Diagnostic Accuracy of Selective 3-T MR Neurography–guided Retroperitoneal Genitofemoral Nerve Blocks for the Diagnosis of Genitofemoral Neuralgia

Abstract

Purpose To determine if 3-T magnetic resonance (MR) neurography-guided retroperitoneal genitofemoral nerve (GFN) blocks are safe and effective for the diagnosis of genitofemoral neuralgia. Materials and Methods Following institutional review board approval and informed consent, 26 subjects (16 men, 10 women; mean age, 42 years [range, 24-78 years]; mean body mass index, 28 kg/m [range, 20-35 kg/m]) with intractable groin pain were included. By using a 3-T MR imaging system, intermediate-weighted turbo spin-echo pulse sequences, and MR-conditional needles, diagnostic MR neurography-guided GFN blocks were performed in the retroperitoneum. Outcome variables included technical success, procedure time, complications, and rates of positive and negative GFN blocks in association with therapeutic outcomes. For the assessment of a learning curve, Mann-Whitney test was used. P values ≤ .05 were considered to indicate a statistically significant difference. Results In 26 subjects, 30 retroperitoneal GFN blocks were performed. Twelve (40%) were performed with an anterior needle path, 12 (40%) with a lateral needle path, and six (20%) with a posterior needle path. GFN blocks were technically successful in 24 of 26 (92%) subjects, achieving appropriate scrotal anesthesia. No complications occurred. The time required for a GFN block was 40 minutes (range, 18-67 minutes). The rate of a successful GFN intervention after a positive GFN block was 88% (14 of 16). The rate of a successful intervention of an alternative target after a negative GFN block was 71% (five of seven). Conclusion Selective retroperitoneally directed MR neurography-guided GFN blocks are safe and effective with high technical success and positive effect on surgical decision making in patients with presumed genitofemoral neuralgia. RSNA, 2017 Online supplemental material is available for this article.

Revisiting the genital and femoral branches of the genitofemoral nerve: Suggestion for a more accurate terminology

“…However, it may be difficult to identify a single nerve as the cause of the neuralgia and paravertebral blockade of the L1 and L2 nerve roots or triple neurectomy may be necessary (Cesmebasi et al, ). Fritz et al () used magnetic resonance neurography‐guided blockade via a retroperitoneal approach for genitofemoral nerve blockade with good results. Moreover, it retroperitoneal neurectomy is performed on one of the genitofemoral nerve branches for example, to treat scrotal pain, and the surgeon assumes that the medial branch of the genitofemoral nerve is its genital branch, based on our study, this assumption could often be incorrect.…”

Instrument visualization using conventional and compressed sensing SEMAC for interventional MRI at 3T

“…The use of a 3T MRI system is beneficial for MR‐guided interventions that require accurate visualization of small anatomical targets, as well as soft tissue and osseous lesions . To ensure successful and safe targeting for drug delivery and tissue sampling, accurate visualization of needles and drills is paramount.…”

“…The use of a 3T MRI system is beneficial for MRguided interventions that require accurate visualization of small anatomical targets, as well as soft tissue and osseous lesions. 13,29,30 To ensure successful and safe targeting for drug delivery and tissue sampling, accurate visualization of needles and drills is paramount. Spin echo-based pulse sequences typically produce smaller needle artifacts than gradient echo pulses sequences, 31,32 because radiofrequencybased spin refocusing avoids the pile-up of field inhomogeneities that occurs with gradient-based spin refocusing.…”

Getting Quantitative Diffusion‐Weighted MR Neurography and Tractography Ready for Clinical Practice

“…The combination of the rate of progression of peripheral neuropathy and the electrodiagnostic characterization can provide insight into causative etiologies. In patients with peripheral neuropathy and diagnostic uncertainty, both diagnostic and interventional magnetic resonance neurography (MRN) can differentiate normal from neuropathic nerves, localize types and sites of abnormalities, and guide management …”

“…In patients with peripheral neuropathy and diagnostic uncertainty, both diagnostic and interventional magnetic resonance neurography (MRN) can differentiate normal from neuropathic nerves, localize types and sites of abnormalities, and guide management. [2][3][4] Qualitative diagnostic MRN techniques can visualize various nerve abnormalities and effects of muscle denervation; however, qualitative MRN has limited abilities to identify microstructural abnormalities of nerves and accurately grade the severity of peripheral neuropathies. Diffusionweighted MRN is a group of qualitative and quantitative noncontrast techniques that can visualize and quantify water diffusivity within nerves.…”