Objective

Cost accounting is the branch of managerial accounting that deals with the analysis of the costs of a product or service. This article reviews methods of classifying and allocating costs and relationships among costs, volume, and revenues.

Conclusion

Radiology practices need to know the cost of a procedure or service to determine the selling price of a product, bid on contracts, analyze profitability, and facilitate cost control and cost reduction.

Purpose

To establish the sensitivity and specificity of indirect signs at magnetic resonance (MR) imaging of anterior cruciate ligament (ACL) tear.

Materials and methods

MR images of the knees of 89 consecutive patients (54 with torn and 35 with normal ACLs) were reviewed.

Results

The indirect signs were as follows (first percentage is sensitivity; the second, specificity): angle between lateral tibial plateau and ACL less than 45 degrees (90%, 97%); angle between Blumenstaat line and ACL more than 15 degrees (89%, 100%); bone contusions in lateral compartment (54%, 100%); position of posterior cruciate ligament (PCL) line (52%, 91%); PCL angle less than 107 degrees (52%, 94%); PCL bowing ratio more than 0.39 (34%, 100%); posterior displacement of lateral meniscus more than 3.5 mm (44%, 94%); anterior displacement of tibia more than 7 mm (41%, 91%); and lateral femoral sulcus deeper than 1.5 mm (19%, 100%).

Conclusion

Because the specificity is high, the presence of indirect signs corroborates the diagnosis of ACL tear. Because the sensitivity is low, the absence of these signs does not exclude the diagnosis of ACL tear.

We present a rare case of a non-calcified pilomatricoma in a 67-year-old man. This tumor was extremely large in size, and its location, in the lower extremity, was very unusual. The clinical, radiographic, and histopathological features are described in detail. The role of magnetic resonance imaging (MRI) in the diagnosis of this entity is discussed. Definite internal reticulations and septations were observed. A possible explanation for this observation is that the high signal intensity reticulations may represent edematous stroma surrounding basaloid cells.

Rationale and objectives

The authors compared saline and dilute gadopentetate dimeglumine as injectants for magnetic resonance (MR) arthrography.

Methods

Sixty-three lesions were created on the joint surfaces of six pig patellas. MR arthrography (1.5 T) was performed with the specimens in saline and then in 2 mmol gadopentetate dimeglumine by using fat-saturated two-dimensional (2D) and three-dimensional (3D) sequences. Two musculoskeletal radiologists independently interpreted the images.

Results

At 2D MR arthrography, reader 1 performed equally well with saline and gadolinium solutes, whereas reader 2 had better sensitivity with the saline solute (P < .05); interobserver agreement was equivalent for saline and gadolinium solutes. With 3D MR arthrography, reader 2 performed equally well with saline and gadolinium solutes, whereas reader 1 had better sensitivity (P < .0001) but poorer specificity (P < .001) with the gadolinium solute; interobserver agreement was significantly better for saline than for gadopentetate dimeglumine (P < .05).

Conclusion

In this initial evaluation, there was no clear advantage to using gadolinium-enhanced MR arthrography over saline MR arthrography for detecting lesions in porcine hyaline cartilage.

Using radiographs and diagrams, this article reviews the most commonly used axes and angles of the foot, including: longitudinal axis of the rearfoot, collum tali axis, talocalcaneal angle, cuboid abduction angle, longitudinal axis of the lesser tarsus, lesser tarsus angle, talonavicular angle, longitudinal axis of the metatarsus, forefoot adductus angle, metatarsus adductus angle, first intermetatarsal angle, hallux valgus angle, proximal and distal articular set angles, and hallux interphalangeal angle, plane of support, collum tali axis, talar declination angle, calcaneal inclination axis, lateral talocalcaneal angle, first metatarsal declination axis and calcaneal inclination angle.

In this paper the problem of improving techniques for rainfall intensity estimation over the sea surface through spaceborne rain radars is analysed. In such case, the backscattered signal is composed of a rainfall volumetric contribution and of the sea surface contribution, which gives rise to the problem of extracting the information of interest from the composite echo. In particular, we focus on the problem of deriving a better estimation of the rain perturbed backscattering coefficient of the sea surface from polarimetric measurements, as a means for achieving such improvements. The effects of the additional roughness of the sea surface due to the rainfall have been taken into account and analysed by resorting to an electromagnetic model able to provide a full polarimetric description of the rainfall perturbed sea surface.

The Minkowski product of unit quaternion sets is introduced and analyzed, motivated by the desire to characterize the overall variation of compounded spatial rotations that result from individual rotations subject to known uncertainties in their rotation axes and angles. For a special type of unit quaternion set, the spherical caps of the 3-sphere S3 in R4, closure under the Minkowski product is achieved. Products of sets characterized by fixing either the rotation axis or rotation angle, and allowing the other to vary over a given domain, are also analyzed. Two methods for visualizing unit quaternion sets and their Minkowski products in R3 are also discussed, based on stereographic projection and the Lie algebra formulation. Finally, some general principles for identifying Minkowski product boundary points are discussed in the case of full-dimension set operands.

Purpose

To investigate if tailoring a transformer-based language model to radiology is beneficial for radiology natural language processing (NLP) applications.

Materials and methods

This retrospective study presents a family of bidirectional encoder representations from transformers (BERT)-based language models adapted for radiology, named RadBERT. Transformers were pretrained with either 2.16 or 4.42 million radiology reports from U.S. Department of Veterans Affairs health care systems nationwide on top of four different initializations (BERT-base, Clinical-BERT, robustly optimized BERT pretraining approach [RoBERTa], and BioMed-RoBERTa) to create six variants of RadBERT. Each variant was fine-tuned for three representative NLP tasks in radiology: (a) abnormal sentence classification: models classified sentences in radiology reports as reporting abnormal or normal findings; (b) report coding: models assigned a diagnostic code to a given radiology report for five coding systems; and (c) report summarization: given the findings section of a radiology report, models selected key sentences that summarized the findings. Model performance was compared by bootstrap resampling with five intensively studied transformer language models as baselines: BERT-base, BioBERT, Clinical-BERT, BlueBERT, and BioMed-RoBERTa.

Results

For abnormal sentence classification, all models performed well (accuracies above 97.5 and F1 scores above 95.0). RadBERT variants achieved significantly higher scores than corresponding baselines when given only 10% or less of 12 458 annotated training sentences. For report coding, all variants outperformed baselines significantly for all five coding systems. The variant RadBERT-BioMed-RoBERTa performed the best among all models for report summarization, achieving a Recall-Oriented Understudy for Gisting Evaluation-1 score of 16.18 compared with 15.27 by the corresponding baseline (BioMed-RoBERTa, P < .004).

Conclusion

Transformer-based language models tailored to radiology had improved performance of radiology NLP tasks compared with baseline transformer language models.Keywords: Translation, Unsupervised Learning, Transfer Learning, Neural Networks, Informatics Supplemental material is available for this article. © RSNA, 2022See also commentary by Wiggins and Tejani in this issue.