颈4-5椎小关节脓毒性关节炎 (Septic arthritis of the C4-C5 facet joint)MRI病例图片影像诊断分析脊椎 2011-01-11
【临床病史】：患者，59岁男性，有良性前列腺增生病史，出现14天的持续性尿路感染，采用了数种抗生素治疗。在第13天病人出现颈痛。A 59-year-old male with a history of BPH presented with a 14-day history of a persistent UTI treated with various antibiotics. On the 13th day the patient developed neck pain.
Figure 1 and Figure 2: There is increased T2 signal at the right sided soft tissues of C4-C5 centered at the facet articulation (red arrow). In addition there is involvement of the adjacent right paravertebral muscles.
Figure 3 and Figure 4: Post contrast images demonstrate enhancement of the right facet articulation of C4-C5 with enhancement of the paravertebral muscles (red arrow). No focal rim enhancing fluid collection
【影像诊断】：Septic arthritis of the C4-C5 facet joint 颈4-5椎小关节脓毒性关节炎
- Septic arthritis is a relatively uncommon disorder but must always be suspected in a patient with a new onset spinal symptoms and fever. 脓毒性关节炎是一种相对少见的病变，但是在病人出现新发的颈部症状和发热是需要考虑到其可能性。
- The source of infection is hematogenous spread from a distant septic focus of which UTIs are the most common source.感染是由远处的脓毒性病灶血性播散而来，而尿路感染是最常见的感染源
Septic arthritis of the facet joints (SAFJ) is uncommon, with only about 40 cases reported to date. Septic arthritis of the facet joint typically presents with fever and localized back pain aggravated by movement. The most common scenario is hematogenous dissemination from a distant focus of infection, which is usually in the urinary tract. Of 54 previously reported cases of SAFJ, 47 were documented by bacteriological studies. The organism was S. aureus in 33 (70%) cases, a streptococcus in 7 (16%) cases, a gram-negative rod in 3 (7%) cases, several organisms were recovered in 2 (4%) cases
Radiographs may show destructive change around the facet joint but may be normal initially. Standard radiographs may remain normal for up to 1 month after symptom onset. In addition, the changes are not specific: they consist of joint space narrowing or widening, erosions, and/or subchondral geodes. Tc 99m bone scanning is a key investigation that localizes the infection to the facet joint, detects other foci (e.g., discitis), and helps to select further imaging studies (CT or MRI). MRI is the investigation of choice for assessing the extent of the infection. MRI is sensitive and more specific than CT. Soft tissue signal abnormalities may be visible after only 48 h. The capsule and ligaments typically produce a low-intensity signal on T1-weighted images that enhances after gadolinium injection. T2-weighted images show high-intensity signal. MRI can rule out concomitant discitis and, above all, detect local spread. Local spread may manifest as abscesses, pyomyositis of the spinal muscles or ilio-psoas muscle, or posterior epidural abscess potentially responsible for spinal cord or nerve root compression.