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.

Differentiation of Critical Illness Myopathy and Critical Illness Neuropathy Using Nerve Ultrasonography

PURPOSE

Intensive care unit-acquired weakness occurs frequently in intensive care unit patients, including critical illness myopathy (CIM) and critical illness polyneuropathy (CIPN). The authors present a prospective study to assess the ultrasound pattern sum score to differentiate between confirmed CIM, sensory neuropathy, and CIPN cases.

METHODS

Cross-sectional areas of 12 predefined nerve segments in 16 patients were sonographically examined. Single-nerve cross-sectional areas and ultrasound pattern sum score values were compared; results are given as P -values and receiver operating characteristic area under the curve (AUC).

RESULTS

In neuropathy, significant single-nerve cross-sectional area enlargement was observed in the median ( P = 0.04), ulnar ( P = 0.04), and fibular nerves ( P = 0.0003). The ultrasound pattern sum score could reliably differentiate between pure CIM and neuropathy ( P = 0.0002, AUC 0.92), CIM and sensory neuropathy ( P = 0.001, AUC 0.88), and CIM and CIPN ( P = 0.007, AUC 0.92), but not between sensory neuropathy and CIPN ( P = 0.599, AUC 0.48).

CONCLUSIONS

Nerve ultrasonography reliably identifies neuropathy in intensive care unit-acquired weakness, yet cannot differentiate between sensory neuropathy and CIPN. A standardized ultrasound algorithm can serve as a fast bedside test for the presence of neuropathy in intensive care unit-acquired weakness.

Occlusion of upper limb artery pseudoaneurysms with US-guided fibrin glue injection: a valid minimally invasive treatment option? Two case reports

Arterial pseudoaneurysms (PSAs) typically occur after (iatrogenic) damage (i.e., puncture) to the arterial wall and are the most frequent complication following percutaneous interventions.In this article we report on successful treatments of two iatrogenic PSAs in two patients (87-year-old male; 69-yearold-female) with a brachial (10 x 7 mm; 10 mm-length "neck") and radial (17 x 7 mm; 3 mm-length "neck") artery PSA by US-guided fibrin glue injection (UGFI). Both PSAs were effectively occluded without any complications. To our knowledge this is the first report on successful treatments of upper limb artery PSAs using UGFI, which may represent a valid first-line, minimally invasive treatment option for brachial artery PSA.

Anatomical considerations of US-guided carpal tunnel release in daily clinical practice

Carpal tunnel syndrome is the most frequent compression neuropathy with an incidence of one to three subjects per thousand. As specific anatomical variations might lead to unintended damage during surgical interventions, we present a review to elucidate the anatomical variability of the carpal tunnel region with important considerations for daily clinical practice: several variants of the median nerve branches in and around the transverse carpal ligament are typical and must - similarly to the variant courses of the median artery, which may be found eccentric ulnar to the median nerve - be taken into account in any interventional therapy at the carpal tunnel. Unintended interference in these structures might lead to heavy arterial bleeding and, in consequence, even underperfusion of segments of the median nerve or, if neural structures such as variant nerve branches are impaired or even cut, severe pain-syndromes with a profound impact on the quality of life. This knowledge is thus crucial for outcome- and safety-optimization of different surgical procedures at the volar aspect of the wrist and surgical therapy of the carpal tunnel syndrome e.g., US-guided carpal tunnel release, as injury might result in dysfunction and/or pain on wrist motion or direct impact in the region concerned. For most variations, anatomical and surgical descriptions vary, as official classifications are still lacking.

Noninvasive CSF shunt patency evaluation by superb microvascular imaging

Occlusion of a ventriculoperitoneal shunt system is a potentially life-threatening complication in patients suffering from hydrocephalus. However, there is no imaging established as standard approach in this acute setting. In the present study, we evaluate the use of superb microvascular imaging for investigation of the patency of ventriculoperitoneal shunt systems. Simulation of low flow rates of cerebrospinal fluid through a small diameter CSF shunt system was performed in a dedicated phantom in order to proof the principle of superb microvascular imaging (SMI) being feasible for the measurement of slow CSF flow through the dedicated CSF shunt system. SMI is able to detect low flow rates in CSF shunt systems effectively and fast. Visualization of a Duplex ultrasound flow and Doppler wave pattern in the VP shunt system after the reservoir has been pressed confirms patency. SMI is an effective method for evaluating CSF shunt patency and diagnosing shunt obstruction. This bears the potential to facilitate evaluation of clinically symptomatic VP shunt patients in an acute setting. Further evaluation of ultrasound flow patterns is granted.

Intraneural vascularity of the median, ulnar and common peroneal nerve: Microvascular ultrasound and pathophysiological implications

Objectives

Changes in the microvascular environment are considered crucial in the pathogenesis of compression neuropathies. Several studies have demonstrated elevated intraneural vascularity in severe neuropathy compared with healthy subjects, where intraneural vascularity is considered predominantly undetectable. The aim of this study was to assess and quantify intraneural vasculature by superb microvascular imaging (SMI) in healthy volunteers in the median, ulnar and common peroneal nerve.

Methods

Intraneural vascularity was quantified in 26 healthy volunteers (312 segments overall) by SMI sonography using a 22-MHz linear transducer. Individual nerve segment vascularity was compared with the mean vascularity using one-way ANOVA and Kruskal-Wallis tests, respectively. Vendor-provided quantification and manual vessel count were compared by linear regression analysis.

Results

Intraneural vascularity was detectable in all nerve segments (100.0%). Vessel density was highest in the median nerve at the wrist (1.54 ± 0.44/mm2, P < 0.0001) and lowest in the sulcal ulnar nerve (0.90 ± 0.34/mm2, P < 0.0001). Vendor-provided automated quantification severely overestimated vascular content compared with manual quantification.

Conclusion

Superb microvascular imaging can facilitate the visualisation of nerve vascularity and even detect local variations in vessel density. The pathophysiological implications for peripheral neuropathies, especially compression neuropathies, warrant further investigation, but the absence of visible intraneural vasculature as a negative finding in the diagnostic of compression neuropathies should be interpreted with caution, as the intraneural vascularity may lie beyond the 18 MHz resolution power of a transducer.

Impact of (forensic) expert opinions according to the Istanbul Protocol in Germany-results and insights of the in:Fo-project

As part of a third-party funded project, expert opinions according to the Istanbul Protocol (IP) standards were compiled in Germany on a larger scale for the first time. The assessment process was initiated for 130 project participants. Statistical analysis on numerous variables was performed to test the impact of the expert opinions, foremost of the forensic medical expert opinions, on the individuals' asylum proceedings. The variables were drawn from forensic medical expert opinions and reports of findings, questionnaires for the study participants' counsellors in the project and a query on the asylum status of the study participants. Regression analysis and bivariate analysis on two dependent variables-subjective impact on the asylum procedure from the counsellors' point of view and objective change in the asylum status-were performed to test for an influence on asylum procedures. No statistically significant results were obtained for the objective change of the study participants' asylum status. For the subjective dependent variable, a positive prediction was possible when simultaneously controlling for the independent variables introduction of a forensic medical expert opinion and highest IP grade; a negative prediction was possible when simultaneously controlling for the independent variables introduction of a forensic medical expert opinion and use of IP grading. Apart from the statistical analysis, a positive effect of the assessment on the psychosocial well-being of the study participants could be demonstrated. The results differed from other European studies which demonstrated a correlation between the objective outcome of an asylum procedure (asylum status) and, for example, specific types of violence or the number of documented injuries. Differences also occurred in the use of the plausibility grades proposed by the IP, which questions their use in cases in which the reported torture happened a relevant time ago. Therefore, compiling individually worded evaluations instead of using the IP grading system-if possible, by an experienced forensic physician-is recommended in this scenario. Still, the assessment of alleged torture experiences should follow the IP guidelines, since psychological assessments are of especially high importance in cases with healed physical injuries and since the results also demonstrated a positive effect on the psychosocial well-being of the study participants.

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.

Ultrasound-guided versus computed tomography-controlled periradicular injections of the first sacral nerve: a prospective randomized clinical trial

AIM

To compare ultrasound (US)-guided versus computed tomography (CT)-controlled periradicular injections of the first sacral spinal (S1) nerve in a prospective randomized clinical trial.

MATERIALS AND METHODS

Thirty-nine patients with S1-radiculopathy were consecutively enrolled for 40 periradicular injections and assigned to an US or CT guided group. Needle position after US-assisted placement was controlled by a low-dose CT-scan. Accessibility, accuracy, and intervention time were compared. The overall effect on pain was matched evaluating the visual analog scale (VAS) decrease before and one month after the intervention.

RESULTS

The mean intervention time was lower in the US-group compared to the CT-group: 4.4±3.46 min (1.3-13.2) vs. 6.5±3.03 min (2.4-12.5). Using CT-controlled infiltration the mean number of needle passes was with 1.15 higher than utilizing US-guidance. The therapeutic effect (mean difference between pre- and post-intervention, VAS scores) for the CT-group was 4.85±2.52 and for the US-group 4.55±2.74 with no significant difference between the two groups (p=0.7).

CONCLUSION

US-controlled infiltrations of the first sacral nerve show a similar therapeutic effect to the time consuming, and ionizing CT-controlled injections and result in a significant reduction of procedure expenditure and avoidance of radiation.

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.

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.

Aspiration-related pneumonia after Taser exposure - A multiple causations mechanism

Arrest-related deaths in the context of Conducted Electrical Weapon (CEW) deployment are rare. The evaluation of such complex events is a challenge for the forensic scientist. We present a case of a 49-year old man, who was exposed to a Taser X26P during a confrontation with the police. He lost consciousness, vomited, aspirated and died after having been hospitalized for several days at the ICU. Based on the patient´s medical history, autopsy findings, witness testimonies, and reliable clinical and toxicological blood parameters, the most probable cause and mechanisms of his death are discussed. The present work demonstrates, based on one case report, the possibilities as well as limitations of forensic assessment in CEW-related deaths.

Cycling-Related Compressive Neuropathy of the Deep Ulnar Motor Branch in the Hand: Is Sonography a Valid Tool?

Repetitive vibratory trauma in cyclists is one of the most common causes of ulnar nerve compression at the wrist. This study describes five cases of clinically suspected compression syndrome of the deep terminal branch of the ulnar nerve (DBUN) defined by high-resolution ultrasound (HRUS) with a 18-MHz linear transducer. Reliable HRUS visualization of the DBUN was feasible in all patients. The affected nerves had focally swollen and hypo-echoic changed segments. HRUS is a good imaging tool for the evaluation of a suspicious DBUN neuropathy if no electrodiagnostic testing is available or in patients with mild to moderate clinical symptoms with inconclusive electrodiagnostic results.

Ultrasound-Guided Minimal Invasive Carpal Tunnel Release: An Optimized Algorithm

PURPOSE

To present a safety-optimized ultrasound-guided minimal invasive carpal tunnel release (CTR) procedure.

MATERIALS AND METHODS

104 patients (67 female, 37 male; mean age 60.6 ± 14.3 years, 95% CI 57.9 to 63.4 years) with clinical and electrophysiological verified typical carpal tunnel syndrome were referred for a high-resolution ultrasound of the median nerve and were then consecutively assigned for an ultrasound-guided CTR after exclusion of possible secondary causes of carpal tunnel syndrome such as tumors, tendovaginitis, ganglia and possible contraindications (e.g., crossing collateral vessels, nerve variations). Applying a newly adapted and optimized algorithm, basing on the work proposed by Petrover et al. CTR was performed using a button tip cannula which has several safety advantages: On the one hand, the button tip cannula acts as a blunt and atraumatic guiding splint for the subsequent insertion of the hook-knife, and on the other hands, it serves as a "hydro-inflation"-tool, i.e., a fluid-based expansion of the working-space is warranted during the whole procedure whenever needed.

RESULTS

In all patients, successful releases were confirmed by the depiction of a completely transected transverse carpal ligament during and in the postoperative ultrasound-controls two weeks after intervention. All patients reported markedly reduction of symptoms promptly after this safety-optimized ultrasound-guided minimal invasive CTR and at the follow-up examination. No complications were evident.

CONCLUSION

The here proposed optimized algorithm assures a reliable and safe ultrasound-guided CTR and thus should be taken into account for this minimal invasive interventional procedure.

Rare median nerve anatomy - possible cause for carpal tunnel syndrome?

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Efficacy of Retreatment After Failed Direct-acting Antiviral Therapy in Patients With HCV Genotype 1-3 Infections

Hepatitis C virus infection is causing chronic liver disease, cirrhosis, and hepatocellular carcinoma. By combining direct-acting antivirals (DAAs), high sustained virologic response rates (SVRs) can be achieved. Resistance-associated substitutions (RASs) are commonly observed after DAA failure, and especially nonstructural protein 5A (NS5A) RASs may impact retreatment options.^1-3 Data on retreatment of DAA failure patients using first-generation DAAs are limited.^4-7 Recently, a second-generation protease- and NS5A-inhibitor plus sofosbuvir (voxilaprevir/velpatasvir/sofosbuvir [VOX/VEL/SOF]) was approved for retreatment after DAA failure.⁸ However, this and other second-generation regimens are not available in many resource-limited countries or are not reimbursed by regular insurance, and recommendations regarding the selection of retreatment regimens using first-generation DAAs are very important. This study aimed to analyze patients who were re-treated with first-generation DAAs after failure of a DAA combination therapy.

Lumbar medial branch cryoneurolysis under ultrasound guidance: initial report of five cases

AIMS

To assess the feasibility and preliminary results of ultrasound guided medial branch cryoneurolysis in the management of facet joint syndrome.

MATERIAL AND METHODS

Between March 2017 and August 2017, a total of 20 patients underwent medial branch blocks, 12 of which were positive. Five patients chose to participate in the study and 8 medial branch cryoneurolysis were performed. The primary endpoint of the study was the feasibility of the procedure. The secondary endpoint was the efficacy on pain assessed over the following year after the procedure.

RESULTS

Technical feasibility of cryoneurolysis under ultrasound guidance was 100%. Accurate needle positioning at the accurate target in the angle between the posterior aspect of the transverse process and the lateral aspect of the facet joint was achieved in all cases. Needle progression could be depicted with US guidance in all cases. Mean pre-procedural Visual Analogue Scale and Oswestry disability Index scores were 6.8 (range 5-8) and 20.6 (range 12- 31), respectively. Follow up showed a decrease of Visual Analogue Scale score at one month (1.75, range 0-7), and at three months (1.75 range 0-3), Mean self-reported improvement at 6 months was 76% (60- 100%) and 77% at 12 months (50-100%). We report one case of failure at one month. No complications were noted during or after the procedure.

CONCLUSION

Our findings suggest that ultrasound is a valid imaging modality to perform lumbar medial branch cryoneurolysis. Initial results show that cryoneurolysis under ultrasound guidance appears as a safe and effective procedure in patients suffering for facet joint pain.

Ultrasound-Guided Fibrin Glue Injection for Treatment of Iatrogenic Femoral Pseudoaneurysms

Introduction:

Arterial pseudoaneurysms (PSAs) are the most common access site complication following transarterial catheter intervention. Ultrasound-guided injection of thrombogenic substances into perfused arterial PSAs followed by compression therapy is a well-established and less invasive treatment option than surgical repair. Different agents are available to induce thrombosis including thrombin and a fibrin-based tissue glue, which is used as first-line treatment at our institution. This paper deals with our experience using ultrasound-guided fibrin glue injection (UGFI).

Materials and Methods:

Retrospective data analysis: all patients (55) treated for iatrogenic femoral PSA following digital subtraction angiography of the lower extremities between January 1, 2010, and December 31, 2018, were included. Data on epidemiology, PSA location and size, vascular risk factors, fibrin glue injection (fibrin glue volume), primary success rate of UFGI, and complications related to the treatment were analyzed.

Results:

A total of 55 consecutive femoral iatrogenic PSAs were treated during the defined period and 32 (58.2%) of the patients were female. Imaging was performed using ultrasound in all cases. The most common PSA location (80.0%) was the common femoral artery, mean PSA size (± SD) was 2.7 ± 1.2 cm, and neck length was 1.6 ± 1.0 cm. The dose (mean ± SD) of fibrin glue was 2.6 mL (± 1.0; maximum: 6 mL). Primary UGFI success rate was 87.3% and conversion rate to open surgery was 12.7%. Two (4%) patients required embolectomy for peripheral embolization after UGFI.

Conclusion:

Early results achieved with UGFI for treatment of iatrogenic femoral PSA are promising. In our cohort, UGFI was a safe and effective first-line alternative to traditional open surgery, which then was unnecessary in the vast majority of PSA cases. Further prospective studies for comparison of ultrasound-guided techniques should be encouraged.

Contrast-Enhanced Ultrasound for Musculoskeletal Applications: A World Federation for Ultrasound in Medicine and Biology Position Paper

This World Federation for Ultrasound in Medicine and Biology position paper reviews the diagnostic potential of ultrasound contrast agents for clinical decision-making and provides general advice for optimal contrast-enhanced ultrasound performance in musculoskeletal issues. In this domain, contrast-enhanced ultrasound performance has increasingly been investigated with promising results, but still lacks everyday clinical application and standardized techniques; therefore, experts summarized current knowledge according to published evidence and best personal experience. The goal was to intensify and standardize the use and administration of ultrasound contrast agents to facilitate correct diagnoses and ultimately to improve the management and outcomes of patients.

Ultrasonography of the Peripheral Nerves of the Forearm, Wrist and Hand: Definition of Landmarks, Anatomical Correlation and Clinical Implications

BACKGROUND

 Peripheral nerve pathologies of the upper extremity are increasingly assessed by high-resolution ultrasonography (HRUS), yet rapid identification of nerve segments can be difficult due to small nerve diameters and complex regional anatomy. We propose a landmark-based approach to speed up and facilitate evaluation and intervention in this region.

METHOD

 Relevant landmarks and section planes for eleven nerve segments of the forearm, wrist and hand were defined by ultrasonography in cadaver arms before cryosection and topographical neurovascular preparation. Information on all nerve segments and a pictorial guide including anatomical cross-sections, topographical preparations and HRUS images are provided. The identification rates of these nerve segments were then assessed in 20 healthy volunteers.

RESULTS AND CONCLUSION

 Sonographic landmarks and guidelines for the rapid identification and assessment of nerves of the forearm, wrist and hand are presented in pictorial and tabular form, including discussion of normal variants. Utilizing this overview should facilitate training, diagnostic examinations and intervention for nerves of the upper extremity.

KEY POINTS

  · High-resolution ultrasound enables assessment of peripheral nerves of the forearm, wrist and hand.. · A landmark-based approach can facilitate and speed up nerve evaluation in these regions.. · High detection rates could be reproduced using the proposed landmark-based approach..

CITATION FORMAT

· Gruber L, Loizides A, Peer S et al. Ultrasonography of the Peripheral Nerves of the Forearm, Wrist and Hand: Definition of Landmarks, Anatomical Correlation and Clinical Implications. Fortschr Röntgenstr 2020; 192: 1060 - 1072.

Ultrasonography of the Peripheral Nerves of the Forearm, Wrist and Hand: Definition of Landmarks, Anatomical Correlation and Clinical Implications

BACKGROUND

 Peripheral nerve pathologies of the upper extremity are increasingly assessed by high-resolution ultrasonography (HRUS), yet rapid identification of nerve segments can be difficult due to small nerve diameters and complex regional anatomy. We propose a landmark-based approach to speed up and facilitate evaluation and intervention in this region.

METHOD

 Relevant landmarks and section planes for eleven nerve segments of the forearm, wrist and hand were defined by ultrasonography in cadaver arms before cryosection and topographical neurovascular preparation. Information on all nerve segments and a pictorial guide including anatomical cross-sections, topographical preparations and HRUS images are provided. The identification rates of these nerve segments were then assessed in 20 healthy volunteers.

RESULTS AND CONCLUSION

 Sonographic landmarks and guidelines for the rapid identification and assessment of nerves of the forearm, wrist and hand are presented in pictorial and tabular form, including discussion of normal variants. Utilizing this overview should facilitate training, diagnostic examinations and intervention for nerves of the upper extremity.

KEY POINTS

  · High-resolution ultrasound enables assessment of peripheral nerves of the forearm, wrist and hand.. · A landmark-based approach can facilitate and speed up nerve evaluation in these regions.. · High detection rates could be reproduced using the proposed landmark-based approach..

CITATION FORMAT

· Gruber L, Loizides A, Peer S et al. Ultrasonography of the Peripheral Nerves of the Forearm, Wrist and Hand: Definition of Landmarks, Anatomical Correlation and Clinical Implications. Fortschr Röntgenstr 2020; 192: 1060 - 1072.

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.

Positioning of a Volar Locking Plate with a Central Flexor Pollicis Longus Tendon Notch in Distal Radius Fractures

Background  Volar locking plates with a central notch were designed to reduce the risk of flexor pollicis longus (FPL) tendon irritation after volar plating for distal radius fractures. Objective  The purpose of this study was to evaluate the course of the FPL tendon after FPL-plate osteosynthesis to identify a plate position that avoids an impingement with the FPL tendon. Patients and Methods  Nineteen patients treated with volar plating using an FPL plate for a distal radius fracture were evaluated. Transverse ultrasound images were used to assess whether the profile of the FPL tendon lied within the plate notch. The position of the FPL tendon on transverse ultrasound images was transferred onto postoperative dorsovolar X-ray images to define an FPL tendon corridor for a plate position not interfering with the FPL tendon. Results  The FPL tendon was aligned inside the plate notch completely in three cases, partially in 11 cases, and missed the notch in five cases. An FPL corridor was defined at the level of the watershed line with all FPL tendons being completely (74%) or partially (26%) aligned inside that corridor. There was a moderate correlation between the plate notch being positioned inside this corridor and the FPL tendon being positioned inside the plate notch ( r  = 0.49; p  = 0.033). Conclusion  It seems advantageous to place the plate notch within a corridor parallel to the radial shaft between the ulnar edge of the scaphoid tubercle and the scapholunate interval for the FPL tendon protection. Level of Evidence  This is Level IV study.

A simple approach for ultrasound-guided pararadicular injections in the sacral spine: a pilot computer tomography controlled cadaver study

AIMS

Injection therapies play an increasingly decisive role in the treatment of lower back pain. Cumulative studies could show the benefits of ultrasound-guided instillation procedures in the cervical and lumbar spine. We conducted this study to provide a new simple sonographic approach for pararadicular injections of the sacral spinal nerves and to prove the feasibility and accuracy by means of CT and anatomic dissection.

MATERIAL AND METHODS

Eight ultrasound-guided injections at four different levels of the sacral spine on a human ethanol-glycerol-embalmed cadaver (S1-S4) were performed. By means of sonography the sacral foramina were identified and the spinal needles were advanced in "in-plane technique" to the medial margin of the respective sacral foramen. Subsequently a solution of blue dye and contrast agent were injected. Then CT scans and anatomic dissection of the cadaver were performed to verify the correct placement of the needle tips and to visualize the dispersion of the injected solution in the respective compartment.

RESULTS

Altogether a 100% success rate for a correct injection could be achieved. CT examination confirmed the correct placement of every needle tip within the intended compartment. Also, the anatomic dissections affirmed the appropriate needle positioning. Moreover, the blue dye dispersion was seen in the correct compartments and around the targeted spinal nerves.

CONCLUSIONS

Although this study was only performed on cadaveric models, this new sonographic approach for pararadicular injections in the sacral spine allows an easy, precise and unerring needle placement within the dorsal sacral foramen.

Effect of Powder Recycling on the Fracture Behavior of Electron Beam Melted Alloy 718

Understanding the effect of powder feedstock alterations during multicycle additive manufacturing on the quality of built components is crucial to meet the requirements on critical parts for aerospace engine applications. In this study, powder recycling of Alloy 718 during electron beam melting was studied to understand its influence on fracture behavior of Charpy impact test bars. High resolution scanning electron microscopy was employed for fracture surface analysis on test bars produced from virgin and recycled powder. For all investigated samples, an intergranular type of fracture, initiated by non-metallic phases and bonding defects, was typically observed in the regions close to or within the contour zone. The fracture mode in the bulk of the samples was mainly moderately ductile dimple fracture. The results show a clear correlation between powder degradation during multi-cycle powder reuse and the amount of damage relevant defects observed on the fracture surfaces. In particular, samples produced from recycled powder show a significant amount of aluminum-rich oxide defects, originating from aluminum-rich oxide particulates on the surface of the recycled powder.

Ultrasonography for the Diagnosis of Carpal Tunnel Syndrome in Diabetic Patients: Missing the Mark?

PURPOSE

 Diabetes mellitus (DM) and carpal tunnel syndrome (CTS) are common pathologies. The diagnosis of CTS can be facilitated by the use of an ultrasound-based wrist-to-forearm ratio (WFR) of the nerve diameter. However, the applicability of WFR in DM-patients is not yet clear.

MATERIALS AND METHODS

 233 wrists of 153 patients were examined. Cross-sectional areas (CSA) of the median nerve were obtained using a linear array probe. The WFR was calculated.

RESULTS

 Diabetics with CTS had significantly lower WFR values than non-diabetics with CTS (p = 0.002). There was no difference between the WFR of diabetics with and without CTS (p = 0.06). The diagnostic accuracy between diabetics with and without CTS was low for measurements of WFR (ROC AUC = 0.630, 95 % CI 0.541 - 0.715, p = 0.011).

CONCLUSION

 Our findings suggest that the WFR has a low diagnostic accuracy in diabetic patients with CTS and should be used with caution in those patients.

KEY POINTS

  · The diagnostic accuracy of WFR is low in patients with DM. · WFR should not be used in patients with DM. · The sonographic evaluation of the median nerve in patients with DM should focus on morphological changes.

CITATION FORMAT

· Steinkohl F, Loizides A, Gruber L et al. Ultrasonography for the Diagnosis of Carpal Tunnel Syndrome in Diabetic Patients: Missing the Mark?. Fortschr Röntgenstr 2019; 191: 117 - 121.

Stellungnahme

von Dr. Nitto auf den Leserbrief von Prof. Dr. Staub und Mitar. bzgl. ihrer Arbeit Nitt A, Baur EM, Gruber H, Löscher W, Loizides A, Mattesich M, Pülzl P. Betreffend der Wrist-to-Forearm-Ratio des N. medianus ist die Sonographie zur Verlaufskontrolle nach Operation eines Karpaltunnelsyndroms ungeeignet. Handchir Mikrochir Plast Chir 2018; 50: 14-18.

[Ultrasound-guided interventions on the peripheral nervous system]

CLINICAL/METHODICAL ISSUE

Up to the advent of high-resolution ultrasound, interventions on the peripheral nervous system, including local anesthesia and pain treatment were performed without visual guidance, which in some cases led to treatment failure or local tissue and nerve damage.

METHODICAL INNOVATIONS

Progress in the field of ultrasound has enabled the functional visualization, anesthesia and anti-inflammatory or neurolytic treatment of many peripheral nerves, such as the brachial plexus, nerves of the upper and lower extremities and various nerves of the trunk. Contrast medium-guided biopsies have also become feasible.

ACHIEVEMENTS

This article discusses the general prerequisites for such interventions and details the visualization and the interventional algorithms for interventions on the brachial plexus, on large nerves often affected by compression neuropathies, such as the median, ulnar, sciatic and femoral nerves and small nerves, such as the lateral cutaneous nerves of the thigh. Furthermore, contrast medium-aided biopsies of intraneural and perineural masses are discussed. Finally, the treatment of stump neuromas via phenol instillation is described.

PRACTICAL RECOMMENDATIONS

Innovations in high-resolution ultrasound allow the reliable and safe diagnosis and treatment of various pathologies of the peripheral nervous system with few side effects. Compared to older methods, which did not use visual guidance ultrasound provides higher success rates and lower adverse event rates in many instances.

[Concerning the Wrist-to-Forearm-Ratio of the Median nerve ultrasound is not a suitable method for assessing the success of a carpal tunnel release]

PURPOSE

The primary aim of the study was to analyze whether there is and - if so - how far a correlation between the clinical findings after carpal tunnel release (CTR) for carpal tunnel syndrome (CTS) and the Wrist-to-Forearm-Ratio (WFR) of the median nerve in ultrasound to answer is question whether the WFR can be used in controlling the operative result.

PATIENTS AND METHODS

In a prospective study the clinical, electrophysiological, and sonographic data of 40 patients with CTR for CTS were collected preoperative and 3 and 9 months postoperative. The data of 21 patients with 23 operated hands completing the study were analyzed. There were 5 men and 16 women with an average age of 58 years.

RESULTS

Neither a correlation between the clinical findings postoperative and the WFR nor the electrophysiological findings postoperative was found.

CONCLUSION

Concerning the Wrist-to-Forearm-Ration of the Median nerve ultrasound is not a suitable method for assessing the success of a carpal tunnel release.

A rare case of an acute soleus arcade syndrome complicated by a ganglion cyst: diagnosis by dynamic ultrasound

The soleus arcade syndrome is a rare compression neuropathy of the tibial nerve that often remains undiagnosed due to low clinical awareness and difficult diagnosis. We present the case of a female patient admitted with acute worsening of a pre-existing sensory tibial neuropathy and acute tibial nerve palsy after knee joint injection. After a knee magnetic resonance imaging remained non-diagnostic, dynamic ultrasonography was performed. Constriction by the soleus arcade and proximal swelling of the tibial nerve could be demonstrated during plantarflexion of the ankle by means of a dynamic examination in the standing patient. The patient underwent surgery and recovered fully. This proposed diagnostic approach can be used to identify soleus arcade syndrome by ultrasound.

Contrast enhanced ultrasound of a rare case of Peliosis hepatis

Peliosis hepatis is a rare benign disorder of the liver, histologically characterized by blood-filled cystic cavities of various sizes and irregular shapes, communicating with the hepatic sinusoids. Only a few cases of peliosis hepatis have been described using contrast enhanced ultrasound showing admittedly various dynamic enhancement patterns. We present a case of peliosis hepatis with a typical target-sign enhancement depicted by means of contrast enhanced ultrasound.

Memory Effect of the Median Nerve: Can Ultrasound Reliably Depict Carpal Tunnel Release Success?

Purpose To evaluate whether ultrasound findings of the median nerve cross-section area (CSA) and wrist-to-forearm ratio (WFR) correlate with neurophysiological and patient-reported outcome after surgery for carpal tunnel syndrome (CTS). Materials and Methods Subjective pain, CSA, WFR, postoperative scar tissue formation and nerve conduction velocity in 21 hands of 20 patients with clinically confirmed CTS were examined before and after carpal tunnel release surgery. Group differences were compared via a 2-sided ratio paired t-test or one-way ANOVA, and correlations were calculated using a linear regression model. Results There were no significant pre- and postoperative changes of the CSA of the median nerve (p = 0.293, 95 % CI 0.826 - 1.063) or WFR (p = 0.230, 95 % CI 0.757 - 1.074). The nerve conduction velocity (p < 0.0001, 95 % CI 0.753 - 0.886) and subjective pain during rest (p = 0.001, 95 % CI 1.615 - 5.797) and exercise (p = 0.008, 95 % CI 0.760 - 4.888) improved significantly, though. There was no correlation between changes in the median nerve CSA and nerve conduction velocity (p = 0.357, r = 0.217, R2 = 0.047) or reported pain intensity (p = 0.441, r = 0.200, R2 = 0.040). Conclusion Contrary to common assumptions, there is no significant reduction of the CSA of the median nerve after successful carpal tunnel release. Morphologic median nerve changes may persist for a longer period regardless of successful surgery and clinical improvement. Accordingly, ultrasound appears unsuitable as the primary means of assessing surgical success due to this "memory effect". Key Points · CSA of the median nerve does not change significantly after successful carpal tunnel release.. · Morphologic median nerve alterations may persist regardless of functional outcome ("memory effect").. · Therefore, ultrasound imaging is not ideally suited to assess the outcome after carpal tunnel release.. Citation Format · Steinkohl Fabian, Gruber Leonhard, Gruber Hannes et al. Memory Effect of the Median Nerve: Can Ultrasound Reliably Depict Carpal Tunnel Release Success?. Fortschr Röntgenstr 2017; 189: 57 - 62.

Doppler-guided haemorrhoidal artery ligation with suture mucopexy compared with suture mucopexy alone for the treatment of Grade III haemorrhoids: a prospective randomized controlled trial

AIM

Novel minimally invasive techniques aimed to reposition the haemorrhoidal zone have been established for prolapsing haemorrhoids. We present a prospective randomized controlled trial to evaluate the efficacy of additional Doppler-guided ligation of submucosal haemorrhoidal arteries (DG-HAL) in patients with symptomatic Grade III haemorrhoids. The trial was registered as ClinicalTrials.gov identifier NCT02372981.

METHOD

All consecutive patients with symptomatic Grade III haemorrhoids were randomly allocated to one of the two study arms: (i) Group A, DG-HAL with mucopexy or (ii) Group B, mucopexy alone. End-points were postoperative pain, faecal incontinence, bleeding, residual prolapse and alterations of the vascularization of the anorectal vascular plexus. Vascularization of the anorectal vascular plexus was assessed by transperineal contrast enhanced ultrasound. Patients recorded their symptoms in a diary maintained for a month.

RESULTS

Forty patients were recruited and randomized to the two study groups. Patients in Group A had less pain in the first two postoperative weeks. At the 12-month follow-up, two patients in Group A (10%) and one in Group B (5%) showed recurrent Grade III haemorrhoids (P = 0.274). No significant morphological changes were observed in the transperineal ultrasound findings between the preoperative assessment and the assessment at 1 and 6 months in either group (P > 0.05).

CONCLUSION

Mucopexy techniques for treating prolapsing haemorrhoids are effective, but DG-HAL does not add significantly to the results achieved by mucopexy. Repositioning the haemorrhoidal zone is the key to success, and mucopexy should be placed at the sites of the largest visible prolapse.