Lower Extremity Growth according to AI Automated Femorotibial Length Measurement on Slot-Scanning Radiographs in Pediatric Patients.

Background Commonly used pediatric lower extremity growth standards are based on small, dated data sets. Artificial intelligence (AI) enables creation of updated growth standards. Purpose To train an AI model using standing slot-scanning radiographs in a racially diverse data set of pediatric patients to measure lower extremity length and to compare expected growth curves derived using AI measurements to those of the conventional Anderson-Green method. Materials and Methods This retrospective study included pediatric patients aged 0-21 years who underwent at least two slot-scanning radiographs in routine clinical care between August 2015 and February 2022. A Mask Region-based Convolutional Neural Network was trained to segment the femur and tibia on radiographs and measure total leg, femoral, and tibial length; accuracy was assessed with mean absolute error. AI measurements were used to create quantile polynomial regression femoral and tibial growth curves, which were compared with the growth curves of the Anderson-Green method for coverage based on the central 90% of the estimated growth distribution. Results In total, 1874 examinations in 523 patients (mean age, 12.7 years ± 2.8 [SD]; 349 female patients) were included; 40% of patients self-identified as White and not Hispanic or Latino, and the remaining 60% self-identified as belonging to a different racial or ethnic group. The AI measurement training, validation, and internal test sets included 114, 25, and 64 examinations, respectively. The mean absolute errors of AI measurements of the femur, tibia, and lower extremity in the test data set were 0.25, 0.27, and 0.33 cm, respectively. All 1874 examinations were used to generate growth curves. AI growth curves more accurately represented lower extremity growth in an external test set (n = 154 examinations) than the Anderson-Green method (90% coverage probability: 86.7% [95% CI: 82.9, 90.5] for AI model vs 73.4% [95% CI: 68.4, 78.3] for Anderson-Green method; χ2 test, P < .001). Conclusion Lower extremity growth curves derived from AI measurements on standing slot-scanning radiographs from a diverse pediatric data set enabled more accurate prediction of pediatric growth. © RSNA, 2024 Supplemental material is available for this article.

Blood Oxygen Level-Dependent MR Imaging of Lower Extremities in Peripheral Artery Disease and Its Correlation With Walking Performance.

BACKGROUND: A noninvasive and reliable approach to quantitatively measure muscle perfusion of lower extremity is needed to aid the diagnosis and treatment of peripheral artery disease (PAD). PURPOSE: To verify the reproductivity of using blood oxygen level-dependent (BOLD) imaging to evaluate perfusion in lower extremities, and explore its correlation with walking performance in patients with PAD. STUDY TYPE: Prospective observational study. SUBJECTS: Seventeen patients with lower extremity PAD (mean age: 67 ± 6 years, 15 males) and eight older adults (controls). FIELD STRENGTH/SEQUENCE: Dynamic multi-echo gradient echo T2* weighted imaging at 3T. ASSESSMENT: Perfusion was analyzed in regions of interest according to muscle groups. Perfusion parameters were measured, such as minimum ischemia value (MIV), time to peak (TTP), and gradient during reactive hyperemia (Grad) by two independent users. Walking performance experiments including short physical performance battery (SPPB) and 6-minute walk were tested in patients. STATISTICAL TESTS: BOLD parameters were compared using Mann-Whitney U test and Kruskal-Wallis test. Relations between parameters and walking performance were assessed by Mann-Whitney U test and Spearman's correlation coefficient. RESULTS: Good to perfect agreement was demonstrated for all perfusion parameters of interuser reproducibility, and the interscan reproducibility of MIV, TTP, and Grad was good. The TTP of the patients was longer than that of the controls (87.85 ± 38.85 s vs. 36.54 ± 7.27 s), while the Grad of patients was smaller (0.16 ± 0.12 msec/s vs. 0.24 ± 0.11 msec/s). Among PAD patients, the MIV was significantly lower in the low SPPB subgroup (score 6-8) than in the high SPPB group (score 9-12), and the TTP was negatively correlated with 6-minute walk distance (ρ = -0.549). DATA CONCLUSION: BOLD imaging method had overall good reproducibility for the perfusion assessment of calf muscles. The perfusion parameters were different between PAD patients and controls, and were correlated with lower extremity function. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Infrapopliteal Segments on Lower Extremity CTA: Prospective Intraindividual Comparison of Energy-Integrating Detector CT and Photon-Counting Detector CT.

BACKGROUND. The higher spatial resolution and image contrast for iodine-containing tissues of photon-counting detector (PCD) CT may address challenges in evaluating small calcified vessels when performing lower extremity CTA by energy-integrating detector (EID) CTA. OBJECTIVE. The purpose of the study was to compare the evaluation of infrapopliteal vasculature between lower extremity CTA performed using EID CT and PCD CT. METHODS. This prospective study included 32 patients (mean age, 69.7 ± 11.3 [SD] years; 27 men, five women) who underwent clinically indicated lower extremity EID CTA between April 2021 and March 2022; participants underwent investigational lower extremity PCD CTA later the same day as EID CTA using a reduced IV contrast media dose. Two radiologists independently reviewed examinations in two sessions, each containing a random combination of EID CTA and PCD CTA examinations; the readers assessed the number of visualized fibular perforators, characteristics of stenoses at 11 infrapopliteal segmental levels, and subjective arterial sharpness. RESULTS. Mean IV contrast media dose was 60.0 ± 11.0 (SD) mL for PCD CTA versus 139.6 ± 11.8 mL for EID CTA (p < .001). The number of identified fibular perforators per lower extremity was significantly higher for PCD CTA than for EID CTA for reader 1 (R1) (mean ± SD, 6.4 ± 3.2 vs 4.2 ± 2.4; p < .001) and reader 2 (R2) (8.8 ± 3.4 vs 7.6 ± 3.3; p = .04). Reader confidence for assessing stenosis was significantly higher for PCD CTA than for EID CTA for R1 (mean ± SD, 82.3 ± 20.3 vs 78.0 ± 20.2; p < .001) but not R2 (89.8 ± 16.7 vs 90.6 ± 7.1; p = .24). The number of segments per lower extremity with total occlusion was significantly lower for PCD CTA than for EID CTA for R2 (mean ± SD, 0.5 ± 1.3 vs 0.9 ± 1.7; p = .04) but not R1 (0.6 ± 1.3 vs 1.0 ± 1.5; p = .07). The number of segments per lower extremity with clinically significant nonocclusive stenosis was significantly higher for PCD CTA than for EID CTA for R1 (mean ± SD, 2.2 ± 2.2 vs 1.6 ± 1.7; p = .01) but not R2 (1.1 ± 2.0 vs 1.1 ± 1.4; p = .89). Arterial sharpness was significantly greater for PCD CTA than for EID CTA for R1 (mean ± SD, 3.2 ± 0.5 vs 1.8 ± 0.5; p < .001) and R2 (3.2 ± 0.4 vs 1.7 ± 0.8; p < .001). CONCLUSION. PCD CTA yielded multiple advantages relative to EID CTA for visualizing small infrapopliteal vessels and characterizing associated plaque. CLINICAL IMPACT. The use of PCD CTA may improve vascular evaluation in patients with peripheral arterial disease.

Magnetic resonance imaging scoring system of the lower limbs in adult patients with suspected idiopathic inflammatory myopathy.

PURPOSE: We aim to propose a visual quantitative score for muscle edema in lower limb MRI to contribute to the diagnosis of idiopathic inflammatory myopathy (IIM). MATERIAL AND METHODS: We retrospectively evaluated 85 consecutive patients (mean age 57.4 ± 13.9 years; 56.5% female) with suspected IIM (muscle weakness and/or persistent hyper-CPK-emia with/without myalgia) who underwent MRI of lower limbs using T2-weighted fast recovery-fast spin echo images and fat-sat T2 echo planar images. Muscle inflammation was evaluated bilaterally in 11 muscles of the thigh and eight muscles of the leg. Edema in each muscle was graded according to a four-point Likert-type scale adding up to 114 points ([11 + 8)] × 3 × 2). Diagnostic accuracy of the total edema score was explored by assessing sensitivity and specificity using the area under the ROC curve. Final diagnoses were made by a multidisciplinary Expert Consensus Panel applying the Bohan and Peter diagnostic criteria whenever possible. RESULTS: Of the 85 included patients, 34 (40%) received a final diagnosis of IIM (IIM group) while 51 (60%) received an alternative diagnosis (non-IIM group). A cutoff score ≥ 18 was able to correctly classify patients having an IIM with an area under the curve of 0.85, specificity of 96%, and sensitivity of 52.9%. CONCLUSION: Our study demonstrates that a quantitative MRI score for muscle edema in the lower limbs (thighs and legs) aids in distinguishing IIM from conditions that mimic it.

A comparative analysis of deep learning and hybrid iterative reconstruction algorithms with contrast-enhancement-boost post-processing on the image quality of indirect computed tomography venography of the lower extremities.

PURPOSE: To examine whether there is a significant difference in image quality between the deep learning reconstruction (DLR [AiCE, Advanced Intelligent Clear-IQ Engine]) and hybrid iterative reconstruction (HIR [AIDR 3D, adaptive iterative dose reduction three dimensional]) algorithms on the conventional enhanced and CE-boost (contrast-enhancement-boost) images of indirect computed tomography venography (CTV) of lower extremities. MATERIALS AND METHODS: In this retrospective study, seventy patients who underwent CTV from June 2021 to October 2022 to assess deep vein thrombosis and varicose veins were included. Unenhanced and enhanced images were reconstructed for AIDR 3D and AiCE, AIDR 3D-boost and AiCE-boost images were obtained using subtraction software. Objective and subjective image qualities were assessed, and radiation doses were recorded. RESULTS: The CT values of the inferior vena cava (IVC), femoral vein ( FV), and popliteal vein (PV) in the CE-boost images were approximately 1.3 (1.31-1.36) times higher than in those of the enhanced images. There were no significant differences in mean CT values of IVC, FV, and PV between AIDR 3D and AiCE, AIDR 3D-boost and AiCE-boost images. Noise in AiCE, AiCE-boost images was significantly lower than in AIDR 3D and AIDR 3D-boost images ( P < 0.05). The SNR (signal-to-noise ratio), CNR (contrast-to-noise ratio), and subjective scores of AiCE-boost images were the highest among 4 groups, surpassing AiCE, AIDR 3D, and AIDR 3D-boost images (all P < 0.05). CONCLUSION: In indirect CTV of the lower extremities images, DLR with the CE-boost technique could decrease the image noise and improve the CT values, SNR, CNR, and subjective image scores. AiCE-boost images received the highest subjective image quality score and were more readily accepted by radiologists.

Effect of a graded running race on lower limb muscle damage, jump performance and muscle soreness in men and women.

PURPOSE: Delayed structural and functional recovery after a 20 km graded running race was analyzed with respect to the sex effect. METHODS: Thirteen female and 14 male recreational runners completed the race and three test sessions: one before (PRE) and two after, once on Day 1 or 2 (D1-2) and then on Day 3 or 4 (D3-4). Muscle damage was assessed indirectly using ultrasonography to quantify changes in cross-sectional area (CSA) of 10 lower-limb muscles. Delayed onset of muscle soreness (DOMS) was assessed for three muscle groups. Functional recovery was quantified by kinetic analysis of a squat jump (SJ) and a drop jump (DJ) test performed on a sledge ergometer. Linear mixed models were used to assess control group reproducibility and recovery patterns according to sex. RESULTS: Regardless of sex, DOMS peaked at D1-2 for all muscle groups and resolved at D3-4. CSA was increased in each muscle group until D3-4, especially in the semimembranosus muscle. A specific increase was found in the short head of the biceps femoris in women. Regardless of sex, SJ and DJ performances declined up to D3-4. Depending on the muscle, positive and/or negative correlations were found between structural and functional changes. Some of these were sex-specific. CONCLUSION: Structural and functional recovery was incomplete in both sexes up to D3-4, although DOMS had disappeared. More emphasis should be placed on hamstring muscle recovery. Highlighting the intermuscular compensations that can occur during multi-joint testing tasks, the structural-functional relationships were either positive or negative, muscle- and sex-dependent.

Quantifying lower limb muscle stiffness in typically developing children and adolescents using acoustic radiation force impulse shear wave elastography (ARFI/SWE)-a pilot study.

OBJECTIVE: To investigate and quantify age-related changes in lower limb muscle stiffness in typically developing children and adolescents using acoustic radiation force impulse shear wave elastography. MATERIALS AND METHODS: Shear wave velocities of bilateral rectus femoris, tibialis anterior, and medial gastrocnemius muscles at rest were obtained in typically developing children and adolescents aged 3 to 18 years. The participants were classified into three age groups: Group 1 (children), 3 to 7 years old; Group 2, 8 to 12 (pre-adolescent); and Group 3 (adolescent), 13 to 18. The shear wave velocities of muscle were compared across the three age groups, as well as compared between right- and left-side limbs. The correlation between shear wave velocities and body weight or body mass index was assessed. RESULTS: Of the 47 participants, 21 were in Group 1, 17 in Group 2, and 9 in Group 3. There were no significant differences among the three age groups' shear wave velocities of bilateral lower limb muscles, and no significant differences between right and left sides. There was no correlation between muscle stiffness and body weight or body mass index. CONCLUSION: The present pilot study applied acoustic radiation force impulse shear wave elastography to quantify lower limb muscle stiffness in typically developing children and adolescents aged 3 to 18 years, suggesting no marked change in muscle stiffness occurs as they develop.

Assessment of lower limb alignment: supine weight-bearing CT scanograms compared with a standing full-length radiograph.

PURPOSE: We identified limb misalignment by applying personalized axial force while the limb was in a supine position to mimic a standing posture. This study aimed to confirm the accuracy of evaluating lower limb alignment using supine weight-bearing CT scanograms. METHODS: We prospectively compared measurements of the weight-bearing line ratio (WBL), hip-knee-ankle (HKA) angle, and joint convergence angle (JLCA) in 46 sets of supine weight-bearing CT scanograms with those obtained from full-length standing anteroposterior lower extremity radiographs. We achieved the weight-bearing CT scanograms by applying six different levels of axial force: zero, 1/5 of body weight, 2/5 of body weight, 3/5 of body weight, 4/5 of body weight, and full body weight. We assessed the impact of age, body mass index, HKA, and JLCA on the observed mechanical axis deviation differences between the two methods. RESULT: The average absolute difference between standing radiographs and supine CT scanograms was 4.32% for the WBL ratio (p < 0.05), 1.25° for HKA (p < 0.05), and 0.46 for JLCA (p < 0.05). The mean absolute difference was minimal when applying full body weight axial pressure during CT scanograms (p > 0.05). Age, body mass index, HKA, and JLCA had no effect on the deviation in the mechanical axis measurements obtained through supine weight-bearing CT scanograms with full body weight. CONCLUSION: No significant differences were found in assessing lower limb alignment between standing radiographs and supine weight-bearing CT scanograms with full body weight. Weight-bearing CT scanograms prove to be a valuable method for assessing lower limb alignment while in a supine position.

Fully Automated Analysis of the Anatomic and Mechanical Axes From Pediatric Standing Lower Limb Radiographs Using Convolutional Neural Networks.

BACKGROUND: Lower limb alignment is the quantification of a set of parameters that are commonly measured radiographically to test for and track a wide range of skeletal pathologies. Determining limb alignment is a commonly performed yet laborious task in the pediatric orthopaedic setting and is therefore an interesting goal for automation. METHODS: We employ a machine learning approach using convolutional neural networks (CNNs) to segment pediatric weight-bearing lower limb radiographs. The results are then used with custom Matlab code to extract anatomic landmarks and to determine lower limb alignment parameters. RESULTS: Measurements obtained from the automated workflow proposed here were compared with manual measurements performed by orthopaedic surgery fellows. Mechanical axis deviation was determined within a mean of 2.02 mm. Lateral distal femoral angle and medial proximal tibial angle were determined with a mean deviation of 1.73 and 2.90 degrees, respectively. The calculation speed for the full set of mechanical and anatomic axis parameters was found to be ~2 seconds per radiograph. CONCLUSIONS: The CNN-based approach proposed in this work was shown to produce results comparable to orthopaedic surgery fellows at fast calculation speed. Although further work is needed to validate these results against radiographs and measurements from other centers, we see this as a promising start and a functional path that can be employed in further research. CLINICAL RELEVANCE: CNNs are a promising approach to automating commonly performed, repetitive tasks, especially those pertaining to image processing. The time savings are particularly important in clinical research applications where large sets of radiographs are routinely available and require analysis. With further development of these algorithms, we anticipate significantly improved agreement with expert-measured results and the calculation speed.

Preoperative photoacoustic versus indocyanine green lymphography in lymphaticovenular anastomosis outcomes for lower extremity lymphedema: A pilot study.

BACKGROUND: Identification of the proper lymphatics is important for successful lymphaticovenular anastomosis (LVA) for lymphedema; however, visualization of lymphatic vessels is challenging. Photoacoustic lymphangiography (PAL) can help visualize lymphatics more clearly than other modalities. Therefore, we investigated the usefulness of PAL and determined whether the clear and three-dimensional image of PAL affects LVA outcomes. METHODS: We recruited 22 female patients with lower extremity lymphedema. The operative time, number of incisions, number of anastomoses, lymphatic vessel detection rate (number of functional lymphatics identified during the operation/number of incisions), and limb volume changes preoperatively and 3 months postoperatively were compared retrospectively. The patients were divided according to whether PAL was performed or not, and results were compared between those undergoing PAL (PAL group; n = 10) and those who did not (near-infrared fluorescence [NIRF] group, n = 12). RESULTS: The mean age of the patients was 55.9 ± 15.1 years in the PAL group and 50.7 ± 14.9 years in the NIRF group. One patient in the PAL group and three in the NIRF group had primary lymphedema. Eighteen patients (PAL group, nine; and NIRF group, nine) had secondary lymphedema. Based on preoperative evaluation using the International Society of Lymphology (ISL) classification, eight patients were determined to be in stage 2 and two patients in late stage 2 in the PAL group. In contrast, in the NIRF group, one patient was determined to be in stage 0, three patients each in stage 1 and stage 2, and five patients in late stage 2. Lymphatic vessel detection rates were 93% (42 LVAs and 45 incisions) and 83% (50 LVAs and 60 incisions) in the groups with and without PAL, respectively (p = 0.42). Limb volume change was evaluated in five limbs of four patients and in seven limbs of five patients in the PAL and NIRF groups as 336.6 ± 203.6 mL (5.90% ± 3.27%) and 52.9 ± 260.7 mL (0.71% ± 4.27%), respectively. The PAL group showed a significant volume reduction. (p = .038). CONCLUSIONS: Detection of functional lymphatic vessels on PAL is useful for treating LVA.

Accuracy, Repeatability, and Reproducibility of a Hand-Held Structured-Light 3D Scanner across Multi-Site Settings in Lower Limb Prosthetics.

The aim of this work was to assess the accuracy, repeatability, and reproducibility of a hand-held, structured-light 3D scanner (EINScan Pro 2X Plus with High Definition Prime Pack, SHINING 3D Tech. Co., Ltd., Hangzhou, China), to support its potential use in multi-site settings on lower limb prosthetics. Four limb models with different shapes were fabricated and scanned with a metrological 3D scanner (EINScan Laser FreeScan 5X, SHINING 3D Tech. Co., Ltd., Hangzhou, China) by a professional operator (OP0). Limb models were then mailed to three sites where two operators (OP1, OP2) scanned them using their own structured-light 3D scanner (same model). OP1 scanned limb models twice (OP1-A, OP1-B). OP0, OP1-A, and OP2 scans were compared for accuracy, OP1-A and OP1-B for repeatability, and OP1-A and OP2 for reproducibility. Among all comparisons, the mean radial error was <0.25 mm, mean angular error was <4°, and root mean square error of the radial distance was <1 mm. Moreover, limits of agreement were <3.5% for perimeters and volumes. By comparing these results with respect to clinically-relevant thresholds and to the literature available on other 3D scanners, we conclude that the EINScan Pro 2X Plus 3D Scanner with High Definition Prime Pack has good accuracy, repeatability, and reproducibility, supporting its use in multi-site settings.

Targeting Lower Limb, Upper Limb, and Face Representation in the Primary Motor Cortex for the Practice of Neuronavigated Transcranial Magnetic Stimulation.

OBJECTIVE: The primary motor cortex (M1) is a usual target for therapeutic application of repetitive transcranial magnetic stimulation (rTMS), especially the region of hand motor representation. However, other M1 regions can be considered as potential rTMS targets, such as the region of lower limb or face representation. In this study, we assessed the localization of all these regions on magnetic resonance imaging (MRI) with the aim of defining three standardized M1 targets for the practice of neuronavigated rTMS. MATERIALS AND METHODS: A pointing task of these targets was performed by three rTMS experts on 44 healthy brain MRI data to assess interrater reliability (including the calculation of intraclass correlation coefficients [ICCs] and coefficients of variation [CoVs] and the construction of Bland-Altman plots). In addition, two "standard" brain MRI data were randomly interspersed with the other MRI data to assess intrarater reliability. A barycenter was calculated for each target (with x-y-z coordinates provided in normalized brain coordinate systems), in addition to the geodesic distance between the scalp projection of the barycenters of these different targets. RESULTS: Intrarater and interrater agreement was good, according to ICCs, CoVs, or Bland-Altman plots, although interrater variability was greater for anteroposterior (y) and craniocaudal (z) coordinates, especially for the face target. The scalp projection of the barycenters between the different cortical targets ranged from 32.4 to 35.5 mm for either the lower-limb-to-upper-limb target distance or the upper-limb-to-face target distance. CONCLUSIONS: This work clearly delineates three different targets for the application of motor cortex rTMS that correspond to lower limb, upper limb, and face motor representations. These three targets are sufficiently spaced to consider that their stimulation can act on distinct neural networks.

The influence of the weight-bearing state on three-dimensional (3D) planning in lower extremity realignment - analysis of novel vs. state-of-the-art planning approaches.

BACKGROUND: The use of 3D planning to guide corrective osteotomies of the lower extremity is increasing in clinical practice. The use of computer-tomography (CT) data acquired in supine position neglects the weight-bearing (WB) state and the gold standard in 3D planning involves the manual adaption of the surgical plan after considering the WB state in long-leg radiographs (LLR). However, this process is subjective and dependent on the surgeons experience. A more standardized and automated method could reduce variability and decrease costs. PURPOSE: The aim of the study was (1) to compare three different three-dimensional (3D) planning modalities for medial open-wedge high tibial osteotomy (MOWHTO) and (2) to describe the current practice of adapting NWB CT data after considering the WB state in LLR. The purpose of this study is to validate a new, standardized approach to include the WB state into the 3D planning and to compare this method against the current gold standard of 3D planning. Our hypothesis is that the correction is comparable to the gold standard, but shows less variability due compared to the more subjective hybrid approach. METHODS: Three surgical planning modalities were retrospectively analyzed in 43 legs scheduled for MOWHTO between 2015 and 2019. The planning modalities included: (1) 3D hybrid (3D non-weight-bearing (NWB) CT models after manual adaption of the opening angle considering the WB state in LLR, (2) 3D NWB (3D NWB CT models) and (3) 3D WB (2D/3D registration of 3D NWB CT models onto LLR to simulate the WB state). The pre- and postoperative hip-knee-ankle angle (HKA) and the planned opening angle (°) were assessed and differences among modalities reported. The relationship between the reported differences and BMI, preoperative HKA (LLR), medial meniscus extrusion, Outerbridge osteoarthritis grade and joint line convergence angle (JLCA) was analyzed. RESULTS: The mean (std) planned opening angle of 3D hybrid did not differ between 3D hybrid and 3D WB (0.4 ± 2.1°) (n.s.) but was higher in 3D hybrid compared to 3D NWB (1.1° ± 1.1°) (p = 0.039). 3D WB demonstrated increased preoperative varus deformity compared to 3D NWB: 6.7 ± 3.8° vs. 5.6 ± 2.7° (p = 0.029). Patients with an increased varus deformity in 3D WB compared to 3D NWB (> 2 °) demonstrated more extensive varus alignment in LLR (p = 0.009) and a higher JLCA (p = 0.013). CONCLUSION: Small intermodal differences between the current practice of the reported 3D hybrid planning modality and a 3D WB approach using a 2D/3D registration algorithm were reported. In contrast, neglecting the WB state underestimates preoperative varus deformity and results in a smaller planned opening angle. This leads to potential under correction in MOWHTO, especially in patients with extensive varus deformities or JLCA. CLINICAL RELEVANCE: Incorporating the WB state in 3D planning modalities has the potential to increase accuracy and lead to a more consistent and reliable planning in MOWHTO. The inclusion of the WB state in automatized surgical planning algorithms has the potential to reduce costs and time in the future.

[Ultrasound of nerves of the lower extremities]. / Nervensonographie der unteren Extremitäten.

The ability to visualize the nerves of the lower extremities differs from that of the upper extremities in sonography because the soft tissue cover is significantly larger in some cases. Landmarks are also defined for the lower extremities, which enable precise visualization of the nerves. Nerves and muscles are to be understood as a functional unit. In addition to the clarification of nerve compression syndromes, polyneuropathies and nerve tumors, sonography is also used to visualize muscle atrophy.

Quantitative Volumetric Measurements of Bone Grafting Sites Within the Lower Extremity on Computed Tomography Scans.

The anterior iliac crest is one of the most used options; however, pain and other complications have been reported. Other options for bone harvest in the lower extremity, such as the proximal tibia and calcaneus, can be useful sites for bone grafting. Computed tomography angiography images of the lower extremity were analyzed using 3-D Slicer™ medical imaging software, creating an advanced 3-dimensional model. Bone volume (cm3) and bone mineral density (Hounsfield units) were measured from the cancellous bone in the anterior iliac crest, posterior iliac crest, proximal tibia, and the calcaneus. Fifteen studies were included. The total volume measured it was of 61.88 ± 14.15 cm3, 19.35 ± 4.16 cm3, 32.48 ± 7.49 cm3, 26.40 ± 7.18 cm3, for the proximal tibia, anterior and posterior iliac crest, and calcaneus, respectively. Regarding Hounsfield units, the densities were 116 ± 58.77, 232.4 ± 68.65, 214.4 ± 74.45, 170.5 ± 52.32, for proximal tibia, anterior and posterior iliac crest, and calcaneus. The intraclass correlation coefficients were in average >0.94. In conclusion, the proximal tibia has more cancellous bone than the anterior and posterior iliac crest. The calcaneus has more cancellous bone than the anterior iliac crest. Bone mineral density was highest in the anterior iliac crest and in proximal tibia was the lowest value.

Arterial involvement of lower limbs in peripheral artery disease - the difference between diabetics and non-diabetics.

OBJECTIVE: To detect peripheral artery disease in diabetic and non-diabetic individuals. METHODS: The case-control study was conducted from October 2018 to September 2019 at Ruth K.M. Pfau Civil Hospital, Karachi, and comprised diagnosed diabetic patients with random blood sugar ≥200mg/dl in group A, and healthy non-diabetic subjects in group B. Ankle brachial pressure index was measured and mean luminal diameters of lower limb arteries were compared using colour Doppler ultrasonography. Data was analysed using SPSS 21. RESULTS: Of the 82 subjects, 41(50%) were in each of the 2 groups. The sample had 42(51.2%) males and 30(48.8%) females with overall mean age of 53.9±5.07 years (range 44-60 years). There was significant difference in the ankle brachial pressure index values between the groups (p=0.004). There was also a significant difference in the mean luminal diameters of distal arteries (p=0.001), while there was no significant difference in proximal arteries (p>0.05). CONCLUSIONS: The diabetics were more prone to developing peripheral arterial disease than nondiabetics.

Tensor fasciae suralis - Prevalence study and literature review.

Tensor fasciae suralis (TFS) is an accessory muscle of the posterior lower extremity. Although TFS has been documented in cadaveric and radiological reports, its prevalence remains unknown. The TFS variant is noteworthy to anatomists, as it may be encountered in the dissection laboratory, and clinicians, as the muscle could potentially cause confusion during physical examination or diagnostic imaging. Multiple variations of TFS have been reported in the literature, suggesting the need for a classification system. We dissected 236 formalin-fixed cadaveric lower limbs to determine the prevalence of TFS. The PubMed and MEDLINE databases were searched to compare the anatomical features of independent TFS case reports. In our prevalence study, the TFS muscle was identified in three lower limbs (1.3%). In total, 38 cases of TFS (32 cadaveric and six radiological) were identified in the literature. Our literature review revealed that the accessory muscle most often arises as a single head from the long head of the biceps femoris, yet many other presentations have been documented. The need for a classification system to distinguish between the subtypes of TFS became apparent during the literature review. Tensor fasciae suralis is a rare muscle, present in only 3 of 236 (1.3%) cadaveric lower limbs dissected in this study. We propose the use of a classification system, based on muscle origin and number of heads, to better organize the subtypes of TFS.

[CT-Like MRI and Calcium-Suppressed Spectral CT Imaging of Multifocal Bone Infarcts in Both Lower Extremities:Report of One Case].

Bone infarction has a low incidence in clinical practice and mostly occurs in the metaphysis and diaphysis.Few studies report the advanced imaging technique for bone infarction.Here we reported the fast field echo resembling a CT using restricted echo-spacing and calcium-suppressed spectral CT imaging for a case of multifocal bone infarcts in both lower extremities,aiming to provide diagnostic experience for clinical practice.

Reliability of 3D freehand ultrasound to assess lower limb muscles in children with spastic cerebral palsy and typical development.

This study investigated the reliability of 3-dimensional freehand ultrasound (3DfUS) to quantify the size (muscle volume [MV] and anatomical cross-sectional area [aCSA]), length (muscle length [ML], tendon length [TL], and muscle tendon unit length [MTUL]), and echo-intensity (EI, whole muscle and 50% aCSA), of lower limb muscles in children with spastic cerebral palsy (SCP) and typical development (TD). In total, 13 children with SCP (median age 14.3 (7.3) years) and 13 TD children (median age 11.1 (1.7) years) participated. 3DfUS scans of rectus femoris, semitendinosus, medial gastrocnemius, and tibialis anterior were performed by two raters in two sessions. The intra- and inter-rater and intra- and inter-session reliability were defined with relative and absolute reliability measures, that is, intra-class correlation coefficients (ICCs) and absolute and relative standard error of measurement (SEM and SEM%), respectively. Over all conditions, ICCs for muscle size measures ranged from 0.818 to 0.999 with SEM%s of 12.6%-1.6%. For EI measures, ICCs varied from 0.233 to 0.967 with SEM%s of 15.6%-1.7%. Length measure ICCs ranged from 0.642 to 0.999 with SEM%s of 16.0%-0.5%. In general, reliability did not differ between the TD and SCP cohort but the influence of different muscles, raters, and sessions was not constant for all 3DfUS parameters. Muscle length and muscle tendon unit length were the most reliable length parameters in all conditions. MV and aCSA showed comparable SEM%s over all muscles, where tibialis anterior MV was most reliable. EI had low-relative reliability, but absolute reliability was better, with better reliability for the distal muscles in comparison to the proximal muscles. Combining these results with earlier studies describing muscle morphology assessed in children with SCP, 3DfUS seems sufficiently reliable to determine differences between cohorts and functional levels. The applicability on an individual level, for longitudinal follow-up and after interventions is dependent on the investigated muscle and parameter. Moreover, the semitendinosus, the acquisition, and processing of multiple sweeps, and the definition of EI and TL require further investigation. In general, it is recommended, especially for longitudinal follow-up studies, to keep the rater the same, while standardizing acquisition settings and positioning of the subject.

Sensorimotor network dynamics predict decline in upper and lower limb function in people with multiple sclerosis.

BACKGROUND: Upper and lower limb disabilities are hypothesized to have partially independent underlying (network) disturbances in multiple sclerosis (MS). OBJECTIVE: This study investigated functional network predictors and longitudinal network changes related to upper and lower limb progression in MS. METHODS: Two-hundred fourteen MS patients and 58 controls underwent functional magnetic resonance imaging (fMRI), dexterity (9-Hole Peg Test) and mobility (Timed 25-Foot Walk) measurements (baseline and 5 years). Patients were stratified into progressors (>20% decline) or non-progressors. Functional network efficiency was calculated using static (over entire scan) and dynamic (fluctuations during scan) approaches. Baseline measurements were used to predict progression; significant predictors were explored over time. RESULTS: In both limbs, progression was related to supplementary motor area and caudate efficiency (dynamic and static, respectively). Upper limb progression showed additional specific predictors; cortical grey matter volume, putamen static efficiency and posterior associative sensory (PAS) cortex, putamen, primary somatosensory cortex and thalamus dynamic efficiency. Additional lower limb predictors included motor network grey matter volume, caudate (dynamic) and PAS (static). Only the caudate showed a decline in efficiency over time in one group (non-progressors). CONCLUSION: Disability progression can be predicted using sensorimotor network measures. Upper and lower limb progression showed unique predictors, possibly indicating different network disturbances underlying these types of progression in MS.