Clinical Value and Diagnostic Accuracy of 3.0T Multi-Parameter Magnetic Resonance Imaging in Traumatic Brachial Plexus Injury

Ultrasound accuracy for brachial plexus pathology

AIM

To determine (a) the accuracy of ultrasound in detecting brachial plexus pathology and (b) outline the advantages and limitations of ultrasound compared to MRI for imaging the brachial plexus.

MATERIAL AND METHODS

cases with clinically suspected brachial plexus pathology were evaluated first by ultrasound, followed by MRI. Patients with prior brachial plexus imaging were excluded. The final diagnosis was based on a combination of ultrasound, MRI, clinical follow-up, and surgical findings. The accuracy of the ultrasound was assessed by comparing the ultrasound and the final diagnoses. The mean clinical follow-up time following ultrasound was 1.8 ± 1.4 years.

RESULTS

Ninety-two (64%) of the 143 cases had normal brachial plexus ultrasound and MRI examinations. Fifty-one (36%) of 143 cases had brachial plexus pathology on MRI, comprising post-radiation fibrosis (n=25, 49%), nerve sheath tumor (n=11, 21%), traumatic injury (n=7, 14%), inflammatory polyneuropathy (n=4, 8%), malignant infiltration (n=2, 4%), desmoid fibromatosis (n=1,2%), and neuralgic amyotrophy (n=1, 2%). Overall diagnostic accuracy of ultrasound for brachial plexus pathology was 98% (140/143), with three discordant cases (neuralgic amyotrophy n=1, inflammatory neuropathy n=1, postradiation fibrosis n=1) regarded as normal on ultrasound assessment. Sensitivity, specificity, and positive and negative predictive value of ultrasound for identifying brachial plexus pathology were 94%, 100%, 100%, and 97%, respectively.

CONCLUSION

Ultrasound identifies brachial plexus pathology with high accuracy and specificity, showing comparable diagnostic efficacy to MRI. Ultrasound can serve as an effective first-line imaging investigation for suspected brachial plexus pathology.

The value of the cinematic volume rendering technique: magnetic resonance imaging in diagnosing tumors associated with the brachial plexus

PURPOSE

To examine the diagnostic advantages and clinical application value of the cinematic volume rendering technique (cVRT) when evaluating the relationship between the brachial plexus, peripheral tumor lesions, and blood vessels.

MATERIALS AND METHODS

Seventy-nine patients with brachial plexus tumors between November 2012 and July 2022 were enrolled in our study. All patients underwent T1WI, T2WI, three-dimensional short recovery time reversal recovery fast spin-echo imaging (3D-STIR-SPACE), and the T1WI enhancement sequence. In addition, cVRT was used to render and obtain a three-dimensional model that clearly showed the location and tissue structure of the brachial plexus nerves and the tumor in all directions.

RESULTS

Seventy-one patients (mean age, 47.1 years; 33 males, 38 females) with tumors around the brachial plexus were included in the study. The brachial plexus nerve, surrounding tumor lesions, and vascular anatomy of all patients were well displayed with cVRT. The tumors of 37 patients manifested as unilateral or bilateral growths along the brachial plexus nerve and were fusiform, spherical, or multiple beaded; seven patients' tumors pushed against the brachial plexus nerve and were circular, lobular, or irregular; sixteen patients' tumors encircled the brachial plexus nerve and were spherical; and eleven patients' tumors infiltrated the brachial plexus nerve and had irregular morphology. The mass has a moderately uniform or uneven signal on T1WI and a high or mixed signal on T2WI. After enhancement, the signal was evenly or unevenly strengthened.

CONCLUSIONS

cVRT clearly showed the origin of tumors associated with the brachial plexus and their relationship with the nerves and peripheral blood vessels, providing reliable information for clinical diagnosis and treatment.

Diagnostic Accuracy of Magnetic Resonance Imaging With 3-Dimensional T2-SPACE Techniques for Preganglionic Injury of the Brachial Plexus

PURPOSE

An accurate diagnosis of the site and severity of a brachial plexus injury is imperative for selecting the appropriate management. Conventional magnetic resonance imaging (MRI) does not allow for the precise interpretation of preganglionic injuries (pre-GIs), especially intravertebral canal injuries. We developed 4 MRI sequences of conventional 1.5-tesla 3-dimensional T2-weighted turbo spin echo sampling perfection with the application of optimized contrasts using different flip angles evolution (T2-SPACE) images to clearly visualize each component of the brachial plexus. The purpose of this study was to introduce basic normal and pathologic findings of our current MRI approach, focusing on its diagnostic accuracy for pre-GIs.

METHODS

We initially examined 119 patients with brachial plexus injuries who underwent surgical exploration by MRI using 4 sequences of the 1.5-tesla 3-dimensional T2-SPACE technique. We obtained coronal, transverse, coronal oblique, and coronal cuts of T2 short time inversion recovery. The images of 595 roots were interpreted by multiple-image synchronizing techniques of the 4 views to precisely interpret the presence of spinal cord edema, numbers of anterior and posterior rootlets, sites of ganglions, meningeal cysts, and the "black line sign" (displaced ruptured dura or bundles of ruptured rootlets). We assessed the accuracy, sensitivity, and specificity of these abnormal findings with regard to diagnosing pre-GIs by comparing surgical exploration.

RESULTS

The absence or decreased numbers of anterior and posterior rootlets and displacement of ganglions were definitive evidence of pre-GIs and the other findings, like spinal cord edema, meningeal cysts, and black line signs, were predictive signs.

CONCLUSIONS

The synchronizing techniques of the four 1.5-tesla 3-dimensional T2-SPACE images provided high diagnostic accuracy of pre-GIs.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

The Application of Contrast-Enhanced 3D-STIR-VISTA MR Imaging of the Brachial Plexus

Objective:

Methods:

Results:

Conclusion:

Rapid Detecting Brachial Plexus Injury by Point-of-Care Ultrasonography

Brachial plexus injury (BPI) is regarded as one of the most devastating injuries of the upper extremity. Brachial plexus neuropathy can have a high morbidity by seriously affecting the motor function and sensation of upper limbs with loss of activities of daily living. The use of computed tomography myelogram and/or magnetic resonance imaging (MRI) assessing brachial plexus offers valuable details including the location, morphology, and severity of preganglionic and postganglionic injuries during the preoperative period. High-field-strength MRI with specific coil and specialized MRI sequences might be not available in every emergency setting and is time-consuming. Point-of-care ultrasonography (POCUS) comes in handy and offers good image resolution of muscles and nerves that makes early detection of neuromuscular injury possible. Here, we present a case report of BPI that POCUS provides indirect evidence of cervical root injury and expedite time to MRI.

Brakial Pleksopatide Klinik, EMG ve MR Nörografi Bulgularının Değerlendirilmesi

Amaç: Çalışmanın amacı brakial pleksopatide MR nörografi sonuçlarını elektrodiagnostik test ile birlikte değerlendirmek ve MR nörografinin yararlığını saptamaktır. Yöntem: Brakial pleksopati şüphesi bulunan ve elektrodiagnostik test yapılan 50 hasta çalışmaya dahil edildi. MR nörografide Brakiyal pleksusun kök, gövde ve kord seviyesinde seyri, kalibrasyonu, sinyal yoğunluğu ve devamlılığı 2 bağımsız radyolog tarafından değerlendirildi. Bulgular: Elektrodiagnostik test altın standart tanı testi kabul edilerek yapılan analizde MR nörografinin tanısal doğruluk, duyarlılık, özgüllüğü; 1. okuyucu için sırasıyla %64, %45.16, %94.73; 2. okuyucu için sırasıyla %74, %67.74, % 84.21. Okuyucular arası tutarlılık %78 idi. Sonuç: Brakial pleksopati klinik şüphesi bulunan hastalarda MR’ın duyarlılığı ve okuyucular arasındaki uyum orta derecede bulundu. MR nörografi brakial pleksopatiyi gösterebilir ancak pleksusun normal görünümü pleksopati tanısını dışlamamalıdır.

Success with dorsal root entry zone lesioning after a failed trial of spinal cord stimulation in a patient with pain due to brachial plexus avulsion

Pain caused by brachial plexopathy (BP) represents a challenging clinical problem with few effective therapeutic options. Here, we present a patient with severe, painful BP after a high-impact motor vehicle accident who failed conservative treatments. A trial of cervical spinal cord stimulation was completed using multiple waveforms (tonic, BurstDR, and 10 kHz) over 14 days with only 30% to 40% pain reduction. Subsequently, he underwent dorsal root entry zone lesioning with a significant decrease in his pain 1 year later. Surgical exploration revealed extensive damage and avulsion of his cervical roots that was not observed on a previous brachial plexus magnetic resonance imaging. We discuss the etiology and diagnosis of traumatic BP, possible reasons for the failed spinal cord stimulation trial, and implications for management.

Diagnostic performance of diffusion-weighted MR neurography as an adjunct to conventional MRI for the assessment of brachial plexus pathology

OBJECTIVE

To investigate the diagnostic performance of diffusion-weighted (DW) MR neurography as an adjunct to conventional MRI for the assessment of brachial plexus pathology.

METHODS

DW MR neurography scans (short tau inversion recovery fat suppression and b-value of 800 s/mm²) of 15 consecutive patients with and 45 randomly selected patients without brachial plexus abnormalities were independently and blindly reviewed by a 5th year radiology resident, a junior neuroradiologist, and a senior neuroradiologist.

RESULTS

Median interpretation times ranged between 20 and 30 s. Interobserver agreement was substantial (κ coefficients of 0.715-0.739). For the 5th year radiology resident, sensitivity was 53.3% (95% CI, 30.1-75.2%) and specificity was 100% (95% CI, 92.1-100%). For the junior neuroradiologist, sensitivity was 66.7% (95% CI, 41.7-84.8%) and specificity was 100% (95% CI, 92.1-100%). For the senior neuroradiologist, sensitivity was 73.3% (95% CI, 48.1-89.1%) and specificity was 95.6% (95% CI, 85.2-98.8%). Traumatic injury, metastases, radiation-induced plexopathy, schwannoma, and inflammatory process of unknown cause could be detected by the majority of readers (100% detection rate for each disease entity by at least two readers). Neuralgic amyotrophy, iatrogenic injury after first rib resection, and cervical disc herniation causing root compression were not detected by the majority of readers (0% detection rate for each disease entity by at least two readers).

CONCLUSION

DW MR neurography may be a useful adjunct when assessing for brachial plexus abnormalities, because interpretation time is relatively short and the majority of abnormalities can be detected.

KEY POINTS

• DW MR neurography interpretation time of the brachial plexus is relatively short (median interpretation times of 20 to 30 s). • Interobserver agreement between three readers with different levels of experience is substantial (κ coefficients of 0.715 to 0.739). • DW MR neurography can detect brachial plexus abnormalities with moderate sensitivity (53.3 to 73.3%) and high specificity (95.6 to 100%).

Anatomy, Imaging, and Pathologic Conditions of the Brachial Plexus

The brachial plexus is an intricate anatomic structure with an important function: providing innervation to the upper extremity, shoulder, and upper chest. Owing to its complex form and longitudinal course, the brachial plexus can be challenging to conceptualize in three dimensions, which complicates evaluations in standard orthogonal imaging planes. The components of the brachial plexus can be determined by using key anatomic landmarks. Applying this anatomic knowledge, a radiologist should then be able to identify pathologic appearances of the brachial plexus by using imaging modalities such as MRI, CT, and US. Brachial plexopathies can be divided into two broad categories that are based on disease origin: traumatic and nontraumatic. In the traumatic plexopathy group, there are distinct imaging findings and management methods for pre- versus postganglionic injuries. For nontraumatic plexopathies, having access to an accurate patient history is often crucial. Knowledge of the timing of radiation therapy is critical to diagnosing post-radiation therapy brachial plexopathy. In acute brachial neuritis, antecedent stressors occur within a specific time frame. Primary and secondary tumors of the brachial plexus are not uncommon, with the most common primary tumors being peripheral nerve sheath tumors. Direct extension and metastasis from primary malignancies such as breast and lung cancer can occur. Although diagnosing a brachial plexus anomaly is potentially perplexing, it can be straightforward if it is based on foundational knowledge of anatomy, imaging findings, and pathologic features. ^©RSNA, 2020.

Diagnostic Accuracy of the Magnetic Resonance Imaging in Adult Post-Ganglionic Brachial Plexus Traumatic Injuries: A Systematic Review and Meta-Analysis

Background: Traumatic brachial plexus injuries are rare but serious consequences of major traumas. Pre-ganglionic lesions are considered irreparable, while post-ganglionic injuries can be potentially treated if an early diagnosis is available. Pre-surgical diagnosis is important to distinguish low-grade from high-grade lesions and to identify their location. The aim of the review is to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) in the identification of adult post-ganglionic lesions due to traumatic brachial plexus injuries, compared to intraoperative findings. Methods: Research on the main scientific electronic databases was conducted. Studies of adults with traumatic post-ganglionic brachial plexus injuries were included. The index test was preoperative MRI and the reference standard was surgical exploration. Pooled sensitivity and specificity were calculated. Results: Four studies were included for the systematic review, of which three articles met the inclusion criteria for the meta-analysis. Pooled sensitivity and pooled specificity values resulted high. The sensitivity value is associated with a high heterogeneity index of the selected literature. Conclusion: MRI can be considered, despite the limits, the gold standard exam in morphological evaluation of brachial plexus injuries, particularly in the diagnosis of post-ganglionic traumatic injuries.

Diffusion-weighted imaging with background body signal suppression (DWIBS) distinguishes benign lesions from malignant pulmonary solitary lesions

This study aimed to determine applicable value of DWIBS in diagnosis of solitary pulmonary lesions. This study involved 32 solitary lung disease patients. T1W1, T2W1, T2WI-SPAIR were examined using MRI scanner and analyzed with View-forum 6.0 workstation. Imaging characteristics of pulmonary solitary lesions on DWIBS and ADC when b=300, 500 and 800 s/mm² were observed. Signal-to-noise ratio (SNR), contrast-noise-ratio (CNR) and ADC value of lesions under different b-values were measured. Image quality in different b-values was compared by analyzing SNR and CNR. ADC values of benign and malignant lesions in different b-value groups were tested using t-test. ROC curve was used to evaluate diagnostic efficacy of ADC value, and obtain diagnostic threshold. The results indicated that SNR and CNR value of 300 and 500 s/mm² group was significantly higher compared to 800 s/mm² group (P<0.05). When b-value was assigned as 500 s/mm², DWIBS demonstrated better and ideal images. ADC value of malignant lesions in different b-values was significantly lower compared to benign lesions (P<0.05), suggesting ADC value is a feasible approach for distinguishing benign from malignant lesions. AUC value of b=500 s/mm² was significantly higher compared to b=300 and b=800 s/mm² group (P<0.05). When b-value was assigned as 500 s/mm², the best ADC threshold value was 1.435×10^-3 mm²/s, with high sensitivity, specificity and accuracy of 80.0%, 83.3% and 84.4%, respectively. In conclusion, quantitative analysis of DWIBS examination and ADC value was helpful for qualitative diagnosis of pulmonary solitary lesions, and demonstrated potential to distinguish benign and malignant pulmonary solitary lesions.

Diagnostic Function of 3-Tesla Magnetic Resonance Imaging for the Assessment of Brachial Plexus Injury

Background:

This study aimed to evaluate the diagnostic function of 3-Tesla (T) magnetic resonance imaging (MRI) during the assessment of brachial plexus injury (BPI), in comparison with intraoperative findings.

Methods:

A retrospective study was performed on 60 patients (47 men and 13 women), who had clinical manifestations of BPI, underwent 3T MRI of the brachial plexus, and were surgically treated at the Viet Duc and Vinmec Times City hospitals, in Hanoi, Vietnam, from March 2016 to December 2019. Preganglionic and postganglionic lesion features were identified on MRI. The diagnostic function of MRI features for the determination of BPI was evaluated and correlated with intraoperative findings.

Results:

The root avulsion and pseudomeningocele preganglionic injuries were observed in 57% and 43% of MRIs, respectively, and were commonly observed at the C7 and C8 roots. Nerve disruption and never edema were observed in 47.56% and 33.53% of MRIs, respectively, and were commonly observed at the C5 and C6 roots. The sensitivity, specificity, accuracy, positive prognostic value, and negative prognostic value of 3T MRI were 64.12%, 92.90%, 80.33%, 87.50%, and 76.96%, respectively, for the diagnosis of total avulsion, and 68.52%, 83.33%, 80.67%, 47.44%, and 92.34%, respectively, for the diagnosis of nerve disruption.

Conclusion:

MRI offers valuable details regarding the location, morphology, and severity of both preganglionic and postganglionic injuries during the preoperative diagnosis of BPI. However, this modality played a moderate diagnostic role. Therefore, 3T MRI should be used as a supplemental evaluation, coupled with clinical tests and electromyography, to determine the most appropriate treatment strategies for BPI patients.

Anatomical Variability Predisposed a Child to Permanent Brachial Plexopathy following Incidental Trauma

Anatomic variations in peripheral nerves and the perineural environment are common and can contribute to acute or chronic neuropathy in certain individuals. Awareness of these variants is relevant to understanding both the etiopathogenesis and the increased susceptibility to nerve injury in some patients. We present a 4-year-old boy who sustained a permanent injury to the upper brachial plexus from a relatively minor trauma. Surgical exploration revealed a variation in upper trunk anatomy that likely contributed to this outcome.

Diagnostic accuracy of MRI for traumatic adult brachial plexus injury: A comparison study with surgical findings

We studied the diagnostic accuracy of MRI in 35 adult patients with traumatic brachial plexus injury in comparison with intra operative findings. The overall sensitivity to detect root avulsions was 39% and specificity was 75%. MRI was more useful in the diagnosis of lower root avulsions. At trunk and division level injuries, the sensitivity was 87% but specificity was only 26%. It was not able to differentiate the type and extent of post-ganglionic injuries. The accuracy of pseudomeningocele as avulsion on surgical finding was 96% (27/28). Pseudomeningocele correlates well with root avulsions. Its presence warrants early referral and surgical exploration.