The evaluation of peripheral nerve disorders has traditionally relied on clinical history, physical examination and electrodiagnostic studies. The electrodiagnostic study is currently the most popular procedure to analyse the nerve lesion, but it is painful and its result is operator dependent. The purpose of this study is to evaluate the significance of MRI signal change of denervated muscle in peripheral nerve as an adjuvant study of electrodiagnostic study. After the compression of sciatic nerves in 20 rabbits and severance of scitic nerve in 10 rabbits, the signal change of both T1WI(TR; 450 msec, TE; 15 msec) and T2WI(TR; 3,000 msec TE; 90 msec) of calf muscles were compared with EMG findings of the same muscles. Signal intensity ratio(SIR) of calf muscles was measured and compaired with the grade of abnormal spontaneous activity in the same muscles in needle EMG study. Serial studies were done on 4th day, 1 week, 2 weeks, 3 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks after sciatic nerve injury. Among 25 rabbits showing abnormal spontaneous activity in needle EMG, the signal intensity of both T1WI and T2WI was increased in 13 rabbits. The signal intensity began to increase at 1 week in 10 rabbits and 2 weeks in 3 rabbits following nerve injury which was about 1 week later than appearance of abnormal spontaneous activity in needle EMG study. There were no signal intensity increase in rabbits which showed no abnormal spontaneous activity in needle EMG study. The signal intensity ratio and grade of abnormal spontaneous activity had a good correlation(Spearman's correlation coefficiency : 0.635). The signal intensity of 3 rabbits which showed regeneration evidence in needle EMG study returned to normal. These findings suggest that MRI study of denervated muscle can be used as an evaluation method for severe peripheral nerve injury, howeverits value is doubtful in mild peripheral nerve injury.
Magnetic Resonance Imaging* ; Muscles ; Needles ; Peripheral Nerve Injuries ; Peripheral Nerves ; Physical Examination ; Rabbits ; Regeneration ; Sciatic Nerve*

PURPOSE: Popliteal artery entrapment syndrome (PAES) is rare but major cause of non-atheromatous popliteal arterial insufficiency in young. Because of its rareness, it is often neglected or misdiagnosed as thrombosis or embolism. Consequently surgeons would lose the appropriate time of treatment. METHOD: We reviewed 11 cases of PAES from 1994 to 2002 regarding to clinical characteristics, image findings, management and their results. RESULT: Two of 11 patients had bilateral involvement. All patients were male and aged 12 to 45 year old (mean; 32.1). Intermittent claudication was presented as initial symptom in all. One had toe gangrene. Conventional arteriography (11 cases) was used as initial diagnostic method. CT (7 cases) and MR (4 cases) angiography were also used to make diagnosis. Type II PAES were most common in 7 limbs. 11 limbs of 10 patients underwent operation. One was managed conservatively because of advanced liver cirrhosis. Resection of medial head of gastrocnemius and popliteal arterial bypass were performed in 7 limbs. One myectomy with femoroposterotibial bypass, one femoropopliteal bypass without myectomy, and myectomy with patch angioplasty were performed. Postoperative complication occurred in two limbs. One had occlusion of graft, another had occluded segment of endarterectomised popliteal artery. Primary graft patency at 6 mo, 1 yr and 3 yr were 81% 81%, 81% respectively. CONCLUSION: In young patients with claudication who have localized lesion at popliteal artery, clinicians should pay attention to rule out PAES. Accurate diagnosis can be achieved by CT or MR angiography. Early surgical correction is recommended to minimize surgical procedure and reduce complication of the disease.
Angiography ; Angioplasty ; Diagnosis ; Embolism ; Extremities ; Gangrene ; Head ; Humans ; Intermittent Claudication ; Liver Cirrhosis ; Male ; Middle Aged ; Popliteal Artery* ; Postoperative Complications ; Thrombosis ; Toes ; Transplants

Background and Objectives: Oropharyngeal squamous cell carcinoma (OPSCC) can be caused by human papilloma virus (HPV) infection or other factors like smoking. The 8th Edition of the AJCC Cancer Staging Manual recommends different staging and treatment approaches based on etiology. Despite criticisms of its low specificity, the current guidelines suggest using p16 immunohistochemistry (IHC) as a surrogate marker for the HPV-related OPSCC. This study assessed the reliability of p16 as a surrogate marker by correlating the survival rates of OPSCC patients with the results of p16 IHC and HPV-DNA testing.Subjects and Method A retrospective analysis was performed on patients treated for tonsil squamous cell carcinoma at a tertiary medical institution between 1994 and 2018. All patients underwent p16 immunostaining and HPV-DNA chip tests. Out of 88 patients, 17 were excluded due to insufficient data or secondary primary cancer, leaving 71 patients. Results: Among the 71 patients, 51 were p16 positive and 49 were HPV-DNA positive; both tests were associated with extended survival. However, discrepancies were noted in 18 patients: specifically, 11 patients were p16 positive but HPV-DNA negative, displaying a different survival pattern compared to HPV-associated and non-HPV-associated patients. Conclusion Both p16 immunostaining and HPV-DNA testing have their pros and cons. p16 immunostaining is cost-effective but has lower specificity. The study found discrepancies in 18 patients, suggesting that relying solely on p16 immunostaining may have limitations. It would be advisable to complement it with additional tests like the HPV-DNA chip test to predict the disease’s prognosis more accurately.