Detrimental effects of scene manipulations on temperature-based time since death estimation.

In forensic casework, time since death (TSD) estimations may play a crucial role to establish chains of events as well as for alibi assessment in homicide cases. Classical TSD estimation relies on reasonably stable ambient temperatures and a correct documentation of ambient and rectal temperatures. This constancy is in some cases disturbed by post-discovery alterations of the crime scene, e.g. opening a window. In order to develop a better understanding of this alteration-based detrimental impact on TSD estimation as well as to identify feasible recommendations for casework, the present pilot study examined ambient temperature effects of different window opening scenarios regarding various time intervals (5 to 360 min) in a furnished 10 m2 apartment during winter. In this context, in addition to the ambient temperature and thus the cooling rate of the room, re-approximation to initial room temperature, potential influences on a nomogram-based time since death estimation using a fictitious case, and the impact of the measurement height above the ground were investigated. Our data indicate a significant reduction of the mean temperature decrease rate after 15 min regardless of the remaining opening time and a correlation with the size of the respective opening surfaces. Re-approximation to initial room temperatures was observed with up to three times longer than the initial opening time. There was no evidence of a substantial advantage of temperature measurements above the level of the corpse (> 0.1 m). The limitations of the study and its applicability for forensic casework are critically reviewed.

Contrast-Enhanced Ultrasound after Endovascular Aortic Repair: Supplement and Potential Substitute for CT in Early- and Long-Term Follow-Up.

BACKGROUND: Endoleaks are the most common complication after endovascular aneurysm repair (EVAR). Computed tomography angiography (CTA) is presently the golden standard for lifelong surveillance after EVAR. Several studies and meta-analyses have shown contrast-enhanced ultrasound (CEUS) to be a good alternative. The main goal of our study was to further validate the inclusion of CEUS in follow-up examination protocols for the systematic surveillance after EVAR. METHODS: A retrospective analysis of patients who had received CEUS as part of their routine surveillance after EVAR at our center was conducted. Detection rate and classification of endoleak types were compared between available postinterventional CTA/magnetic resonance angiography and follow-up CEUS examinations. Last preinterventional CTAs before EVAR served as baselines with focus on potential cofactors such as age, body mass index, maximum aortic aneurysm diameters, endoleak orientation, and distance-to-surface influencing detection rates and classification. RESULTS: In total, 101 patients were included in the analysis. Forty-four endoleaks (43.5% of cases) were detected by either initial CEUS or CTA, mostly type II (37.6% of the included patients). Initial CEUS showed an endoleak sensitivity of 91.2%, a specificity of 100%, a positive predictive value of 100%, and a negative predictive value of 84.6%. No covariate with an influence on the correct classification could be identified either for CEUS or CT. CONCLUSIONS: CEUS should be considered a valid complementary method to CTA in the lifelong surveillance after EVAR. As type II endoleaks seem to be a common early-term, sometimes spontaneously resolving complication that can potentially be missed by CTA, we suggest combined follow-up protocols including CEUS in the early on postinterventional assessment.

Evaluation of a Condition Monitoring Algorithm for Early Bearing Fault Detection.

Roller bearings are critical components in various mechanical systems, and the timely detection of potential failures is essential for preventing costly downtimes and avoiding substantial machinery breakdown. This research focuses on finding and verifying a robust method that can detect failures early, without creating false positive failure states. Therefore, this paper introduces a novel algorithm for the early detection of roller bearing failures, particularly tailored to high-precision bearings and automotive test bed systems. The featured method (AFI-Advanced Failure Indicator) utilizes the Fast Fourier Transform (FFT) of wideband accelerometers to calculate the spectral content of vibration signals emitted by roller bearings. By calculating the frequency bands and tracking the movement of these bands within the spectra, the method provides an indicator of the machinery's health, mainly focusing on the early stages of bearing failure. The calculated channel can be used as a trend indicator, enabling the method to identify subtle deviations associated with impending failures. The AFI algorithm incorporates a non-static limit through moving average calculations and volatility analysis methods to determine critical changes in the signal. This thresholding mechanism ensures the algorithm's responsiveness to variations in operating conditions and environmental factors, contributing to its robustness in diverse industrial settings. Further refinement was achieved through an outlier detection filter, which reduces false positives and enhances the algorithm's accuracy in identifying genuine deviations from the normal operational state. To benchmark the developed algorithm, it was compared with three industry-standard algorithms: VRMS calculations per ISO 10813-3, Mean Absolute Value of Extremums (MAVE), and Envelope Frequency Band (EFB). This comparative analysis aimed to evaluate the efficacy of the novel algorithm against the established methods in the field, providing valuable insights into its potential advantages and limitations. In summary, this paper presents an innovative algorithm for the early detection of roller bearing failures, leveraging FFT-based spectral analysis, trend monitoring, adaptive thresholding, and outlier detection. Its ability to confirm the first failure state underscores the algorithm's effectiveness.

Gunshots through laminated glass: expelled compounded fragments as a function of bullet type.

In the frame of an experimental setting, the formation of round-shaped compounded glass fragments on the exit site after gunshots through a windshield was examined. For that purpose, a 9 × 19 mm pistol (HK P30) and two different cartridges containing (a) a full metal jacketed round-nosed projectile and (b) a deformation projectile were used. On the basis of 52 gunshots, the morphology, impact angles and terminal ballistics of occurring compounded glass fragments were examined. The results showed that the compounded glass fragments' morphology allowed for the differentiation of two used projectiles. Fragments were able to cause round-shaped defects in a single cotton layer (T-shirt) with subsequent penetration of up to 2.4 cm into ballistic gelatin (10%, 4 °C). As a function of the projectile type, the compounded glass fragments showed different reproducible impact angles that differed notably from the known conical pattern of expelled glass fragments after bullet penetration. These findings might help to explain the atypical morphology of gunshot wounds with laminated glass as an intermediate target and prevent possible misinterpretations when reconstructing the sequence of events.

Imaging of Anatomical Variants of the Lower Limb Nerves: Clinical and Preoperative Relevance.

Anatomical variants of peripheral nerves of the lower limb are relatively frequent and vulnerable to injury if not considered by the surgeon. Surgical procedures or percutaneous injections are often performed without knowing the anatomical situation. In a patient with normal anatomy, these procedures are mostly performed smoothly without major nerve complications. But in the case of anatomical variants, surgery may be challenging as "new" anatomical prerequisites complicate the procedure. In this context, high-resolution ultrasonography as the first-line imaging modality to depict peripheral nerves, has become a helpful adjunct in the preoperative setting. It is crucial, on the one hand, to gain knowledge of anatomical nerve variants and, on the other hand, to depict the anatomical situation preoperatively, to minimize the risk of surgical trauma to a nerve and make surgeries safer.

Operative versus conservative treatment of acute Achilles tendon ruptures: preliminary results of clinical outcome, kinematic MRI and contrast-enhanced ultrasound.

INTRODUCTION: There is no uniform consensus on the gold standard therapy for acute Achilles tendon rupture. The aim of this pilot study was to compare operative and conservative treatment regarding imaging findings and clinical outcome. MATERIALS AND METHODS: Surgically or conservatively treated patients with acute Achilles tendon rupture were retrospectively evaluated. Differences in tendon length and diameter with and without load were analysed using kinematic MRI, tendon perfusion, structural alterations, movement and scar tissue by means of grey-scale and contrast-enhanced ultrasound (CEUS). Intra- and interobserver agreement were recorded. RESULTS: No significant difference was detected regarding clinical outcome, B mode ultrasonography, contrast-enhanced sonography or MRI findings, although alterations in MRI-based measurements of tendon elasticity were found for both groups. Considerable elongation and thickening of the injured tendon were detected in both groups. CONCLUSION: Both, conservative and surgical treatment showed comparable outcomes in our preliminary results and may suggest non-inferiority of a conservative approach.

Ultrasound of Small Nerves.

Nerve ultrasound has become an integral part of the diagnostic workup of peripheral neuropathies. Especially in the examination of small nerves, ultrasound provides superior image quality by using high frequency transducers. For a selection of small nerves, this article summarizes the local anatomy and common pathologies and offers simple instructions for determining their location with ultrasound including some cases with pathologies. This selection of nerves comprises the great auricular nerve, the supraclavicular nerves, the suprascapular nerve, the medial antebrachial cutaneous nerve, the lateral antebrachial cutaneous nerve, the palmar cutaneous branch of the median nerve, the long thoracic nerve, the intercostobrachial nerve, the posterior cutaneous nerve, the infrapatellar branch of the saphenous nerve, the medial calcaneal nerve, and the deep peroneal nerve at the ankle. Following our recommendations, these nerves can be swiftly located and tracked along their course to the site of the pathology.

Role of high-resolution ultrasound in detection and monitoring of peripheral nerve tumor burden in neurofibromatosis in children.

PURPOSE: Peripheral nerve sheath tumors are hallmark findings in neurofibromatosis types 1 and 2. With increasing size, they typically lead to neurological symptoms, and NF1 patients have a lifetime risk of 8-13% for developing malignant peripheral nerve sheath tumors. Medical imaging is therefore highly needed for early detection and exact localization of symptomatic or potentially malignant tumors. This review will give an overview of the ultrasound characteristics of peripheral nerve sheath tumors and findings in patients with neurofibromatosis types 1 and 2. METHODS: A systematic search of electronic databases, reference lists, and unpublished literature was conducted including the keywords "schwannoma," "neurofibroma," "neurofibromatosis," "benign and malignant peripheral nerve sheath tumor." RESULTS: The high-resolution allows a clear analysis of tumor echotexture, definition of margins, and the relation to the parent nerve. The use of color duplex/Doppler and contrast agent adds valuable information for the differentiation of benign and malignant tumors. CONCLUSION: High-resolution ultrasound is a well-established, non-invasive, and easily repeatable first-line tool in diagnostic procedures of soft tissue tumors.

Soft-Tissue Tumor Contrast Enhancement Patterns: Diagnostic Value and Comparison Between Ultrasound and MRI.

OBJECTIVE: The purpose of this study was to assess and compare contrast-enhanced ultrasound and MRI patterns in the diagnosis of soft-tissue masses. MATERIALS AND METHODS: Two hundred fifty-five consecutively registered patients with histologically confirmed soft-tissue masses were included in this retrospective study. The diagnostic properties of four predefined contrast enhancement (CE) patterns were assessed, and logistic regression analysis was performed to determine the correlation between diagnosis and CE pattern, lesion size, and patient age and sex. The influence of lesion size on the occurrence of inhomogeneous CE patterns in malignancies was also determined. RESULTS: Homogeneous CE patterns were highly specific for benignity, and inhomogeneous CE was moderately specific for malignancy in both ultrasound and MRI. A combination of homogeneous and inhomogeneous CE patterns led to 88.3% and 88.7% sensitivity, 66.7% and 59.7% specificity, 73.4% and 68.2% correct classification, 54.6% and 47.8% positive predictive value, 92.6% and 92.7% negative predictive value, 2.65 and 2.20 positive likelihood ratio, and 0.18 and 0.19 negative likelihood ratio for contrast-enhanced ultrasound and contrast-enhanced MRI. Cases with homogeneous CE in either ultrasound or MRI also were predominantly benign. The occurrence of inhomogeneous CE in malignant lesions increased with size. CONCLUSION: CE patterns in ultrasound and MRI offer additional information about the differentiation of an unknown soft-tissue mass. The results of this study showed that homogeneous or absent CE was specific for benign differentiation and that heterogeneous CE was linked to malignancy. The routine analysis of CE patterns should increase diagnostic reliability in unclear soft-tissue masses.

A case of crossed-doubled patellar tendon: an atavistic variant, simple mutation or pathologic finding?

Anatomical variants can be found throughout the whole body. Especially in the knee region, some variability has been reported concerning the osseous, tendinous, and muscular system. Beside a few cases of patellar tendon aplasia, no anatomical variations of this tendon are known. We present a rare case of a doubled patellar tendon as an anatomical variant, which to our knowledge, has not been described previously.

Does size reliably predict malignancy in soft tissue tumours?

PURPOSE: In this retrospective study we examined whether size is a viable marker of tumour malignancy in soft tissue masses (STM) and if the ratio of width and length (RALD) of an STM reflects tumour biology more accurately. METHODS: Measurements of maximal lesion size and perpendicular diameter were performed in available MRI and ultrasonography studies of 212 patients (mean age 54.4 ± 17.2 years, male:female 1:1.12) with a histologically verified diagnosis. RESULTS: Overall, 28.2 % of lesions were malignant, 11.1 % intermediate, and 58.8 % benign. Size alone was a weak predictor of malignancy in STMs (sensitivity 68.8 %, specificity 50.3 %, positive predictive value [PPV] 44.0 %, negative predictive value [NPV] 80.4 %). RALD showed better discriminatory power with greater separation between benign and malignant entities and higher values for sensitivity (83.6 %), specificity (53.6 %), and NPV (89.0 %). A weighted combination of size, age and RALD improved diagnostic power, demonstrating higher values for sensitivity (77.0 %), specificity (80.1 %), PPV (61.0 %), and NPV (89.6 %). CONCLUSIONS: Size should not be used alone to estimate an STM's malignancy. RALD better reflects a lesion's growth pattern and a combination of age, size, and RALD helps to discriminate more accurately between benign, intermediate, and malignant entities. These findings should help to estimate easily whether a newly found STM is benign or malignant prior to further workup. KEY POINTS: •Size does not reliably differentiate between benign, intermediate, and malignant tumours •The R ALD (ratio of lateral to axial diameter) improves diagnostic confidence •When combined with age and size, STM differentiation was further enhanced •These measurements can aid in earlier detection of sarcomas.

Pathological fracture of the patella due to an atypical located aneurysmal bone cyst: verification by means of ultrasound-guided biopsy.

INTRODUCTION: We report on a rare case of an atypical located aneurysmal bone cyst (ABC) in the patella presenting with pathological fracture after trauma. MATERIALS AND METHODS: Using all available diagnostic modalities and by means of ultrasound-guided core-needle biopsy an unclear and suspected pathological fractured cystic bone lesion in the patella of a young man could be further clarified. RESULTS: The acquired images suggested the diagnosis of a pathological fractured aneurysmal bone cyst after mild trauma. However, due to the extraordinary location and clinical presentation the diagnosis was secured by means of ultrasound-guided biopsy through a small cortical gap. CONCLUSION: As shown in this rare case of an atypical aneurysmal bone cyst of the patella, the quite seldom but sometimes possible ultrasound-guided biopsy of intraosseous lesions can help to achieve the diagnostic clarification and should also be taken into account as a non-standard procedure.

A rare case of a punched nerve syndrome of the deep motor branch of the ulnar nerve.

INTRODUCTION: Peripheral compression neuropathy of the ulnar nerve is a frequent condition, most likely encountered at the ulnar sulcus or the Guyon's canal. High-resolution ultrasound (HRUS) can often identify the site of injury. Primarily idiopathic, compression neuropathy can stem from a punched nerve syndrome, in which direct contact between an arterial branch and the nerve leads to compression. MATERIALS AND METHODS: A 42-year-old male patient was examined by means of HRUS using a 17-5 MHz linear transducer on a Philips iU22(®) (Philips, Bothell, Washington, USA). RESULTS: After reporting a punched nerve syndrome of the deep motor branch of the ulnar nerve distal to the Guyon's canal, the patient underwent surgery and showed electrophysiological and clinical improvement 6 months after decompression. CONCLUSION: HRUS is a viable method to demonstrate a punched nerve syndrome. In conjunction with clinical presentation, even unlikely sites of compression such as the deep motor branch of the ulnar nerve can be identified.

Triple hourglass-like fascicular constriction of the posterior interosseous nerve: a rare cause of PIN syndrome.

Supinator syndrome or posterior interosseous nerve (PIN) syndrome is a compression neuropathy of the deep branch of the radial nerve in the region of the Arcade of Frohse. An extremely rare cause of an acute onset supinator syndrome is the hourglass-like fascicular constriction of the posterior interosseous nerve due to torsion. To our knowledge, only a limited number of cases which describe the sonographic appearance of fascicular torsions are known in the literature. We present a rare case of a supinator syndrome associated with hourglass-like constrictions of the PIN diagnosed by means of sonography.