Muscle Injury Around the Shoulder

Acute shoulder tendon and intra-articular injuries are common and their imaging well described. However, a subset of patients present with more unusual acute shoulder muscle injury. Of these, pectoralis major muscle injuries are encountered the most often and are increasingly prevalent due to a focus on personal fitness, particularly bench-press exercises. Other muscle injuries around the shoulder are rare. This article reviews the anatomy, mechanism of injury, and the imaging findings in relation to injuries of these muscles around the shoulder. We focus on pectoralis major injury but also review proximal triceps, latissimus dorsi, teres major, and deltoid muscle injuries, providing imaging examples.

Quality of life, walking ability and change of living situation after trochanteric femur fracture in geriatric patients-Comparison between sliding hip screw and cephalomedullary nails from the registry for geriatric trauma

BACKGROUND

There is no well-established gold standard for treating trochanteric femur fractures in the elderly. The two common treatment options are cephalomedullary nails (CMN) and sliding hip screws (SHS). In this study, treatment using CMN and SHS were compared for a cohort of patients older than 70 years of age: The main outcomes were quality of life and main residence after surgery.

METHODS

In this retrospective study we analyzed 24,919 patients from 100 hospitals, treated between 2016 and 2019 and documented in the Registry for Geriatric Trauma. The impact of CMN vs. SHS on the walking ability, quality of life (QoL), living situation, mortality, and revision rate were analyzed. To analyze the change of the living situation, the main residence 120 days after surgery for patients, who lived in their own home before fracture, was described for both groups.

FINDINGS

A total of 10,995 patients could be included of which 10,436 patients were treated with CMN and 369 patients with SHS. 120 days postoperative the QoL differed significantly (p = 0.020) in favor of treatment using CMN. 26% of the SHS group who lived at home prior to surgery had to reside in a nursing home after surgery, whereas the rate was only 18% in the CMN group (p < 0.001). No significant difference in the mortality rate nor a difference in the walking ability 120 days postoperative were found. CMN were implanted more promptly (median: 13.9 vs. 18.4 hours; p < 0,001). No differences were found concerning the revision rate between the two groups, neither during inpatient treatment (p = 0.723) nor during the 120 day follow-up period (p = 0.524).

INTERPRETATION

There might be a benefit for geriatric patients with trochanteric femur fractures to be treated with a proximal femur nail in regard to a higher QoL and a reduced institutionalization rate. Mortality or revision rate was not affected by the chosen implant.

Do quantitative and qualitative shear wave elastography have a role in evaluating musculoskeletal soft tissue masses?

Objectives

To determine if quantitative and qualitative shear wave elastography have roles in evaluating musculoskeletal masses.

Methods

105 consecutive patients, prospectively referred for biopsy within a specialist sarcoma centre, underwent B-mode, quantitative (m/s) and qualitative (colour map) shear wave elastography. Reference was histology from subsequent biopsy or excision where possible. Statistical modelling was performed to test elastography data and/or B-mode imaging in predicting malignancy.

Results

Of 105 masses, 39 were malignant and 6 had no histology but benign characteristics at 12 months. Radiologist agreement for B-mode and elastography was moderate to excellent Kw 0.52-0.64; PABAKw 0.85-0.90). B-Mode imaging had 78.8% specificity, 76.9% sensitivity for malignancy. Quantitatively, adjusting for age, B-mode and lesion volume there was no statistically significant association between longitudinal velocity and malignancy (OR [95% CI] 0.40[0.10, 1.60], p=0.193), but some evidence that higher transverse velocity was associated with decreased odds of malignancy (0.28[0.06, 1.28], p=0.101). Qualitatively malignant masses tended to be towards the blue spectrum (lower velocities); 39.5% (17/43) of predominantly blue masses were malignant, compared to 14.3% (1/7) of red lesions.

Conclusions

Quantitatively and qualitatively there is no statistically significant association between shear wave velocity and malignancy. There is no clear additional role to B-mode imaging currently.

Key Points

• Correlation between shear wave velocity and soft tissue malignancy was statistically insignificant

• B-mode ultrasound is 76.9 % sensitive and 78.8 % specific

• Statistical models show elastography does not significantly add to lesion assessment

Can a single isotropic 3D fast spin echo sequence replace three-plane standard proton density fat-saturated knee MRI at 1.5 T?

OBJECTIVE

To assess whether a single isotropic three-dimensional (3D) fast spin echo (FSE) proton density fat-saturated (PD FS) sequence reconstructed in three planes could replace the three PD (FS) sequences in our standard protocol at 1.5 T (Siemens Avanto, Erlangen, Germany).

METHODS

A 3D FSE PD water excitation sequence was included in the protocol for 95 consecutive patients referred for routine knee MRI. This was used to produce offline reconstructions in axial, sagittal and coronal planes. Two radiologists independently assessed each case twice, once using the standard MRI protocol and once replacing the standard PD (FS) sequences with reconstructions from the 3D data set. Following scoring, the observer reviewed the 3D data set and performed multiplanar reformats to see if this altered confidence. The menisci, ligaments and cartilage were assessed, and statistical analysis was performed using the standard sequence as the reference standard.

RESULTS

The reporting accuracy was as follows: medial meniscus (MM) = 90.9%, lateral meniscus (LM) = 93.7%, anterior cruciate ligament (ACL) = 98.9% and cartilage surfaces = 85.8%. Agreement among the readers was for the standard protocol: MM kappa = 0.91, LM = 0.89, ACL = 0.98 and cartilage = 0.84; and for the 3D protocol: MM = 0.86, LM = 0.77, ACL = 0.94 and cartilage = 0.64.

CONCLUSION

A 3D PD FSE sequence reconstructed in three planes gives reduced accuracy and decreased concordance among readers compared with conventional sequences when evaluating the menisci and cartilage with a 1.5-T MRI scanner.

ADVANCES IN KNOWLEDGE

Using the existing 1.5-T MR systems, a 3D FSE sequence should not replace two-dimensional sequences.

Changes in the Paramagnetic Centres in Irradiated and Heated Dental Enamel Studied Using Electron Paramagnetic Resonance

The EPR signals in dental enamel produced by radiation and by heat were studied. The inherent background signal at g = 2.005, and a radiation-produced signal at g = 2.002 have different saturation behaviour with microwave power, and this affords a method of signal optimization. Heating enamel at temperatures from 100 degrees C to 450 degrees C produces a range of radical species from g = 2.002 to g = 2.005, which have been characterized by their g-values, line widths and saturation behaviour. Standard dental drilling produces a range of radicals which appear to be similar to those produced by heat.

Soft tissue lipoma with the radiographic appearance of a neoplasm within the mandibular canal

Lipomas and lipoma variants are common soft tissue tumours but are not commonly found in the oral and maxillofacial region. We report a case of a classic lipoma located on the medial aspect of the mandibular ramus, but not within bone, first seen by an oral and maxillofacial surgeon during treatment planning for routine extractions. Initial panoramic radiography indicated an expansive tumour in the area of the mandibular foramen and proximal end of the mandibular canal, apparently within the body of the mandible. Subsequent imaging with CT revealed a well-circumscribed soft tissue tumour on the medial aspect of the left mandibular ramus, not within the bone itself. Histological analysis of the operative specimen indicated a classic lipoma.

The 3rd international intercomparison on EPR tooth dosimetry: Part 1, general analysis

The objective of the 3rd International Intercomparison on Electron Paramagnetic Resonance (EPR) Tooth Dosimetry was the evaluation of laboratories performing tooth enamel dosimetry below 300 mGy. Participants had to reconstruct the absorbed dose in tooth enamel from 11 molars, which were cut into two halves. One half of each tooth was irradiated in a 60Co beam to doses in the ranges of 30-100 mGy (5 samples), 100-300 mGy (5 samples), and 300-900 mGy (1 sample). Fourteen international laboratories participated in this intercomparison programme. A first analysis of the results and an overview of the essential features of methods applied in different laboratories are presented. The relative standard deviation of results of all methods was better than 27% for applied doses in the range of 79-704 mGy. In the analysis of the unirradiated tooth halves 8% of the samples were identified as outliers with additional absorbed dose above background dose.

Collective radiation biodosimetry for dose reconstruction of acute accidental exposures: a review

Quantification of the biologically relevant dose is required to establish cause and effect between radiation detriment or burden and important biological outcomes. Most epidemiologic studies of unanticipated radiation exposure fail to establish cause and effect because researchers have not been able to construct a valid quantification of dose for the exposed population. However, no one biodosimetric technique (biophysical or biological) meets all the requirements of an ideal dosimeter. This paper reviews how the collection of biodosimetric data for victims of radiation accidents can be used to create a dosimetric "gold standard." Particular emphasis is placed on the use of electron spin resonance, a standard for radiation accident dosimetry. As an example of this technique, a review will be presented of a previously reported study of an individual exposed to a 60Co sterilization source.

A new method of retrospective radiation dosimetry: optically stimulated luminescence in dental enamel

Currently, retrospective biophysical radiation dosimetry lacks a technique that is sensitive, non-invasive, and portable. This has made reliable cause and effect relationships between radiation exposure and its outcomes in humans difficult to establish. Since optical technology is amenable to miniaturization, a search for optically stimulated luminescence in dental enamel was begun. The first successful detection of time dependent optically stimulated luminescence from gamma irradiated enamel was accomplished. This luminescence is absent in enamel that is not irradiated or that was heated following irradiation. Thermoluminescence observations were made concurrently with the optical measurements which clarified the role of the organic component of enamel.

Collective biodosimetry as a dosimetric "gold standard": a study of three radiation accidents

Quantification of the biologically relevant dose is required for the establishment of cause-and-effect between radiation detriment or burden and important biological outcomes. Most epidemiological studies of unanticipated radiation exposure fail to establish cause and effect because of an inability to construct a valid quantification of dose for the exposed population. No one biodosimetric technique (biophysical or biological) meets all the requirements of an ideal dosimeter and thus qualify as a "gold standard." This report combines new results with previously published data in order to establish a collective biodosimetry as a dosimetric "gold standard" for the victims of three radiation accidents. Combining new and previously published data is necessary as execution and planning of a comprehensive dosimetry is rarely done at the initial stages of a radiation accident. The first subject was a fireman during the initial moments of the Chernobyl nuclear accident; the second was the victim of an unspecified occupational accident; and the third was exposed to a 60Co sterilization source. There was generally good agreement among the various biodosimetric techniques used for the three accident victims.

6-bit and 8-bit digital radiography for detecting simulated periodontal lesions

The purpose of this study was to compare the diagnostic performance of a digital radiography system that uses 6- and 8-bit displays with conventional D-speed film for the detection of simulated periodontal bone lesions. Eleven human hemimandibles were used as specimens. Simulated lesions were created at the buccal cortical plate in the marginal bone area with the use of a round bur 1.4 mm in diameter. Lesions were created in a defined sequence to preclude visual cues as to the depth of the lesions. Lesion size progressed in 0.5 mm increments. At each stage the mandibles were imaged with a Sens-A-Ray system (REGAM Medical Systems AB, Sundsvall, Sweden) and D-speed film. Exposure parameters for each specimen/receptor combination were standardized by either the mean optical density or mean gray value at the approximal crestal bone area. Film images and digital images displayed with 64 and 256 gray levels were presented to six observers for evaluation. Observers were ask to rate their confidence as to the presence or absence of a lesion using a 5-point confidence scale. A total of 96 lesion sites and 96 control sites were presented to the observers. Receiver operating characteristic curves were generated for each system. The area under the curve was used as the index of diagnostic accuracy. The mean receiver operating characteristic areas for 6-bit and 8-bit displays and D-speed film were 0.746 +/- 0.043, 0.717 +/- 0.056 and 0.742 +/- 0.059, respectively. Analysis of variance was used to compare the means. No statistical difference was found between any of the three image displays (p > 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

An analysis of paramagnetic centers in irradiated dentin using electron spin resonance

The ESR spectra produced in irradiated dentin have been studied over a range of incident radiation energies from 50 kVp to 25 MVp. The behavior of the dentin ESR signal strength is similar to that of enamel as a function of the energy of the incident radiation. The magnitude of the dentin ESR signals are, however, up to 10 times smaller than the signals of dental enamel for a given radiation energy. The possible contributions of radiation interaction coefficients, chemical structure, and crystallite size to the differences in ESR spectra are discussed.

Dental enamel as an in vivo radiation dosimeter

The determination of the radiation exposure history of the population has become increasingly important in the study of the effects of low-level radiation. The present work was started to try to obtain an in vivo dosimeter that could give an indication of radiation exposure. Dental enamel is the only living tissue which retains indefinitely its radiation history, and electron spin resonance measurements have shown that the radiation signal can be resolved down to about 10 cGy. Measurements on samples from the general population give radiation exposure estimates that are reasonable, and one measurement on a patient who had radiotherapy to the mouth area showed a good correlation with tumor dose. We believe that this is an important new indicator of radiation dose and taken together with exposure histories should provide important data for epidemiological studies as well as accidental exposures.