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.

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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.

Purpose Target delineation in lung cancer radiotherapy using CT and/or PET-CT is affected by large variability. MRI has excellent soft tissue visualization and better spatial resolution than PET-CT. The main purpose of this study is to analyze delineation variability for lung cancer using MRI. Methods and materials Seven physicians delineated the tumor volumes of ten patients for the following scenarios: (1) CT only; (2) PET-CT fusion images registered to CT (“clinical standard”); and (3) post-contrast 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 (BLDs) between individual observers’ contours and the reference contour were analyzed. Results CT- and MRI-based tumor volumes normalized relative to PET-CT-based volumes were31.62±0.76 (mean±SD) 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 – 3.82×10−9). The tumor-atelectasis interface had a significantly higher variability than other interfaces for all modalities combined (p=0.0006). The interfaces with the smallest uncertainties were tumor-lung (on CT) and tumor-mediastinum (on PET-CT and MRI). Conclusions While 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 of 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.

No abstract

The use of an IR technique leads to qualitative and quantitative improvements in image noise and image quality in obese patients undergoing CTPA.

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.Disclaimer: The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists, and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient's clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient's condition are ranked. Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document. The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the FDA have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged. The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in a...

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 1.5T 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/µm2, pixel size = 1.98×1.98 mm2, 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/µm2 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/µm2 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/µm2 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/µm2, and all three b-value sets with 250, 1000 µs/µm2 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.