Quantitative diffusion-weighted magnetic resonance imaging for the diagnosis of partial-thickness rotator cuff tears.

BACKGROUND: This study investigated diffusion-weighted (DWI) magnetic resonance imaging (MRI) as an alternative to fat-suppressed T2-weighted imaging (FS-T2WI) for assessment of partial-thickness rotator cuff tears (RCTs). METHODS: Patients with arthroscopy proven partial-thickness RCTs who also received MRI (FS-T2WI and DWI) before surgery were prospectively included. Receiver operating characteristic curves were used to compare DWI vs. FS-T2WI using lesion-to-muscle signal intensity ratios. A cutoff point for predicting partial-thickness tears was determined using the Youden index. RESULTS: Included were 146 patients, with a mean age of 48.3 years (range, 19-86 years), of whom 43 had full-thickness RCTs, 67 had partial-thickness RCTs, and 36 had no tears. Areas under receiver operating characteristic curves for diagnosing partial-thickness tears were significantly higher for DWI (0.910) than for FS-T2WI (0.822, P = .016). Lesion-to-muscle signal intensity ratio cutoff values were 1.06 for DWI vs. 1.65 for FS-T2WI, respectively. The sensitivity and accuracy of DWI (89.1% [98 of 110] and 87.7% [128 of 146], respectively) for diagnosing partial-thickness and full-thickness tears were higher than for FS-T2WI (65.5% [72 of 110] and 72.6% [106 of 146], respectively). FS-T2WI, however, had higher specificity (94.4% [34 of 36]) than DWI (83.3% [30 of 36]). CONCLUSIONS: DWI is more accurate and sensitive than FS-T2WI for diagnosing partial-thickness RCTs.

Myelopathy and polyneuropathy caused by nitrous oxide toxicity: a case report.

A 19-year-old man presented with a 1-month history of progressive 4-limb numbness and gait imbalance. Physical examination revealed mild general muscular weakness, areflexia, and wide-based, ataxic, steppage gait. Sensory tests showed diminished superficial sensation below the level of the cervical-thoracic junction and a glove-and-stocking pattern of sensory loss at the 4 extremities. An initial magnetic resonance imaging examination of the cervical spine revealed an increased bilateral signal from the posterior and anterior columns on T(2)-weighted images. Nerve conduction velocity and electromyographic tests revealed polyneuropathy. On further inquiry, the patient admitted to chronic recreational use of nitrous oxide. The final diagnosis was nitrous oxide-induced neurotoxicity. The patient was treated for 5 days with injections of 1000 µg/day vitamin B(12), followed by an additional 2-month treatment at a dose of 1000 µg/week. The numbness resolved after the first week, but there remained a mild sensory ataxic gait. The patient recovered fully after 2 months of treatment and nitrous oxide abstinence. We recommend an investigation of the patient's history of nitrous oxide exposure in cases where an individual presents to the emergency department or outpatient department with acute numbness characterized by megaloblastic red blood cells and symmetric neurologic deficits.

Comparison of radiological measures for diagnosing flatfoot.

BACKGROUND: In the Taiwanese military, flatfoot is indicated by a calcaneal-fifth metatarsal angle (arch angle) ≥165°. However, the arch angle is not always easily defined. PURPOSE: To assess correlations between the arch angle and other radiographic measures and thus identify an alternative radiographic measure for diagnosing flatfoot. MATERIAL AND METHODS: Eighty-seven male Taiwanese military recruits were studied (median age 22 years, interquartile range 20-23 years). Lateral, weight-bearing radiographs were taken. Five radiographic measurements, including the calcaneal-fifth metatarsal angle (arch angle), medial arch angle (MAA), calcaneal pitch angle (CP), talus angle (TA), and talar-first metatarsal angle (TFM) were made. Correlations between the arch angle and all other measures were determined. A cut-off value for predicting flatfoot (arch angle ≥165°) was determined for each measure using the Youden index and receiver-operating characteristic (ROC) curves were generated for each measure to assess diagnostic accuracy. RESULTS: All measures were significantly correlated with arch angle (P < 0.05); however, the strongest correlation was for CP (ρ = -0.905, P < 0.001). CP was associated with the highest area under the ROC (0.988 vs. 0.711-0.912 for the other measures). Further, CP (cut-off <12.3°) had the highest sensitivity (92.0%), positive predictive value (76.7%), and negative predictive value (96.5%). TFM (>9.5°) had the highest specificity (90.3% vs. 88.75 for CP <12.3°). CONCLUSION: CP is inversely correlated with arch angle in Taiwanese male military recruits. CP < 12.3° is a significant predictor of flatfoot. Assessment of CP may be used as an alternative means of diagnosing flatfoot when the arch angle is not easily defined.

Impact of beverage consumption, age, and site dependency on dual energy X-ray absorptiometry (DEXA) measurements in perimenopausal women: a prospective study.

INTRODUCTION: The aim of this study was to determine the best site for bone mineral density (BMD) measurements based on T-scores, age, and beverage consumption. MATERIAL AND METHODS: In this prospective study, 271 women stratified by age (average age: 61.9 years) underwent dual energy X-ray absorptiometry (DEXA) scanning of their lumbar spine, hips, and forearms. Osteoporosis was defined as a BMD of 2.5 standard deviations or more below the mean peak bone mass based on a reference population of adult women (translated as a T-score ≤ -2.5), as measured by DEXA. Participants were also evaluated regarding alcohol and caffeine consumption by a semiquantitative questionnaire. RESULTS: A significant discrepancy was observed in the classification of osteoporosis at different locations, with hip and forearm showing the best correlation (Pearson's r = 0.627, p < 0.001). In addition, for participants over 50 years of age, hip and forearm showed the best correlation. Significant correlations were also noted between forearm T-scores and caffeine consumed and, to a lesser extent, the level of alcohol consumption. In the group ≤ 50 years of age, lumbar spine and forearm T-scores were only associated with alcohol consumption. In the group over 50 years of age, hip and forearm T-scores were only associated with caffeine consumption. CONCLUSIONS: Bone mineral density measurements at the hip and forearm correlated with caffeine consumption in elderly Taiwanese women. This is an important finding since age and caffeine consumption are known risk factors for osteoporosis.

Transarterial treatment of acute gastrointestinal bleeding: prediction of treatment failure by clinical and angiographic parameters.

BACKGROUND: Acute gastrointestinal bleeding (GIB) is a life-threatening abdominal emergency and can be treated by transarterial embolization (TAE). Rehemorrhage and poor outcome are associated with several clinical factors. This study investigated the clinical and angiographic parameters associated with treatment failure for patients with acute GIB undergoing TAE. METHODS: Sixty-seven patients who had angiographic evidence of contrast extravasation and who received subsequent TAE were included in this study. Treatment failure was defined as continuous or recurrent bleeding that required surgery within 7 days after the bleeding episode and/or death within 1 month. Univariate and multivariate logistic regression was applied to analyze the clinical and angiographic parameters affecting treatment failure. RESULTS: Patients were divided into two groups: success (n = 35, 52.3%) and failure (n = 32, 47.7%). In the failure group, 22 patients (68.9%) re-bled and then received surgery. With the aid of angiographic localization, 68.2% (15 of 22 patients) survived after surgery. The other 10 patients who did not receive surgery died within 30 days. Several clinical and angiographic parameters analyzed by multivariate analysis were associated with treatment failure (p < 0.05), including presence of coagulopathy [odds ratio (OR), 14.7], number of supplying arteries >1 (OR, 13.2), and a distance of >5 cm (OR, 6.3) during TAE. CONCLUSION: Angiographic parameters associated with treatment failure in patients undergoing TAE are established when the number of supplying arteries is >1, and a distance of >5 cm. Patients with these risk factors should be watched carefully for recurrence in the post-procedural period.

Extramedullary-intradural spinal metastasis of small cell lung cancer causing cauda equina syndrome.

Small cell lung cancer (SCLC) has a very aggressive clinical progression with widespread metastases. We describe the case of a patient with SCLC treated with concurrent chemoradiotherapy. One month later, after finishing the scheduled treatment, the patient was admitted to the hospital again with symptoms of low back pain that radiated to bilateral lower legs with painful paresthesias, urinary incontinence, and constipation. After a series of examinations, including bone scan and magnetic resonance imaging, the patient received an L2-L3 laminectomy. The concluded diagnosis through histopathologic examination with immunohistochemistry was extramedullary-intradural spinal metastasis causing cauda equina syndrome. The metastatic tumour originated from the SCLC. To the best of our knowledge, this is the first reported case of SCLC metastasized to the cauda equina causing cauda equina syndrome.