Quantification of calcium burden by coronary CT angiography compared to optical coherence tomography.

Coronary artery calcifications (CAC) are frequently observed in patients referred for coronary CT angiography (CTA). Calcification volume (in mm3) can accurately be assessed during catheterization by optical coherence tomography (OCT). The aim of the present study was to investigate the accuracy of CTA-derived assessment of calcification volume as compared with OCT. 66 calcified plaques (32 vessels) from 31 patients undergoing OCT-guided PCI with coronary CT acquired as a standard of care were included. Coronary CT and OCT images were matched using fiduciary points. Calcified plaques were reconstructed in three dimensions to calculate calcium volume. A Passing-Bablok regression analysis and the Bland-Altman method were used to assess the agreement between imaging modalities. Twenty-seven left anterior descending arteries and 5 right coronary arteries were analyzed. Median calcium volume by CTA and OCT were 18.23 mm3 [IQR 8.09, 36.48] and 10.03 mm3 [IQR 3.6, 22.88] respectively; the Passing-Bablok analysis showed a proportional without a systematic difference (Coefficient A 0.08, 95% CI - 1.37 to 1.21, Coefficient B 1.61, 95% CI 1.45 to 1.84) and the mean difference was 9.69 mm3 (LOA - 10.2 to 29.6 mm3). No differences were observed for minimal lumen area (Coefficient A 0.07, 95% CI - 0.46 to 0.15, Coefficient B 0.85, 95% CI 0.64 to 1.2). CTA volumetric calcium evaluation overestimates calcium volume by 60% compared to OCT. This may allow for an appropriate interpretation of calcific burden in the non-invasive setting. Even in presence of calcific plaques, a good agreement in the MLA assessment was found. Coronary CT may emerge as a tool to quantify calcium burden for invasive procedural planning.

Ectopic gastric pancreatitis: unusual cause of epigastric pain.

Ectopic pancreatic tissue has the same characteristics than normal pancreatic tissue.Therefore it may be affected by the same diseases. We report a rare cause of epigastric pain due to gastric heterotopic pancreatitis.The rare diagnosis was suspected by ultrasound and CT and definitively confirmed by echo-endoscopic guided biopsies.

MRI findings of hepatobiliairy fascioliasis.

Hepatobiliary fascioliasis is an uncommon disease. Depending on the stage of the disease it can present with a wide variability of clinical symptoms. Knowledge of the specific radiological findings of the disease is crucial to shorten the time to final diagnosis, which is usually long. We report a case of hepatobiliary fascioliasis in a 26-year-old woman with intermittent abdominal discomfort showing non specific findings at computed tomography and ultrasound. A hypothesis of an infectious disorder was formulated based on MRI findings and a recent history of travelling. Final diagnosis was confirmed by subsequent serology testing.

Acute calcific prevertebral tendinitis.

Acute calcific prevertebral tendinitis, also known as retropharyngeal calcific tendinitis and longus colli tendinitis, is an uncommon benign condition presenting as acute neck pain.Typical characteristics of this entity are calcifications at the superior insertion of the longus colli tendons at C1-C2 level and a fluid collection in the retropharyngeal space. Differential diagnosis consists of retropharyngeal abscess, traumatic injury or infectious spondylitis. Knowledge of the clinical and imaging findings can prevent misdiagnosis with inappropriate attempts at surgical drainage.

Epithelioid hemangioendothelioma of the liver: radiologic-pathologic correlation.

Epithelioid hemangioendothelioma of the liver is a rare vascular tumor with intermediate malignant potential. On imaging studies, the lesion has a solid appearance and may mimic metastatic disease. We present a case in which the morphologic features (multifocal aspect, peripheral location, and capsular retraction) and the clinical history aided in including this entity in the differential diagnosis.

Autoimmune pancreatitis associated with primary sclerosing cholangitis: MR imaging findings.

Autoimmune pancreatitis is a relatively rare type of chronic pancreatitis that may be associated with other autoimmune disorders. The imaging features of this entity may be misleading and suggest the presence of a malignant tumour. We present a case in which MR imaging allowed us to diagnose autoimmune pancreatitis associated with primary sclerosing cholangitis, which is another autoimmune-related disease. Typical MR characteristics of autoimmune pancreatitis include focal or diffuse enlargement of the pancreas, the absence of parenchymal atrophy and significant dilation proximal to the site of stenosis, the absence of peripancreatic spread, the clear demarcation of the lesion and the presence of a peripancreatic rim.

MR imaging findings in two patients with hepatic veno-occlusive disease following bone marrow transplantation.

The aim of this study was to describe the MRI features of veno-occlusive disease (VOD) following bone-marrow transplantation in two patients. The MRI features consisted of hepatomegaly, hepatic vein narrowing, periportal cuffing, gallbladder wall thickening, marked hyperintensity of the gallbladder wall on T2-weighted images, ascites, and pleural effusion. In one patient, signs of reduced portal venous flow velocity were also observed. It is concluded that the use of MRI as a complementary technique following non-conclusive US examination enabled a timely diagnosis of this life-threatening disease in both patients.

Effectiveness of imaging studies in acute appendicitis: a simplified decision model.

Computed tomography (CT) and ultrasonography (US) have been proposed as non-invasive diagnostic aids in patients with suspected acute appendicitis. Currently, clear guidelines about the indications to use these techniques are lacking. Using the concepts of decision analysis, a model was created to calculate the effectiveness of US and CT in patients with clinically suspected appendicitis. The perspective chosen was the health of individual patients. The model makes use of published data and provides a critical threshold probability (ctp). Decisions in individual cases can be made by comparing ctp with the clinical probability of disease. The calculated ctp-values for US and CT were 0.58 and 0.74, respectively. In other words, on average, US (CT) is indicated only if the expert clinician considers the probability of disease to be smaller than 58% (74%). It is concluded that in patients with suspected acute appendicitis, selective rather than routine use of imaging studies is recommended. The exact value of the decision threshold should be determined in function of the local situation.

Three-dimensional imaging of acetabular dysplasia: diagnostic value and impact on surgical type classification.

OBJECTIVE: To investigate the diagnostic value and the impact on surgical type classification of three-dimensional (3D) images for pre-surgical evaluation of dysplastic hips. MATERIALS AND METHODS: Three children with a different surgical type of hip dysplasia were investigated with helical computed tomography. For each patient, two-dimensional (2D) images, 3D, and a stereolithographic model of the dysplastic hip were generated. In two separate sessions, 40 medical observers independently analyzed the 2D images (session 1), the 2D and 3D images (session 2), and tried to identify the corresponding stereolithographic hip model. The influence of both image presentation (2D versus 3D images) and observer (degree of experience, radiologist versus orthopedic surgeon) were statistically analyzed. The SL model choice reflected the impact on surgical type classification. RESULTS: Image presentation was a significant factor whereas the individual observer was not. Three-dimensional images scored significantly better than 2D images (P=0.0003). Three-dimensional imaging increased the correct surgical type classification by 35%. CONCLUSION: Three-dimensional images significantly improve the pre-surgical diagnostic assessment and surgical type classification of dysplastic hips.