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Objectives. To assess the impact of combining low-tube voltage acquisition with iterative reconstruction (IR) techniques on the iodine dose in coronary CTA. Methods. Three minipigs underwent CCTA to compare a standard of care protocol with two alternative study protocols combining low-tube voltage and low iodine dose with IR. Image quality was evaluated objectively by the CT value, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) in the main coronary arteries and aorta and subjectively by expert reading. Statistics were performed by Mann–Whitney U test and Chi-square analysis. Results. Despite reduced iodine dose, both study protocols maintained CT values, SNR, and CNR compared to the standard of care protocol. Expert readings confirmed these findings; all scans were perceived to be of at least diagnostically acceptable quality on all evaluated parameters allowing image interpretation. No statistical differences were observed (all p values > 0.11), except for streak artifacts (p=0.02) which were considered to be more severe, although acceptable, with the 80 kVp protocol. Conclusions. Reduced tube voltage in combination with IR allows a total iodine dose reduction between 37 and 50%, by using contrast media with low iodine concentrations of 200 and 160 mg I/mL, while maintaining image quality.

An asymptomatic obese 60-year-old man with an increased cardiovascular risk profile (arterial hypertension and hypercholesterolemia) was checked prior to hip surgery. Resting ECG was normal. Exercise test was not possible. A dipyridamole myocardial perfusion scintigraphy showed inferolateral ischemia and a preserved left ventricular (LV) function. Coronary angiography demonstrated moderate atherosclerosis in the proximal segment of the right coronary artery (RCA) and a moderate stenosis in the distal segment of the posterolateral branch (Fig. A). The left anterior descending artery (LAD) and diagonal branches were visualized simultaneously. No additional coronary ostium could be found. The contrast enhanced cardiac CT was performed and it confirmed the absence of a left coronary ostium and a single RCA with two large right ventricular (RV) branches continuing to the left coronary artery (LCA). The first RV branch continued to the diagonal branch. The second RV branch continued to the LAD. Interestingly, in the anterior interventricular sulcus, the LAD had a bidirectional course proximally and distally, with proximally the emergence of an hypoplastic left circumflex artery (LCX) (Fig. B, C). None of the branches were running between the pulmonary artery and the ascending aorta, corresponding with a R-II A classification according to Lipton/ Yamanaka.

Gallbladder carcinoma is a relatively rare malignant epithelial neoplasm, arising from gallbladder mucosa. It is the fifth most common gastrointestinal malignancy and the most common biliary tract cancer. Early diagnosis remains difficult, because clinical symptoms are sparse and non-specific, often resulting in advanced stage disease at the time of diagnosis. The most common feature of gallbladder carcinoma on different imaging modalities is focal wall thickening, associated with a large eccentric tumor mass. In this case we report the imaging characteristics of gallbladder carcinoma on ultrasound, MDCT and 18F-FDG PET/CT.

In order to exclude acute pulmonary embolism, a lung perfusion scintigraphy was performed in a 53-year-old male, with a history of Fallot’s tetralogy. He had been immobilized because of a tibial fracture and complained of worsening chest pain and dyspnea.

Our purpose is to discuss MRI findings in non-ischemic myocardial disease (NIMD). Emphasis is placed on the typical locations and patterns of delayed enhancement. Clinicopathological and MRI features of amyloidosis, arrythmogenic right ventricular dysplasia, left ventricular non-compaction, myocarditis, hypertrophic cardiomyopathy, and dilated cardiomyopathy are discussed. Currently, cardiac MRI is the best imaging method for diagnosis and follow-up of NIMD. In particular, the radiologist should be familiar with the different patterns of delayed enhancement on DE-CMR since they play an important role in the detection and differential diagnosis of NIMD.

In order to avoid unnecessary therapy or treatment delay, it is important for the radiologist to be aware of the wide range of differential diagnoses for cystic lesions of the female reproductive system. This paper gives an overview of radiological findings in the variety of physiologic and pathologic cysts which may be encountered in this field.

DaTSCAN® is a solution of I-ioflupane (I-FP-CIT), a cocaine analogue with high binding affinity for presynaptic dopamine transporters (DaT), in particular in the striatal region of the brain, suitable for SPECT imaging. It is mainly indicated for detecting loss of functional dopaminergic neuron terminals in the striatum in patients with clinically uncertain parkinsonian syndromes in order to help differentiate essential tremor from parkinsonian syndromes [1, 2]. A 72-year-old woman, with a history of tremor and postural hypotension, was admitted to our hospital because of a fall with crush syndrome. I-FP-CIT SPECT was performed and demonstrated besides normal dopaminergic activity in the striatum (a) focal extracerebral tracer uptake in the right temporal region (b). Correlation of the Iioflupane scan with MRI of the brain localized the extracerebral I focus in the right temporal muscle corresponding to an intramuscular haematoma (c). Because of a new fall, 4 months later, CT of the brain was repeated and demonstrated restored symmetry of the temporal muscles due to resorption of the haematoma (d). I-FP-CIT SPECT was repeated and showed resolution of the right temporal activity (e). Extrastriatal I-FP-CIT uptake has already been described in a brain tumour in the case of a monoaminesynthesizing neuroendocrine cell tumour [3]. This case is a unique report of extracerebral I-ioflupane uptake due to subacute post-traumatic injury.

Torsion of the lesser omentum is a rare cause of acute abdomen. We report a case of a primary torsion of the lesser omentum in a 10-year-old girl with epigastric pain. Computed tomographic (CT) study showed a well-circumscribed oval fatty mass between the left hepatic lobe and the lesser gastric curvature. Surgical exploration revealed a fatty inflammatory structure of soft consistency within the lesser omentum, which appeared to have twisted on its omental pedicle. There was macroscopically and microscopically no evidence of a mass. Knowledge of this pathology is important to the surgeon because it mimics the common causes of acute surgical abdomen.

We present a 43-year old female patient, admitted to the intensive care unit, recovering from a Bentall procedure because of a supra-coronary aneurysm and unicuspid aortic valve. Few hours following surgery,a marked lactic acidosis, hypoxemia and increased central venous pressure developed. Pulmonary angio-CT was performed to exclude pulmonary embolism. Because of severe peripheral vasoconstriction, iodine contrast could only be administered through a narrow lumen central venous catheter, which limited the maximum flow rate to 1.5 ml/s. Images were performed with triggering in the pulmonary trunk. Review of the images showed no evidence for pulmonary embolism. Despite the low flow rate, a clear enhancement of the pulmonary artery was observed (up to 460 HU) (Fig. 1). Such an enhancement of the pulmonary artery is normally only achieved when injecting contrast at a flow rate of 4-5 ml/s. These perfect images, obtained at a low contrast flow rate in fact indicate severely impaired right ventricular function.

Purpose To assess a classification scheme for predicting local tumor progression (LTP) after radiofrequency (RF) ablation of liver metastases, using predefined patterns on contrast-enhanced computed tomography (CT) and positron emission tomography (PET) combined with CT (PET/CT) acquired 24 hours after RF ablation. Materials and Methods There were 45 metastases in 20 patients treated. After 24 hours, imaging of the ablation zones was performed with contrast-enhanced PET/CT. Three independent radiologists prospectively assessed contrast-enhanced CT and combined PET/CT images to identify three patterns: pattern I, no tissue enhancement or fluorodeoxyglucose uptake between the ablation zone and the liver parenchyma; pattern II, a rimlike pattern; and pattern III, a peripheral nodule. PET/CT images obtained after 8–10 weeks were evaluated for LTP. The patterns were analyzed for their sensitivity, specificity, positive predictive value, and negative predictive value for predicting LTP. Results Pattern I was most frequently observed (81% for contrast-enhanced CT and 61% for PET/CT) as well as for ablation zones that showed LTP (52% and 37%, respectively). Conversely, pattern II was observed for tumors that were completely ablated (6% and 29%, respectively). Patterns II and III together had the highest sensitivity for predicting LTP (48% and 63%, respectively); pattern III had the highest specificity (94% and 95%, respectively). For nodular patterns, test characteristics were better for PET/CT compared with contrast-enhanced CT, but the difference was not significant. Nodular patterns > 1 cm achieved high positive predictive value (both 100%). Conclusions Inflammation and hyperemia can hinder interpretation on imaging 24 hours after RF ablation, especially on PET/CT. Nodular patterns around the ablation zone on early contrast-enhanced CT and PET/CT have a high predictive value for LTP and should be taken into account for disease management.