Diagnosis of obstetric brachial plexus injury in a 2-year-old girl using high­frequency ultrasonography.

We describe an unusual case of infant obstetric brachial plexus injury located in the cervical (C)5-C6 brachial plexus nerve, which was preoperatively diagnosed using high-frequency ultrasonography (US) at 2 years of age. The girl was diagnosed with a right clavicular fracture because of shoulder dystocia. She had been showing movement limitations of her entire right upper limb after fracture healing and was then referred to our hospital at 2 years of age. High-frequency US showed that the roots of the right brachial plexus ran continuously, but the diameter of C6 was thinner on the affected side than on the contralateral side (right 0.12 cm vs. left 0.20 cm). A traumatic neuroma had formed at the upper trunk, which was thicker (diameter: right 0.35 cm vs. left 0.23 cm; cross-sectional area: right 0.65 cm2 vs. left 0.31 cm2) at the level of the supraclavicular fossa. Intraoperative findings were consistent with ultrasound findings. Postoperative pathology confirmed brachial plexus traumatic neuroma.

Diagnosis of thoracic outlet syndrome with the lower trunk compression of brachial plexus by high-frequency ultrasonography.

BACKGROUND: Thoracic outlet syndrome (TOS) with the lower trunk compression of brachial plexus (BP) is difficult to diagnosis. This study aimed to summarize the features of thoracic outlet syndrome (TOS) with the lower trunk compression of brachial plexus observed on high-frequency ultrasonography (HFUS). METHODS: The ultrasound data of 27 patients who had TOS with the lower trunk compression of brachial plexus were collected and eventually confirmed by surgery. The imaging data were compared, and the pathogenesis of TOS was analyzed on the basis of surgical data. RESULTS: TOS occurred predominantly in females (70.4%). Most cases had unilateral involvement (92.6%), mainly on the right side (66.7%). The HFUS features of TOS can be summarized as follows: (1) Lower trunk compression. HFUS revealed focal thinning that reflected compression at the level of the lower trunk; furthermore, the distal part of the nerve was thickened for edema (Affected side: 0.49 ± 0.12 cm vs. Healthy side: 0.38 ± 0.06, P = 0.009), and the cross-sectional area of brachial plexus cords was markedly greater on the injured side than on the healthy side (0.95 ± 0.08 cm² vs. 0.65 ± 0.11 cm², P = 0.004). (2) Hyperechoic fibromuscular bands behind the compressed nerve (mostly the scalenus minimus muscle). (3) Abnormal bony structures: cervical ribs or elongated transverse processes of the 7th cervical vertebra (C7). Surgical results showed that the etiological factors contributing to TOS were (1) muscle hypertrophy and/or fibrosis (100%) and (2) cervical ribs/elongated C7 transverse processes (20.7%). CONCLUSION: TOS with the lower trunk compression of brachial plexus can be diagnosed accurately and reliably by high-frequency ultrasound.

Rare malignant melanotic nerve sheath tumors of the upper limb nerves: utility of high-frequency ultrasonography in preoperative imaging.

Melanotic nerve sheath tumor (MNST) is a rare variant of schwannoma. Here, we report an unusual case of multiple MNST lesions located in the upper limb nerves. The patient presented with a mass on the left wrist in 2016 and another mass on the left thumb in 2017. In both instances, magnetic resonance imaging scans confirmed multiple giant-cell tumors of the tendon sheath. Persistent pain in the left upper limb and numbness in the ring finger and little finger recurred in 2021. High-frequency ultrasound (HFUS) showed that the left brachial plexus nerves (C5-8) were widened compared with those on the contralateral side; the neuroma formed at the lateral cord, and the median nerve was markedly thickened. The surgical findings were consistent with the ultrasound results. Pathology confirmed that the tumors were malignant MNSTs. HFUS is important for preoperative diagnosis and lesion localization, even identifying some lesions that are unrecognized on magnetic resonance imaging; thus, HFUS is crucial for improving surgical strategy and decision-making.

Diagnosis of cervical plexus tumours by high-frequency ultrasonography.

BACKGROUND: Cervical plexus (CP) tumours are difficult to diagnose because of atypical symptoms. This study aimed to summarize the features of a normal CP and CP tumours observed on high-frequency ultrasonography. METHODS: The ultrasound data of 11 CP tumour patients and 22 normal volunteers were collected. All 11 patients underwent magnetic resonance imaging (MRI), and 4 patients also underwent computed tomography (CT). The imaging data were compared with surgery and pathology data. RESULTS: The C7 vertebra and bifurcation of the carotid common artery (CCA) were useful anatomic markers for identifying the CP. In contrast to the C1 nerve (22.7%), the C2-4 nerves were well displayed and thinner than the brachial plexus (P < 0.05). CP tumours were more common in females (72.7%) and generally located at C4 (72.7%) on the right side (81.8%). Additionally, the nerve trunk in tumour patients was obviously wider than that in normal controls (7.49 ± 1.03 mm vs 2.67 ± 0.36 mm, P < 0.01). Compared with pathology, the diagnostic rates of CP tumours by MRI, CT and high-frequency ultrasound were 72.7% (8/11), 25% (1/4) and 90.9% (10/11), respectively. CONCLUSIONS: The diagnosis of CP neuropathy is accurate and reliable by high-frequency ultrasound, and the C7 vertebra and bifurcation of the CCA are useful anatomic markers in CP ultrasonography.

Computer-Aided Diagnosis Systems in Diagnosing Malignant Thyroid Nodules on Ultrasonography: A Systematic Review and Meta-Analysis.

BACKGROUND: Computer-aided diagnosis (CAD) systems are being applied to the ultrasonographic diagnosis of malignant thyroid nodules, but it remains controversial whether the systems add any accuracy for radiologists. OBJECTIVE: To determine the accuracy of CAD systems in diagnosing malignant thyroid nodules. METHODS: PubMed, EMBASE, and the Cochrane Library were searched for studies on the diagnostic performance of CAD systems. The diagnostic performance was assessed by pooled sensitivity and specificity, and their accuracy was compared with that of radiologists. The present systematic review was registered in PROSPERO (CRD42019134460). RESULTS: Nineteen studies with 4,781 thyroid nodules were included. Both the classic machine learning- and the deep learning-based CAD system had good performance in diagnosing malignant thyroid nodules (classic machine learning: sensitivity 0.86 [95% CI 0.79-0.92], specificity 0.85 [95% CI 0.77-0.91], diagnostic odds ratio (DOR) 37.41 [95% CI 24.91-56.20]; deep learning: sensitivity 0.89 [95% CI 0.81-0.93], specificity 0.84 [95% CI 0.75-0.90], DOR 40.87 [95% CI 18.13-92.13]). The diagnostic performance of the deep learning-based CAD system was comparable to that of the radiologists (sensitivity 0.87 [95% CI 0.78-0.93] vs. 0.87 [95% CI 0.85-0.89], specificity 0.85 [95% CI 0.76-0.91] vs. 0.87 [95% CI 0.81-0.91], DOR 40.12 [95% CI 15.58-103.33] vs. DOR 44.88 [95% CI 30.71-65.57]). CONCLUSIONS: The CAD systems demonstrated good performance in diagnosing malignant thyroid nodules. However, experienced radiologists may still have an advantage over CAD systems during real-time diagnosis.

High-resolution ultrasonography for the diagnosis of brachial plexus root lesions.

The aim of this study was to investigate the feasibility of using high-resolution ultrasonography in the diagnosis of brachial plexus (BP) root lesions. A prospective study of ultrasonographic evaluation of BP nerve roots was performed in 37 patients with BP root lesions (29 with root injuries, 8 with tumors). The pre-operative ultrasonographic findings were compared with the surgical and pathohistological findings. All C5-7 roots were detected by ultrasonography in all patients, whereas 92% (68/74) of C8 and 51% (38/74) of T1 nerve roots were visualized. Among 29 patients with BP root avulsion, partial injuries or totally interrupted BP roots were detected in all patients. Cystic masses and neuromas were detected in 16 and 23 patients, respectively. In 8 patients with BP root tumors, 8 hypo-echoic masses were detected inside or partly outside of intervertebral foramina connecting to nerve roots. Surgical exploration revealed that there were 57 BP root avulsions in 29 patients. However, 2 T1 nerve root avulsions had been missed by pre-operative ultrasonography. Pathohistology revealed that all 8 BP root tumors pre-operatively diagnosed by ultrasonography were schwannomas. High-resolution ultrasonography can provide a convenient and accurate imaging modality for quick diagnosis and location of BP root lesions.

Diagnosis of closed injury and neoplasm of the brachial plexus by ultrasonography.

PURPOSE: To evaluate the feasibility and accuracy of high-frequency sonography (US) in diagnosing traumatic brachial plexus (BP) lesions and neoplasms in the adult. METHODS: Eleven patients with suspected BP closed trauma, 6 patients with BP neoplasm, and 12 healthy volunteers were scanned. The US findings were compared with surgical findings. RESULTS: The interscalene space and intervertebral foramina were useful anatomic markers in identifying the BP. In the 24 sites examined in the normal group (12 subjects examined on both sides), the fifth to seventh cervical nerve roots (C5-7, including upper and middle trunk) were seen, whereas the eighth cervical and first thoracic nerve roots (C8, T1, including the lower trunk) were seen in 91.7% (22/24) of the subjects. The BP appeared as three or four discrete rounded hypoechoic nodules between the anterior scalene and middle scalene muscle in transverse views at the C5-7 level, representing the trunks in the sagittal oblique section. In the BP trauma group (n = 11), the normal nerve trunk was interrupted, and lesions were shown as thickening and swelling with indistinct inner structures. In the neoplasm group (n = 6), masses were shown as hypoechoic masses. CONCLUSIONS: High-frequency US is valuable in diagnosing BP closed injuries and neoplasms.

High-intensity focused ultrasound ablation of myocardium in vivo and instantaneous biological response.

OBJECTIVE: This study aimed to evaluate the instantaneous biological response of canine myocardium in vivo to high-intensity focused ultrasound (HIFU) ablation, and thereby determine the feasibility of this method. METHODS: Left ventricle myocardium HIFU ablation was performed on six dogs at four levels of HIFU energy (acoustic intensity was 3000 W/cm2 ; ablation durations were 1.2, 2.4, 3.6, and 4.8 sec, respectively). Gross lesion volumes were confirmed and assessed by tetrazolium chloride (TTC) staining, hematoxylin-eosin (HE) staining, and electron microscopy. Global cardiac function and focal wall motion were evaluated by echocardiography. Blood enzymes and cardiac troponin T (CTnT) were tested after ablation. HIFU ablation was repeated on another set of six fresh canine hearts in vitro at the same four energy levels. Focal maximum temperatures were detected both in vivo and in vitro. RESULTS: Different sizes of ablation via HIFU can be created in beating hearts using controlled energy emission. Focal maximum temperatures varied from 62 ± 4.8 °C to 81 ± 12.9 °C. The lesion sizes were significantly smaller in vivo than in vitro, as verified by TTC and HE staining. Focal wall motion immediately decreased after ablation (P < 0.05), although the ejection fraction (EF) and E/A ratio were unchanged (P > 0.05). Enzymes and CTnT immediately increased. CONCLUSION: HIFU can be used for the controllable ablation of myocardial tissue, with instantly increased serum markers, decreased regional wall motion, and unaffected left ventricular global function.

Differential diagnosis between pre- and postganglionic adult traumatic brachial plexus lesions by ultrasonography.

The goal of this study was to prospectively investigate the feasibility of preoperative ultrasonography evaluation in the differentiation between pre- and postganglionic traumatic brachial plexus lesions. Two expert radiologists employed ultrasonography to observe the morphology of the brachial plexus in 23 patients with suspected traumatic brachial plexus lesions and 40 healthy volunteers. The detection rate was 100% (126/126) for the C5 through C7 nerve roots and upper and middle trunks and three fascicles, 84% (106/126) for the C8 roots and the lower trunks and 64% (81/126) for T1 roots in all subjects. Surgical inspections found 58 lesions in 23 patients (40 preganglionic lesions and 18 postganglionic lesions). Ultrasonography detected most of the brachial plexus lesions (56/58) but misjudged two preganglionic and two postganglionic lesions. The rate of differentiation was 93% (52/56). This study demonstrated that ultrasonography is a useful but experience-dependent supplemental imaging technique for preoperative diagnosis of brachial plexus lesions and differentiation between pre- and postganglionic brachial plexus lesions.

[Inhibitory effects of rosiglitazone against endothelin-1-induced proliferation of rat cardiac myocytes: the role of PKC-c-fos pathway].

OBJECTIVE: To investigate the mechanism of rosiglitazone (RSG, the activator of peroxisome proliferators activated receptor lambda) for inhibiting endothelin-1 (ET-1)-induced neonatal rat cardiac myocyte hypertrophy and the role of protein kinase C (PKC) and c-fos. METHODS: In vitro cultured neonatal rat cardiac myocytes were treated with ET-1, phorbol ester (PMA, the PKC activator), ET-1+RSG, ET-1+chelerythrine (che, the PKC inhibitor), PMA+RSG, or without treatment (control), respectively. The effects of RSG on the protein content, (3)H-leucine incorporation, PKC activity and C-fos protein expression were observed in the cardiac myocytes stimulated with ET-1 or PMA. RESULTS: After two days of culture, the intracellular protein content in ET-1 group and PMA group were increased by 15% (339-/+15 microg/ml) and 13% (329-/+14 microg/ml) as compared with the control cells (290-/+13 microg/ml), respectively (P<0.01). Compared with the ET-1 group, cells treated with ET-1+10(-8) mol/L RSG, ET-1+10(-7) mol/L RSG, and ET-1+che showed decreased intracellular protein content by 10% (303-/+14 microg/ml, P<0.05), 12% (292-/+11 microg/ml, P<0.05), and 13% (291-/+12 microg/ml, P<0.01), respectively. The intracellular protein content in PMA+10(-7) mol/LRSG group was decreased by 10% (P<0.05) in comparison with the PMA group. RSG inhibited protein synthesis enhancement and increased (3)H-leucine incorporation induced by ET-1 and PMA, and antagonized the effects of ET-1 and PMA in promoting PKC activity and c-fos protein expression in the myocytes. CONCLUSION: The inhibitory effect of RSG on ET-1- or PMA-induced myocyte hypertrophy is associated with PKC-c-fos pathway.

[Prognostic value of ventricular longitudinal systolic velocities and maximal oxygen consumption in patients with dilated cardiomyopathy].

OBJECTIVE: To compare the prognostic value of regional longitudinal ventricular systolic velocities with that of maximal oxygen consumption (VO(2max)) in patients with dilated cardiomyopathy (DCM). METHODS: VO(2max) derived from cardiopulmonary exercise tests and regional longitudinal ventricular systolic velocities obtained from tissue Doppler imaging were compared in 18 DCM patients with cardiac events (death, cardiac transplantation, hospitalization, group A) and 24 patients without cardiac events (group B). Peak velocities during isovolumic contraction (is) and ejection (ez) were interrogated at the mitral or tricuspid annulus (site 1), at the mid parts of the walls (site 3, at the level of papillary muscle), and at the midpoints (site 2) between sites 1 and 3 of interventricular septum (S), lateral wall of LV (L) and of RV (R) in apical 4 chambers view. RESULTS: R1is, R2is, R2ez, R3is, S1is, S1ez, S2ez, L1is, L1ez and L2ez of group A were significantly lower than those in group B (all P < 0.05). Independent of VO(2max), high sensitivity and specificity were shown for R3ez, S1ez, L1ez, L1is, L2is and L3is in predicting cardiac events of DCM patients. CONCLUSION: LV and RV systolic velocities could independently predict cardiac events in DCM patients.

[Relationship between cardiomyocyte protein synthesis and cell viability].

OBJECTIVE: To observe the relationship between protein sythesis and cardiomyocyte viability in neonatal rats. METHODS: The protein sythesis in neonatal rat cardiomyocytes was measured according to Brandford's method, the absorbance at 490 nm (A(490 nm)) of the cells was measured with MTT assay and the cell viability evaluated by the ratio of A(490 nm) to the total cell number. RESULTS: ET-1 increased cardiomyocyte protein synthesis dose-dependently, and this effect was attenuated by the application of lacidipine and tetramethylpyrazines Higher doses of ET-1 resulted in lower A(490 nm)/total cell number ratio, which was further lowered by larcidipine and tetramethylpyrazine. CONCLUSION: The status of protein synthesis is not associated with the viability of neonatal rat cardiomyocytes.

[Comparison study on uterine and umbilical artery blood flow during pregnancy at high altitude and at low altitude].

OBJECTIVE: To evaluate the effect of high altitude on uterine and umbilical artery blood flow dynamics during normal pregnancy. METHOD: Uterine artery blood flow parameters of the pregnant (34) and nonpregnant (37) subjects and umbilical artery blood flow parameters of 119 subjects living at high altitude or at low altitude were measured with color Doppler flow imaging system. RESULTS: Uterine artery diameter, blood flow volume increased during pregnancy at both altitude, and uterine artery blood flow volume and diameter were smaller at high altitude than at low altitude [(0.35 +/- 0.04) cm vs (0.45 +/- 0.04) cm, (280 +/- 48) ml/min vs (425 +/- 55) ml/min, P < 0.01]. Umbilical artery blood flow velocity systolic to diastolic (S/D) value, resistant index of different pregnant period were greater at high altitude than at low altitude (P < 0.01). CONCLUSION: High altitude has effect on placental and infant blood flow that causes the decrease of placental blood infusion and the increase of uterine and umbilical artery flow velocity S/D and reactive index.