A. Lo Casto

Comparison of iodinated contrast media for the assessment of atherosclerotic plaque attenuation values by CT coronary angiography: observations in an ex vivo model

OBJECTIVE To compare the influence of different iodinated contrast media with several dilutions on plaque attenuation in an ex vivo coronary model studied by multislice CT coronary angiography. METHODS In six ex vivo left anterior descending coronary arteries immersed in oil, CT (slices/collimation 64×0.625 mm, temporal resolution 210 ms, pitch 0.2) was performed after intracoronary injection of a saline solution, and solutions of a dimeric isosmolar contrast medium (Iodixanol 320 mgI ml(-1)) and a monomeric high-iodinated contrast medium (Iomeprol 400 mgI ml(-1)) with dilutions of 1/80 (low concentration), 1/50 (medium concentration), 1/40 (high concentration) and 1/20 (very high concentration). Two radiologists drew regions of interest in the lumen and in calcified and non-calcified plaques for each solution. 29 cross-sections with non-calcified plaques and 32 cross-sections with calcified plaques were evaluated. RESULTS Both contrast media showed different attenuation values within lumen and plaque (p<0.0001). The correlation between lumen and non-calcified plaque values was good (Iodixanol r=0.793, Iomeprol r=0.647). Clustered medium- and high-concentration solutions showed similar plaque attenuation values, signal-to-noise ratios (SNRs) (non-calcified plaque: medium solution SNR 31.3±15 vs 31.4±20, high solution SNR 39.4±17 vs 37.4±22; calcified plaque: medium solution SNR 305.2±133 vs 298.8±132, high solution SNR 323.9±138 vs 293±123) and derived contrast-to-noise ratios (p>0.05). CONCLUSION Differently iodinated contrast media have a similar influence on plaque attenuation profiles. ADVANCES IN KNOWLEDGE Since iodine load affects coronary plaque attenuation linearly, different contrast media may be equally employed for coronary atherosclerotic plaque imaging.

Sialodochoplasty in the treatment of salivary-duct stricture in chronic sialoadenitis: technique and results

Purpose.This study was undertaken to investigate peroral balloon angioplasty of salivary-duct strictures (sialodochoplasty) in chronic sialadenitis, analysing the technique, results and limitations.Materials and methods.Nine patients underwent sialodochoplasty: seven for Stensens-duct strictures and two for Whartons-duct strictures. One patient had a double stricture of Stensens duct and another a salivary stone associated with a Whartons-duct stricture. All patients were subjected to preliminary sialography to evaluate stricture site, length and grade. Sialodochoplasty was performed after local anaesthesia and progressive dilation of the salivary-duct orifice.Results.The stricture was successfully dilated in 7/9 patients. The stricture was unchanged after dilatation in one patient, and in another, it recurred after 13 months. In the patient with a double stricture of Stensens duct, one was resolved and the other was only partially dilated, with significant symptom improvement. One patient developed a new episode of sialadenitis after 3 months, which resolved with medical therapy. Five out of seven patients were asymptomatic at follow-up.Conclusions.Sialodochoplasty is an effective procedure in the treatment of salivary-duct strictures, improving symptoms in the majority of patients. The procedure is repeatable and can be proposed as a first-line treatment for symptomatic salivary-duct stricture.

Intratumoral Haemorrhage Causing an Unusual Clinical Presentation of a Vestibular Schwannoma.

We present a case of an elderly woman with no history of audiological disease with sudden onset of visual and hearing deficits associated with systemic clinical signs. On examination she had impairment of right CNs from V to X. CT and MR imaging demonstrated a cystic vestibular schwannoma with a rare intralesional fluid-fluid level correlated to a recent bleed. We include high quality MR images to show the acute impairment of the cranial nerves next to the tumour after acute bleeding. Our case report includes a voxel-based morphometry (VMB) analysis of the tumour that, as far as we know, has never been done before for such a tumour. VBM analysis was performed to calculate the hypothesized volume changes after the acute bleed which likely resulted in a sudden increase in the overall size of the tumour resulting in atypical clinical signs and symptoms due to the establishment of a mechanical conflict with the adjacent cranial nerves.

Sialographic findings in Wharton duct evagination

Ductal evagination is a rare condition affecting the Wharton duct. The aim of this study was to establish the incidence, imaging features and clinical significance of ductal evagination in patients undergoing submandibular gland sialography. The sialographic findings and reports of 322 patients undergoing submandibular gland sialography during the period 1998-2007 were retrospectively reviewed. Ductal evagination was identified on sialograms as a unique diverticulum, filled with contrast medium, of the Wharton duct, with a narrow neck and a blind end. A ductal evagination was found in 5/322 patients with swelling and pain in the submandibular gland. It was always located in the middle tract of the Wharton duct. Other findings were: in 5/5 patients, an enlargement of the primary and secondary ducts due to sialodochitis; in 3/5 patients, salivary stones; in 1/5 patients, a sinuous distal tract of the Wharton duct; in 2/5 patients, a stenosis of the proximal tract of the Wharton duct. In our series, the incidence of wharton duct evagination was 1.6% incidence. It may represent a form of duct wall weakness although its cause is uncertain. It is, however, a condition that needs to be highlighted on sialograms for eventual inflammatory consequences or in guiding sialoendoscopy to avoid eventual ductal perforation.

Imaging of “Malignant” External Otitis

“Malignant” external otitis or necrotizing external otitis (NEO) is a rare and severe infection of the external auditory meatus, causing destructive changes of the petrous bone, infiltrating inframastoid and intracranial tissues, with potentially lethal consequences. Five male diabetic patients, aged 61 to 85 years-old (mean age was 74 y.o), referred with biopsy-proven NEO, underwent CT and MRI studies for the assessment of the extension of the disease. Clinical data concerning the examined patients are summarized in table 1. Contrast-enhanced MRI does not seem to help in differentiating granulation from neoplastic tissues, as both demonstrate inhomogeneous enhancement. In conclusion, NEO remains a life-threatening disease and early diagnosis is necessary for adequate pharmacological and hyperbaric therapy. Although non-specific, MRI appears to be the choice modality in demonstration of the extension and follow-up of NEO and related complications. CT, however, still maintains a complementary role in the assessment of bony erosion secondary to the disease.