Feasibility study of pre-clinical Thiel embalmed human cadaver for MR-guided focused ultrasound of the spine

Background Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive treatment option based on high acoustic absorption and minimal thermal conductivity of the bone to destroy nerves and reduce pain. There is lack of a preclinical validation tool with correct human anatomy. This work introduces usage of an ex-vivo Thiel embalmed human tissue model for preclinical verification of MRgFUS on intervertebral discs or bone metastases within the spinal body. Material and methods Thiel embalmed human cadaver was subjected to FUS sonication of the vertebra (with energies 250J, 420J, 600J) and the intervertebral disc (with energies 310J, 610J, 950J) of the lumbar spine for 20s of sonication under MR guidance. Results For the vertebra, maximum temperatures were recorded as 38?°C, 58.3?°C, 69?°C. The intervertebral disc reached maximum temperatures of 23.7?°C, 54?°C, 83?°C. The temperature measurements showed that the spinal canal and adjacent organs were not heated > 0.1?°C. Conclusions A heating pattern that can induce thermal ablation was achieved in the vertebral body and the intervertebral disc. Adjacent structures and nerves were not heated in lethal levels. Thus, the Thiel embalmed human cadaver can be a safe and efficient model for preclinical study of application of MRgFUS on the upper lumbar spine.     

Gelatin‐Agar Lumbosacral Spine Phantom

This report describes the preparation of a gelatin‐agar spine phantom that was used for spinal sonography and to practice the hand‐eye coordination skills required to perform sonographically guided central neuraxial blocks. The phantom was prepared by embedding a lumbosacral spine model into a mixture of gelatin and agar in a plastic box. Cellulose powder and chlorhexidine were also added to the mixture, after which it was allowed to solidify. Sonography of the osseous elements of the lumbosacral spine in the phantom was then performed, and their sonographic appearances were compared to those in volunteers. Simulated real‐time sonographically guided paramedian spinal needle insertions were also performed in the phantom. The texture and echogenicity of the phantom were subjectively comparable to those of tissue in vivo. The osseous elements of the spine in the phantom were clearly delineated, and their sonographic appearances were comparable to those seen in vivo in the volunteers. During the simulated sonographically guided spinal injections, the needle could be clearly visualized, but the phantom provided little tactile feedback. In conclusion, the gelatin‐agar spine phantom is a simple and inexpensive sonographic spine model that has a tissuelike texture and echogenicity. It can be used to study the osseous anatomy of the lumbar spine and practice the skills required to perform sonographically guided central neuraxial blocks.     

Ultrasound-guided facet joint injections in the middle to lower cervical spine: a CT-controlled sonoanatomic study

OBJECTIVES: The aim of this study was to investigate the efficacy of ultrasound as a guiding tool for simulated cervical facet joint injections in cadavers. METHODS: A total of 40 ultrasound examinations at 5 levels (C6-7 to C2-3) were performed on 4 embalmed cadavers. The zygapophyseal joints were located with ultrasound. First, the transverse processes of C6 and C7 were established and the facet joint of C6-7 was demonstrated. The midpoint of this joint space, defined as the middle of its cranio-caudal extension on its lateral surface, was taken as a reference point. Ipsilateral distances (A, B, C, and D) between this point and each one of the 4 facet joints of the cervical spine up to the facet joints C2-3 were then computed. Subsequently, coronal computed tomography (CT) scans were taken to verify these distances. In a second experiment, a spinal needle was advanced under ultrasound guidance to the zygapophyseal joints from C2-3 to C6-7 on both sides of 1 cadaver. The exact placement of the needle tips was again verified by CT. RESULTS: In 4 attempts, a depiction of the joint space was not possible. Ultrasound and CT provided the same mean measurements of 1.2+/-0.2 cm, 2.0+/-0.3 cm, 3.0+/-0.2, and 4.0+/-0.5 cm for distances A, B, C, and D, respectively. All 10 needle tips were located in the joint space during simulated facet joint injections, as also verified by CT. DISCUSSION: This preclinical study suggests that ultrasound is a useful guiding tool for facet joint injections in the cervical spine.     

Biliary cystadenocarcinoma: sonographic and cytologic findings.

Biliary cystadenocarcinoma is a rare hepatic cystic tumor. We report sonographic, CT, and MRI findings in an unusual case in an 87-year-old man. The diagnosis was aided by sonographically guided needle aspiration of the lesion, which revealed elevated levels of carcinoembryonic antigen and CA 19-9 in the cystic fluid.     

Sacroiliac joint injections performed with sonographic guidance.

OBJECTIVE: To investigate the feasibility and effectiveness of sonographic guidance for therapeutic intra-articular sacroiliac joint injections in patients with sacroiliitis. METHODS: Thirty-four consecutive patients with sacroiliitis were enrolled in this study. The synovial portions of 60 sacroiliac joints received injections under sonographic guidance. For treatment, a mixture of a corticosteroid and a local anesthetic was injected intra-articularly. Fluoroscopic spot images were obtained to assess the accuracy of the sonographically guided technique. RESULTS: Of the 60 sonographically guided injections, 46 (76.7%) were successful (i.e., intra-articular), and 14 (23.3%) were missed. The successful intra-articular injection rate was 60% in the first 30 injections, and it gradually improved, reaching 93.5% in the last 30 injections. The mean procedure time was 9 minutes. CONCLUSIONS: Our initial experience suggests that sonographically guided therapeutic injections to sacroiliac joints could be valuable alternatives to other guidance modalities in patients with sacroiliitis. In the hands of experienced radiologists, this technique is safe, rapid, and reproducible.     

Lumbar extraforaminal ligaments act as a traction relief and prevent spinal nerve compression

Background

In a previous study, ligaments that connect the extraforaminal lumbar spinal nerves with the fibrous capsule of the facet joints and the dorsolateral side of the intervertebral disc were described. This anatomical configuration suggests a mechanical role in transferring extraforaminal spinal nerve traction.

Methods

One embalmed human lumbar spine was dissected from the twelfth thoracic vertebra to the first sacral vertebra to isolate the twelfth thoracic to the fourth lumbar spinal nerves. The spinal nerves from L1 to L4 were pulled at different angles with respect to the axis of the spine. Forces of 1–6 N were applied. The displacements of reflective markers glued to the proximal and distal ends of the adjoining ligaments were recorded with a video system.

Findings

The spinal nerve proximal of the extraforaminal ligaments stays centred in the intervertebral foramen when pulling at an angle. At levels L1–L4 strain reduction by the extraforaminal ligaments was largest when pulling at a wider angle to the spinal axis in the sagittal plane. Proximal to the extraforaminal ligaments less displacement was seen compared to the displacement distal of the extraforaminal ligaments when pulling in longitudinal direction. A graded decrease in the displacement proximal to the extraforaminal ligaments was seen from the levels L1–L4.

Interpretation

Extraforaminal ligaments play an important role in the prevention of damage due to spinal nerve traction. The proximal attachments secure a spinal nerve position central in the intervertebral foramen and also reduce longitudinal tension.     

Contrast-enhanced sonography of a hepatocellular carcinoma undergoing spontaneous necrosis

Spontaneous necrosis of hepatocellular carcinoma (HCC) is rare. We report the case of a 72-year-old woman with an HCC nodule that underwent necrosis after sonographically guided needle biopsy. Baseline sonographic examination revealed only a nonspecific change in the echogenicity of the lesion. Subsequent necrosis was suggested on contrast-enhanced sonographic examination and was confirmed on spiral CT.     

Metastatic Squamous Cell Carcinoma Presenting as Diffuse and Punctate Cervical Lymph Node Calcifications

Objective. The purpose of this series was to show the sonographic appearance of calcified cervical lymph nodes and the utility of sonographically guided fine-needle aspiration biopsy (FNAB) in the setting of metastatic squamous cell carcinoma (SCC). Methods. Two cases of confirmed metastatic SCC to cervical lymph nodes were identified. Sonography and sonographically guided FNAB were performed in both cases with positron emission tomography (PET)/computed tomography (CT) correlation. Results. In case 1, sonography identified a diffusely calcified, avascular cervical lymph node. Positron emission tomography/CT suggested granulomatous disease as a cause for hypermetabolism; however, sonographically guided FNAB identified metastatic SCC. In the second case, FNAB initially performed without sonographic guidance did not show malignancy. Subsequent FNAB with sonographic guidance identified an abnormal cervical lymph node with focal calcifications and internal color Doppler flow. Metastatic SCC was diagnosed on histopathologic examination. Subsequent PET/CT confirmed multiple punctate calcifications in a hypermetabolic lymph node. Conclusions. Calcifications in cervical lymph nodes from metastatic SCC are very rare. These 2 cases show the variable sonographic appearances and the utility of sonographically guided FNAB in establishing the correct diagnosis.     

Metastases to intramammary lymph nodes in patients with breast cancer: sonographic findings

PURPOSE: To describe the sonographic characteristics of intramammary lymph node metastasis (ILNM) in patients with breast cancer and to assess the value of sonography and sonographically guided fine needle aspiration biopsy (FNAB) in their diagnosis. METHODS: We retrospectively reviewed the charts and films of 19 women with biopsy-documented ILNM who were seen in our breast diagnostic center between December 1999 and July 2003. The sonographic appearance of the nodes was analyzed and correlated with clinical and mammographic findings and with biopsy results. RESULTS: The ILNMs were clinically and mammographically occult in 7 (37%) of the 19 women. The diameter of the ILNMs was less than 1 cm in 15 (79%) cases. The volume of the central echogenic hilum was less than 50% of the total volume of the node in each of the patients. There was marked decrease in cortical echogenicity of the ILN in all cases. Metastatic involvement was established via sonographically guided FNAB in each of the 19 suspicious intramammary lymph nodes. CONCLUSION: Sonography and sonographically guided FNAB are valuable methods of assessment for ILNM in patients with known or suspected breast cancer. The most consistent sonographic features associated with ILNM were reduction in the volume of the central echogenic hilum and marked hypoechogenicity of the node's cortex.     

High-resolution sonographic guidance for transjugular liver biopsy

A prospective randomized study was performed to compare conventional right internal jugular vein catheterization technique with high-resolution sonographically guided catheterization for transjugular liver biopsy. Forty-seven patients were assigned to undergo either conventional or high-resolution sonographically guided right internal jugular vein catheterization for transjugular liver biopsy. Sonographic guidance was significantly better than conventional guidance, reducing the number of failed catheterizations from 22% (5 of 23) to 0% (0 of 24) (p<.05). Sonography also reduced the mean number (± SD) of passes required to catheterize the vein from 4.21±1.53 to 1.54±0.66 (p<.001) and was successful in 100% (5 of 5) of patients in whom conventional catheterization failed. High-resolution sonographic guidance is strongly recommended for transjugular liver biopsy in patients at high risk for bleeding.     

Design of quality assurance for sonographic prostate brachytherapy needle guides.

OBJECTIVE: Needles are guided to their proper anatomic locations in sonographically guided percutaneous prostate brachytherapy by a mechanical system (template). A quality assurance procedure has been designed to test this template's alignment with the needle position overlay grid displayed in the sonographic image. METHODS: A mechanical arrangement was designed to position the needles properly with respect to the prostate probe's transducer in a liquid-filled test tank. Two liquids were tested: tap water and an ethylene glycol mixture with an acoustic velocity of 1540 m/s. Needle images with the superposed grid were analyzed for needle placement accuracy. RESULTS: The tap water produced misregistration of the needle images. The ethylene glycol mixture yielded images of vertical and horizontal needle positions accurate to 0.3 and 1 mm, respectively. Also, the importance of selecting the lowest possible equipment echo amplitude dynamic range in these tests was shown. CONCLUSIONS: This quality assurance test with the ethylene glycol mixture will permit accurate alignment of the brachytherapy needle position overlay grid for each separate transrectal probe used.     

Sonographically guided small-bore chest tubes and sonographic monitoring for rapid sclerotherapy of recurrent malignant pleural effusions.

OBJECTIVE: To evaluate the role of sonographically guided small-bore chest catheters and sonographically based monitoring of fluid evacuation in rapid sclerotherapy of malignant pleural effusions. METHODS: In 50 patients with recurrent malignant pleural effusions, a 9F catheter was inserted into the pleural space under sonographic guidance. When sonography documented complete fluid evacuation, bleomycin (0.75 mg/kg) was injected via the tube. Fluid drainage was monitored for 12 hours; if fluid output was less than 100 mL, the pleural catheter was removed; otherwise, a second dose of bleomycin was administered after 24 hours. If loculations or fluid reaccumulations due to tube malfunctioning were detected, they were evacuated by sonographically guided thoracentesis, and bleomycin (1.5 mg/100 mL of fluid) was injected through the thoracentesis needle. All patients were monitored for fluid recurrence with thoracic sonography. RESULTS: Twenty-nine patients received 1 dose of bleomycin, and 21 received 2 doses. In 11 patients with residual loculations, sonographically guided thoracentesis was performed, and bleomycin was injected into the loculations. In 29 patients, pleurodesis was completed within 24 hours; in 21, it was completed within 48 hours. The 30-day response was 84%; the long-term response was 60%. No complications or serious side effects were observed. CONCLUSIONS: Rapid pleurodesis can be accomplished within 24 to 48 hours, with good short- and long-term responses. Thoracic sonography plays a pivotal role. It guides placement of the pleural catheter and is valuable in the monitoring of fluid evacuation for determining the right time for sclerosing agent administration and in the detection and treatment of loculations or residual pleural fluid due to tube malfunctioning.     

Plantar fasciitis treated with local steroid injection: comparison between sonographic and palpation guidance

PURPOSE: To compare the effectiveness of sonographically guided and palpation-guided steroid injection for the treatment of proximal plantar fasciitis. PATIENTS AND METHODS: Twenty-five consecutive patients with unilateral proximal plantar fasciitis were recruited and randomly divided into a sonographically guided group (n = 12) and palpation-guided group (n = 13). Proximal plantar fascia was assessed with a 5- to 12-MHz linear-array transducer. Pain intensity was quantified using a "tenderness threshold" (TT) and a visual analog scale (VAS). Injection of 7 mg (1 ml) of betamethasone and 0.5 ml of 1% lidocaine into the inflamed proximal plantar fascia was performed under the guidance of sonography or palpation. Patients were evaluated clinically and sonographically before injection and at 2 weeks, 2 months, and 1 year after injection. VAS- and TT-measured pain intensity, thickness, and echogenicity of the proximal plantar fascia, as well as the recurrence of heel pain, were assessed. RESULTS: Both VAS- and TT-measured levels of pain improved significantly after steroid injection in both groups (p < 0.001). Also, the thickness decreased significantly after injection (p < 0.01 in the palpation-guided group; p < 0.001 in the sonographically guided group). The number of patients with hypoechogenicity at the proximal plantar fascia decreased after steroid injection in both groups (p < 0.01 for both groups). The recurrence rate of plantar fasciitis in patients of the palpation-guided group (6/13) was significantly higher than that of the sonographically guided group (1/12) (p < 0.05). CONCLUSIONS: Steroid injection can be an effective way to treat plantar fasciitis, and injection under sonographic guidance is associated with lower recurrence of heel pain.     

Diagnostic accuracy of sonography and combined sonographic assessment and sonographically guided cytology in nonpalpable solid breast lesions

PURPOSE: The aim of this study was to assess the diagnostic accuracy of sonography alone and combined sonographic assessment and sonographically guided fine-needle aspiration cytology in solid, nonpalpable lesions of the breast. METHODS: We retrospectively evaluated the sonograms from a series of 174 consecutive nonpalpable masses that were cytologically diagnosed using fine-needle aspiration under sonographic guidance and then histologically verified through surgical excision. We examined the relationships between the findings from sonography, combined sonographic assessment and cytopathology, and histology. RESULTS: Histologically, 95 lesions (55%) were malignant and 79 (45%) were benign. The overall sensitivity of sonography alone for diagnosing cancer was 98. 9% (94 of 95 lesions), and the specificity was 45.6% (36 of 79 lesions). One (3%) of 37 masses considered at sonography to be benign was correctly diagnosed on cytologic examination to be cancer. By establishing the benign status of 11 of 13 masses that were indeterminate at sonography, cytology increased the specificity of the combined method (to 56.3%). Cytology appropriately suspected or confirmed malignancy in 79 (84%) of 94 carcinomas considered at sonography to be suspicious or malignant. CONCLUSIONS: In this study, sonography alone demonstrated a high sensitivity but limited specificity in evaluating nonpalpable breast masses. The addition of sonographically guided cytology substantially increased the specificity of the combined method without compromising sensitivity.     

Sonographically guided core needle biopsy of bone and soft tissue tumors.

OBJECTIVE: To determine the value of sonographically guided core needle biopsies of musculoskeletal tumors as a reliable alternative to fluoroscopy and computed tomography. METHODS: A prospective study was performed in 74 patients referred for image-guided needle biopsy of primary or recurrent musculoskeletal neoplasms and suspected solitary metastasis. Imaging studies performed before biopsy established the feasibility of sonographic guidance in 65 lesions, of which 38 were soft tissue tumors and 27 were bone lesions with extraosseous masses. The lesions were located mainly in the appendicular skeleton. Tissue samples were obtained with a 14-gauge cutting needle coupled to an automated biopsy device under local anesthesia and sonographic guidance. Statistical analysis was based on 48 biopsies confirmed by successful clinical treatment (10 cases) or surgical resection (38 cases). RESULTS: An accurate diagnosis was obtained in 47 (97%) of 48 biopsies; sensitivity was 96%, and specificity was 100%. The method did not yield sufficient tissue to establish a diagnosis in 1 case. Considering all 65 biopsies, high-quality specimens were obtained in 96%. The procedure was carried out expeditiously, and there were no complications. CONCLUSIONS: Sonographically guided core needle biopsy is accurate and safe, obviating open biopsy in most soft tissue masses and bone tumors with extraosseous masses in the appendicular skeleton. In such patients, the sonographically guided procedure is the most prompt and effective method for obtaining tissue samples.     

CT引导下神经根周围阻滞治疗椎间盘源性腰骶神经根痛

目的 探讨CT引导下神经根周围阻滞治疗椎间盘源性腰骶神经根痛的方法和疗效。方法 对有腰腿痛的79例腰椎间盘突出症的患者，采取CT引导下神经根周围注射皮质类固醇加局麻药，观察患者腰骶神经根痛的变化情况。结果 79例均成功完成CT引导下的神经根阻滞术，43例完成了治疗后6个月的随访，其中25例(58．1％)效果好，11例(25．6％)效果较好，7例(16．3％)效果较差。结论 CT引导下神经根周围阻滞治疗腰椎间盘突出症所致的腰骶神经根痛，操作方法简便、安全、有效、微创，值得临床推广。     

Sonographically guided fine-needle aspiration biopsy of lytic lesions of the spine: technique and indications

PURPOSE: We report the use of sonography to guide fine-needle aspiration biopsies (FNABs) of lytic lesions of the spine. METHODS: Twenty-nine patients with lytic vertebral lesions with or without associated extraosseous soft-tissue extension underwent sonographically guided FNAB. Twelve cervical, 7 thoracic, 7 lumbar, and 3 sacral lesions were biopsied. Tissue samples were taken from either the bony lesion through a break in the cortex (n = 9) or the associated soft-tissue extension (n = 20). RESULTS: Adequate diagnostic material obtained in 27 cases (93%) revealed an inflammatory (n = 13) or malignant process (n = 14). Of the 2 patients with inconclusive FNAB findings, 1 patient was lost to follow-up, and the other underwent surgery, which revealed tuberculosis. No complications of FNAB were encountered. CONCLUSIONS: We conclude that sonography is a safe and effective guidance modality for FNAB of lytic lesions of the spine, especially for lesions in the cervical region. In the thoracic, lumbar, and sacral regions, however, the role of sonographically guided FNAB is limited to lesions affecting the posterior elements.     

Sonographically guided distal radioulnar joint injection: technique and validation in a cadaveric model

Distal radioulnar joint (DRUJ) disorders are uncommon but important causes of ulnar-sided wrist pain and disability. Fluoroscopically guided injections may be performed to diagnose or treat DRUJ-related pain or as part of a diagnostic arthrogram. Sonographic guidance may provide a favorable alternative to fluoroscopic guidance for distal DRUJ injections. This report describes and validates a sonographically guided technique for DRUJ injections in an unembalmed cadaveric model. An experienced clinician used sonographic guidance to inject diluted colored latex into the DRUJs of 10 unembalmed cadaveric specimens. Subsequent dissection by a fellowship-trained hand surgeon confirmed accurate injections in all 10 specimens. Two cases of ulnocarpal flow, indicative of triangular fibrocartilage injury, were noted during injection and subsequently confirmed during dissection. Clinicians should consider using sonographic guidance to perform DRUJ injections when clinically indicated. Further research should explore the efficacy of sonographically guided DRUJ injections to treat patients with painful DRUJ syndromes or to evaluate the triangular fibrocartilage complex in patients with ulnar wrist pain syndromes.     

Intermittent sonographic guidance in air enemas for reduction of childhood intussusception.

OBJECTIVE: The purpose of this study was to prospectively assess the value of intermittent sonographic guidance in nonsurgical air reduction of childhood intussusception. METHODS: The study group included 86 consecutive childhood intussusceptions confirmed on sonography for which we designed an air enema. With intermittent sonographic guidance of our own method, air was gradually injected to the initial intracolonic pressure of 60 mm Hg, which we attempted for 30 seconds on the initial attempt. If the air enema reduction attempts were not successful at a given pressure setting, we repeated the technique at each pressure setting upgraded by increments of 20 mm Hg up to 120 mm Hg. Surgery was performed when even repeated reduction attempts at the maximum intracolonic pressure of 120 mm Hg were unsuccessful. We calculated the successful reduction rate for the intussusceptions at each pressure setting. RESULTS: The overall success rate of sonographically guided air enema reductions was 95% (82/86). The success rates of air enema reductions at 60, 80, 100, and 120 mm Hg showed progressive increases of 53% (42/86), 67% (58/86), 78% (67/86), and 95% (82/86), respectively, with no immediate recurrence and no gross perforation. CONCLUSIONS: The use of intermittent sonographic guidance in air enemas is thought to help safely increase successful reductions of childhood intussusception even with sufficient air enema attempts.     

Primary small cell carcinoma of the pancreas with an unusual sonographic appearance

We present a case of primary pancreatic small cell carcinoma with an unusual sonographic feature. A 75-year-old woman presented with poor appetite and weight loss. Abdominal sonographic examination revealed a diffusely enlarged pancreas with relative increased echogenicity and smooth contour. CT also confirmed the diffuse infiltrative pattern of the tumor. The diagnosis was confirmed via sonographically guided biopsy. The tumor was composed of small cells with hyperchromatic nuclei and scanty cytoplasm infiltrating the pancreatic tissue, consistent with small cell carcinoma of the pancreas. Primary pancreatic small cell carcinoma rarely presents as the diffuse infiltrating type. These unusual sonographic features must be differentiated from other pancreatic tumors presenting as diffuse pancreatic enlargement.