Demystifying MR Neurography of the Lumbosacral Plexus: From Protocols to Pathologies

Table 2

Summary of anatomic features of the lumbosacral plexus nerves.

Nerve	Origin	Muscles innervated	Sensory distribution
Lumbar plexus
Anterior rami	L2-3	(i) Psoas	None
Iliohypogastric	T12-L1	(i) Transversus abdominus; (ii) Internal oblique	(i) Anteromedial abdominal wall; (ii) Lateral buttock
Ilioinguinal	L1	(i) Transversus abdominus; (ii) Internal oblique	(i) Medial aspect of the upper thigh; (ii) Base of penis and anterior scrotum; (iii) Mons pubis and superior labia majora
Genitofemoral	L1-L2	(i) Cremaster (males)	(i) Anterior aspect of the upper thigh. Spermatic cord and posterior scrotum; (ii) Inferior labia majora
Femoral	L2–L4	(i) Rectus femoris; (ii) Vastus lateralis; (iii) Vastus medialis; (iv) Sartorius; (v) Pectineus; (vi) Iliacus	(i) Anterior and medial aspects of the mid and distal thigh; (ii) Knee joint
Lateral femoral cutaneous	L1–L3	None	(i) Lateral thigh
Obturator	L2–L4	(i) Obturator externus; (ii) Adductor magnus; (iii) Adductor longus; (iv) Adductor brevis; (v) Gracilis; (vi) Pectineus	(i) Medial aspect of the upper thigh
Lumbosacral trunk	L4-L5	None	None
Sacral plexus
Sciatic	L4–S3	(i) Biceps femoris; (ii) Semitendinosus; (iii) Semimembranosus; (iv) Adductor magnus	(i) Leg
Superior gluteal	L4–S1	(i) Gluteus medius; (ii) Gluteus minimus; (iii) Tensor of the fascia lata	None
Inferior gluteal	L5–S2	(i) Gluteus maximus	None
Pudendal	S2–S4	(i) External anal sphincter; (ii) External urinary sphincter	(i) External genitalia
Posterior femoral cutaneous	S1–S3	None	(i) Inferior and medial buttock; (ii) Hip joint; (iii) Perineum; (iv) Popliteal fossa