Bianca Bignotti

Reliability of side-to-side ultrasound cross-sectional area measurements of lower extremity nerves in healthy subjects

Introduction: In peripheral nerve ultrasound, the healthy contralateral side may be used as internal control. Therefore, inherent side‐to‐side differences must be minimal. The goal of this study was to assess intrastudy, intraobserver, and interobserver reproducibility of ultrasound in comparative side‐to‐side evaluation of lower limb nerves. Methods: Lower limb nerves of 60 normal subjects were evaluated by 3 radiologists. Bilateral sciatic, tibial, common fibular, sural, lateral femoral cutaneous, femoral, obturator, and saphenous nerves were evaluated. Results: Overall, side‐to‐side differences were not statistically significant at any level. In the lower limb nerves, in a between‐limb comparison, the minimum detectable difference of cross‐sectional area ranged from 16.4 mm2 (sciatic nerve at the level of piriformis muscle) to 0.4 mm2 (saphenous nerve). Conclusion: In general, the healthy contralateral side can be used as an internal control. Muscle Nerve 46: 717–722, 2012

Diagnostic performance of contrast-enhanced spectral mammography: Systematic review and meta-analysis

PURPOSE To estimate sensitivity and specificity of CESM for breast cancer diagnosis. METHODS Systematic review and meta-analysis of the accuracy of CESM in finding breast cancer in highly selected women. We estimated summary receiver operating characteristic curves, sensitivity and specificity according to quality criteria with QUADAS-2. RESULTS Six hundred four studies were retrieved, 8 of these reporting on 920 patients with 994 lesions, were eligible for inclusion. Estimated sensitivity from all studies was: 0.98 (95% CI: 0.96-1.00). Specificity was estimated from six studies reporting raw data: 0.58 (95% CI: 0.38-0.77). The majority of studies were scored as at high risk of bias due to the very selected populations. CONCLUSION CESM has a high sensitivity but very low specificity. The source studies were based on highly selected case series and prone to selection bias. High-quality studies are required to assess the accuracy of CESM in unselected cases.

Breast Density Assessment Using a 3T MRI System: Comparison among Different Sequences

Purpose To compare MRI sequences for breast density measurements on a 3T MRI system using IDEAL (Iterative Decomposition of water and fat with Echo Asymmetry and Least squares estimation) as possible physiology-like reference. Materials and Methods MRI examination was performed in 48 consecutive patients (mean age 41, years; range, 35–67 years) on a 3.0T scanner and 46 were included. All (fertile) women, were examined between days 5 and 15 of their menstrual cycle. MRI protocol included: T1-turbo spin-echo (T1-tSE), T2-turbo spin-echo (T2-tSE), VIBRANT (Volume Imaging for Breast Assessment) before and after injection of contrast media and IDEAL. Breast density was calculated with semi-automated software. Statistical analysis was performed with non-parametric tests. Results Mean percentage of breast density calculated in each sequence was: T1-tSE  = 56%; T2-tSE  = 52%; IDEAL FatOnly  = 55%; IDEAL WaterOnly  = 53%, VIBRANT  = 55%. Significant differences were observed between T2-tSE and both T1-tSE (p<0.001), VIBRANT sequences (p = 0.009), T1-tSE and both IDEAL WaterOnly (p = 0.007) and IDEAL FatOnly (p = 0.047). Breast density percentage showed a positive linear correlation among different sequences: r≥0.93. Conclusions Differences exist between MRI sequences used to assess breast density percentage. T1-weighted sequences values were similar to IDEAL sequences.

Elbow US: Anatomy, Variants, and Scanning Technique

As with other musculoskeletal joints, elbow ultrasonography (US) depends on the examination technique. Deep knowledge of the relevant anatomy, such as the bone surface anatomy, tendon orientation, nerves, and vessels, is crucial for diagnosis. It is important to be aware of the primary imaging pitfalls related to US technique (anisotropy) in the evaluation of deep tendons such as the distal biceps and peripheral nerves. In this article, US scanning technique for the elbow as well as the related anatomy, primary variants, and scanning pitfalls are described. In addition, an online video tutorial of elbow US describes a possible approach to elbow evaluation. Online supplemental material is available for this article.

Imaging finger joint instability with ultrasound.

Closed injuries affecting the metacarpophalangeal and interphalangeal joints and their stabilizers in the thumb and fingers occur very commonly in athletes, possibly leading to finger joint instability and long-standing or permanent disability. This article reviews the spectrum of joint injuries of the thumb and fingers that are common in the athletic population with a main focus on the ultrasound features of collateral ligament tears, palmar plate injuries, and thumb sesamoid fractures. A thorough understanding of the complex anatomy, mechanism of injury, soft tissue abnormalities, and imaging findings is critical in the diagnostic work-up of closed finger joint trauma and may help improve outcomes.

Anatomical study of the iliohypogastric, ilioinguinal, and genitofemoral nerves using high-resolution ultrasound

Introduction: In this study we aimed to determine whether high‐resolution ultrasound (US) can identify the iliohypogastric (IH), ilioinguinal (II), and genitofemoral (GF) nerves and their relations. Methods: This investigation, initially undertaken in cadavers, was followed by a high‐resolution US study in 30 healthy adult volunteers (180 nerves) by 2 musculoskeletal radiologists on separate occasions, using 2 different approaches (proximal to distal and distal to proximal). A 0–3 scale was used to assess nerve visibility. Location and course of the IH, II, and GF nerves and their relations to adjacent anatomical structures were analyzed. Results: Nerves and their terminal branches were better visualized with the distal‐to‐proximal approach (P < 0.05). Visualization of the terminal branches was possible in up to 60% of volunteers. Conclusions: High‐resolution ultrasound (US) can identify the IH, II, and GF nerves at the level of the abdominal wall and the terminal branches in the majority of volunteers. Muscle Nerve 51: 42–48, 2015

Fascicular involvement in common fibular neuropathy: Evaluation with ultrasound

The aim of this study was to demonstrate single fascicular involvement in common fibular (CF) neuropathy using high‐resolution ultrasound (US). Methods: We prospectively enrolled 40 adult patients with clinical and electrodiagnostic suspected CF neuropathy between April 2012 and December 2014. Two musculoskeletal radiologists used high‐resolution US probes to prospectively and independently evaluate the CF nerve bilaterally in these patients. The presence of single fascicular involvement (increased cross‐sectional area and loss of fascicular echotexture) was recorded. Results: US revealed involvement of only 1 fascicular component of the CF nerve in 7 patients. In all these patients, US revealed involvement of the anterior fascicles corresponding to fibers for the deep fibular nerve. Conclusions: High‐resolution US allowed identification of single fascicular involvement in CF neuropathy. Anterior fascicular involvement was present in up to 17% of patients with suspected CF neuropathy. Muscle Nerve 53: 532–537, 2016

Update on Ultrasound-Guided Interventional Procedures on Peripheral Nerves

This article is a practical review update on ultrasound (US)-guided interventional procedures on peripheral nerves. Technical considerations, biopsy techniques, and some examples of injections are described. US is considered a safe imaging guidance for interventional procedures, due to its high spatial resolution and the possibility to image the needle and inject drugs in real time. US-guided injections could be considered a diagnostic and therapeutic option in the most common neuropathy, before or as an alternative to surgery. US-guided injection techniques in patients with carpal tunnel syndrome, cubital tunnel syndrome, meralgia paresthetica, and Morton neuroma are reviewed. US-guided injections of the iliohypogastric, ilioinguinal, genitofemoral, and pudendal nerve are also illustrated. Knowledge of anatomy is crucial; therefore a brief description of the courses of anatomical nerves and clinical notes are also reported. Treatment of stump neuromas treatment was excluded.

Imaging of skeletal muscle in vitamin D deficiency.

Elderly people are prone to accidental falls and one of the main risk factor is considered muscle weakness. Several studies focused on muscle weakness and muscle morphology changes in the elderly that may be associated with vitamin D deficiency. The prevalence of vitamin D deficiency is higher than previously though representing an important issue for public health and prevention. There is an increased interest in vitamin D effects in skeletal muscle and imaging modalities are particularly involved in this field. In patients with vitamin D deficiency, ultrasound, computed tomography, densitometry and magnetic resonance imaging (MRI) can efficiently describe changes in muscle morphology and size. Moreover, new imaging modalities, such as MRI spectroscopy, may improve knowledge about the metabolic effects of vitamin D in skeletal muscle. In this narrative review we will discuss the role of skeletal muscle imaging in vitamin D-deficient individuals. The aim of this paper is to improve and encourage the role of radiologists in this field.

Accuracy and reading time for six strategies using digital breast tomosynthesis in women with mammographically negative dense breasts

AbstractObjectiveTo compare six strategies using digital breast tomosynthesis in women with mammographically negative dense breasts.Materials and methodsThis is a substudy of the ‘ASTOUND’ trial. 163 women who underwent tomosynthesis with synthetically reconstructed projection images (S-2D) inclusive of 13 (7.9%) cases diagnosed with breast cancer at histopathology after surgery were evaluated. Accuracy measures and screen-reading time of six reading strategies were assessed: (A) Single reading of S-2D alone, (B) single reading of tomosynthesis alone, (C) single reading of joint interpretation of tomosynthesis + S-2D, (D) double-reading of S-2D alone, (E) double reading of tomosynthesis alone, (F) double reading of joint interpretation of tomosynthesis + S-2D.ResultsThe median age of the patients was 53 years (range, 36–88 years). The highest global accuracy was obtained with double reading of tomosynthesis + S2D (F) with an AUC of 0.979 (p<0.001) and a mean reading time of 154 s versus 34 s for the fastest strategy (single reading of S-2D alone). The AUCs for the other five strategies did not differ from each other.ConclusionDouble reading of tomosynthesis+ S2D had the best accuracy of six screen-reading strategies although it had the longest reading time.Key Points• Tomosynthesis acquisitions are progressively implemented with reconstructed synthesized 2D images • Double reading using S-2D plus tomosynthesis had the highest global accuracy (p<0.001). • Double reading of S-2D plus tomosynthesis increased reading time.