detection. METHODS: In consecutive oncology patients undergoing CT imaging of the chest for indications other than PE detection, CT pulmonary angiography (CTPA) was systematically included as part of the imaging protocol. Each imaging study was prospectively analyzed for the presence of PE. A 6-month follow-up was performed. Institutional review board approval was obtained. RESULTS: Four hundred seven oncology patients were included. Indications for chest CT imaging included baseline staging (31%), restaging after therapy (53%), routine surveillance (15%), or assessment of extrathoracic disease (1%). Clinically unsuspected PE were detected in 18 patients (4.4%). The prevalence of unsuspected PE was 6.4% among inpatients and 3.4% among outpatients. PE was more prevalent among patients with metastatic disease (7% versus 2%, p = 0.007) and in patients who had received recent chemotherapy (11% versus 3%, p = 0.008). In 7 (39%) of the 18 patients with clinically unsuspected PE, emboli were only identifiable on the CTPA study and not on the routine chest CT study. The diagnosis of PE led to immediate changes in patient management. CONCLUSION: Clinically unsuspected PE is present in up to 4.4% of oncology patients undergoing CT imaging for indications other than PE diagnosis. Modifying standard CT imaging protocols to include a CTPA examination optimizes their detection and leads to changes in patient management.

Clinical utility of PET/CT in lymphoma.

OBJECTIVE: The purpose of this review is to assist interpreting radiologists in becoming familiar with the role of PET/CT in baseline staging and therapeutic response assessment in the management of lymphoma, in becoming aware of imaging pitfalls, and in understanding the natural behavior of lymphoma and the therapeutic options. CONCLUSION: Therapeutic strategies for the management of lymphoma are constantly being refined to improve long-term survival with the lowest risk of toxicity to the patient. PET/CT is accurate for baseline staging and yields important prognostic information for determining the most appropriate initial treatment. Used for evaluation of treatment response, PET/CT can depict residual viable malignant lesions with greater accuracy than can other imaging techniques. The findings thereby influence decisions about the need for additional or alternative treatment.

Imaging of pulmonary fusariosis in patients with hematologic malignancies.

OBJECTIVE: The purpose of this study was to assess the radiographic features of pulmonary fusariosis, an increasingly encountered cause of severe opportunistic mold pneumonia. CONCLUSION: Pulmonary fusariosis has radiographic manifestations that are suggestive of an angioinvasive mold. Nodules or masses were the most common findings at CT, seen in 82% of patients compared with only 45% on chest radiography. The halo sign was not seen. Chest radiographs showed nonspecific findings in 30% of patients, and findings were normal at presentation in 25%. All of the patients had underlying hematologic malignancies. Thirteen of the 20 patients studied (65%) died within 1 month of diagnosis of pulmonary fusariosis. Because early initiation of intense antifungal therapy offers the best chance for survival in pulmonary fusariosis, early CT and appropriate microbiologic investigation should be obtained in severely immunocompromised patients.

Imaging of non-small cell lung cancer of the superior sulcus: part 1: anatomy, clinical manifestations, and management.

Non-small cell carcinomas of the superior pulmonary sulcus represent 3% of all lung cancers and are associated in most cases with a poor clinical outcome. Multimodality therapy with irradiation, chemotherapy, and surgery offers the best possibility for long-term survival and cure in most cases. For patients with pulmonary sulcus tumors that are not surgically resectable, chemoradiotherapy may help prolong survival and provide long-term pain relief. To accurately determine tumor resectability and to help optimize the planning and delivery of therapy, radiologists need a detailed knowledge of the clinical and imaging manifestations of disease in the individual patient and an awareness of the therapeutic options available. Accurate three-dimensional imaging and image interpretation are essential for mapping of the primary tumor before irradiation or surgical resection. Familiarity with the complex anatomy of the superior pulmonary sulcus is particularly crucial for determining the local-regional extension of a tumor and the most appropriate surgical approach.

Imaging of non-small cell lung cancer of the superior sulcus: part 2: initial staging and assessment of resectability and therapeutic response.

Imaging plays a crucial role in the diagnosis and staging of superior sulcus tumors, assessment of their resectability, determination of the optimal approach to disease management, and evaluation of the response to therapy. Computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET)/CT contribute important and complementary information. Whereas CT is optimal for depicting bone erosion and for staging of intrathoracic disease, MR imaging is superior for evaluating tumor extension to the intervertebral neural foramina, the spinal cord, and the brachial plexus, primarily because of the higher contrast resolution and multiplanar capability available with MR imaging technology. Use of PET/CT enables the detection of unsuspected nodal and distant metastases. However, imaging has only limited usefulness for evaluating the response of a tumor to induction therapy and detecting local recurrence, and surgical biopsy often is necessary to verify the results of therapy.

PET/CT and hepatic radiation injury in esophageal cancer patients.

This paper evaluates the imaging appearance of radiation injury in the liver on positron emission tomography (PET)/computed tomography (CT) in patients with distal esophageal cancer who underwent pre-operative chemoradiation therapy. Twenty-six patients with distal esophageal cancer who received chemoradiotherapy before esophagectomy were included. All patients had baseline and follow-up PET/CT. Fluorodeoxyglucose (FDG) uptake in both left and right lobes of the liver was evaluated. CT findings suggesting radiation damage were documented. Abnormal FDG uptake in the liver was observed in 5 (19%) patients after therapy. These abnormalities were in the left lobe (12%) and right lobe (12%) of the liver. In the irradiated left lobe, FDG uptake increased focally greater than 50% over baseline in two patients (54% and 133%); in one of these patients, biopsy confirmed radiation injury. In the non-irradiated right lobe, standard uptake values (SUV) increased diffusely in two different patients. In one patient, SUV decreased by at least 50% in both the right and left lobes. In the remaining patients, there were no significant changes in FDG uptake. Atrophy and attenuation changes of irradiated liver on CT were found in 15 (58%) patients. In patients receiving chemoradiotherapy, PET/CT may identify metabolic abnormalities in irradiated liver. Such abnormalities should be correlated with other imaging, clinical and laboratory findings to avoid confusion with hepatic metastases.

PET/CT of esophageal cancer: its role in clinical management.

Positron emission tomography (PET)/computed tomography (CT) has important utility and limitations in the initial staging of esophageal cancer, evaluation of response to neoadjuvant therapy, and detection of recurrent malignancy. Esophageal cancer is often treated by using a combined modality approach (chemotherapy, radiation therapy, and esophagectomy); correct integration of PET/CT into the conventional work-up of esophageal cancer requires a multidisciplinary approach that combines the information from PET/CT with results of clinical assessment, diagnostic CT, endoscopic gastroduodenoscopy, and endoscopic ultrasonography. PET/CT has limited utility in T staging of esophageal cancer and relatively limited utility in detection of dissemination to locoregional lymph nodes. However, PET/CT allows detection of metastatic disease that may not be identifiable with other methods. PET/CT is not sufficiently reliable in the individual patient for determination of treatment response in the primary tumor. Interpretation of PET/CT results is optimized by understanding the diagnostic limitations and pitfalls that may be encountered, together with knowledge of the natural history of esophageal cancer and the staging and treatment options available.

Development of pulmonary arteriovenous communications within pulmonary metastases after chemotherapy.

The development of acquired pulmonary arteriovenous communications within pulmonary metastases from an extrathoracic malignancy is a rare phenomenon, but it has potentially serious clinical consequences for the patient. We describe two such patients, both of whom developed intrametastatic pulmonary arteriovenous communications after chemotherapy of the pulmonary metastases, and one of whom required coil embolization for control of symptoms related to the right-to-left shunt. In both cases, computed tomographic angiography was useful for the detection and pre-therapeutic evaluation of the arteriovenous malformations.

Integrated CT-PET imaging of esophageal cancer: unexpected and unusual distribution of distant organ metastases.

CT-PET imaging is being increasingly used for the initial staging, assessment of treatment response, and follow-up of patients with esophageal carcinoma, primarily because of its superior detection of distant metastases compared to conventional methods. Our recent experience has shown that metastases from esophageal cancer can occur in unusual locations and have an unexpected presentation. Recognition of the distribution and appearance of esophageal metastases is important for optimal image interpretation in order to avoid confusion with more benign disease. This article reviews the location and appearance of metastases detected by CT-PET imaging in patients with esophageal cancer either at presentation or after preoperative or definitive chemoradiation therapy.