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Perineural edema in early CTS. Level of the pisifom (SE 2,300/90 msec): The earliest change produced by chronic nerve compression is a reduced epineural blood flow with formation of perineural edema depicted as a hyperintense margin surrounding the isointense median nerve (arrow).
Source publication
The purpose of this prospective study was to determine the potential of MR imaging to depict morphologic alterations of the median nerve correlating with the stage of carpal tunnel syndrome (CTS). Eighteen wrists of normal subjects and 81 wrists of patients with CTS were examined. MR imaging was performed with proton-density- and T2-weighted spin-e...
Citations
... [6] Recently, wrist magnetic resonance images (W-MRI) has been demonstrated as a reasonable diagnostic modality for the CTS diagnosis. [7][8][9] W-MRI can clearly distinguish the anatomy of peripheral nerve along with the pathological change related to mechanical compression and are noninvasive. The increased intracarpal canal pressure (ICP), the medial nerve flattening within the carpal tunnel (CT), bowing of the flexor retinaculum, and swelling of the median nerve in the distal and proximal CT are important anatomical location of the CT anatomy. ...
... Kleindienst et al have concluded that W-MRI can demonstrates severity of nerve compression. [9] The current study has multiple limitations. First, there can be some biases associated with measurement of the PLTCSA on W-MRI. ...
Carpal tunnel syndrome (CTS) is correlated with increased intracarpal canal pressure (ICP). The effect of palmaris longus tendon (PLT) loading on ICP is documented in previous researches. PLT loading induces the greatest absolute increase in ICP. Therefore, to analyze the connection between the PLT and CTS, we newly made the measurement of the PLT cross-sectional area (PLTCSA). We assumed that PLTCSA is a reliable diagnostic parameter in the CTS. PLTCSA measurement data were acquired from 21 patients with CTS, and from 21 normal subjects who underwent wrist magnetic resonance imaging (W-MRI). We measured the PLTCSA at the level of pisiform on W-MRI. The PLTCSA was measured on the outlining of PLT. The two different cutoff values in the analysis were determined using receiver operating characteristic (ROC) analysis. The mean PLTCSA was 2.34 ± 0.82 mm2 in the normal group and 3.97 ± 1.18 mm2 in the CTS group. ROC curve analysis concluded that the best cutoff point for the PLTCSA was 2.81 mm2, with 76.2% sensitivity, 71.4% specificity, and area under the curve of 0.88 (95% CI, 0.78-0.98). PLTCSA is a sensitive, new, objective morphological parameter for evaluating CTS.
... (2005) proposed a computer vision elastography by utilizing the ultrasound sequences with the estimation of speckle adaptive motion. It has the hardware limitations of 30 frames that show the storage of FT with potentially high trajectory density with every reference template from minimal Computation time drift(23,(43)(44).Chih-Kuang Yeh et.al. (2008) proposed a compound ultrasound imaging approach in CTS diagnosis on the mixture of electrophysiological abnormalities as well as characteristic symptoms. ...
CTS is the most common occupational disease. It is a form of median nerve compression and is caused by prolonged or repetitive motions of the wrist. CTS led to numbness and tingling sensation in the hand. CTS hinder activities of daily life and therefore diagnosis in good time is very important. The conventional diagnosis of CTS involves manual examination through electrophysiological testing. Manual diagnosis is not only time consuming but it is also not a proactive approach. With the recent advancement in computer vision, imaging, and soft computing techniques, predictive diagnosis of CTS has become an important research field. The aim of this research paper is to review the state of art of early detection and prediction of CTS. Major methods and algorithms used in this context are reviewed with their advantages and limitations. The research paper also points out the research gap and recommends direction for future research.
... Nerve conduction study (NCS) was performed by an electrophysiologist with at least 20 years of experience, according to the guidelines and recommendations is sued by the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM) [6]. Patients were classified as mild, moderate, and severe CTS based on the measurement of the median nerve conduction velocity [7,8]. The electrophysiologist was blinded to the clinical characteristics of patients before performing the NCS. ...
Purpose:
Imaging is gaining a more prominent role in the diagnosis of carpal tunnel syndrome (CTS), especially ultrasonography. Shear wave elastography (SWE) is a novel qualitative method to study mechanical changes in tissue. In this study, we aim to assess the role of SWE in diagnosing and staining of the disease.
Material and methods:
A total of 124 wrists were included in the study. Seventy wrists had CTS, and 54 were included as the control group. All of the wrists with CTS had staging done with nerve conduction study. All patients underwent ultrasonography by an expert radiologist and had the SWE and cross-section of the median nerve determined. These values were compared among the 2 groups and different stages of CTS. The receiver operating characteristic curve was utilized to assess the diagnostic role of each of the variables.
Results:
Cross-section area (CSA) and SWE were significantly different between the 2 groups (p = 0.0001). CSA was also significantly different among various stages of CTS. SWE was not significantly different among moderate and severe stages of CTS. Both of the variables had a good ability to distinguish mild CTS from healthy wrists (p = 0.0001).
Conclusion:
SWE can be used in diagnosing CTS and in the staging of the disease.
... This reduction was evident one month post-ECT [11,30,34], although, similar to previous studies, after one month, no further reduction occurred for up to 12 months post-ECTR [11,18]. This early reduction in median nerve CSA is most likely due to reduced neural venous congestion [12,35], while persistent median nerve swelling thereafter [7,11,29,30], most likely reflects irreversible or slowly reversible endoneural fibrosis due to chronic compressive neuropathy [29,33,36]. Even though most patients had moderate to complete symptom resolution post-ECTR, the median nerve remained swollen from, on average, 13.8 mm 2 to 17.3 mm 2 at 12 months post-ECTR. ...
Objective:
To investigate changes in the median nerve, retinaculum, and carpal tunnel on ultrasound after successful endoscopic carpal tunnel release (ECTR).
Materials and methods:
This prospective study involved 37 wrists in 35 patients (5 male, 30 female; mean age ± standard deviation [SD], 56.9 ± 6.7 years) with primary carpal tunnel syndrome (CTS). An in-house developed scoring system (0-3) was used to gauge the clinical improvement after ECTR. Ultrasound was performed before ECTR, and at 1, 3, and 12 months post-ECTR. Changes in the median nerve, flexor retinaculum, and carpal tunnel morphology on ultrasound after ECTR were analyzed. Ultrasound parameters for different clinical improvement groups were compared.
Results:
All patients improved clinically after ECTR. The average clinical improvement score ± SD at 12 months post-ECTR was 2.2 ± 0.7. The median nerve cross-sectional area proximal and distal to the tunnel decreased at all time intervals post-ECTR but remained swollen compared to normal values. Serial changes in the median nerve caliber and retinacular bowing after ECTR were more pronounced at the tunnel outlet than at the tunnel inlet. The flexor retinaculum had reformed in 25 (68%) of 37 wrists after 12 months.
Conclusion:
Postoperative changes in median nerve and retinaculum parameters were most pronounced at the tunnel outlet. Even in patients with clinical improvement after ECTR, nearly all ultrasound parameters remain abnormal at one year post-ECTR. These ultrasound parameters should not necessarily be relied upon to diagnose persistent CTS after ECTR.
... Median nerve swelling is consistently the best imaging discriminator of CTS in patients who do not undergo surgery [12,13,[26][27][28]. Median nerve swelling in CTS may be due to reversible neural edema or more chronic irreversible neural damage, including endoneural fibrosis, demyelination, and axonal degeneration [15,27]. ...
... Median nerve swelling in CTS may be due to reversible neural edema or more chronic irreversible neural damage, including endoneural fibrosis, demyelination, and axonal degeneration [15,27]. Even though most patients in this study had a good to excellent clinical response to ECTR, the median nerve remained enlarged to a degree that would be considered indicative of CTS on Fig. 4-63- [13,25,26,29,30]. One should be wary, therefore, about using increased nerve swelling as a sign of persistent neural compression after ECTR, because the nerve remains enlarged even in patients with good symptomatic improvement. ...
... Flattening ratio is not a reliable imaging discriminator of CTS in patients who do not undergo surgery [26,33,34]. After ECTR, the median nerve became less flattened, though only at the tunnel inlet at 3 months. ...
OBJECTIVE. Flexible PET (fxPET) was designed to fit existing MRI systems. The newly modified nonlocal means (NLM) algorithm is combined with the 3D dynamic row-action maximum likelihood algorithm (DRAMA). We investigated qualitative and quantitative acceptability of fxPET images reconstructed by modified NLM compared with whole-body (WB) PET/CT images and conventional 3D DRAMA reconstruction alone. MATERIALS AND METHODS. Fifty-nine patients with known or suspected malignancies underwent WB PET/CT scanning approximately 1 hour after the injection of 18F-FDG, after which they underwent fxPET scanning. Two readers rated the quality of fxPET images by consensus. Detection rate (the proportion of lesions found on PET), maximal standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), tumor-to-normal liver ratio (TNR), and background liver signal-to-noise ratio (SNR) were compared among the three datasets. RESULTS. Higher image quality was obtained by modified NLM reconstruction than by conventional reconstruction without statistical significance. The detection rate was comparable among three datasets. SUVmax was significantly higher, and MTV and TLG were significantly lower in the modified NLM dataset (p < 0.002) than in the other two datasets, with significantly positive correlations (p < 0.001; Spearman rank correlation coefficient, 0.87-0.99). The TNRs in modified NLM images were significantly larger than in the other datasets (p < 0.05). The background SNRs in modified NLM images were comparable with those in WB PET/CT images, and significantly higher than in the conventional fxPET images (p < 0.005). CONCLUSION. The modified NLM algorithm was clinically acceptable, yielding higher TNR and background SNR compared with conventional reconstruction. Image quality and the lesion detection rate were comparable in this population.
... Conclusions: Even though both MNCSA and MNT were significantly associated with CTS, MNT was identified as a more suitable measurement parameter. 55 tunnel magnetic resonance imagings (CTMRI) have been demonstrated as a good diagnostic tool for the diagnosis of CTS [4][5][6]. CTMRI are noninvasive and can clearly depict the anatomical detail of peripheral nerves along with the pathological changes related to compression. The bowing of the flexor retinaculum, flattening of the medial nerve within the carpal tunnel, and the swelling of the nerve in the proximal and distal carpal tunnel are morphologically important anatomical features of the carpal tunnel area [7]. ...
... The bowing of the flexor retinaculum, flattening of the medial nerve within the carpal tunnel, and the swelling of the nerve in the proximal and distal carpal tunnel are morphologically important anatomical features of the carpal tunnel area [7]. The morphological changes in the median nerve resulting from prolonged increased mechanical pressure within the carpal tunnel have already been demonstrated [6]. Apparently, the median nerve cross-sectional area (MNCSA) is considered a useful morphological parameter for the evaluation of CTS [4,[8][9][10][11][12]. ...
... CTS is a debilitating neuropathy that is frequently encountered in the primary care unit. It is the most common entrapment disorder of the upper extremity, affecting approximately 3.0% of the general adult population [6,[13][14][15][16]. Females are three times more likely to have CTS than males, and the severity and prevalence have been reported to increase with age [17,18]. ...
Background:
The median nerve cross-sectional area (MNCSA) is a useful morphological parameter for the evaluation of carpal tunnel syndrome (CTS). However, there have been limited studies investigating the anatomical basis of median nerve flattening. Thus, to evaluate the connection between median nerve flattening and CTS, we carried out a measurement of the median nerve thickness (MNT).
Methods:
Both MNCSA and MNT measurement tools were collected from 20 patients with CTS, and from 20 control individuals who underwent carpal tunnel magnetic resonance imaging (CTMRI). We measured the MNCSA and MNT at the level of the hook of hamate on CTMRI. The MNCSA was measured on the transverse angled sections through the whole area. The MNT was measured based on the most compressed MNT.
Results:
The mean MNCSA was 9.01 ± 1.94 mm2 in the control group and 6.58 ± 1.75 mm2 in the CTS group. The mean MNT was 2.18 ± 0.39 mm in the control group and 1.43 ± 0.28 mm in the CTS group. Receiver operating characteristics curve analysis demonstrated that the optimal cut-off value for the MNCSA was 7.72 mm2, with 75.0% sensitivity, 75.0% specificity, and an area under the curve (AUC) of 0.82 (95% confidence interval [CI], 0.69-0.95). The best cut off-threshold of the MNT was 1.76 mm, with 85% sensitivity, 85% specificity, and an AUC of 0.94 (95% CI, 0.87-1.00).
Conclusions:
Even though both MNCSA and MNT were significantly associated with CTS, MNT was identified as a more suitable measurement parameter.
... Carpal tunnel syndrome (CTS) is the most common type of neural entrapment [1][2][3]. Nerve entrapment is due to impingement, most commonly at the tunnel inlet [4][5][6][7][8][9], though also at the tunnel outlet [10][11][12]. Median nerve impingement leads to neural edema with disruption of axoplasmic flow [13,14]. ...
... The median nerve proximal to the carpal tunnel is recognized to increase in size [5,10,11,24,33] and be significantly larger in CTS patients than in normal subjects. Median nerve CSA proximal to the tunnel is the most commonly applied criterion for diagnosing CTS on MRI with a recommended cut-off level of larger than 15 mm 2 . ...
Objective
To study MRI criteria for diagnosing and predicting severity of carpal tunnel syndrome (CTS).
Methods
Sixty-nine wrists in 41 symptomatic CTS patients and 32 wrists in 28 asymptomatic subjects were evaluated by MRI. Circumferential surface area (CSA), flattening ratio, relative median nerve signal intensity, and retinacular bowing were measured. CTS severity was classified as mild, moderate, or severe. Parameters for patients with and without CTS and for the three severity groups were compared. ROC curves were plotted to assess accuracy for CTS diagnosis and severity prediction.
Results
Significant differences were found between CTS and control wrists for median nerve CSA, flattening ratio at inlet, relative median nerve signal intensity, and retinacular bowing. ROC curve analysis revealed a sensitivity, specificity, and accuracy of median nerve CSA > 15 mm² proximal to the tunnel (CSAp) of 85.5, 100, and 90.1%. Using either CSAp or CSAd > 15 mm² as a diagnostic criterion, MRI could achieve a sensitivity of 100% and specificity of 94% for diagnosis of CTS while overall accuracy was 98%.
Significant differences were found among the three severity groups. Sensitivity, specificity, and accuracy of prediction of severe CTS using for CSAp > 19 mm² were 75.0, 65.9, and 69.6%, respectively.
Conclusions
MRI is highly accurate at diagnosing CTS and moderately accurate at determining CTS severity. We recommend using CSA > 15 mm² either proximal to or distal to the tunnel as a diagnostic criterion for CTS and CSA > 19 mm² proximal to the tunnel as a marker for severe CTS.
... The diagnosis of carpal tunnel syndrome (CTS) has been generally based on clinical features and electrophysiological data; however, localization of the entrapment point in the median nerve and quantification of the severity of the disease has been difficult. Recent advanced magnetic resonance (MR) imaging technology with the use of dedicated microscopy coils has provided high-resolution axial images of the wrist, allowed detailed morphological assessment regarding thickness, the cross-sectional area of the median nerve and has allowed bowing of the flexor retinaculum [1][2][3][4][5][6][7][8]. Although some relationships between those measurements and clinical symptoms have been shown in previous studies, accurate detection of abnormal regions along the median nerve has remained difficult. ...
... In our study, the median nerve could be clearly visualized in the sagittal direction with successful demonstration of nerve T2 mapping in all patients. Nerve T2 values remained constant through the carpal tunnel in normal volunteers, as other studies have revealed [3,6]. Interestingly, localization of most abnormal T2 regions in the median nerve differed among patients. ...
Purpose: To evaluate patients with carpal tunnel syndrome (CTS) by using 3-Tesla magnetic resonance imaging (MRI) sagittal T2 mapping of the median nerve for localization of abnormal regions. Material and Methods: Nine hands of seven patients with CTS and five hands of five healthy volunteers were evaluated using sagittal T2 mapping and axial spoiled gradient-echo (SPGR) images. Three regions of interest (ROIs) at the carpal tunnel (ROI-1 to ROI-3) and one control ROI distal to the carpal tunnel (ROIC) were defined on the median nerve and T2-ratios at ROI-1 to ROI-3 relative to ROI-C were calculated. The flattening ratio (F-ratio; width/height of the median nerve) was also calculated from the axial SPGR images. Results: On sagittal T2 mapping, the medial nerve of normal volunteers showed constant T2 values at all ROIs. In the patients with CTS, there was large variation in T2 among the ROIs and the region of highest T2 value varied among the patients. T2-ratios at ROI-2 and -3 and the F-ratios along all carpal tunnel levels were significantly higher in the patients with CTS than in the normal volunteers. A significant correlation was found between terminal latency and T2-ratio at ROI-2 but not between terminal latency and F-ratio. Conclusion: Sagittal T2 mapping was feasible for the localization of abnormal T2 regions of the median nerve in patients with CTS.
... Quantitative analysis based on CTS studies showed that the enlargement of the carpal tunnel area and the flexor tendon area were characteristic findings with changes in signal intensity and in the configuration of the median nerve [13]. Enlargement of the cross sectional area of the median nerve at the entrance to the tunnel had a diagnostic value for idiopathic CTS [16,17]. Martins et al. [2] also reported that median nerve area at hamate bone level gives more frequently correlations with clinical and electrophysiological measures and should be considered as the more relevant in comparison. ...
... It is also well known that the pathophysiology varies with the disease stage and disease severity can affect the imaging outcome [7,21]. Supporting this knowledge, T2 signal intensity can decrease in the advanced CTS because of fibrosis within the nerve [17]. All these findings discussed above says that increased intensity is an important finding and can be used to follow the patients with CTS [5,7,19,20,22,23]. ...
In this study,
we showed that T2 intensity of median nerve measured by wrist MRI may be considered as a valuable indicator but it is not superior to electrophysiological studies in grading the severity of disease in patients with idiopathic carpal tunnel syndrome.
... Enlargement of the cross-sectional area (CSA) of the median nerve at the proximal end of the carpal tunnel, enhanced signal intensity over the median nerve, and palmar bowing of the TCL are typical features of idiopathic CTS [17]. These observations depend on the progres-sion of the disease: proximal enlargement of the CSA and high signal intensity of the median nerve are more significant during the advanced stage of the disease [18]. Enlargement of the median nerve and a high signal intensity on T2-weighted images are suggestive of accumulation of the axonal transportation, myelin sheath degeneration or edema [19]. ...
Carpal Tunnel Syndrome (CTS) is the most common form of entrapment neuropathy. Several authors have investigated the anatomical and pathophysiological features of CTS and have identified several parameters that, in combination, play a significant role in its pathophysiology. Advancement in biological research on CTS has enabled the advent of efficient diagnostic techniques such as provocative tests and nerve conduction studies. Sophisticated technologies, such as magnetic resonance imaging (MRI) and ultrasonography (US), have facilitated the diagnosis of CTS. This review article aims at consolidating the relevant medical literature pertaining to the symptoms, pathophysiology, clinical diagnosis and treatment strategies of CTS. It also compares the various methods of diagnosis and discusses their benefits and disadvantages. Finally, it sheds light on the conservative vs. surgical approach to treatment and compares them. While the surgical approach has proved to be more efficient relative to the conservative methods of steroid injections and splinting, many studies have demonstrated both advantages and adverse effects of the surgical methods. Surgical options and complications are discussed in detail. This article comprehensively summarizes all medical aspects of CTS to update medical professionals’ knowledge regarding the disease.
