ACR Appropriateness Criteria® Intensive Care Unit Patients.

Chest radiography is the most frequent and primary imaging modality in the intensive care unit (ICU), given its portability, rapid image acquisition, and availability of immediate information on the bedside preview. Due to the severity of underlying disease and frequent need of placement of monitoring devices, ICU patients are very likely to develop complications related to underlying disease process and interventions. Portable chest radiography in the ICU is an essential tool to monitor the disease process and the complications from interventions; however, it is subject to overuse especially in stable patients. Restricting the use of chest radiographs in the ICU to only when indicated has not been shown to cause harm. The emerging role of bedside point-of-care lung ultrasound performed by the clinicians is noted in the recent literature. The bedside lung ultrasound appears promising but needs cautious evaluation in the future to determine its role in ICU patients. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Hemoptysis.

Hemoptysis, the expectoration of blood, ranges in severity from nonmassive to massive. This publication reviews the literature on the imaging and treatment of hemoptysis. Based on the literature, the imaging recommendations for massive hemoptysis are both a chest radiograph and CT with contrast or CTA with contrast. Bronchial artery embolization is also recommended in the majority of cases. In nonmassive hemoptysis, both a chest radiograph and CT with contrast or CTA with contrast is recommended. Bronchial artery embolization is becoming more commonly utilized, typically in the setting of failed medical therapy. Recurrent hemoptysis, defined as hemoptysis that recurs following initially successful cessation of hemoptysis, is best reassessed with a chest radiograph and either CT with contrast or CTA with contrast. Bronchial artery embolization is increasingly becoming the treatment of choice in recurrent hemoptysis, with the exception of infectious causes such as in cystic fibrosis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Rib Fractures.

Rib fractures are the most common thoracic injury after minor blunt trauma. Although rib fractures can produce significant morbidity, the diagnosis of injuries to underlying organs is arguably more important as these complications are likely to have the most significant clinical impact. Isolated rib fractures have a relatively low morbidity and mortality and treatment is generally conservative. As such, evaluation with standard chest radiographs is usually sufficient for the diagnosis of rib fractures, and further imaging is generally not appropriate as there is little data that undiagnosed isolated rib fractures after minor blunt trauma affect management or outcomes. Cardiopulmonary resuscitation frequently results in anterior rib fractures and chest radiographs are usually appropriate (and sufficient) as the initial imaging modality in these patients. In patients with suspected pathologic fractures, chest CT or Tc-99m bone scans are usually appropriate and complementary modalities to chest radiography based on the clinical scenario. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Lung Cancer Screening.

Lung cancer remains the leading cause of cancer death in both men and women. Smoking is the single greatest risk factor for the development of lung cancer. For patients between the age of 55 and 80 with 30 or more pack years smoking history who currently smoke or who have quit within the last 15 years should undergo lung cancer screening with low-dose CT. In patients who do not meet these criteria but who have additional risk factors for lung cancer, lung cancer screening with low-dose CT is controversial but may be appropriate. Imaging is not recommended for lung cancer screening of patient younger than 50 years of age or patients older than 80 years of age or patients of any age with less than 20 packs per year history of smoking and no additional risk factor (ie, radon exposure, occupational exposure, cancer history, family history of lung cancer, history of COPD, or history of pulmonary fibrosis). The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Variabilities of Magnetic Resonance Imaging-, Computed Tomography-, and Positron Emission Tomography-Computed Tomography-Based Tumor and Lymph Node Delineations for Lung Cancer Radiation Therapy Planning.

PURPOSE: To investigate interobserver delineation variability for gross tumor volumes of primary lung tumors and associated pathologic lymph nodes using magnetic resonance imaging (MRI), and to compare the results with computed tomography (CT) alone- and positron emission tomography (PET)-CT-based delineations. METHODS AND MATERIALS: Seven physicians delineated the tumor volumes of 10 patients for the following scenarios: (1) CT only, (2) PET-CT fusion images registered to CT ("clinical standard"), and (3) postcontrast T1-weighted MRI registered with diffusion-weighted MRI. To compute interobserver variability, the median surface was generated from all observers' contours and used as the reference surface. A physician labeled the interface types (tumor to lung, atelectasis (collapsed lung), hilum, mediastinum, or chest wall) on the median surface. Contoured volumes and bidirectional local distances between individual observers' contours and the reference contour were analyzed. RESULTS: Computed tomography- and MRI-based tumor volumes normalized relative to PET-CT-based volumes were 1.62 ± 0.76 (mean ± standard deviation) and 1.38 ± 0.44, respectively. Volume differences between the imaging modalities were not significant. Between observers, the mean normalized volumes per patient averaged over all patients varied significantly by a factor of 1.6 (MRI) and 2.0 (CT and PET-CT) (P=4.10 × 10-5 to 3.82 × 10-9). The tumor-atelectasis interface had a significantly higher variability than other interfaces for all modalities combined (P=.0006). The interfaces with the smallest uncertainties were tumor-lung (on CT) and tumor-mediastinum (on PET-CT and MRI). CONCLUSIONS: Although MRI-based contouring showed overall larger variability than PET-CT, contouring variability depended on the interface type and was not significantly different between modalities, despite the limited observer experience with MRI. Multimodality imaging and combining different imaging characteristics might be the best approach to define the tumor volume most accurately.

ACR Appropriateness Criteria® Suspected Pulmonary Hypertension.

Pulmonary hypertension may be idiopathic or related to a large variety of diseases. Various imaging examinations that may be helpful in diagnosing and determining the etiology of pulmonary hypertension are discussed. Imaging examinations that may aid in the diagnosis of pulmonary hypertension include chest radiography, ultrasound echocardiography, ventilation/perfusion scans, CT, MRI, right heart catheterization, pulmonary angiography, and fluorine-18-2-fluoro-2-deoxy-d-glucose PET/CT. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Apparent diffusion coefficient (ADC) change on repeated diffusion-weighted magnetic resonance imaging during radiochemotherapy for non-small cell lung cancer: A pilot study.

OBJECTIVES: Serial diffusion-weighted magnetic resonance imaging (DW-MRI) during radiochemotherapy of non-small cell lung cancer (NSCLC) is analyzed to investigate the apparent diffusion coefficient (ADC) as a potential biomarker for tumor response. METHODS: Ten patients underwent DW-MRI prior to and at three and six weeks during radiochemotherapy. Three methods of contouring primary tumors (PT) were performed to evaluate the impact of tumor heterogeneity on ADC values: PTT: whole tumor volume; PTT-N: PTT-necrosis; PTL: small volume of presumed active tumor with low ADC value. Pretreatment and during-treatment absolute ADC values and ADC value changes were analyzed for PT and involved lymph nodes (LN). RESULTS: ADC values for PTT, PTT-N, PTL and LN increased by 8-14% (PT) and 15% (LN) at three weeks, and 19-26% and 23% at 6 weeks post initial treatment (p=0.04-0.002). Average percent ADC value increase was smaller than tumor volume regression (p=0.06-0.0005). Patients with overall survival <12 months had a lower increase of ADC values compared to longer surviving patients (p=0.008 for PTT). CONCLUSIONS: Significant ADC value increases during radiochemotherapy for non-small cell lung cancer were observed. ADC value change during treatment appears to be an independent marker of patient outcome and warrants further investigation.

Estimation of optimal b-value sets for obtaining apparent diffusion coefficient free from perfusion in non-small cell lung cancer.

The purpose of this study was to determine optimal sets of b-values in diffusion-weighted MRI (DW-MRI) for obtaining monoexponential apparent diffusion coefficient (ADC) close to perfusion-insensitive intravoxel incoherent motion (IVIM) model ADC (ADCIVIM) in non-small cell lung cancer. Ten subjects had 40 DW-MRI scans before and during radiotherapy in a 1.5 T MRI scanner. Respiratory triggering was applied to the echo-planar DW-MRI with TR ≈ 4500 ms, TE = 74 ms, eight b-values of 0-1000 µs µm(-2), pixel size = 1.98 × 1.98 mm(2), slice thickness = 6 mm, interslice gap = 1.2 mm, 7 axial slices and total acquisition time ≈6 min. One or more DW-MRI scans together covered the whole tumour volume. Monoexponential model ADC values using various b-value sets were compared to reference-standard ADCIVIM values using all eight b-values. Intra-scan coefficient of variation (CV) of active tumour volumes was computed to compare the relative noise in ADC maps. ADC values for one pre-treatment DW-MRI scan of each of the 10 subjects were computed using b-value pairs from DW-MRI images synthesized for b-values of 0-2000 µs µm(-2) from the estimated IVIM parametric maps and corrupted by various Rician noise levels. The square root of mean of squared error percentage (RMSE) of the ADC value relative to the corresponding ADCIVIM for the tumour volume of the scan was computed. Monoexponential ADC values for the b-value sets of 250 and 1000; 250, 500 and 1000; 250, 650 and 1000; 250, 800 and 1000; and 250-1000 µs µm(-2) were not significantly different from ADCIVIM values (p > 0.05, paired t-test). Mean error in ADC values for these sets relative to ADCIVIM were within 3.5%. Intra-scan CVs for these sets were comparable to that for ADCIVIM. The monoexponential ADC values for other sets-0-1000; 50-1000; 100-1000; 500-1000; and 250 and 800 µs µm(-2) were significantly different from the ADCIVIM values. From Rician noise simulation using b-value pairs, there was a wide range of acceptable b-value pairs giving small RMSE of ADC values relative to ADCIVIM. The pairs for small RMSE had lower b-values as the noise level increased. ADC values of a two b-value set-250 and 1000 µs µm(-2), and all three b-value sets with 250, 1000 µs µm(-2) and an intermediate value approached ADCIVIM, with relative noise comparable to that of ADCIVIM. These sets may be used in lung tumours using comparatively short scan and post-processing times. Rician noise simulation suggested that the b-values in the vicinity of these experimental best b-values can be used with error within an acceptable limit. It also suggested that the optimal sets will have lower b-values as the noise level becomes higher.

Total artificial heart implantation: clinical indications, expected postoperative imaging findings, and recognition of complications.

OBJECTIVE: The purposes of this article are to review the treatment options for late-stage biventricular heart failure, discuss the clinical indications for total artificial heart (TAH) implantation, illustrate the expected imaging findings after uncomplicated TAH implantation, and highlight the radiologic findings of common and uncommon complications associated with TAH implantation through case examples. CONCLUSION: TAH implantation is an effective therapeutic option for the treatment of patients with end-stage biventricular heart failure. The duration of implantation varies depending on a particular patient's medical condition and the eventual availability of a human heart for orthotopic transplantation. TAH recipients often undergo imaging with conventional radiography, CT, or both for the assessment of device-related issues, many of which are life-threatening and require emergency management. As the clinical use of the TAH increases and becomes more commonplace, it is imperative that radiologists interpreting imaging studies recognize both the expected and the unexpected imaging findings that affect patient care.

Tumoral calcinosis: pearls, polemics, and alternative possibilities.

Massive periarticular calcinosis of the soft tissues is a unique but not rare radiographic finding. On the contrary, tumoral calcinosis is a rare familial disease. Unfortunately, the term tumoral calcinosis has been liberally and imprecisely used to describe any massive collection of periarticular calcification, although this term actually refers to a hereditary condition associated with massive periarticular calcification. The inconsistent use of this term has created confusion throughout the literature. More important, if the radiologist is unfamiliar with tumoral calcinosis or disease processes that mimic this condition, then diagnosis could be impeded, treatment could be delayed, and undue alarm could be raised, possibly leading to unwarranted surgical procedures. The soft-tissue lesions of tumoral calcinosis are typically lobulated, well-demarcated calcifications that are most often distributed along the extensor surfaces of large joints. There are many conditions with similar appearances, including the calcinosis of chronic renal failure, calcinosis universalis, calcinosis circumscripta, calcific tendonitis, synovial osteochondromatosis, synovial sarcoma, osteosarcoma, myositis ossificans, tophaceous gout, and calcific myonecrosis. The radiologist plays a critical role in avoiding unnecessary invasive procedures and in guiding the selection of appropriate tests that can result in a conclusive diagnosis of tumoral calcinosis.

Electronic publishing in radiology: beginnings, current status, and expanding horizons.

Electronic publishing in radiology began in the 1980s and gathered momentum as use of the personal computer and subsequently the World Wide Web became commonplace. The ease of access and wide distribution that the Internet affords have presented both experts and lay users with the challenge of distinguishing reliable from unreliable material. In the field of radiology, peer-reviewed journals, the sine qua non of reliability in the scientific realm, began to appear in online versions in 1988, and now, nearly all such journals currently have online versions. Electronic versions of textbooks and textbook-like material have become more common, although the vast majority of publishers' catalogs are traditional print books. Electronic material is more common in the fields of internal, emergency, and family medicine than in the field of diagnostic radiology. The latest publishing medium is the personal digital assistant. Challenges that face electronic publishing include the issues of permanent archiving, citation, and indexing. Peer review seems to be the best method for distinguishing reliable from unreliable information. The use of Web technology has improved the logistics of peer review, and some journals have begun posting peer reviews themselves on the Web alongside peer-reviewed articles. Electronic publishing has changed the manner in which radiologists obtain information, providing wider, more immediate access.

Electronic publishing in radiology: economics and the future.

Scholarly publishing is a large market involving thousands of peer-reviewed journals but a decreasing number of publishers. An economic model can be described in which authors give their work to publishers who then sell access to this work. Because each published article is a unique work with few if any substitutes, publishers have some degree of monopoly power and can price their products accordingly. The advent of desktop publishing using personal computers made it possible for individuals to publish material without publishers, an activity that gained momentum when the publishing medium shifted from paper to electronic, and from electronic publishing to the Internet. This activity destabilized the industry, and in the rush to gain market share by providing free content, unsustainable business models were created. Scholarly publishing is now dominated by a small number of multinational corporations that acquired many smaller publishing operations. As these companies have exercised their monopoly power, an open access movement has gained traction in which authors (or their institutions) initially pay for publication, but readers have free and open access to the published articles. This movement is in diametric opposition to the commercial publishing model, and it remains to be seen whether and how well the two can coexist in the future.