The relationship between the cross-sectional area of the cauda equina and the preoperative symptoms in central lumbar spinal stenosis.

STUDY DESIGN: A cross-sectional registry and imaging cohort study. OBJECTIVES: To study the association between typical symptoms and signs of central spinal stenosis and the minimum cross-sectional area (mCSA) of the cauda equina in patients subsequently undergoing surgery. SUMMARY OF BACKGROUND DATA: Relations between mCSA and the symptoms of spinal stenosis have not been studied before. SUBJECTS AND METHODS: The preoperative walking ability, pain in the leg(s) and back, duration of symptoms and quality of life in 82 men and women subsequently operated for spinal stenosis were related to the digitally determined CSA of the single most constricted level, mCSA of their lumbar spines. RESULTS: A smaller mCSA was directly related to a shorter walking distance before claudication. A small mCSA meant more leg and back pain and a lower health-related quality of life. For those with a walking ability <100 m, the average mCSA was around 53 mm; whereas it was just <69 mm for those able to walk >500 m. The average mCSA did not differ depending on gender, age, or vertebral level. CONCLUSIONS: The mCSA was a strong predictor of the preoperative walking ability, leg and back pain, and was directly related to the quality of life of patients with central spinal stenosis.

Comparison of color LCD and medical-grade monochrome LCD displays in diagnostic radiology.

In diagnostic radiology, medical-grade monochrome displays are usually recommended because of their higher luminance. Standard color displays can be used as a less expensive alternative, but have a lower luminance. The aim of the present study was to compare image quality for these two types of displays. Images of a CDRAD contrast-detail phantom were read by four radiologists using a 2-megapixel (MP) color display (143 cd/m(2) maximum luminance) as well as 2-MP (295 cd/m(2)) and 3-MP monochrome displays. Thirty lumbar spine radiographs were also read by four radiologists using the color and the 2-MP monochrome display in a visual grading analysis (VGA). Very small differences were found between the displays when reading the CDRAD images. The VGA scores were -0.28 for the color and -0.25 for the monochrome display (p = 0.24; NS). It thus seems possible to use color displays in diagnostic radiology provided that grayscale adjustment is used.

Long-term effects of reflux nephropathy on blood pressure and renal function in adults.

AIMS: We investigated whether the grade of renal damage assessed by urography in adult patients with vesicoureteral reflux can be used to identify patients at risk of developing hypertension and/or deterioration of renal function. In addition, maternal and fetal outcome of pregnancy was studied. METHODS: Vesicoureteral reflux was diagnosed at a median age of 27 years (range 16-60) in 115 patients (98 women). Excluding patients subjected to nephrectomy or heminephrectomy after inclusion (n = 12), 88 patients had renal damage at inclusion urography and a median follow-up time of 16 years. The median follow-up time was 18 years in 15 patients without renal damage. Grading of renal damage was performed and blood pressure, serum creatinine concentration and albuminuria were measured. Hypertension was considered to be present if the systolic blood pressure was > or =140 mm Hg and/or the diastolic blood pressure was > or =90 mm Hg. It was classified as mild (<180 mm Hg systolic and <105 mm Hg diastolic), or moderate to severe (> or =180 mm Hg systolic and/or > or =105 mm Hg diastolic). Renal function was classified as stable or deteriorating. RESULTS: There was no significant difference in the frequency of hypertension among those with (52%) or without (33%) renal damage, but moderate to severe hypertension (16 patients) was only seen in patients with renal damage. Median systolic and diastolic blood pressure were higher in patients with than in those without renal damage. Malignant hypertension developed in 4 patients, all had extensive renal damage. Deterioration of renal function occurred in 25 patients, 1 with unilateral and 24 with extensive renal damage (bilateral or in a solitary kidney). This was associated with a high frequency of hypertension (92%) and albuminuria (88%). Sixteen patients developed end-stage renal disease. A total of 242 pregnancies occurred in 89 of the 98 women. Preeclampsia occurred in 16 (18%) women. CONCLUSION: Hypertension in adult patients with reflux nephropathy occurs with any grade of renal damage, whereas deterioration of renal function was strongly associated with extensive bilateral renal damage or damage in a solitary kidney.