Ugolino Alfonsi

Coronary artery anatomy and variants

Variants and congenital anomalies of the coronary arteries are usually asymptomatic, but may present with severe chest pain or cardiac arrest. The introduction of multidetector CT coronary angiography (MDCT-CA) allows the detection of significant coronary artery stenosis. Improved performance with isotropic spatial resolution and higher temporal resolution provides a valid alternative to conventional coronary angiography (CCA) in many patients. MDCT-CA is now considered the ideal tool for three-dimensional visualization of the complex and tortuous anatomy of the coronary arteries. With multiplanar and volume-rendered reconstructions, MDCT-CA may even outperform CCA in determining the relative position of vessels, thus providing a better view of the coronary vascular anatomy. The purpose of this review is to describe the normal anatomy of the coronary arteries and their main variants based on MDCT-CA with appropriate reconstructions.

Normal anatomy and variants of the venous cardiac system in MDCT coronary angiography

Three separate venous systems drain the blood returning from the heart walls. These veins are characterised by remarkable variability in terms of frequency, size and course. The knowledge of cardiac venous anatomy is of primary importance during interventional cardiac procedures that require catheterisation of cardiac veins. Some anatomical variants may hinder or contraindicate access to target veins. Coronary angiography (CA) with multidetector computed tomography (MDCT-CA) and multiplanar reformations (MPR), maximum intensity projection (MIP) and 3D reconstructions provides noninvasive visualisation of normal cardiac veins and anatomical variants. The purpose of this pictorial review is to describe by MDCT-CA the anatomy and main variants of the cardiac venous system.RiassuntoIl sangue refluo dal cuore è raccolto da tre sistemi di vene caratterizzate da una notevole variabilità in termini di frequenza, calibro e decorso. Conoscere l’anatomia venosa cardiaca è importante in relazione a manovre di cardiologia interventistica che richiedono la cateterizzazione delle vene cardiache, dal momento che alcune varianti anatomiche possono ostacolare o controindicare l’accesso alle vene target. L’angiografia coronarica mediante tomografia computerizzata multistrato (TCMS) permette, tramite ricostruzioni 3D, ricostruzioni multiplanari (MPR), MPR curve e proiezioni di massima intensità (MIP), la visualizzazione dell’anatomia venosa cardiaca normale e delle sue varianti in modo non invasivo, fornendo una valida alternativa alla venografia retrograda. Lo scopo di questo pictorial consiste nella descrizione mediante immagini TCMS con ricostruzioni 3D dell’anatomia e delle principali varianti delle vene cardiache.

Learning curve in multidetector CT coronary angiography (MDCT-CA).

PurposeCoronary angiography using multidetector computed tomography (MDCT-CA) is a recent technique for the nonivasive study of coronary arteries. This study assessed the diagnostic accuracy of coronary artery stenosis evaluation obtained by three readers at different levels of training or at different points of the learning curve proposed by the international guidelines.Materials and methodsThree radiologists in training with different levels of experience in MDCT-CA scored 50 cases at various time points of the learning curve: baseline, 4 weeks, 8 weeks and 6 months. The trainee radiologists evaluated the degree of stenosis on each coronary segment, and overall accuracy was calculated on a per-segment, pervessel and per-patient basis.ResultsAll readers improved analysis accuracy per segment (range, 73–90%); sensitivity reached 45% per segment, 84% per vessel and 93% per patient; specificity was 99% per segment and vessel and 98% per patient. Positive and negative predictive values increased to 94% and 92%, respectively.ConclusionsAlthough all readers improved in diagnostic performance with growing experience with MDCT-CA, a longer training period may be necessary to achieve adequate levels of expertise in MDCT-CA to be able to perform as independent readers.RiassuntoObiettivoValutare l’accuratezza diagnostica nella stima di stenosi coronarica con l’angiografia coronarica mediante TCMS (AC-TCMS) ottenuta da tre lettori nei vari livelli di training proposti dalle linee guida internazionali come curva di apprendimento.Materiali e metodiTre lettori medici in formazione con esperienza in AC-TCMS differente hanno eseguito l’analisi sistematica delle AC-TCMS di 50 pazienti in diversi step della curva di apprendimento: iniziale, a 4 settimane, 8 settimane, 6 mesi. Per ogni segmento è stato valutato il grado di stenosi ed è stata calcolata l’accuratezza globale mediante analisi per segmento, vaso e paziente.RisultatiTutti i lettori hanno incrementato la loro accuratezza (range 73–90%) nell’analisi per segmento; la sensibilità con valori massimi per segmento pari a 45%, per vaso a 84% e per paziente a 93%; la specificità con valori massimi per l’analisi per segmento e vaso pari a 99% e per paziente pari a 98%. Anche i valori di predittività positiva e negativa sono incrementati raggiungendo valori rispettivamente pari a 94% e 92%.ConclusioniSebbene tutti i lettori abbiano migliorato la loro performance diagnostica aumentando la loro esperienza in AC-TCMS, può essere necessario un tempo più lungo per raggiungere un’esperienza adeguata in ACTCMS tale da consentire una valutazione indipendente.

Role of coronary angiography MDCT in the clinical setting: changes in diagnostic workup in the real world.

PurposeThe authors sought to evaluate the incremental value of introducing coronary angiography with multidetector computed tomography (MDCT-CA) compared with the conventional diagnostic workup in managing patients with suspected coronary artery disease (CAD) workup.Materials and methodsA total of 531 consecutive patients underwent MDCT-CA between April 2008 and August 2010. For each patient the pretest probability of CAD was obtained by using the Morise score as well as the diagnostic performance of the exercise test and of MDCT-CA, considering conventional coronary angiography (CCA) as the gold standard. Based on these results, we calculated the posttest likelihood of CAD after stress testing, comparing the incremental diagnostic value for each category of cardiovascular risk with data obtained with MDCT-CA. The conventional diagnostic workup (without MDCT-CA) was then compared with the modified workup (including MDCT-CA).ResultsThe diagnostic performance of the exercise test for identifying patients with significant lesions had a sensitivity and specificity of 20% and 88%, respectively, with positive (PPV) and negative (NPV) predictive value of 41% and 72%, respectively. Taking CA as the gold standard, MDCT-CA had 93% sensitivity, 89% specificity, 88% PPV and 93% NPV compared with CCA in evaluating significant stenoses in the per-patient analysis. The overall diagnostic accuracy of MDCT-CA was 91%. The exercise tests provided no significant incremental diagnostic value compared with cardiovascular history in patients with a low to intermediate risk. Comparison of the diagnostic accuracy of these protocols showed improved performance results for the modified protocol.ConclusionsMDCT-CA is the reference modality for the noninvasive exclusion of critical CAD. It provides a very high incremental diagnostic value compared with exercise testing in patients with a low to intermediate risk of CAD. The use of diagnostic protocols based on MDCT-CA ensures improved diagnostic performance compared with those involving conventional exercise electrocardiograms.RiassuntoObiettivoScopo del nostro lavoro è valutare il valore incrementale dell’introduzione della angiografia coronarica mediante tomografia assiale multistrato (AC-TCMS) nella gestione diagnostica del paziente con sospetta malattia coronarica (CAD) rispetto al tradizionale workup diagnostico.Materiali e metodiSono stati presi in considerazione 531 pazienti consecutivi sottoposti ad AC-TCMS tra marzo 2008 e agosto 2010. Per ogni paziente è stato calcolata la probabilità pre-test di CAD mediante Morise score e la performance diagnostica del cicloergometro e della ACTCMS considerando l’AC come standard di riferimento; Sulla base dei risultati è stata calcolata la probabilità post-test di CAD dopo stress test, confrontandone il valore diagnostico incrementale per ogni categoria di rischio cardiovascolare con i dati ottenuti dalla AC-TCMS. è stato confrontato il percorso diagnostico tradizionale senza ACTCMS, con quello modificato dall’introduzione dell’ACTCMS.RisultatiLa performance diagnostica dello stress test nella individuazione dei pazienti con lesioni significative ha dimostrato una sensibilità e specificità del 20% e 88% con valore predittivo positivo (VPP) e valore predittivo negativo (VPN) di 41% e 72%. Considerando come standard di riferimento la AC il confronto tra AC e ACTCMS nella valutazione di stenosi significative mediante analisi per paziente ha rilevato una sensibilità pari a 93%, una specificità pari a 89%, un VPP e VPN pari a 88 % e 93%. L’accuratezza diagnostica globale della metodica è risultata essere pari a 91%. Lo stress test ha dimostrato di non fornire un significativo valore diagnostico incrementale rispetto all’anamnesi cardiovascolare nei pazienti a basso-medio rischio. Il confronto tra l’accuratezza diagnostica dei protocolli ha dimostrato una migliore performance del protocollo che prevede l’introduzione dell’ACTCMS nei confronti del protocollo tradizionale.ConclusioniLa AC-TCMS è una metodica di riferimento non invasiva per l’esclusione di coronaropatia critica. Fornisce un valore diagnostico incrementale molto elevato rispetto allo stress test nei pazienti a basso-medio rischio. L’utilizzazione del protocollo diagnostico che prevede l’utilizzo dell’AC-TCMS garantisce una migliore perfomance diagnostica rispetto al protocollo tradizionale.

Adenocarcinoma of the Prostate

Prostate cancer is the most common cancer and the second most common cause of cancer-related death among men. Because of the advent of prostate-specific antigen (PSA) concentration in serum screening, most prostate cancer new cases are clinically localized at diagnosis, and the 5-year relative survival rate approaches 100 %. Until now, patients with an elevated PSA level or with abnormal findings at digital rectal examination were candidates for further diagnostic evaluation with a transrectal ultrasonography (US)-guided prostate random biopsy for determining the cancer grade; however, random biopsy has some limits, for example, undersampling (35 % cancers missed on first biopsy) or underestimation of the grading. Instead, magnetic resonance (MR) imaging has been shown to be of particular help not only in the detection and localization of prostate cancer but also in staging; accurate assessment is a prerequisite for optimal clinical management and therapy selection. Traditional prostate MR imaging has been based on morphologic imaging with standard T1-weighted and T2-weighted sequences, which has limited accuracy in the detection of prostate cancer: recently, the accuracy is significantly improved by the combined use of standard T2-weighted MR imaging and advanced MR imaging techniques such as diffusion-weighted imaging, dynamic contrast-enhanced imaging, and MR spectroscopy. Multiparametric MR imaging provides the highest accuracy in the diagnosis and staging of prostate cancer. In addition, improvements in MR imaging hardware and software (3-T vs 1.5-T imaging) continue to improve spatial and temporal resolution and the signal-to-noise ratio of MR imaging examinations.

Neoplasms of the Biliary Tree

Neoplasms of the biliary tree include a wide spectrum of lesions that range from benign tumors, such as adenomas, to malignant lesions, such as adenocarcinomas. Cholangiocarcinoma is the tumor of the biliary tract that has the highest incidence and the poorest prognosis, which depends most of all on the therapeutic strategy. Accurate characterization in terms of diagnosis and staging of the neoplasms can be crucial for determining prognosis and treatment planning, and different imaging techniques can be used to achieve the best diagnostic setting of the case. Magnetic resonance cholangiopancreatography (MRCP) is one of the best imaging techniques for the depiction of the biliary tree, and it can be very helpful in cases of tumors with poor prognosis in which a life-saving therapeutic strategy depends mostly on the initial staging of the disease (e.g., in cholangiocarcinoma). For these reasons, in this chapter, cholangiocarcinoma is first comprehensively described, and following on from this there are brief descriptions of benign neoplasms of the biliary tree.

Neoplasm of the Biliary Tree

Magnetic resonance cholangiopancreatography (MRCP) : , Magnetic resonance cholangiopancreatography (MRCP) : , کتابخانه دیجیتال جندی شاپور اهواز

Artifacts in Cardiac CT

The reliability, simplicity and repeatability of the scan make CT a very interesting modality for noninvasive diagnostic imaging of the coronary arteries. The success of the technique is also due to the considerable technologic development of spiraI multidetector CT (MDCT) scanners, which has produced elevated spatial and temporal resolution, indispensable parameters for the study of the heart and the coronary tree. These structures are in fact characterized by significant and rapid motion, as well as vessels with millimetric diameters and tortuous course, and until a few years ago were considered beyond the capabilities of CT.

Rare Pancreatic Tumors

Rare pancreatic tumors are a heterogeneous group of tumors infrequently seen in any given individual clinical practice. These lesions show some clinical and imaging features different from the more common pancreatic adenocarcinoma, islet cell neoplasms or cystic tumors.

Collateral Findings on Cardiac CT

Noninvasive imaging of the coronary arteries is an important clinical application since cardiac computed tomography (CCT) has proven to be an accurate imaging alternative to conventional coronary angiography [1, 2, 3, 4]. The technique has a significant clinical role to play in patients with low-to-intermediate pre-test probability of coronary artery disease (CAD) and negative or equivocal findings on exercise stress testing.