CT of the abdomen: degree and quality of enhancement obtained with two concentrations of the same iodinated contrast medium with fixed iodine delivery rate and total iodine load.

OBJECTIVES: to compare vascular and parenchymal enhancement in abdominal computed tomography (CT) using two iodine concentrations (370 vs 300mgI/mL) of the same contrast medium (CM) molecule (iopromide), using fixed iodine delivery rate (IDR, 1.2gI/s) and total iodine load (630mgI/kg). METHODS: 144 patients were randomized into two groups: group A receiving iopromide 370 and group B receiving iopromide 300. Attenuation values (AV) were measured in correspondence to key anatomical structures on different phases and compared between groups with parametrical tests. Qualitative analysis was also performed. Peak injection pressure and local discomfort at the site of injection (pain and warmth) were registered. RESULTS: mean AV of abdominal aorta in late arterial phase were 300.32±59.76 for group A and 298.2±59.14 for group B (p=0.8); mean AV of portal vein in portal phase were 190.5±29.92 for group A and 192.91±24.12 for group B (p=0.6). Mean AV of liver parenchyma in portal phase were 124.73±18.22 for group A and 125.11±15.7 for group B (p=0.9); mean AV of liver at equilibrium were 85.11±7.75 for group A and 85.41±8.09 for group B (p=0.8). Qualitative analysis did not show significant differences between groups (p>0.05). Median peak injection pressure was lower in group B (93psi, 76-172) than in group A (115psi, 88-288, p<0.0001), while discomfort at injection site was not significantly different (p>0.05). CONCLUSIONS: with fixed IDR and total iodine load, comparable quantitative and qualitative enhancement can be achieved with different concentrations of the same CM. Peak injection pressure increases using CM with higher iodine concentration.

Crohn's disease: value of diagnostic imaging in the evaluation of anastomotic recurrence.

UNLABELLED: In patients who had previously undergone ileocolic resection due to Crohn's disease (CD) complications, anastomotic recurrence is a frequent event, which may lead to further surgical interventions. Optical colonoscopy with retrograde ileoscopy is currently the reference standard technique to confirm the clinical suspicion of anastomotic recurrence; however, the ileal side of ileocolic anastomoses may not be assessed due to technical complexities in approximately 1/3 of cases. Moreover, endoscopy allows for an investigation limited to the mucosal surface without demonstrating trans-mural involvement and/or penetrating complications (i.e. fistulas and abscesses). Imaging plays an important role in the assessment of both ileocolic and entero-enteric anastomoses in patients with CD. Conventional radiological methods (i.e. small bowel enteroclysis and small bowel follow through) can effectively depict the presence of aphthous ulcers and other mild and subtle mucosal abnormalities, but they are not precise for the diagnosis of transmural and extramural disease. CT - and MR- enterography accurately demonstrate both the extent of bowel wall involvement and the presence of penetrating complications. The main cross-sectional imaging findings observed in CD (including anastomotic recurrence) are small bowel wall thickening with bilaminar or trilaminar stratification, hyperdensity and oedema of the mesenteric fat, engorged mesenteric vasa recta ("comb sign"), sub-mucosal fibro-fatty infiltration and mesenteric adenopathy. Ultrasonography performed after distension of small bowel loops with anechoic contrast agents (Small Intestine Contrast Ultrasonography - SICUS -) is a non-invasive imaging technique which can detect early inflammatory alterations of the anastomosis. On the other hand ultrasonography is an operator-dependent technique and it lacks of a large anatomic field of view. KEY WORDS: Computed Tomography enterography, Crohn's disease, Ileocolic anastomosis, Magnetic Resonance Imaging.

Crohn's disease recurrence in patients with ileocolic anastomosis: value of computed tomography enterography with water enema.

OBJECTIVES: The main objective of the present work was to determine the diagnostic value of CT-enterography with water enema (CTe-WE) in the assessment of the ileocolic anastomosis in patients with Crohn's disease (CD). The prevalence of synchronous inflammatory lesions (SILs) involving gastrointestinal segments distinct from the anastomosis was also determined. Further, the association between the type of ileocolic anastomosis and the behavior (i.e. inflammatory, stricturing, penetrating) of CD recurrence was evaluated. METHODS: 51 patients were retrospectively included (26 [51%] male and 25 [49%] female; mean age: 52.88 years ± 13.35). Ileocolic anastomoses were: 18 (35.3%) stapled side-to-side, 17 (33.3%) end-to-side, and 16 (31.4%) end-to-end. CTe-WEs were reviewed in consensus by two gastrointestinal radiologists. Endoscopy and medical records were used as reference standards. RESULTS: CTe-WE yielded 95.35% sensitivity (CI 95%: 84.19-99.43%), 75.00% specificity (CI 95%: 34.91-96.81%), and 92.15% diagnostic accuracy (CI 95%: 81.31-98.02%). Anastomotic recurrence was found in 41/51 (80.4%) patients, including 30/41 (73.2%) cases of isolated anastomotic recurrence, and 11/41 (26.8%) cases of anastomotic recurrence with a SIL. A significant lower prevalence of stricturing recurrence was observed in patients with stapled side-to-side anastomoses (p=0.033). CONCLUSIONS: CTe-WE provides a good distension of both sides of ileocolic anastomoses allowing the detection of SILs.

Hip ultrasound.

In newborns, US has an established role in the detection and management of developmental dysplasia of the hip. Later in childhood, when the limping child is a major diagnostic dilemma, US is extremely helpful in the identification of the varied disease processes underlying this condition, as transient synovitis, septic arthritis, Perthes disease and slipped femoral capital epiphysis. In adolescent practicing sporting activities, US is an excellent means to identify apophyseal injures about the pelvic ring, especially when avulsions are undisplaced and difficult-to-see radiographically. Later on, in the adulthood, US is an effective modality to diagnose tendon and muscle injuries about the hip and pelvis, identify effusion or synovitis within the hip joint or its adjacent bursae and guide the treatment of these findings. The aim of this article is to provide a comprehensive review of the most common pathologic conditions about the hip, in which the contribution of US is relevant for the diagnostic work-up.

US imaging of the musculocutaneous nerve.

PURPOSE: To describe the potential value of high-resolution sonography for evaluation of the musculocutaneous nerve (MCN). MATERIALS AND METHODS: The normal anatomy of the MCN was evaluated on three cadaveric limbs and correlated with the US images obtained in 15 healthy subjects. Seven consecutive patients with MCN neuropathy were then evaluated with sonography using 17.5 and 12.5-MHz broadband linear array transducers. All patients had abnormal nerve conduction studies and underwent correlative MR imaging on a 1.5-T system. RESULTS: One-to-one comparison between cadaveric specimens and sonographic images showed that the MCN can be reliably identified from the axilla through the elbow, including the lateral antebrachial cutaneous (LAbC) nerve. In the patients group with MCN neuropathy, sonography allowed detection of a wide spectrum of abnormalities. In 5/7 cases, a spindle neuroma was depicted in continuity with the nerve. In one case, US identified focal swelling of the nerve and in another case US was negative. The neuroma was hyperintense on T2-weighted sequences in 75% of cases. In one patient, the nerve showed Gd-enhancement on fat-suppressed T1-weighted sequences. The nerve was never detected on unenhanced T1-scans. Owing to its small-size and out-of-plane course, the MCN may be more reliably depicted with sonography rather than with MR imaging. CONCLUSIONS: US is promising for evaluating traumatic injuries of the MCN. By providing unique information on the entire course of the nerve, US can be used as a valuable complement of clinical and electrophysiologic findings.

Traumatic neuropathies: spectrum of imaging findings and postoperative assessment.

Traumatic injury to peripheral nerves is a significant cause of morbidity and disability. Until reinnervation occurs, electrodiagnostic studies cannot differentiate severe axonotmetic lesions (Sunderland class 4) from complete nerve transection or neurotmesis (Sunderland class 5). This limitation is relevant clinically because in cases of neurotmesis an improved outcome may be achieved with an early surgical repair (within 1 week after trauma). High-resolution ultrasound (US) is an efficient modality to visualize injured nerves and is becoming increasingly important among radiologists and surgeons. Magnetic resonance (MR) imaging is complementary to high-resolution US, especially in evaluating deep-seated and proximal nerve segments. This article describes the imaging features of traumatic peripheral nerve lesions. The role of diagnostic imaging in stretching injuries, contusion trauma, penetrating wounds, and after surgery is discussed. A multimodality diagnostic approach including physical examination, electrophysiology, and US and MR imaging allows an accurate evaluation of most peripheral nerves. Imaging assessment of peripheral nerves trauma is useful for the diagnosis, follow-up, and postoperative evaluation.

Peripheral nerves: ultrasound-guided interventional procedures.

Specific ultrasound (US)-guided interventional procedures on peripheral nerves are reviewed in this article including regional anesthesia, biopsy of neural lesions, and some injection therapies. For these procedures, US is the best modality to provide a safe imaging guidance because of its excellent spatial resolution and real-time capabilities. With US guidance, the radiologist can visualize the needle tip continuously and ensure that the needle is placed precisely in the desired location, avoiding the risk of inadvertent nerve damage. Practical tips and tricks for US-guided needle placement, biopsy of neural lesions, and US-guided therapy are reviewed in this article. The use of US-guided injections in specific clinical settings, such as the percutaneous treatment of carpal tunnel syndrome, Morton's and saphenous neuromas, painful stump neuromas, piriformis syndrome, and meralgia paresthetica are also illustrated here. US allows the clinician to inject drugs with little or no patient discomfort.