Iliofemoral venous stenting extending into the femoral region: initial clinical experience with the purpose-designed Zilver Vena stent.

AIM: The aim of the study was to assess the early clinical experience with the Zilver Vena stent in treating patients with iliofemoral venous obstruction at a tertiary referral hospital. METHODS: Demographic, procedural, and follow-up data of 20 patients (12 women; mean age of 59 ± 17 years) treated for iliofemoral vein obstruction between January 2011 and December 2012 were retrospectively reviewed. Most patients presented with acute obstruction (N.=14; 70%), and 10 patients (50%) had an active malignancy. Patency was established venographically at procedure end, and was evaluated with Duplex ultrasound in follow-up. RESULTS: Venous obstructions were attributed primarily to extrinsic compression from a malignant or other mass in the pelvis (N.=9) and May-Thurner (N.=5). Flow was re-established through the obstructed venous segment in all patients at procedure end. In follow-up, three patients experienced early stent thrombosis (<30 days); the clinical patency rate was 85% (17/20 patients). Clinical improvement was demonstrated by decreased leg swelling in the remaining 17 patients. CONCLUSION: The Zilver Vena stent performed favorably in this challenging patient population; these results need to be confirmed in multicenter studies.

MR enterography in the evaluation of small bowel dilation.

Magnetic reasonance (MR) enterography enables high contrast resolution depiction of the location and cause of bowel obstruction through a combination of predictable luminal distension and multiplanar imaging capabilities. Furthermore, because the patient is not exposed to ionizing radiation, sequential "dynamic" MR imaging can be performed repeatedly over time further facilitating depiction of the site and/or the cause of obstruction. With increasing availability of MR imaging and standardization of the oral contrast medium regimens, it is likely that this technique will assume an ever-increasing role in the evaluation of small bowel dilation in the coming years. We illustrate the utility of MR enterography in the evaluation of small bowel dilation, whether it be mechanical, functional (e.g., ileus), or related to infiltrative mural disease.

Imaging of the gastrointestinal complications of systemic chemotherapy.

Gastrointestinal complications of chemotherapy may be serious and potentially life-threatening. Familiarity with and awareness of the potential complications associated with various chemotherapeutic agents/regimens is paramount to enable accurate and timely diagnosis. In this article we review the radiological manifestations of the most notable gastrointestinal complications associated with chemotherapeutic administration.

CT evaluation of Chamberlain's, McGregor's, and McRae's skull-base lines.

AIM: To evaluate the mean distance from the odontoid process of C2 to the standard skull-base lines (Chamberlain's, McGregor's, and McRae's lines) on computed tomography (CT) imaging. To compare these measurements to previously documented plain radiograph and magnetic resonance imaging (MRI) measurements. MATERIALS AND METHODS: Reformatted midline sagittal CT images of 150 adults were retrospectively evaluated. The shortest perpendicular distance was measured from the Chamberlain's, McGregor's and McRae's baselines for each subject to the odontoid tip. Statistical analysis was performed to compare the CT data with the previously obtained MRI and plain film data. RESULTS: The mean position of the odontoid process was 1.4mm below Chamberlain's line (median 1.2 mm, SD 2.4 mm), 0.8 mm (median 0.9 mm, SD 3 mm) below McGregor's line and 5 mm (median 5 mm, SD 1.8 mm) below McRae's line. There is no significant difference between male and female results (p>0.05) or between these CT and previous MRI measurements (p>0.05). CONCLUSION: These results provide the mean and range of normal distance from the odontoid process to the most frequently used skull-base lines on the current population on CT.

Low-dose, time-resolved, contrast-enhanced 3D MR angiography in cardiac and vascular diseases: correlation to high spatial resolution 3D contrast-enhanced MRA.

AIM: To evaluate the effectiveness of low-dose, contrast-enhanced, time-resolved, three-dimensional (3D) magnetic resonance (MR) angiography (TR-MRA) in the assessment of various cardiac and vascular diseases, and to compare the results with high-resolution contrast-enhanced MRA (CE-MRA). MATERIALS AND METHODS: Thirty consecutive patients underwent contrast-enhanced 3D TR-MRA and high spatial resolution 3D CE-MRA for evaluation of cardiac and thoracic vascular diseases at 1.5 T, and neurovascular, abdominal and peripheral vascular diseases at 3T. Gadolinium-based contrast medium was administered at a constant dose of 5 ml for TR-MRA, and 20 ml (lower extremity 30 ml) for CE-MRA. Two readers evaluated image quality using a four-point scale (from 0=excellent to 3=non-diagnostic), artefacts and findings on both datasets. Interobserver variability was tested with kappa coefficient. RESULTS: The overall image quality for TR-MRA was in the diagnostic range (median 0, range 0-1; k=0.74). Readers demonstrated important additional dynamic information on TR-MRA in 28 of 30 patients (k=0.84). Confident evaluation of organ perfusion (n=23), arteriovenous malformation/fistula flow patterns (n=7), exclusion of intra-cardiac shunts (n=6), and assessment of stent and conduit patency (n=5) were performed by both readers using TR-MRA. Readers demonstrated fine vascular details with higher confidence in 10 patients on CE-MRA. Using CE-MRA, Reader 1 and 2 depicted anatomical details in 6 and 5 patients, respectively, only on CE-MRA. CONCLUSION: Low-dose TR-MRA yields rapid and important functional and anatomical information in patients with cardiac and vascular diseases. Due to limited spatial resolution, TR-MRA is inferior to CE-MRA in demonstrating fine vascular details.

Assessment of craniospinal arteriovenous malformations at 3T with highly temporally and highly spatially resolved contrast-enhanced MR angiography.

BACKGROUND AND PURPOSE: Patients with arteriovenous malformation (AVM) are known to have an elevated risk of complications with conventional catheter angiography (CCA) but nonetheless require monitoring of hemodynamics. Thus, we aimed to evaluate both anatomy and hemodynamics in patients with AVM noninvasively by using contrast-enhanced MR angiography (CE-MRA) at 3T and to compare the results with CCA. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this Health Insurance Portability and Accountability Act-compliant study. Twenty control subjects without vascular malformation (6 men, 18-70 years of age) and 10 patients with AVMs (6 men, 20-74 years of age) underwent supra-aortic time-resolved and high-spatial-resolution CE-MRA at 3T. Large-field-of-view coronal acquisitions extending from the root of the aorta to the cranial vertex were obtained for both MRA techniques. Image quality was assessed by 2 specialized radiologists by using a 4-point scale. AVM characteristics and nidus size were evaluated by using both CE-MRA and CCA in all patients. RESULTS: In patients, 96.6% (319/330) of arterial segments on high-spatial-resolution MRA and 87.7% (272/310) of arterial segments on time-resolved MRA were graded excellent/good. MRA showed 100% specificity for detecting feeding arteries and venous drainage (n = 8) and complete obliteration of the AVM in 2 cases (concordance with CCA). Nidus diameters measured by both MRA and CCA resulted in a very strong correlation (r = 0.99) with a mild overestimation by MRA (0.10 cm by using the Bland-Altman plot). CONCLUSION: By combining highly temporally resolved and highly spatially resolved MRA at 3T as complementary studies, one can assess vascular anatomy and hemodynamics noninvasively in patients with AVM.

MRI evaluation and measurement of the normal odontoid peg position.

AIM: To measure the normal distances (and range) from the tip of the odontoid peg to the different reference skull baselines (Chamberlain's, McGregor's, and McRae's line) using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We retrospectively evaluated midline sagittal MRI brain images of 200 adults chosen randomly. Patients did not have symptoms or signs suggestive of basilar impression, spinal trauma, vertebral collapse or disease. Using SPSS data analysis program histograms, mean and standard deviation (SD), median and range values were calculated. These findings were then compared with previous plain radiograph measurements. RESULTS: The mean position of the odontoid peg was 1.2 mm (median 1.5 mm, SD 3 mm) below Chamberlain's line; 0.9 mm (median 1.1, SD 3 mm) below McGregor's line; and 4.6 mm (median 4.8, SD 2.6) below McRae's line. CONCLUSION: Based on the current population, these results provide the mean and range of normal distances from the odontoid peg to the most frequently used skull baselines using MRI.

Modification of pain on injection of propofol. A comparison of pethidine and lignocaine.

One hundred and fifty ASA 1 and 2 patients were randomly allocated to receive pethidine 25 mg (1 ml), lignocaine 10 mg (1 ml) or 0.9% saline (1 ml) on a double-blind basis, as pretreatment to reduce pain on injection of propofol. Both active treatments were significantly better than placebo at preventing pain (p < 0.01). Lignocaine was most effective in preventing pain in men (p < 0.05) whilst pethidine was more effective in women (p < 0.05).

Intra-articular analgesia for arthroscopic meniscectomy.

Intra-articular morphine has been shown to provide prolonged analgesia after arthroscopic knee surgery; the addition of local anaesthetic agents has been reported to improve this analgesic effect. Pethidine possesses local anaesthetic properties, and therefore this study was designed to evaluate its analgesic efficacy after arthroscopic meniscectomy. Sixty patients were allocated randomly to receive intra-articular injections of pethidine 50 mg, morphine 5 mg or saline after elective arthroscopic meniscectomy. Postoperative pain was assessed using an interval visual analogue scale and measuring analgesic requirements. Both treatment groups had significantly lower pain scores compared with the control group. Patients in the pethidine group had lower pain scores than those in the morphine group at 0.5, 1 and 2 h, but significantly higher scores at 12 and 24 h. These observations suggest that the local anaesthetic effect of pethidine may be responsible for the improved early analgesia, but its duration of action appears to be less than that of morphine.