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INTRODUCTION AND OBJECTIVE:There has been a significant development of minimally invasive surgical techniques (MISTs) for the treatment of BPH. Prostatic artery embolization (PAE) is one of the mos...

Poster: "ECR 2019 / C-0822 / "Balloon-assisted" technique (BAT) in peripheral interventions: a useful tool. " by: " F. Sacconi , R. Pozzi Mucelli, F. Pozzi Mucelli, S. Cernic, M. Braini, M. A. Cova; trieste/IT"

PURPOSE: Our aim was to evaluate the usefulness of computed tomography angiography (CTA) in vascular mapping for planning breast reconstruction after mastectomy using a free flap made with the deep inferior epigastric perforators (DIEP). MATERIALS AND METHODS: We retrospectively evaluated 41 patients, mean age 57 years, scheduled for mastectomy. CTA was performed with a 64-row scanner (Aquilion 64, Toshiba Medical Systems, Japan), with injection of 100 ml of contrast medium (iomeprol 350 mgI/ml, Bracco, Italy) at 4.5 ml/s. Maximum intensity projection (MIP) and threedimensional volume-rendering (VR) reconstructions were made to mark perforator positions. Presentation frequency, anatomy and artery opacification quality were evaluated. RESULTS: DIEP were always depicted (n=81) and subdivided according to Taylor's classification into type I (65%), type II (28%), and type III (7%). We observed a mean of three (range, 1-5) DIEP arteries on the right and two (range, 1-5) on the left side. The superficial inferior epigastric artery (SIEA) was depicted in 6/41 patients, bilaterally in three cases. Opacification was optimal in 30/41 cases, venous contamination due to late arterial phase in eight and low opacification due to early scan in three. CONCLUSIONS: Studying DIEP with CTA is useful in the surgical planning of breast reconstruction, even though it requires careful optimisation owing to the critical timing of opacification typical of that vascular district.

The aim of this study was to report the different findings that can be visualised with virtual angioscopy starting from rotational angiography (RA) and three-dimensional (3D) image processing (3DRA) in the evaluation of the abdominal aorta and iliac arteries. Fifty-seven patients showing an occlusive or aneurysmal disease of the abdominal aorta and iliac arteries underwent intraarterial digital subtraction angiography (DSA) equipped with the RA function and a 3D workstation. We found that 3DRA is able to generate images of the examined vessels with a very effective 3D appearance; furthermore, it is able to create images of the lumen and wall of the vessel through two different modalities: endoviews and cross sections. The possibility of matching high-density structures (i.e. calcified plaques and stents) to standard 3D reconstructions of the examined arteries was applied. Different aspects of the arteries can be demonstrated in the angioscopic elaborations: the normal and stenotic lumen, artery bifurcations, the collateral vessel origins and the severity and extensions of atheromatous calcifications and their relationships to the vessel wall. Virtual angioscopy is able to visualise some devices (catheters, stents) introduced during diagnostic and interventional procedures. The constant technological evolution of diagnostic imaging is offering new image-processing techniques, providing new types of previously unexplored information. We present a summary of the different radiological findings that can be demonstrated with this new imaging technique.

A brief introduction is given about the diagnostic role of angiography, which, at present, is significantly reduced compared to the other noninvasive techniques such as color Doppler ultrasound, multidetector CT angiography, and magnetic resonance angiography. Then, there is a focus on technical aspects in diagnostic angiography, discussing materials and imaging parameters; subsequently, the technical aspects of interventional vascular procedures are considered. Anatomy is then reviewed as is apparent on angiographic studies.

Applicazioni dell'ecografia nella patologia del rene e nel trapianto renale

From pathological point of view the chronic renal infections include two types, interstitial chronic pyelonephritis and granulomatous pyelonephritis, namely xanthogranulomatous, malacoplakia and renal tuberculosis. Indications for imaging modalities are more common compared to the acute types and allow to depict both factors causing obstruction and infection such as stones ant the renal and extrarenal extension of the disease. In this article the authors review the findings and the role of plain film and urography, computed tomography and ultrasonography.

High-flow priapism (HFP) secondary to Nesbit operation: management by percutaneous embolization and colour Doppler-guided compression

L'obiettivo di questo lavoro è stato quello di valutare l'efficacia della Angiografia tridimensionale TC (3D-TCA) in pazienti con patologia a carico del distretto carotideo extracranico. Sono stati esaminati 15 pazienti con stenosi di natura arteriosclerotica (14 casi) o arteritica (1 caso) a livello della biforcazione carotidea. Tutti i casi erano stati precedentemente indagati con arteriografia che è stata considerata il test di confronto. Le immagini tridimensionali, presentano una qualità molto valida e sono paragonabili a quelle angiografiche nella maggioranza dei casi. La tecnica 3D-TCA presenta a suo favore alcuni vantaggi: scarsa invasività; semplicità e rapidità di esecuzione; buona dimostrazione delle placche calcifiche che possono essere rimosse mediante software. I limiti attuali sono rappresentati da: necessità di una adeguata concentrazione di mezzo di contrasto nei vasi: possibili artefatti da calcificazioni e strutture ossee: mancanza di informazioni sul flusso dei vasi; difficile separazione tra arterie e vene in alcuni distretti; scarsa panoramicità rispetto alla angiografia.

Purpose: We describe the US and CT examinations of 4 patients with renal angiomyolipoma with an “aggressive” appearance, and review the literature. Material and Methods: The imaging findings in 4 patients with benign renal angiomyolipomas associated with thrombosis of the renal vein and/or inferior vena cava are presented. In one case, enlarged lymph nodes at the renal hilum were found. Results: CT demonstrated fat densities within both tumor and thrombus. In one patient, small lymph nodes with low density internal areas were detected in the para-aortic region. When considering our patients together with those reported in the literature, we found that most angiomyolipomas with venous invasion were large and centrally located within the kidney. Venous thrombosis was observed in 9 lesions of the right kidney, and in only 4 of the left one; detection of the site of origin was impossible in one case. One patient only had symptoms due to the thrombus; 10 had problems due to the tumor; and 3 were asymptomatic. Only 4 patients with pararenal enlarged lymph nodes have been reported on in the imaging literature. Fat-containing nodes were detected by CT in one case only; the others had enlarged nodes of soft-tissue density. In one patient the diagnosis of hamartomatous lymph node invasion was established by angiography. Conclusion: In patients with renal angiomyolipoma, demonstration of both fatty thrombus and the fatty infiltration of lymph nodes of the renal hilum cannot be regarded as an indication of malignancy, but only of local aggressive behavior. Although surgery is commonly contemplated to prevent symptoms from venous thrombosis, conservative treatment seems possible. Detection of enlarged lymph nodes of soft tissue density may cause difficult diagnostic problems, with the diagnosis addressed only by the presence of associated lesions. Increased awareness that renal angiomyolipoma can sometimes appear “aggressive” could help to prevent such lesions from being considered malignant, and thus avoid surgical confirmation of their nature.

The computed tomography (CT) findings in twelve patients with acute renal infection examined immediately and 3 h after i.v. contrast medium are reported. Three patients also had delayed scans at 6 h. Three main features were observed on the delayed scans: 1 a delayed nephrogram with streaky, wedge shaped or round high density areas. The areas of high density were at the same sites of the inhomogeneous areas of reduced density on the early scans; 2 focal contrast medium staining or a rim of increased density around abscesses; 3 focal areas of increased density at sites distant from the low density areas seen on the early scans. It is postulated that the delayed areas of increased density replace early areas of reduced density caused by ischemia due to vasospasm and/or compressing oedema of the vascular bed or by tubular obstruction. Delayed CT appears to be useful because it improves diagnostic confidence and gives a more exact evaluation of the extent of infection.

In order to consider the prognostic value of hyperdensity of the middle cerebral artery (MCA), we studied retrospectively the medical records of 80 consecutive patients with the diagnosis of ischemic stroke who underwent a non-enhanced computed tomography no longer than 24 h after the onset of the symptoms. To determine the mortality and disability, a follow-up of 30 days was obtained. Mortality does not differ significantly in acute ischemic stroke patients with and without increased density of MCA. When disability, calculated with the Rankin scale, is considered, the two groups are different since patients with hyperdensity of the middle cerebral artery (MCA) have a significantly worse outcome. The two groups do not differ for age, sex, the presence of atrial fibrillation, hypertension, diabetes, myocardial infarction and/or angina, and these factors do not influence the prognosis being equally present in the dead and in the survivors. In the multivariate discriminant analysis with stepwise variable selection, the dense MCA sign was significantly correlated either to mortality or to disability, along with atrial fibrillation, age and diabetes. We conclude that the dense MCA sign can be a useful prognostic factor in the early phase of ischemic stroke.

The aim of this study was to assess the prevalence of extravascular collateral findings during 64-slice CT angiography of the abdominal aorta (AA-CTA) and lower limbs (LL-CTA). The images of 536 AA-CTA and LL-CTA examinations performed for suspected aortic and peripheral vascular disease in 500 patients were retrospectively reviewed. Two radiologists evaluated the 5-mm axial images independently using appropriate window settings for the area under investigation. Collateral findings were divided according to their clinical significance into significant, nonsignificant and meriting further investigation. No collateral findings were identified in 97/500 patients (19.4%). In the remaining patients, 821 collateral findings were detected, of which 43 (5.24%) were classified as significant, 135 (16.44%) as meriting further investigation and 643 (78.32%) as nonsignificant. The findings indicative of the presence of a malignant lesion totalled 36 (4.5%). AA-CTA and LL-CTA demonstrate a nonnegligible prevalence of collateral findings, many of them major. It therefore appears that the evaluation should focus not only on the image reconstructions to identify vascular disease, but also on the native axial images to detect incidental findings.

This study was undertaken to evaluate the potential of 64-row multislice computed tomography (CT) versus digital subtraction angiography (DSA) in detecting significant lesions of lower-extremity inflow and runoff arteries.Fifty-three patients underwent 64-row multislice CT and DSA over a mean of 36 days. The vascular tree was divided into 33 segments. Three readers independently reviewed the axial CT scans and multiplanar oblique and two- and three-dimensional reconstructions (maximum intensity projection and volume rendering) images to assess degree of stenosis according to four categories: 1 (0%-49% stenosis); 2 (50%-99% stenosis); 3 (occluded); 4 (not evaluable). In all cases, DSA was performed by arterial catheterisation.In 53 patients, 1,440 segments were evaluated (infrarenal aorta and 16 arterial segments for each leg; 42 bilateral studies, 11 unilateral studies). Compared with DSA, CT angiography yielded 97.2% sensitivity, 97% specificity, 92.5% positive predictive value, 98.9% negative predictive value, 97.1% diagnostic accuracy and 95.4% concordance on the degree of stenosis.Sixty-four-row multislice CT proved to be helpful in detecting haemodynamically significant lesions in peripheral arterial occlusive disease and improved the results obtained with 4- and 16-slice multidetector CT. In addition, owing to the high spatial resolution and rigorous technique, no variations in the data obtained below the knee were detected, overcoming a limitation of earlier generations of CT scanners.

This study was undertaken to evaluate the accuracy of contrast-enhanced magnetic resonance angiography (CE-MRA) in detecting renal artery stenosis using intra-arterial digital subtraction angiography (DSA) as the gold standard.Thirty-five consecutive patients with possible renovascular hypertension were prospectively studied; 26 of them underwent both MRA and DSA. In these 26 cases, two readers assessed the number of renal arteries, the presence of stenoses and their degree. Results were compared with DSA, and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy of MRA were determined. Interobserver variability was also calculated.DSA showed 51 main renal arteries (one patient had a single kidney) and six accessory arteries (total number of arteries 57) in the 26 patients considered. Both MRA readers detected all of the 51 main renal arteries and only one accessory vessel. When the presence of stenosis was considered, the readers' results, respectively, were as follows: sensitivity 77% and 72%, specificity 69% and 69%, PPV 86% and 85%, NPV 55% and 50% and diagnostic accuracy 75% and 71%. When the detection of significant stenosis was considered, the results, respectively, were: sensitivity 83% and 83%, specificity 73% and 78%, PPV 60% and 65%, NPV 90% and 91%, and diagnostic accuracy 76% and 80%. Interobserver variation was good when considering stenosis detection (kappa=0.69) and excellent when considering detection of significant stenosis (kappa=0.85).MRA results do not appear as positive as in the majority of papers in the literature. Multiple reasons can probably be invoked to explain this difference. The mean age of our patients, higher than in many other studies, should be noted and may have accounted for their possible poor cooperation. Moreover, all of the missed significant stenoses were distally located, and therefore, the failure to detect them might be related to the suboptimal spatial resolution of MRA. Nevertheless, MRA showed a high NPV for detecting significant stenoses, a finding of considerable clinical relevance in that it allows patients with normal MRA findings to be spared additional more invasive procedures.

Purpose To compare the contribution of 64 channel multidetector row computed tomography angiography (64MDCT-angiography) with digital subtraction angiography (DSA) in the detection of intracranial aneurysms. Methods and materials Twenty-nine patients (10 males and 19 females, age: 40–84 years; average: 61.9 years) with clinical and imaging findings strongly suggesting the presence of subaracnoid hemorrhage underwent 64MDCT-angiography and DSA with a short interval between the two examinations (less than 12 h–5 days). CT parameters were: 64 mm × 0.5 mm collimation, pitch—0.828 and helical pitch—53. DSA were performed with standard technique (four vessel catheterization) and multiple projections. Axial CT scans as well as maximum intensity projection, volume rendering and multiplanar reformations and angiographic views were independently reviewed by four readers (two for 64MDCT-angiography and two for DSA). Consensus was reached for discordant cases. DSA was considered as the standard of reference. Results In 29 patients, 28 aneurysms were found (14 patients had 1 aneurysm, 4 patients had 2 aneurysms and 2 patients had 3 aneurysms; in 9 patients no aneurysm were found). 64MDCT-angiography detected 26/28 aneurysms. No false-positive sites were recognized. The sensitivity, specificity, positive and negative predictive values and diagnostic accuracy were, respectively, 92.8, 100, 100, 99.4 and 99.5%. Conclusions 64MDCT-angiography is helpful in detecting intracranial aneurysms with results similar to those of DSA but with less discomfort and risks for the patients and can be considered for the first line imaging technique. Conventional angiography is still needed in doubtful cases or negative MDCT-angiography associated with a strong clinical suspect.

Three-Dimensional Rotational Angiography (3DRA) is a new technique based on a rotational angiographic acquisition able to display arterial vessels in a 3D rendering mode. The system was mainly developed for neuroradiological evaluations but preliminary extracranial experiences have also been reported. The aim of our work was to compare the results of three-dimensional angiography of the carotid arteries done with high-flow injection of contrast medium from the aortic arch with the results of selective angiography.Twenty patients underwent digital angiography of the supra-aortic vessels in order to quantify a stenosis of the carotid bifurcations previously detected at Doppler Ultrasound. Examinations were performed with the Philips Integris Allura system provided with the rotational angiography (RA) tool connected to a workstation for three-dimensional reconstruction able to display vessels in a 3D fashion (Volume Rendering, Gradient Rendering, Shaded Surface Display), automatically remove bone structures (cervical spine, calcified plaque, etc.) and perform an automatic analysis of the vessel diameter and surface area at the point of major stenosis and in the disease-free vessel segments above and below. The carotid evaluation was done either with selective catheterization and the two standard AP and LL projections and with RA after contrast medium injection from the aortic arch followed by 3D reconstruction.The comparison of the selective angiography and three-dimensional images was possible in 37 out of 40 carotid bifurcations (3 internal carotid arteries were occluded) and a good diagnostic quality was obtained in 35 out of 37 cases with an high correlation in the degree of stenosis. In 2/37 cases with calcified plaques the degree of stenosis was effectively demonstrated only after electronic subtraction of the calcified component of the plaque.The technique we propose proved to be feasible in all cases with a good correlation in the quantification of the degree of stenosis. The practical advantage of our technique is the almost complete exclusion of risks of neurological complications due to selective catheterization, and reduced examination time.

A 53-year-old woman presented with systemic hypertension that was not responsive to medical treatment with lacidipine 4 mg. daily. The patient had no risk factors for atherosclerosis. Laboratory results were normal. Abdominal color Doppler ultrasound and selective renal angiography showed fibromuscular dysplasia of the main right renal artery consisting of multiple stenoses and 1 cm. saccular aneurysm (fig. 1). The left renal artery was normal. Various therapeutic options were discussed with the patient, and she elected to undergo an endovascular stent-graft procedure to avoid surgery. The procedure was performed percutaneously via the left axillary artery, in order to obtain a better angle while positioning the stent, through a 7Fr introducer sheath. Heparin 5,000 IU was administered. After renal artery selective catheterization with a multipurpose catheter, the lesion was crossed with a 0.014-inch guide wire. The wire was exchanged via the same catheter with a 0.035-inch Amplatz Super Stiff Guide Wire (Boston, Scientific Corp., Natick, Massachusetts). A 28 mm. Jostent Periphel Stent Graft (JOMED, Helsingborg, Sweden) was then mounted on a 5 40 mm. balloon catheter and advanced through the guide wire. The stent was delivered across the lesion and inflated at 8 atm. for 15 seconds. A final right renal arteriogram showed excellent graft position, aneurysmal exclusion and no sign of residual stenosis (fig. 2). There were no complications, and the patient was discharged home on postoperative day 2 on a regimen of aspirin 100 mg. daily for 3 months. The patient remained normotensive for 10 months. At 24month followup blood pressure was observed in the normal range with amlodipine 5 mg. daily, and serum creatinine was 1.2 mg./dl. (normal 0.4 to 1.3). Color Doppler ultrasound showed wide patency of the renal artery, normal renal perfusion and aneurysmal exclusion.

In clinical practice, physical examination is often unreliable in patients who are sedated, intoxicated, paralyzed, have head injures, or otherwise are unable to communicate symptoms. Moreover, intra-abdominal injury in particular can be present in the absence of signs and symptoms in blunt trauma patients. So for an accurate evaluation of the patient with multiple trauma the utilization of diagnostic modalities is often required. Three diagnostic imaging tools are utilized for the evaluation of thoraco-abdominal visceral trauma: standard X-ray plain film, ultrasonography (US), and computed tomography (CT). Furthermore, we must remember that in the last 10 years interventional radiology has been shown to be able to contribute to the treatment of these conditions due to its low invasiveness.

The association between venous thromboembolism and cancer has been known for many years. The clotting system may be activated because of enhanced platelet aggregation and adhesion or by stimulation from the endothelial cells or the tumour cells themselves. Furthermore, thrombosis may develop as a result of prolonged immobilization, surgery, chemotherapy or hormone therapy. We present a case of a patient who underwent surgery for excision of a Clark level II melanoma on the back who developed pulmonary metastasis four years after the operation. The metastasis manifested with very severe venous thromboembolism which, despite anticoagulant therapy and the placement of a vena caval filter, led to the patient's death from pulmonary embolism. The case is uncommon, in terms of both the rarity with which venous thromboembolism is associated to melanoma, and the severity with which it manifested.

Effusions and collections that form in the peritoneal cavity and in the infra-peritoneal spaces are usually secondary to pathological processes of the intra-peritoneal organs and only rarely do they represent the extension of collections of juxta- and retroperitoneal compartments. They can be formed by transudates, exudates, blood, pus, bile, lymph, urine, pancreatic enzymes or food, and are caused by a wide range of inflammatory, vascular, traumatic, neoplastic or dys-metabolic processes, by hepatic, renal or cardiac failure, and by surgery.

From pathological point of view the chronic renal infections include two types, interstitial chronic pyelonephritis and granulomatous pyelonephritis, namely xanthogranulomatous, malacoplakia and renal tuberculosis. Indications for imaging modalities are more common compared to the acute types and allow to depict both factors causing obstruction and infection such as stones ant the renal and extrarenal extension of the disease. In this article the authors review the findings and the role of plain film and urography, computed tomography and ultrasonography.

CT scans of the kidneys obtained approximately 3 hours after contrast administration often reveal useful information in patients with renal infections. In this article, we discuss three main features of these delayed scans. Feature 1 shows a nephrogram replacing a variable portion of the low density areas present in the early enhanced phase. The nephrogram can be streaky, band-like, cone or horseshoe-shaped; Feature 2 exhibits a focal staining or a hyperdense rim surrounding microabscesses and macroabscesses; Feature 3, very rare, is characterized by hyperdense areas located far from the lesions detected on early scans. These features make it possible to better define the actual extent of infection and the presence of the edema, improving diagnostic confidence.

Three-dimensional computed tomographic angiography (3D-CTA) and digital subtraction angiography of the cervical carotid artery were performed bilaterally in 15 patients with suspected stenoses. A new semi-automatic segmentation and new rendering methods were used. The degree of stenosis of internal carotid arteries, as determined both by axial slices and 3D images (surface, integral, maximum-intensity-projection, and raysum-rendered images), was compared qualitatively and quantitatively to angiographic findings. In correlation to angiography, the accuracy in determining the stenosis classification of internal carotid arteries was of 97% for axial slices and 59-90% for 3D images, respectively. Raysum (pseudoradiograph) rendering was found to be the most reliable rendering method and gave the most similar results to angiography. The accuracy of all rendering methods was improved by applying calcification removing algorithm, with a statistically significant difference between surface rendering without plaque removal and raysum rendering using the removing algorithm.

The evolution of computer technology has significantly improved the performances of three-dimensional reconstructions from Computed Tomographic images. The authors discuss the examination technique and the modalities of three-dimensional reconstruction based upon a new advanced workstation. This unit is based on a Sun Sparkstation linked with the main computer of the CT scanner. The workstation is extremely fast, the processing time for a high resolution three-dimensional image of the maxillofacial region being about 3 minutes. The scanning parameters, image reconstruction and visualization were investigated on cases of maxillofacial (mainly posttraumatic) conditions. The most important scanning parameters are slice thickness, table incrementation, dose, scan plane. Slice thickness and table incrementation are the parameters bearing the greatest influence on the quality of the three-dimensional images. Dose is also important but bears no influence on image quality: therefore it can be kept as low as possible to reduce patient exposure. The scanning plane has some minor effect; coronal images have some advantages over axial images but in many cases only axial images can be acquired. The reconstruction parameters are the threshold and the matrix. The threshold may range 70 to 300 HU but in most cases ranges 120 to 200 HU. An advantage offered by this system is that it allows threshold values to be changed after the reconstruction has been completed, without performing a new reconstruction. The visualization parameters include four rendering methods, i.e. the surface mode, the integral mode, the maximum intensity projection and the ray sum. The surface mode is the one yielding the best results for bones while the others are used for the reconstruction of soft tissues and vessels. The workstation enables the three-dimensional images to be processed with shading parameters, and to be modified with cut planes, disarticulation methods and other interactive methods.

Three-dimensional Computed Tomographic Angiography (3D CTA) is a new imaging technique for vascular structures. This study was aimed at investigating the diagnostic role of 3D CTA in the intracranial and extracranial arteries. Fifteen patients with intracranial artery disease (thirteen with aneurysms and two with arteriovenous malformations) and fifteen patients with stenosis of the common, internal or external carotid arteries underwent 3D CTA. All patients had been examined with intraarterial angiography. The CT examinations were performed with dynamic scanning during intravenous contrast agent administration. Three-millimeter thick contiguous slices were obtained in the cervical region and 1.5-mm contiguous slices in the intracranial region. CT findings were processed to produce 3D views on an independent workstation. 3D CTA results were compared with those of intraarterial DSA in all cases. Agreement was found in 13 of 15 cases of intracranial vascular abnormalities, and in 26 of the 30 carotid arteries in classifying the severity of the stenosis. The 3D views, which exhibit an excellent image quality, seem to be comparable to angiography in the intracranial and extracranial arteries. The main advantages of this technique are: 1) its low invasivity since only an intravenous contrast agent injection is required; 2) its easy and fast acquisition (2-3 minutes are needed if a non-spiral CT unit is used and less than one minute with spiral CT); 3) good demonstration of the calcified plaques which can be also removed with the softwares available at the workstation, to show the overall vessel lumen; 4) thanks to its simplicity the examination can also be performed in emergency (i.e. in patients with subarachnoid hemorrhage, if plain CT is positive for subarachnoid bleeding). Its main limitations are: 1) the need of an adequate concentration of contrast agent in the vessels; 2) artifacts due to calcified and bone structures; 3) no information about vessel inflow; 4) limited discrimination between arteries and veins in some areas (cavernous sinus); 5) limited field of view compared to angiography.

Small hypodense renal lesions with a round shape are frequently detected on CT scans of the upper abdomen after contrast medium administration. In nearly all cases these round hypodensities are simple small cysts with no clinical significance. However, the fluid density of these cysts cannot be always defined, due to the partial volume averaging which occurs on CT when 10-mm-thick slices and contrast enhancement are used. Therefore, a malignant tumor--i.e., small renal tumors or metastatic lesions--cannot be ruled out in some cases. Since the limitations of CT are related to partial volume averaging, the authors used both 5-mm and 10-mm slices to reduce this artifact. Forty-eight small hypodensities (15 mm) were studied after contrast agent administration: 42 of them were simple cysts and 5 were tumoral lesions--i.e., 3 renal cell carcinomas and 2 lymphomatous lesions. The results showed that, with 5-mm slices, the density of the fluid hypodensities decreased in nearly all cases and in 81.3% of cases it was below 30 HU. The difference in densities between 10-mm and 5-mm slices was about 50 HU (75 +/- 30 to 21 +/- 16 HU). In the 5 tumoral hypodensities, lesion density was still in the soft tissue range also with 5-mm slices, with no major decrease. These results show that this technique is simple and effective in the differential diagnosis of small renal hypodensities since it requires only a short additional examination time.

As a rule, renal angiomyolipomas (AML) present with characteristic patterns on US and CT images. However, in a limited number of cases US and CT findings are atypical, so that no diagnosis can be made on their basis. The authors reviewed their personal series of renal tumors and now report the US and CT findings of 5 cases with atypical features on one or both examinations. Two patients had hyperechoic lesions with typical AML patterns, but no fatty densities were visible with CT. Both patients underwent surgery and histology which showed two AMLs with muscular and vascular components and very few fatty cells. Two cases were observed in patients with Bourneville disease. Even though the cases exhibited atypical features on US and CT images, the diagnosis was suspected on the basis of the well-known association of tuberous sclerosis with AML. One case presented with a complex cystic mass on US; CT showed a bleeding tumor. Even though no unquestionable diagnosis of AML could be made in this case, the hypothesis of a bleeding AML was considered in the differential diagnosis. Such atypical imaging features were related to low fatty content inside the lesion and to bleeding complications. Absent/low fatty component represented a cause of atypical lesion appearance on CT which showed a mass with soft-tissue density which could not be differentiated from a solid tumor. In these cases, AMLs remained typically hyperechoic on US images. Bleeding represented a cause of error mainly on US since the typical hyperechoic pattern was replaced by a iso-hypoechoic pattern. CT is helpful in these cases because it shows both the bleeding and possible low-density fatty areas.

A hundred patients with different conditions underwent CT and the results were retrospectively reviewed to evaluate the visibility of the celiac trunk, of its branches and of the superior mesenteric artery. Thirty-six patients underwent angiography too, which allowed the anatomical variants suspected on CT to be demonstrated, according to Kuhns' criteria. The other 64 patients were consecutively selected and only aneurysmal changes were not included. All examinations were performed using a General Electric 9800 Advantage scanner, with 2 second scanning time and 10 mm-thick contiguous scans. In 20 patients 5 mm contiguous scans were performed. All examinations followed i.v. injections of contrast agents which were given with an automatic injector. The cases with suspected anatomical variants on CT but with no angiographic confirmation were not considered. A hundred CT exams were retrospectively reviewed: the celiac trunk and the common hepatic artery were demonstrated in all of them. Visibility of the other branches was 40% for the hepatic artery, 53% for the right branch of the hepatic artery and 39% for its left branch, 70% for the gastroduodenal artery, 82% for the left gastric artery, 97% for the splenic artery and 100% for the superior mesenteric artery. As for the 36 patients who underwent both CT and angiography, right hepatic artery from the superior mesenteric artery was seen in 19% of cases with both modalities; common hepatic artery arising from the superior mesenteric artery was detected in 2% of cases. In both instances, these anatomical variants appeared as a vessel running posterior to the portal vein. The careful investigation of axial CT scans showed the level of origin of the artery from the superior mesenteric artery. These results are in agreement with the angiographic data reported in the literature. Our study demonstrated that the celiac trunk and its variants are always depicted by the new CT scanner. The knowledge of these variants may be useful in the patients to submit to liver surgery. The celiac trunk and its variants are demonstrated with conventional 10 mm slices. The use of 5 mm slices improves the visibility of thin anatomical branches but is not essential to recognize the major vessels and anatomical variants.

In order to consider the prognostic value of hyperdensity of the middle cerebral artery (MCA), we studied retrospectively the medical records of 80 consecutive patients with the diagnosis of ischemic stroke who underwent a non-enhanced computed tomography no longer than 24 h after the onset of the symptoms. To determine the mortality and disability, a follow-up of 30 days was obtained. Mortality does not differ significantly in acute ischemic stroke patients with and without increased density of MCA. When disability, calculated with the Rankin scale, is considered, the two groups are different since patients with hyperdensity of the middle cerebral artery (MCA) have a significantly worse outcome. The two groups do not differ for age, sex, the presence of atrial fibrillation, hypertension, diabetes, myocardial infarction and/or angina, and these factors do not influence the prognosis being equally present in the dead and in the survivors. In the multivariate discriminant analysis with stepwise variable selection, the dense MCA sign was significantly correlated either to mortality or to disability, along with atrial fibrillation, age and diabetes. We conclude that the dense MCA sign can be a useful prognostic factor in the early phase of ischemic stroke.

The diagnostic imaging of renal masses has greatly benefitted from US and CT. Nevertheless, a certain number of problems and errors are still present, and they must be discussed once more. In the authors' experience, problems and errors have 3 fundamental causes: operator, examination technique and complex patterns of renal masses. The latter is the most important cause of error in CT diagnosis. Complex patterns are seen in a limited number of cystic masses--i.e., hemorrhagic, inflammatory, and septated cysts, and cystic tumors. Hemorrhagic cysts, if hemorrhage is not recent, can cause some diagnostic difficulties since the typical high density of the recent hemorrhage is no longer present. Other renal masses may appear hyperdense on unenhanced CT scans, and therefore they must be considered in the differential diagnosis. Inflammatory cysts and abscesses are sometimes difficult to differentiate from other masses due to their aspecific appearance; clinical correlation is important in these instances to support CT diagnosis. Multiseptated cysts and cystic tumors cause huge problems of differential diagnosis. A good knowledge of differential CT findings is sure to reduce the problems in differentiating benign from malignant tumors and, among the latter, the different histotypes and metastases, when present as solitary masses. Also in this case, the correlation between CT, clinical history and other modalities can reduce the number of questionable cases.

Cystic renal tumors represent a variety of lesions in which both solid and liquid components coexist. These lesions may be either benign or malignant and include the multilocular cystic nephroma (MCN), the renal cell carcinoma (RCC), and the papillary adenocarcinoma (PAC). The MCN is a rare neoplasm formed of multiple loculated cystic masses divided by septa. The tumor is benign, although there are some rare reports of malignant cases. The RCC and the PAC may appear with cystic patterns. This is rather uncommon for the RCC, which inside has a unilocular or multilocular cystic appearance, if the necrotic component is large. PAC is an infrequent renal tumor, which has a greater tendency to appear as a large mass with a unilocular large cystic space. The ultrasonography (US) and computed tomographic (CT) features of 27 cystic tumors are presented. Both US and CT allowed the recognition of the cystic components, the septa, and the vegetations. The two imaging techniques made it possible to distinguish the tumors into "unilocular" and "multilocular" masses: the former correspond to RCC and PAC, the latter to MCN and RCC. CT added some information on calcified or partially calcified tumors. CT more than US enabled the differentiation between the malignant RCC and the benign MCN for which conservative surgery may be indicated. The two techniques did not allow the differentiation between RCC and PAC, which has different prognostic behavior.

Fifteen cases with complete myelographic stop were examined by CT. CT showed stenosis of the spinal canal in 11/12 cases with extradural lesion (92%). The stenosis was or was not associated to disk pathology; one case was due to a large herniated disk. Three cases were due to a neurinoma and were not visualized at CT without intrathecal contrast medium. This situation represents a limitation of CT and therefore an indication for myelography.

The incidence of small renal tumors (less than cm 3) has increased in the past few years. Reasons for the increased number of reports are related to the contribution of Sonography and Computed Tomography--which enable a greater number of kidneys to be examined and allow a more detailed study of renal parenchyma. In order to assess the diagnostic value and role of the various imaging techniques in this pathology, the authors reviewed all renal tumors observed between 1982 and 1987. Nineteen cases presented with the characteristics of small renal tumors with "solid" findings on both US and CT. Sixteen cases were histologically proven (15 adenocarcinomas, 1 oncocytoma). Three recent, unoperated, cases are included since their features are the same as in the other cases. Metastases and other kinds of tumors (i.e. angiomyolipomas) are not included in this series. Ivp was performed in 14/19 cases; US and CT were always performed. CT proved to be the most sensitive technique, being positive in all cases. Ivp was positive in 9/14 cases (64%) and US in 14/19 (73%). A significant increase in the number of small renal tumors detected was observed, mainly in 1985-1987. This increase is correlated with the increase in the total number of abdominal examinations which US and CT have made possible. Most patients were asymptomatic; in fact, 15/19 cases were incidentally discovered with US and CT of the upper abdomen. US and CT appear to give a substantial contribution to an early diagnosis of small renal tumors, which may have a significant impact on both surgery and prognosis.

Ultrasound (US) and computed tomography (CT) criteria for “solid” and “liquid” abdominal lesions are well established and have long been codified. Nevertheless, there are a number of lesions which cannot be classified as solid or liquid and which are usually described as complex, either because they tend to show intermediate findings or because they have characteristics of both solid and liquid lesions at the same time. Based upon US and CT criteria there are two fundamental patterns of “complex” lesions [3]

The diagnostic value of Computed Tomography (CT) in the diagnosis of the aseptic necrosis of the femoral head is discussed. The CT findings in the different evolutive stages are reported and the respective diagnostic value of Conventional Radiology and CT are discussed. The CT findings of femoral head necrosis in the early phases are emphasized. The capability of CT to demonstrate structural changes in femoral heads with regular morphology allows to consider this technique when there exists a clinical doubt of osteonecrosis of the femoral head and in risk patients.

A series of thirteen cases of adrenal tuberculosis with Addison's disease is presented. At the onset of disease, CT findings consisted of an enlargement of both glands, with peripheral enhancement after contrast medium was injected. The CT differential diagnosis among tubercular, metastatic and amyloidotic etiology was not possible. When the course of the illness was favourable, CT showed a generalized glandular atrophy with calcifications. In two fatal cases, the diagnosis could be made only at post-mortem examination.

Computed Tomography (CT) of the spine was performed on 17 patients with myeloma in order to assess the role of the technique in recognizing and evaluating the extent of the lesions. Myelomatous lesions followed two patterns at CT: first of all, multiple focal lesions, whose density is either solid, liquid, or fatty; second, an extensive pattern involving the spongiosa of the vertebra, including the posterior arch. CT detected more lesions than conventional radiology; furthermore, the extent of the lesions was much better demonstrated by CT. CT should thus be performed: a) in case of pain and/or neurological findings in negative radiological examinations; b) to evaluate the extent of myelomatous lesions (mainly in the spine); c) in solitary myeloma CT may be performed on different bone segments with clinical symptomatology but normal X-ray findings.

Computed tomography allows today to reconstruct three-dimensional (3D) images from axial scans. The authors report their experience in cranio-facial pathology achieved in two Departments of Radiology (University of Trieste, Italy and University of Stanford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The applications in maxillo-facial traumas, cranio-facial malformations and head tumours are discussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demonstration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

Up to now three-dimensional reconstructions in computed tomography have been applied mainly to the skeleton. This limitation is due to technical difficulties when dealing with images of the soft tissues. In order to overcome these limitations three new softwares were developed, thus enabling the operator to pre-elaborate and modify the axial CT images. The first program allows the operator to isolate the lesion and/or the anatomical structures of interest from the surrounding areas. The second program eliminates the areas of isodensity with the lesion it is obtained by means of a trackball. The third program enables the operator to write the modified axial images on the original file. The lesion and/or the structures of interest can thus be processed more easily by the 3D reconstructive program. The new softwares have been applied to 3D reconstructions of brain lesions, and two significant cases are presented. Furthermore, since the new softwares can enhance the quality of 3D images of the skeleton, the programs were also tested in cases of acetabular traumas.

Addison's disease of the adrenal glands presents with different pathological findings depending on the stage. In the acute phase the adrenal glands are bilaterally enlarged while in the chronic phase the glands are small and calcified. A case of Addison's disease with follow-up over a period of a year by CT is reported. CT showed the evolution of the adrenal glands from bilateral masses to small calcified glands. The differential diagnostic problems in the acute phase are also discussed.

The aim was to investigate the regional and systemic haemodynamic consequences of bolus injection of fluids with different physical properties in the course of routine aortography. Iopamidol was compared with an equiosmolar solution of mannitol and with a 0.9 N saline solution. Continuous blood flow and Pulsatility Index (PI), as an index of regional vascular resistance, were measured by Doppler technique. Finger arterial pressure and heart rate were monitored at the time and for 3 min following each intraaortic bolus injections. The patients who underwent routine aortography were grouped according to the site of the flow measurements: common femoral artery, common carotid artery and brachial artery. Flow changes induced by the bolus infusion were evident for all the fluids but only at the femoral artery level. After an immediate (3 +/- 2 s) and brief (2 +/- 2 s) but marked reduction of flow and in-phase increase of PI following the bolus, further haemodynamic changes were observed only in the femoral artery, with a peak at 35 +/- 10 s and returning to baseline values after 70 +/- 15 s, in terms of both increased mean blood velocity and decreased PI. Saline and mannitol induced overall blood velocity alterations of 54\% and 80\%, respectively, and PI reductions of 44\% and 57\% compared with those induced by iopamidol. In the other vascular areas there was only a 17 +/- 2\% increase of the physiological early diastolic backflow at the brachial artery level. Blood pressure decreased and heart rate increased in phase with the flow changes of the femoral artery. In conclusion: (1) a dramatic rheodynamic perturbation at the site of injection induces a vasodilating stimulus; (2) the haemodynamic response following injection results in marked vasodilation of only the tributary vascular bed; (3) flow steal may occur from other beds towards the lower limb vascular beds owing to vascular impedance imbalance; (4) a reduction of systemic arterial pressure is induced in phase with the regional vascular events and a reflex increase of the heart rate; and (5) the physical properties of the injected fluids influence the intensity of the perturbation, although the decisive triggering factor is the counterflowing bolus per se.