A new simplified sonographic approach for pararadicular injections in the lumbar spine: a CT-controlled cadaver study

Ultrasonographic Imaging Protocol and Sonoanatomy of the Lumbar Spine in Healthy Dogs

Ultrasound is an imaging technique commonly used in veterinary medicine. Ultrasound devices are widely available, their means of examination are relatively short and cheap, and they do not generate ionizing radiation. In addition, ultrasound generally does not need to be performed under general anesthesia. This study was performed on 23 canine cadavers with full clinical histories and with no confirmed pathological changes in the spine region. The imaging modalities were established in dogs in lateral recumbency, with the selected side being the uppermost angle, in a neutral position. All dogs were examined in the transverse and longitudinal planes. Sacral crest, intertransverse ligament, vertebral canal floor, vertebral body, and intervertebral discs were only visible in the longitudinal plane. Vertebral arch, supraspinal ligament, dorsal wall of the vertebral canal and muscles were visualized only in the transverse plane. This article provides a brief and relatively easy-to-perform protocol for ultrasound imaging of the lumbar spine of dogs. In addition, it presents a detailed description of the sonoanatomy of the area under investigation.

Chinese Association for the Study of Pain: Experts consensus on ultrasound-guided injections for the treatment of spinal pain in China (2020 edition)

Spinal pain (SP) is a common condition that has a major negative impact on a patient’s quality of life. Recent developments in ultrasound-guided injections for the treatment of SP are increasingly being used in clinical practice. This clinical expert consensus describes the purpose, significance, implementation methods, indications, contraindications, and techniques of ultrasound-guided injections. This consensus offers a practical reference point for physicians to implement successfully ultrasound-guided injections in the treatment of chronic SP.

Ultrasound-Guided Lumbar Transforaminal Epidural Injection: A Narrative Review

Transforaminal epidural steroid injection is often administered to patients with radiculopathy under fluoroscopic guidance, although it has disadvantages of radiation hazards and requirement of a special area to perform the block. To avoid these disadvantages, ultrasound-guided transforaminal injection (USTFI) has recently been described and is continually developed. This review article describes the indexed articles published on USTFI and ultrasound-guided selective nerve block (SNRB) to evaluate current evidence on best approach to perform the block. Through literature search, eight articles and one case report on USTFI and five articles on ultrasound-guided SNRB were found. Most of the studies have utilized parasagittal orientation of curvilinear probe to perform the block. Nevertheless, with the present literature, it is difficult to come to any conclusion. Further studies with larger sample size and description of dye spread patterns are recommended to come to a more definite conclusion.

Restriction Spectrum Imaging Improves Risk Stratification in Patients with Glioblastoma

BACKGROUND AND PURPOSE

ADC as a marker of tumor cellularity has been promising for evaluating the response to therapy in patients with glioblastoma but does not successfully stratify patients according to outcomes, especially in the upfront setting. Here we investigate whether restriction spectrum imaging, an advanced diffusion imaging model, performed after an operation but before radiation therapy, could improve risk stratification in patients with newly diagnosed glioblastoma relative to ADC.

MATERIALS AND METHODS

Pre-radiation therapy diffusion-weighted and structural imaging of 40 patients with glioblastoma were examined retrospectively. Restriction spectrum imaging and ADC-based hypercellularity volume fraction (restriction spectrum imaging-FLAIR volume fraction, restriction spectrum imaging-contrast-enhanced volume fraction, ADC-FLAIR volume fraction, ADC-contrast-enhanced volume fraction) and intensities (restriction spectrum imaging-FLAIR 90th percentile, restriction spectrum imaging-contrast-enhanced 90th percentile, ADC-FLAIR 10th percentile, ADC-contrast-enhanced 10th percentile) within the contrast-enhanced and FLAIR hyperintensity VOIs were calculated. The association of diffusion imaging metrics, contrast-enhanced volume, and FLAIR hyperintensity volume with progression-free survival and overall survival was evaluated by using Cox proportional hazards models.

RESULTS

Among the diffusion metrics, restriction spectrum imaging-FLAIR volume fraction was the strongest prognostic metric of progression-free survival (P = .036) and overall survival (P = .007) in a multivariate Cox proportional hazards analysis, with higher values indicating earlier progression and shorter survival. Restriction spectrum imaging-FLAIR 90th percentile was also associated with overall survival (P = .043), with higher intensities, indicating shorter survival. None of the ADC metrics were associated with progression-free survival/overall survival. Contrast-enhanced volume exhibited a trend toward significance for overall survival (P = .063).

CONCLUSIONS

Restriction spectrum imaging-derived cellularity in FLAIR hyperintensity regions may be a more robust prognostic marker than ADC and conventional imaging for early progression and poorer survival in patients with glioblastoma. However, future studies with larger samples are needed to explore its predictive ability.

Ultrasonography of the lumbar spine: sonoanatomy and practical applications

Ultrasonography of the bones and joints has gained considerable ground in the field of rheumatology over the past decade and is now used in everyday practice both for diagnostic purposes and to guide local injections. However, the use of ultrasonography is virtually confined to the peripheral joints, whereas spinal diseases make a major contribution to rheumatology practice. Studies have established that ultrasonography of the lumbar spine is feasible. Adequate equipment and familiarity with spinal sonoanatomy are required. In this update, we suggest starting with a systematic examination of the lumbar spine to assess the various anatomic structures, from the thoracolumbar fascia superficially to the posterior part of the vertebras at the deepest level. The ligaments, erector spinae muscles, facet joints, and transverse processes can be visualized. Ultrasonography can serve to guide injections into the facet joints, about the nerve roots, and into the iliolumbar ligaments; as well as to identify relevant landmarks before epidural injection. Although diagnostic applications are more limited at present, systematic studies of abnormal ultrasonography findings will allow evaluations of the potential usefulness of ultrasonography for diagnosing spinal disorders. The depth of the spinal structures limits the ability to obtain high-resolution images. However, future technical improvements in ultrasound transducers and machines, together with the growing number of physicians trained in ultrasonography, can be expected to benefit the development of spinal ultrasonography in the near future.

Ultrasound-guided versus computed tomography-controlled periradicular injections in the middle and lower cervical spine: a prospective randomized clinical trial

PURPOSE

We conducted this study to evaluate accuracy, time saving, radiation doses, safety, and pain relief of ultrasound (US)-guided periradicular injections versus computed tomography (CT)-controlled interventions in the cervical spine in a prospective randomized clinical trial.

METHODS

Forty adult patients were consecutively enrolled and randomly assigned to either a US or a CT group. US-guided periradicular injections were performed on a standard ultrasound device using a broadband linear array transducer. By basically following the osseous landmarks for level definition in "in-plane techniques", a spinal needle was advanced as near as possible to the intended, US-depicted nerve root. The respective needle tip positioning was then verified by CT. The control group underwent CT-guided injections, which were performed under standardized procedures using the CT-positioning laser function.

RESULTS

The accuracy of US-guided interventions was 100%. The mean time to final needle placement in the US group was 02:21 ± 01:43 min:s versus 10:33 ± 02:30 min:s in the CT group. The mean dose-length product radiation dose, including CT confirmation for study purposes only, was 25.1 ± 16.8 mGy cm for the US group and 132.5 ± 78.4 mGy cm for the CT group. Both groups showed the same significant visual analog scale decay (p < 0.05) without "inter-methodic" differences of pain relief (p > 0.05).

CONCLUSIONS

US-guided periradicular injections are accurate, result in a significant reduction of procedure expenditure under the avoidance of radiation and show the same therapeutic effect as CT-guided periradicular injections.

Transverse process and needles of medial branch block to facet joint as landmarks for ultrasound-guided selective nerve root block

BACKGROUND

Selective lumbar nerve root block (SNRB) is generally accepted as an effective treatment method for back pain with sciatica. However, it requires devices producing radioactive materials such as C-arm fluoroscopy. This study evaluated the usefulness of the longitudinal view of transverse process and needles for medial branch block as landmarks under ultrasonography.

METHODS

We performed selective nerve root block for 96 nerve roots in 61 patients under the guidance of ultrasound. A curved probe was used to identify the facet joints and transverse processes. Identifying the lumbar nerve roots under the skin surface and ultrasound landmarks, the cephalad and caudal medial branch blocks were undertaken under the transverse view of sonogram first. A needle for nerve root block was inserted between the two transverse processes under longitudinal view, while estimating the depth with the needle for medial branch block. We then injected 1.0 mL of contrast medium and checked the distribution of the nerve root with C-arm fluoroscopy to evaluate the accuracy. The visual analog scale (VAS) was used to access the clinical results.

RESULTS

Seven SNRBs were performed for the L2 nerve root, 15 for L3, 49 for L4, and 25 for L5, respectively. Eighty-six SNRBs (89.5%) showed successful positioning of the needles. We failed in the following cases: 1 case for the L2 nerve root; 2 for L3; 3 for L4; and 4 for L5. The failed needles were positioned at wrong leveled segments in 4 cases and inappropriate place in 6 cases. VAS was improved from 7.6 ± 0.6 to 3.5 ± 1.3 after the procedure.

CONCLUSIONS

For SNRB in lumbar spine, the transverse processes under longitudinal view as the ultrasound landmark and the needles of medial branch block to the facet joint can be a promising guidance.

Ultrasound guided versus CT-controlled pararadicular injections in the lumbar spine: a prospective randomized clinical trial

BACKGROUND AND PURPOSE

Injection therapies play a major role in the treatment of lower back pain and are to date performed mainly under CT- or fluoroscopic guidance. We conducted this study to evaluate the accuracy, time savings, radiation doses, and pain relief of US-guided pararadicular injections versus CT-controlled interventions in the lumbar spine in a prospective randomized clinical trial.

MATERIALS AND METHODS

Forty adult patients were consecutively enrolled and assigned to a US or CT group. US-guided pararadicular injections were performed on a standard US device by using a broadband curved-array transducer (9-4 or 5-1 MHz). In the in-plane technique, the needle was advanced through the respective segmental intertransverse ligament. The needle tip position was verified by CT. The CT-guided approaches were performed under standardized procedures by using the CT-positioning laser function.

RESULTS

The accuracy of US-guided interventions was 90%. The mean time to final needle placement in the US group was 4.0 ± 1.8 minutes, and in the CT group, 7.6 ± 2.1 minutes. The mean radiation doses, including CT confirmation for study purposes only, were 20.3 ± 9.0 mGy cm for the US group and 42.6 ± 36.1 mGy cm for the CT group. Both groups showed the same significant pain relief (P < .05) without relevant "intermethodic" differences of pain relief (P > .05).

CONCLUSIONS

US-guided pararadicular injections show a therapeutic effect similar to that in the time-consuming, expensive, ionizing CT or fluoroscopically guided pararadicular injections and result in a significant reduction of procedure time expenditure and avoidance of radiation.

Spine ultrasonography: interventions and diagnostics

SUMMARY Ultrasound-guided procedures are well established and utilized in the regional anesthesia and radiology practice. Conversely, there have been considerable difficulties in implementation of ultrasound in pain medicine. Ultrasonography has to compete with the more established modalities such as fluoroscopy and computed tomography; however, ultrasound has the advantage of radiation safety and point-of care imaging. It also allows direct visualization of tissue planes, blood vessels and nerves. Ultrasound-guided spine interventions are technically feasible and reasonably accurate when validated with conventional radiological modalities. Epidural, zygapophysial joint and caudal injection techniques have been published. The main pitfall of the ultrasound-guided spinal procedures lies in the inability to diagnose intravascular injections. Future technological improvements will help to solve this problem. Diagnostic spinal sonography may also contribute to the practice of medicine helping in the clinical workup of scoliosis and paraspinal pathology.