Limb Fluid Research Articles

Association between Bioimpedance Spectroscopy and Magnetic Resonance Lymphangiography in the Diagnosis and Assessment of Lymphedema.

This study assesses associations between bioimpedance spectroscopy (BIS) and magnetic resonance lymphangiography (MRL) in the staging and assessment of lymphedema. Adults who received MRL and BIS between 2020 and 2022 were included. We collected fluid, fat, and lymphedema severity ratings, and measured fluid stripe thickness, subcutaneous fat width, and lymphatic diameter on MRL. BIS lymphedema index (L-Dex) scores were collected from patient charts. We assessed sensitivity and specificity of L-Dex scores to detect MRL-identified lymphedema, and examined associations between L-Dex scores and MRL imaging measures. Forty-eight limbs across 40 patients were included. L-Dex scores had 72.5% sensitivity and 87.5% specificity for detecting MRL-defined lymphedema, with a 96.7% estimated positive predictive value and 38.9% negative predictive value. L-Dex scores were associated with MRL fluid and fat content scores (p ≤ 0.05), and lymphedema severity (p = 0.01), with better discrimination between fluid than fat content levels on pairwise analysis, and poor discrimination between adjacent severity levels. L-Dex scores were correlated with distal and proximal limb fluid stripe thickness (distal: rho = 0.57, p < 0.01; proximal: rho = 0.58, p < 0.01), partially correlated with distal subcutaneous fat thickness when accounting for body mass index (rho = 0.34, p = 0.02), and were not correlated with lymphatic diameter (p = 0.25). L-Dex scores have high sensitivity, specificity, and positive predictive value for the identification of MRL-detected lymphedema. L-Dex has difficulty distinguishing between adjacent severity levels of lymphedema and a high false negative rate, explained in part by reduced discrimination between levels of fat accumulation.

Short partial doffs of release/relock sockets may effectively stabilize limb fluid volume in prosthesis users with transtibial amputation

BackgroundA challenge often faced by people with lower extremity amputation is management of prosthetic socket fit due to changes in fluid volume within their residual limb. Prior research suggests that intermittently doffing the prosthetic socket may help stabilize daily residual limb fluid volume. MethodsTo assess the effects of partial doff duration on residual limb fluid volume retention, participants with transtibial amputation were tested by walking on a treadmill in a controlled, laboratory setting under three conditions. An automated system to release the locking pin and enlarge the socket was used to produce the partial doffing. Percent limb fluid volume changes after partial doffing for 4 min (Short Rest) and for 10 min (Long Rest) were compared with no partial doffing (No Release). Limb fluid volume was monitored using bioimpedance analysis. FindingsMean percent fluid volume changes in the posterior region were ‐1.2% for No Release, 2.7% for Short Rest, and 1.0% for Long Rest. Short and Long Rests had larger increases than No Release (P = 0.005 and 0.03, respectively); Short and Long Rests were not statistically different (P = 0.10). Eight of the thirteen participants experienced a higher percent fluid volume gain for both release protocols while four experienced a higher percent fluid volume gain for only one release protocol. InterpretationA partial doff duration as short as 4 min may be an effective strategy to stabilize limb fluid volume in prosthesis users with transtibial amputation. Trials in at-home settings should be pursued.

Using magnetic panels to enlarge a transtibial prosthetic socket

A novel method is described to connect a prosthetic liner to the panels of an adjustable socket to facilitate limb fluid volume stabilization in prosthesis users. Magnets are placed in the socket panels, and iron powder is embedded in the user's prosthetic liner. When the magnet is in close proximity to the liner, a firm connection is formed. The system's capability to execute panel pull on transtibial prosthesis users was tested. The backs of the panels were supported by a bracket mounted to the external surface of the socket that allowed the radial position of the panels to be adjusted. Bench testing demonstrated an optimized strength-to-weight ratio using 1.27-cm thick annular-shaped magnets supported by 0.32-cm thick backplates. Testing on four people with transtibial amputation showed that the maximum socket increase achieved using magnetic panel pull ranged from 5.3% to 13.8% of the initial (panels flush) socket volume. The results indicate that magnetic panel pull induces a meaningful increase in socket volume during sitting. The clinical relevance is a novel strategy that may help stabilize prosthesis users' limb fluid volume over the day.

Cyclic socket enlargement and reduction during walking to minimize limb fluid volume loss in transtibial prosthesis users

The purpose of this research was to pursue an innovative cyclic panel-pull strategy during ambulation to minimize limb fluid volume loss in transtibial prosthesis users. Participants’ traditional socket shapes were duplicated, and test sockets prepared with three adjustable motor-driven panels that were controlled by a microprocessor. After donning the prosthesis, participants’ liners were fastened to the panels. During a 40 min test session, participants conducted three cycles of sitting (5 min) and walking (8 min). During the 5th and 6th min of each cycle of walking, the panels were cyclically pulled outward in late stance phase, decreasing pressure on the residual limb. Panels were returned to their original position in swing phase. Eight of twelve participants gained more fluid volume while walking when panel-pull was added than when it was removed. When the liner was uncoupled from the panels and panel-pull was executed, eight of twelve participants gained less fluid volume compared to when the liner was fastened to the panels. Panel-pull may facilitate limb fluid volume retention in transtibial prosthesis users. Efforts to simplify the design so that it can be implemented in long-term testing during at-home use should be considered.

Performance of an auto-adjusting prosthetic socket during walking with intermittent socket release.

IntroductionA challenge in the engineering of auto-adjusting prosthetic sockets is to maintain stable operation of the control system while users change their bodily position and activity. The purpose of this study was to test the stability of a socket that automatically adjusted socket size to maintain fit. Socket release during sitting was conducted between bouts of walking.MethodsAdjustable sockets with sensors that monitored distance between the liner and socket were fabricated. Motor-driven panels and a microprocessor-based control system adjusted socket size during walking to maintain a target sensed distance. Limb fluid volume was recorded continuously. During eight sit/walk cycles, the socket panels were released upon sitting and then returned to position for walking, either the size at the end of the prior bout or a size 1.0% larger in volume.ResultsIn six transtibial prosthesis users, the control system maintained stable operation and did not saturate (move to and remain at the end of the actuator’s range) during 98% of the walking bouts. Limb fluid volume changes generally matched the panel position changes executed by the control system.ConclusionsStable operation of the control system suggests that the auto-adjusting socket is ready for testing in users’ at-home settings.

Mechanically and physiologically optimizing prosthetic elevated vacuum systems in people with transtibial amputation: a pilot study.

The most suitable elevated vacuum (EV) pressure may differ for each individual prosthesis user depending on suspension needs, socket fit, prosthetic components, and health. Mechanical and physiological effects of EV were evaluated in an effort to determine the optimal vacuum pressure for three individuals. Instrumented EV sockets were created based on the participants' regular EV sockets. Inductive distance sensors were embedded into the wall of the socket at select locations to measure limb movement relative to the socket. Each participant conducted an activity protocol while limb movement, limb fluid volume, and user-reported comfort were measured at various socket vacuum pressure settings. Increased socket vacuum pressure resulted in reduced limb-socket displacement for each participant; however, 81-93% of limb movement was eliminated by a vacuum pressure setting of 12 (approximately -9 inHg). Relative limb-socket displacement by sensor location varied for each participant, suggesting distinct differences related to socket fit or residual limb tissue content. The rate of limb fluid volume change and the change in socket comfort did not consistently differ with socket vacuum pressure, suggesting a more complex relationship unique to each individual. Practitioners may use individual responses to optimize socket vacuum pressure settings, balancing mechanical and physiological effects of EV for improved clinical outcomes.

Effect of compression stockings on overnight rostral fluid shift and obstructive sleep apnea: A meta-analysis

ObjectiveThe overnight rostral fluid shift from the lower limbs is one of the causes of obstructive sleep apnea (OSA). Compression stockings (CS) prevent lower limb fluid retention and have been reported to decrease nighttime fluid shift. The aim of this study is to evaluate the effect of CS on fluid shift and the severity of OSA. MethodsA systematic literature search was performed in the PubMed, EMBASE and Cochrane Library databases. The data were analyzed using Comprehensive Meta-Analysis software (Version 3; Biostat, Englewood, NJ). Studies evaluating the effect of CS on the overnight fluid shift and OSA severity were included in the analysis. ResultsA total of 4 studies were included in this meta-analysis. The pooled analysis showed that the apnea-hypopnea index (AHI) of the overall study group was significantly lower after using CS (SMD, -1.08; 95% CI, -1.49 to -0.67). Decreases in the AHI were also observed in the normal fluid status (SMD, -1.05; 95% CI, -1.73 to -0.37) and fluid overload status (SMD, -1.17; 95% CI, -1.76 to -0.58) populations. The overall study group had significant decreases in overnight changes in neck circumference (SMD, -1.05; 95% CI, -2.06 to -0.03) and leg fluid volume (SMD, -1.14; 95% CI, -1.88 to -0.41) after using CS. However, no significant differences in overnight changes in neck circumference and leg fluid volume were observed in normal fluid status patients. ConclusionCS may help decrease overnight fluid shift and could be a treatment option for OSA.

Does actively enlarging socket volume during resting facilitate residual limb fluid volume recovery in trans-tibial prosthesis users?

BackgroundResidual limb volume loss is a source of prosthetic socket fit problems in people with lower-limb amputation. The aim of this study was to investigate a novel volume recovery strategy for people with trans-tibial amputation. MethodsTest sockets for people with trans-tibial amputation were created that allowed panels of an adjustable socket and the underlying elastomeric liner to be pulled radially outward, using small motors mounted to the socket. One Control and one Intervention session were conducted with each participant. During Intervention sessions, panel-pull was executed during the sits of a multi-cycle sit/walk protocol. No panel-pull was executed during the Control sessions. Residual limb fluid volume was monitored in anterior and posterior regions using bioimpedance analysis. FindingsResults from 12 participants demonstrated that short-term (12 min after the intervention was applied) median posterior residual limb fluid volume change for Intervention (0.44%) was higher than that for Control (−0.02%) (P = .015). Long-term (40 min after the intervention was applied) median posterior residual limb fluid volume change for Intervention (0.95%) was higher than that for Control (−0.26%) (P = .002). InterpretationIf a panel-pull mechanism that was easy to assemble and operate could be created, then panel-pull may be an effective accommodation strategy to reduce daily limb volume loss in trans-tibial prosthesis users.

Fluid Volume Management in Prosthesis Users: Augmenting Panel Release with Pin Release.

Management of fluid in the limbs is a challenge faced by people with disabilities. In prosthetics, a means for transtibial prosthesis users to stabilize their residual limb fluid volume during the day may improve socket fit. To determine if releasing the panels and locking pin of a cabled-panel adjustable socket during socket release significantly improved limb fluid volume recovery and retention over releasing the panels alone. Repeated-measures experiment to assess the effects on limb fluid volume retention. Participants were tested in a laboratory setting while walking on a treadmill. Release of a locking pin tether during sitting as a limb volume accommodation strategy. Percent limb fluid volume retention for panel and pin release compared with panel release alone at 2 minutes (short term) and 50 minutes (long term) after subsequent activity. Limb fluid volume was monitored using bioimpedance analysis. Median percent limb fluid volume retention for the panel and pin release was significantly greater than panel release alone for both anterior and posterior regions for the long term (P = .0499 and .0096, respectively) but not the short term (P = .0712 and .1580, respectively). Augmenting panel release with pin release may be an effective accommodation strategy for prosthesis users with transtibial amputation to better retain limb fluid volume.

Effectiveness of elevated vacuum and suction prosthetic suspension systems in managing daily residual limb fluid volume change in people with transtibial amputation

Previous studies investigating limb volume change with elevated vacuum have shown inconsistent results and have been limited by out-of-socket volume measurements and short, single-activity protocols. To evaluate the effectiveness of elevated vacuum for managing limb fluid volume compared to suction suspension with an in-socket measurement modality during many hours of activity. Fixed-order crossover design with a standardized out-of-laboratory activity protocol. Transtibial electronic elevated vacuum users participated in two sessions. Elevated vacuum was used during the first session, and suction suspension in the second. Participants completed a 5.5-h protocol consisting of multiple intervals of activity. In-socket residual limb fluid volume was continuously measured using a custom portable bioimpedance analyzer. A total of 12 individuals participated. Overall rate of fluid volume change was not significantly different, though the rate of posterior fluid volume change during Cycle 3 was significantly lower with elevated vacuum. Although individual results varied, 11 participants experienced lower overall rates of fluid volume loss in at least one limb region using elevated vacuum. Elevated vacuum may be more effective as a volume management strategy after accumulation of activity. Individual variation suggests the potential to optimize the limb fluid volume benefits of elevated vacuum by reducing socket vacuum pressure for some users. A better understanding of how elevated vacuum (EV) affects residual limb fluid volume will allow prosthetists to make more informed clinical decisions regarding accommodation strategies designed to improve daily socket fit.

Multi-segment bioimpedance can assess patients with bilateral lymphedema

Bioimpedance spectroscopy (BIS) is used to assess lymphedema by measuring limb fluid content as an electric current passes through cell membranes and tissues. There are two primary device modalities, through which BIS is used clinically: single-segment bioimpedance (SSB) and multi-segment bioimpedance (MSB), which differ in their mechanisms of gathering measurements. In this cross-sectional study, we study the difference between SSB and MSB in evaluating lymphedema by referencing the results with indocyanine Green (ICG) lymphography. Patients with unilateral and bilateral lymphedema, presented to our department, were assessed with both SSB and MSB as part of a pre-lymphatic surgery evaluation between May 1, 2017, and November 31, 2017. Patients were imaged with ICG lymphography to confirm lymphedema presence. Standardized device measurement outputs from SSB and MSB were recorded and statistically analyzed. SSB was more sensitive (0.9) than MSB (0.75) for unilateral lymphedema. However, MSB had the added ability to assess patients with bilateral lymphedema with a sensitivity of 0.56 and specificity of 0.60. Furthermore, MSB had a stronger correlation with relative disease severity compared to SSB and quantified the differential extents of edema. In comparison, SSB provided a manipulated number, which was derived from a comparison of the abnormal to the normal limb. Medical staff reported MSB being easier to perform, and all patients reported the MSB measurement experience being more favorable. While both SSB and MSB provide diagnostic information on lymphedema, MSB is notably easier to perform, can detect bilateral disease states, and objectively quantifies limb fluid volume, allowing for disease tracking and assessment of surgical and rehabilitative treatment efficacy. On the basis of this study, our department has switched to universal MSB measurement.

How do transtibial residual limbs adjust to intermittent incremental socket volume changes?

Strategies to maintain prosthesis users' daily limb volume are needed. Test how intermittent incremental socket volume adjustments affect limb fluid volume and limb-socket distance. Repeated measures. People with transtibial limb loss walked on an outdoor trail wearing a motor-driven adjustable socket that they adjusted a small amount, approximately 0.3% socket volume, every 2 min using a mobile phone app. Limb fluid volume and sensed distance between the socket and a target in their elastomeric liner were monitored. A gradual socket enlargement phase was followed by a gradual socket reduction phase. An incremental socket enlargement significantly increased limb fluid volume (p < 0.001) but not sensed distance (p = 0.063). An incremental socket reduction significantly decreased both limb fluid volume (p < 0.001) and sensed distance (p < 0.001). Participants' residual limb fluid volume increases during ambulation compensated for incremental socket volume increases. For incremental socket volume decreases, residual limb fluid volume decreases did not compensate and the socket fit became tighter. Results support the hypothesis that for people without co-morbidities, intermittent incremental socket volume enlargements are an effective accommodation strategy to increase limb fluid volume while maintaining socket fit. Intermittent incremental socket volume reductions decreased limb fluid volume but also made the socket fit tighter.

A portable bioimpedance instrument for monitoring residual limb fluid volume in people with transtibial limb loss: A technical note

People with transtibial limb loss experience daily changes in volume of their residual limb that affect the fit of their prosthetic socket. A portable instrument was developed to monitor fluid volume changes outside of the laboratory setting. The bioimpedance system applied 26 current bursts per second at frequencies between 3 kHz and 1 MHz, and sensed voltage at up to six channels. Among six voltage-controlled current source circuits and five receive-channel amplifier topologies considered, a differential Howland current pump and a single receive-channel instrumentation amplifier proved the best combination of low noise and low power consumption. Mean RMS errors were 0.07% for extracellular fluid resistance, 2.23% for intracellular fluid resistance, and 1.15% for membrane capacitance.

Socket size adjustments in people with transtibial amputation: Effects on residual limb fluid volume and limb-socket distance

BackgroundSmall intermittent adjustments of socket size using adjustable sockets may be a means for people with transtibial amputation to better maintain residual limb fluid volume and limb position while using a prosthesis. MethodsSocket size, limb fluid volume, and distance from the limb to the socket, termed “sensed distance,” were recorded while participants with transtibial amputation walked on a treadmill wearing a motor-driven, cabled-panel, adjustable socket. Researchers made frequent socket size adjustments using a mobile phone app to identify participants' acceptable socket size range. Limb fluid volume and sensed distance were then monitored as incremental adjustments were made to the socket. FindingsProsthesis users in this study (n = 10) accepted socket sizes between −5% and +5% of their neutral socket volume. There was a rapid increase in limb fluid volume and sensed distance upon socket enlargement, and a rapid decrease upon reduction. Subsequently, there were gradual changes in fluid volume and sensed distance. While visually monitoring limb fluid volume data in real time, researchers were able to adjust socket size to maintain consistent limb fluid volume within a −0.7% to +0.9% volume change for 24 min. InterpretationParticipant residual limbs compensated to socket size adjustment. Using socket-mounted sensors to monitor limb-socket mechanics, an automatic adjustable socket that maintains limb fluid volume may be possible and may improve socket fit in instances where fit deteriorates during use.

Adjustable sockets may improve residual limb fluid volume retention in transtibial prosthesis users.

Loss of residual limb volume degrades socket fit and may require accommodation. To examine if either of two accommodation strategies executed during resting, socket release with full socket size return and socket release with partial socket size return, enhanced limb fluid volume retention during subsequent activity. Two repeated-measures experiments were conducted to assess the effects of socket release on limb fluid volume retention. Limb fluid volume was monitored while participants wore a socket with a single adjustable panel. Participants performed eight activity cycles that each included 10 min of sitting and 2 min of walking. The socket's posterior panel and pin lock were released during the fifth cycle while participants were sitting. In one experiment (Full Return), the socket was returned to its pre-release size; in a second experiment (Partial Return), it was returned to 102% of its pre-release size. Short-term and long-term limb fluid volume retention were calculated and compared to a projected, No Intervention condition. Partial Return and Full Return short-term retentions and Partial Return long-term retention were greater than those projected under the control condition ( p < 0.05). Socket release during resting after activity, particularly when the socket is returned to a slightly larger size, may be an effective accommodation strategy to reduce fluid volume loss in transtibial prosthesis users. This study suggests that existing prosthetic technologies' adjustable sockets and locking pin tethers can be used in novel ways to help maintain residual limb fluid volume in active prosthesis users.

How Do Socket Size Adjustments during Ambulation Affect Residual Limb Fluid Volume? Case Study Results

ABSTRACT Introduction Adjustable prosthetic sockets may be useful in management of limb volume in individuals with amputation. Incrementally increasing socket size during ambulation may increase residual limb fluid volume, deterring daily volume loss without sacrificing gait stability. Materials and Methods Participants with transtibial limb loss wore motor-controlled cabled-panel adjustable sockets while residual limb fluid volume was monitored using bioimpedance analysis. Participants walked on a treadmill with a safety harness while socket size was adjusted to establish users' ranges of acceptable sizes and optimal size. Then single controlled size adjustments were made. In longer duration testing outside the laboratory, participants used a portable system controlled by a mobile phone app to incrementally increase or decrease their socket size. Results For the two participants tested, comfortable socket sizes spanned as low as a 1.6% range of socket volume to as high as a 6.1% range. Limb fluid volume changed in proportion to socket size when adjustments were near users' optimal socket size setting. Conclusions Adjustable sockets are a viable means to manipulate limb fluid volume during ambulation. Incremental changes in socket size, approximately 0.33% socket volume, were sufficient to induce detectable changes in socket fit.

Calf Muscle Pump Stimulation Increases Lower Limb Bone Density in Perimenopausal Women

Nutrient delivery to bone tissue, as for all tissues in the body, is provided through interstitial fluid flow. This flow is driven by the differential fluid pressures between the intramedullary canal and the tissues outside of the bone. Correspondingly, reductions in tissue fluid pressure should enhance interstitial bone fluid flow, nutrient delivery, and thereby increase bone mineral density. This hypothesis was tested in a one year long pilot clinical study of healthy, employed, perimenopausal women (42 - 68 years). Soleus muscle (calf muscle pump) stimulation was utilized with the intent of increasing lower limb fluid return to the heart, serving to both reduce lower limb tissue pressures and to increase intramedullary pressures by increasing cardiac output. Dual-energy x-ray absorptiometry (DXA) assessments of bone mineral density (BMD) were obtained at 12 month intervals. Muscle stimulation usage ranged from 0.7 to 4.8 hours/work-day. Dose dependent responses between duration of daily soleus muscle stimulation and changes in both proximal femur BMD (+0.5% per hour of daily use; p = 0.05) and proximal tibia BMD (+1.5% per hour of daily use; p = 0.0004), were observed; no significant effect was observed at the lumbar spine. These results are consistent with the hypothesis that calf muscle pump stimulation, which is sufficient to reduce lower limb fluid pooling, is capable of significantly reducing the rate of bone loss in perimenopausal women as well as enhancing new bone formation.

Effects of activity intensity, time, and intermittent doffing on daily limb fluid volume change in people with transtibial amputation.

The volume of a prosthesis user's residual limb changes during the day and may affect the fit of the prosthesis. These changes must be managed by the user to prevent discomfort, skin breakdown, and falls. The objectives were to test how activity, time of day, and intermittent doffing affected residual limb fluid volume in people with transtibial amputation. Standardized, repeated measure (A-B-A) out-of-laboratory protocol. Participants with transtibial amputation completed three 6-h test sessions. Two sessions served as controls (A protocol) during which participants left their prosthesis donned, and one session was an intervention (B protocol) where participants doffed their prosthesis twice for 20 min during the 6 h of testing. Within-socket fluid volume was measured using a custom portable bioimpedance analysis system. A total of 13 participants completed the study. The rate of limb fluid volume loss was higher early in the session compared with late in the session. Participants experienced less fluid volume loss during high activity than low activity. Socket users with pin suspension experienced less posterior fluid volume loss when they intermittently doffed their prosthesis. Intermittent doffing did not benefit limb fluid volume of mechanical vacuum and suction suspension users. High activity may reduce fluid volume loss compared with low activity. Intermittent doffing may provide volume accommodation for transtibial prosthesis users with pin suspension. Prosthetists should query their patients about the intensity of activity they conduct when advising them on limb volume management. Patients using sockets with pin suspension may be able to offset limb fluid volume loss by periodically doffing the prosthesis.

Assessment of limb edema in pediatric post‐thrombotic syndrome

BackgroundPediatric tools for diagnosis of post‐thrombotic syndrome (PTS) include the assessment of limb edema as a symptom (patient/proxy‐reported) and as a sign. However, it is unclear whether these two approaches refer to the same clinical aspect of PTS. This could result in overestimation of disease severity. We sought to evaluate the correlation among different techniques to assess limb edema as a sign and as a symptom in children who sustained upper extremity (UE) or lower extremity (LE) deep vein thrombosis (DVT) and were, therefore, at risk of PTS. MethodsLimb edema was cross‐sectionally measured as a symptom (ie, patient‐ or proxy‐reported) and as a sign (ie, clinician‐assessed limb circumference difference, limb volume ratio, bioimpedance spectroscopy ratio (BIS), and durometry ratio) in 140 children at risk of PTS (n = 70 UE‐DVT, n = 70 LE‐DVT). Item‐item correlations were estimated using Pearson or Spearman correlation coefficients, as appropriate, and separately for the UE and LE groups. ResultsIn the UE‐DVT group, proxy‐reported swelling correlated weakly to moderately with circumference difference and with volume ratio, but not with BIS ratio. In the LE‐DVT group, proxy‐reported swelling correlated moderately with thigh circumference difference and volume ratio, and patient‐reported swelling correlated moderately with BIS ratio. ConclusionOur findings suggest that patient/proxy‐reported and clinician‐assessed limb edema measure slightly different aspects of PTS, justifying their inclusion in pediatric PTS tools. In addition, proxy‐reported swelling was in closer agreement with clinician‐assessed total limb size (ie, observed edema), and patient‐reported swelling in the LE seemed to reflect limb fluid content (ie, perceived edema).

Diagnostic accuracy of bioimpedance spectroscopy in patients with lymphedema: A retrospective cohort analysis

Bioimpedance spectroscopy (BIS) is used by healthcare specialists to diagnose lymphedema. BIS measures limb fluid content by assessing tissue resistance to the flow of electric current. However, there is debate regarding the validity of BIS in diagnosing early lymphedema. Indocyanine green (ICG) lymphography has been established as the most accurate diagnostic modality to date for lymphedema diagnosis. In this retrospective study, we test the sensitivity, specificity, and diagnostic accuracy of BIS in diagnosing lymphedema by referencing its results with ICG lymphography. Patients presented to the University of Iowa Lymphedema Center from 2015 to 2017 were evaluated with a standardized protocol that included history and physical examination, a validated lymphedema-specific quality-of-life assessment (LYMQOL), circumference -measurement-based index, BIS, and ICG lymphography. Diagnostic accuracy of BIS was assessed using ICG lymphography as a reference test. Fifty-eight patients had positive ICG lymphography results, which confirmed the diagnosis of lymphedema. ICG lymphographic findings consistently correlated with clinical examination, LYMQOL evaluation, and lymphedema indices. By contrast, BIS demonstrated a false-negative rate of 36% - 21 out of 58 patients had normal BIS readings, but a positive ICG lymphography result. The 21 false-negative results occurred in patients with early-stage disease. Sensitivity and specificity for BIS were 0.64 and 1, respectively. BIS carries an excessively high rate of false-negative results to be dependably used as a diagnostic modality for lymphedema. ICG lymphography highly correlates with other tracking modalities, and it remains the most reliable tool for diagnosing lymphedema.