Low-dose unenhanced CT protocols according to individual body size for evaluating suspected renal colic: cumulative radiation exposures.

PURPOSE: The aim of this study was to assess the radiation dose of dose-reduced unenhanced abdominal multidetector computed tomography (MDCT) scan protocols for suspected renal colic in patients within normal weight range and overweight-obese patients and to record the cumulative dose of repeated examinations. MATERIALS AND METHODS: Over a 2-year period, we performed 1,026 unenhanced CT examinations for urolithiasis; among these, 675 were performed on 636 patients referred from the emergency department. Patients were divided into two groups on the basis of body mass index (BMI): normal weight (BMI <25 kg/m(2) group 1); overweight and obese (BMI >25 kg/m(2) group 2). For patients in group 1 and group 2, the protocols of our 64-row scanner prescribe tube current settings at 70 mAs and 150 mAs, respectively. The dose-length product (DLP) estimated by using the manufacturer's software was converted into effective dose (ED). RESULTS: Mean DLP and ED were 177 and 345 mGy/cm and 2.4 and 4.8 mSv for group 1 and group 2, respectively. A subset of 25 patients (3.7%) underwent two or more examinations, with estimated ED ranging from 4.8 to 19.2 mSv. CONCLUSIONS: Although radiation dose is nearly double in overweight-obese patients undergoing MDCT, it remains lower than that delivered by a standard-dose protocol. Patients with flank pain, who are often young, are at increased risk for serial CT examinations. Use of a low-dose protocol is mandatory in both normal-weight and obese patients to minimise radiation exposure.

Subintimal angioplasty as the first-choice revascularization technique for infrainguinal arterial occlusions in patients with critical limb ischemia.

Our aim was to appraise the feasibility and outcomes of subintimal angioplasty (SA) for the percutaneous revascularization of infrainguinal arterial occlusions in patients with critical limb ischemia (CLI). We retrospectively assessed 117 SA procedures in 109 limbs with complete infrainguinal occlusions from 105 patients with CLI. Among these, the superficial femoral artery (SFA) was the only occluded vessel in 27 limbs, while infrapopliteal (IP) occlusions occurred in 82. Average clinical follow-up was 13.5 months (range 1-37). Outcomes were assessed according to the site of SA (SFA vs. IP) and the length of the occlusion (< vs. > or =10 cm). Univariate analyses for the rate of limb salvage and patient survival according to the Kaplan-Meier method were performed. SA-based revascularization had a success rate of 84.4% per limb (89% in SFA and 83% in IP occlusions). During follow-up 12 patients (11.3%) underwent major limb amputation, 11 (10.3%) underwent bypass surgery, and 14 (13.7%) died. Most amputations occurred in patients in whom SA had been unsuccessful and were associated with long (> or =10 cm) occlusions (p = 0.055). Clinical restenosis occurred in seven (6.6%) patients. Survival analysis showed at 6, 12, and 24 months limb salvage rates of 90%, 87%, and 85% and overall survival rates of 90%, 88%, and 83%, respectively. Complications of SA were uncommon (4.7%) and all were successfully managed percutaneously. Infrainguinal SA is an effective revascularization technique that provides a high likelihood of limb salvage and should be the first-choice strategy in the management of patients with CLI.

The value of computed tomography in the diagnosis of low back pain. A review of 2,012 cases.

AIM: The aim of this study was to establish the effective role of CT in the diagnosis of low back pain, and whether CT features correlate with clinical signs and symptoms. METHODS: Two thousand and twelve consecutive patients, of which 866 males and 1,146 females, aged 22 to 91 years, affected by generic painful back, have been studied in the period between January 2000 and October 2002. Volumetric CT of the lumbo-sacral column was performed on all the patients, employing a Philips Tomoscan SR 7000 (Eindhoven, The Netherlands). Sections of 3 mm in thickness were obtained, employing window and level of window both for bone and soft tissues. Contrast medium was not injected. RESULTS: Regarding the distribution of lesions, 172 males were affected by one, 586 from 2 to 4, 102 more than 4 lesions; 6 subjects were without. On the contrary, 196 females had a single lesion, 611 from 2 to 4, 331 more than 4 and 8 did not have any one. In females, the age group most involved is encompassed between 51 and 80 years; the more frequent alterations, in decreasing order, were: bulging disc, synovial facet syndrome, disc herniation and vacuum phenomenon. In males incidence age related and frequency of various pathologies were overlapped to that observed in females; however the incidence of disc herniation in males is greatest between 41 to 50 years. CONCLUSIONS: Low back pain, with or without radiation to the sciatic and femoral nerves, is one of the most common diseases, involving approximately 2/3 of the adult population sooner or later in life. Anatomically the center of pain is the lumbar column (from L3 to L5), the lumbo-sacral junction, the sacrum, the sacro-iliac joints, and the sacral-coccygeal region. Generally, it is a benign syndrome; however, since a pathologic condition is recognized in 15% of cases, then this condition must always be diagnosed. The list of events producing lumbar pain seems to be endless: therefore differential diagnosis must be based on appropriate anatomic and etiologic factors, also considering that pathogenesis (due to mechanical, compression, inflammatory, and neuropathic factors) is directly influenced by social and psychologic factors. Initially a conventional X-ray was used for the diagnosis of images, subsequently, arthrography and myelography were used; today CT is useful in the detection of bone and soft tissue structures, especially using multiplanar reformatted images. It is a noninvasive procedure that usually reveals the cause of radicular compression and demonstrates lateral and intraforaminal pathologic condition well. MRI represents the last technical development. The characteristics of all these techniques are such as to achieve a full diagnosis. Their reconciled use is in relation to the current clinical question, and it also depends on various considerations, not only technical matters, but availability of equipment and costs too, even if conventional radiography must always precede every other survey.