Massimiliano Danti

Pancreatic carcinoma: The role of high-resolution multislice spiral CT in the diagnosis and assessment of resectability

Abstract. The purpose of our study was to evaluate multislice computed tomography (MSCT) in the assessment of patients with clinical, laboratory, and US suspicion of pancreatic neoplasm, and to evaluate resectability status. Forty-six patients with a suspected pancreatic tumor underwent MSCT. After a preliminary precontrast survey, a postcontrast scan was performed in the arterial and portal venous phase with the following protocol: 4×1-mm collimation; 1.25- and 5-mm slice thickness width, respectively, and 1- and 5-mm reconstruction interval. In all patients pathological correlation was obtained. The evaluation of all images provided a diagnosis in 44 patients, with a sensitivity, specificity, and accuracy of 97, 80, and 96%, respectively. The MSCT correctly provided a diagnosis of unresectability with sensitivity of 96%, specificity of 86%, and accuracy of 93%. Evaluation of 1-mm slices demonstrated 83 of the 91 liver metastases found at surgery; conversely, the 5-mm slices detected only 76 of these lesions. Infiltration of peripancreatic major vessels was demonstrated, and was confirmed at surgery in 18 patients. High-resolution MSCT improves prediction of resectability in patients with suspected pancreatic carcinoma. Parenchymal and vascular information can be achieved with a single MSCT examination.

Multidetector–row CT angiography of renal artery stenosis in 50 consecutive patients: prospective interobserver comparison with DSA

Purpose.The purpose of this study was to establish the diagnostic value of multidetector–row computed tomography (MDCT) angiography compared with digital subtraction angiography (DSA) for detection and quantification of both main and accessory renal artery stenosis in patients with secondary hypertension.Materials and methods.Fifty consecutive patients scheduled for DSA were considered candidates for MDCT angiography. In all patients, MDCT angiography of the abdominal aorta was performed before DSA. For the purpose of interpretation, the arteries were separately interpreted either with DSA or MDCT angiography in order to provide qualitative and quantitative information. For qualitative evaluation, one experienced reader graded the opacification of renal arteries as excellent, good or poor; for quantitative evaluation, MDCT and DSA were independently evaluated for the number of renal arteries and the presence, location and degree of stenosis in random order by three readers. On the basis of consensus readings, calculations of sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) for detection of degree of stenosis were made by using DSA findings as the standard of reference. Interobserver variability was also assessed.Results.With regard to qualitative analysis, arterial enhancement was considered excellent in 39 patients and good in 11. For quantitative analysis, 73 arteries were classified as normal with DSA. Although 72 of these were also classified as normal with CT angiography, one was overestimated by one grade; at DSA, 16 arteries were classified as moderately stenotic; in two arteries, there was an overestimation of one grade. Perfect correlation was achieved for the diagnosis of occlusion. In two patients, all three readers detected multiple severe stenoses on both modalities, with a “string–of–beads” appearance typical of fibromuscular dysplasia. Accessory arteries were correctly identified as such by all three readers on either DSA or MDCT. Levels of sensitivity, specificity and accuracy regarding degree of stenosis were 100%, 98.6% and 96.9%, respectively, with PPV and NPV of 97.6% and 100%, respectively. When we considered significant arterial stenosis (50%–100% luminal narrowing), sensitivity, specificity and accuracy were 100%, 97.3% and 97.8%, respectively, with a PPV and NPV of 98.2% and 97.8%, respectively. For all observers, interobserver agreement was almost perfect (k=0.81–1) for both MDCT and DSA, with a k value between 0.82 and 0.95.Conclusions.MDCT angiography is very accurate and robust, even for the assessment of renal artery stenosis, and has the potential to become a viable substitute, in most cases, for diagnostic catheter–based DSA.

MDCT of the abdominal aorta: basics, technical improvements, and clinical applications

ConclusionMultiple diagnostic techniques have been proposed for the evaluation of the abdominal aorta and iliac arteries so as to avoid the use of DSA.The development of MDCT has improved the assessment of the aorta and its branches allowing increasingly faster acquisition of thin sections. The increasing speed of the acquisition requires more attentive administration of iodinated contrast agent, at higher flow rates and with higher iodine concentration so that a homogeneous enhancement throughout the acquisition is achieved. Compared to other techniques, MDCT angiography has several advantages related to transverse data acquisition and the possibility of performing multiplanar interactive reconstructions. Furthermore, the rapid diffusion of MDCT scanners worldwide, not followed by the diffusion of high-field-strenght MR systems, enable to perform high quality MR angiography, has allowed an increasing number of CT angiography examinations to be performed.There are two major limitations of MDCT angiography in the evaluation of patients with peripheral arterial disease: the use of ionizing radiation and iodinated contrast agents. Regarding the radiation issue, it has been recently noted that it is not that important in older individuals who are the typical patients with peripheral arteriopathy, and that the radiation dose, compared with that of DSA, is significantly lower. Furthermore, as shown in other areas, it might be possible to reduce the radiation dose to the patient by optimizing the acquisition protocol. Concerning the use of iodinated contrast agents, it must be noted that several patients present with poor renal function and cannot tolerate administration of a possibly nephrotoxic agent; nevertheless, the nephrotoxicity of nonionic contrast agents has been significantly reduced as compared with ionic contrast agents and their administration can be considered safe and well tolerated, even in high-risk populations. Furthermore, the amount of iodinated contrast agent needed for MDCT angiography is significantly lower than that of single-slice spiral CT angiography, and the further increase in speed of new multidetector-row CTs will allow the use of even smaller amounts.

Cardiac magnetic resonance imaging: diagnostic value and utility in the follow-up of patients with acute myocarditis mimicking myocardial infarction.

PurposeThe aim of our study was to evaluate the efficacy of magnetic resonance imaging (MRI) in the differential diagnosis between active myocarditis and myocardial infarction in patients with clinical symptoms mimicking acute myocardial infarction.Materials and methodsBetween 1 January 2006 and 30 June 2007, 23 consecutive patients (21 men and 2 women) presenting with electrocardiographic abnormalities mimicking acute myocardial infarction and a clinical suspicion of acute myocarditis (fever, chest pain and elevated troponin levels) underwent contrast-enhanced cardiac MRI within a week of admission. All patients also underwent coronary angiography, which demonstrated the absence of significant coronary artery lesions. The mean follow-up period was 2±4 months.ResultsCardiac MRI with injection of contrast material showed late subepicardial and intramyocardial enhancement in all patients. Subendocardial late enhancement, a typical pattern of myocardial infarction, was never seen. In addition, in agreement with the literature, there was prevalent involvement of the lateral segments of the left ventricular wall.ConclusionsCardiac MRI could be a valuable tool for the early diagnosis of acute myocarditis, as it can demonstrate specific patterns that help rule out acute myocardial infarction.RiassuntoObiettivoScopo dello studio è dimostrare l’efficacia diagnostica della risonanza magnetica cardiaca nella diagnosi differenziale tra miocardite acuta ed infarto miocardico,in pazienti con quadro clinico simil-infartuale.Materiali e metodiDal 1 gennaio 2006 al 30 giugno 2007, ventitre pazienti consecutivi ricoverati con alterazioni elettrocardiografiche di tipo simil-infartuale (stemi) e sospetto clinico di miocardite acuta (febbre, dolore toracico, positività dei valori di troponina) sono stati sottoposti, entro 6 giorni dall’esordio, a risonanza magnetica (RM) cardiaca con MdC. Tutti i pazienti sono stati sottoposti a coronarografia, che non ha evidenziato lesioni a carico delle coronarie. La maggioranza dei pazienti erano uomini (21 uomini, 2 donne). L’intervallo medio per il follow-up è stato di 2±4 mesi.RisultatiLa RM con MdC ha evidenziato in tutti i pazienti la presenza di late enhancement (LE) a primitiva sede subepicardica o intra-miocardica. In nessun caso si è riscontrata presenza di LE sub-endocardico, quadro tipico della necrosi a genesi ischemica. Inoltre, in accordo con quanto riportato in letteratura, prevalente è stato l’interessamento dei segmenti laterali della parete del ventricolo sinistro rispetto alle altre pareti.ConclusioniLa RM cardiaca può avere ruolo fondamentale nella diagnosi precoce di miocardite acuta, documentando un quadro di alterazioni di segnale del miocardio che esclude la genesi ischemica.

High-resolution CT angiography of the abdomen.

Multislice computed tomographic angiography (MSCTA) is a versatile technique that combines speed, excellent contrast, superb spatial resolution, and extreme simplicity. It has a wide range of applications in the abdomen including all vascular pathologies, occlusive or dilative, with excellent demonstration of atherosclerotic plaques in large or smaller branches. MSCTA is the method of choice in the follow-up of patients undergoing endovascular procedures for aneurysms. It provides excellent results in assessing vascular involvement by neoplasms arising from the liver, biliary tract, pancreas, kidneys, and all other abdominal organs. MSCTA can be used successfully in potential living donors and in the follow-up of recipients. Although MSCTA is a brand new technique, several developments are under investigation, which should allow further advancements in speed and spatial resolution.

Leriche Syndrome Visualized by 3-Dimensional Multislice Computed Tomography Angiography

A 39-year-old man presented to our hospital with severe thigh, hip, and buttock claudication and diminished femoral pulses. Color Doppler ultrasonography revealed absence of flow in both common iliac arteries, suggesting the diagnosis of Leriche syndrome. Preoperative computed tomography (CT) angiography was subsequently performed using a multislice spiral CT scanner (Somatom Plus 4 Volume Zoom, Siemens) to confirm the diagnosis and provide a vascular “road map” for the surgical procedure. …

Cardiac magnetic resonance in patients with acute cardiac injury and unobstructed coronary arteries

AIM To define the role of cardiac magnetic resonance (CMR) by analyzing a particular group of patients with suspected acute coronary syndrome (ACS) and normal coronary angiogram. METHODS From January 2009 to December 2015, we examined 220 patients with clinical suspicion of ACS, Troponin elevation [the threshold used to define a positive Troponin T test (TnT) was 0.1 ng/mL] and no significant coronary disease at angiography (the patients were considered to have significant angiographic disease only a 50% stenosis was detected in any of their coronary arteries). The role of CMR with the late gadolinium enhancement was evaluated. RESULTS CMR was performed to 190 patients (86%) of this group which reveals: Myocarditis in 90 patients (47%); apical ballooning (Tako-Tsubo syndrome) in 32 patients (17%); myocardial infarction (MI) in 40 patients (21%) and no clear diagnosis identified by CMR in 28 patients (15%). A comparison with previous studies was also made. Clinical and echocardiographic follow-ups were performed at 12 ± 2 mo and no major adverse cardiac events were revealed. CONCLUSION There is a group of patients with clinical suspicion of ACS displaying normal coronary angiograms. CMR was demonstrated to be a valuable tool in the differential diagnosis evaluation of myocarditis, apical ballooning and MI.

Bilateral Carotid Body Tumor Evaluated by Three-Dimensional Multislice Computed Tomography Angiography

A 22-year-old man presented to our institution with a palpable mass in the right side of his neck associated with mild dysphagia. Ultrasonography of the neck demonstrated a hypervascular mass within the right carotid bifurcation, consistent with a carotid body tumor. No other abnormality was detected either at palpation or at ultrasonography on the left side of the neck. Preoperative computed tomography (CT) angiography …