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Hepatocellular Carcinoma (HCC) is the sixth most common cancer in the world. Patients with intermediate stage (Barcelona Clinic Liver Cancer, B stage) hepatocellular carcinoma (HCC) have been able to benefit from TACE (transarterial chemoembolization) as a treatment option. MicroRNAs (miRNAs), i.e., a subclass of non-coding RNAs (ncRNAs), participate in post-transcriptional gene regulation processes and miRNA dysfunction has been associated with apoptosis resistance, cellular proliferation, tumor genesis, and progression. Only a few studies have investigated the role of miRNAs as biomarkers predicting TACE treatment response in HCC. Here, we review the studies' characteristics from a radiological point of view, also correlating data with radiological images chosen from the cases of our institution.

Interventional radiology of the male urogenital system includes percutaneous and endovascular procedures, and these last consist mostly of transcatheter arterial embolizations. At the kidney level, arterial embolizations are performed mainly for palliative treatment of parenchymal tumors, for renal traumas and, less frequently, for arteriovenous fistulas and renal aneurysms and pseudoaneurysms. These latter may often require emergency intervention as they can cause renal or peri-renal hematomas or significant hematuria. Transcatheter arterial embolization is also an effective therapy for intractable severe bladder hematuria secondary to a number of neoplastic and inflammatory conditions in the pelvis, including unresectable bladder cancer and radiation-induced or cyclophosphamide-induced hemorrhagic cystitis. Endovascular interventional procedures for the penis are indicated for the treatment of post-traumatic priapism. In this article, we review the main endovascular radiological interventions of the male urogenital system, describing the technical aspects, results, and complications of each procedure at the various anatomical districts.

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 three-dimensional 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.

Purpose: This study reviews our experience over the last 10 years with procedures of embolisation and/or exclusion of the renal arteries, their parenchymal branches and the polar arteries [renal artery embolisation (RAE)]., Materials and Methods: Twenty-seven patients (19 men and eight women; age range 37-93 years; mean 74 years) underwent RAE. The indications were: symptomatic gross haematuria in nine patients (33.3%) (tumour-related in seven and iatrogenic in two), symptomatic inoperable renal tumour in five (18.5%), large subcapsular or perirenal haematoma in three (11.1%) and aneurysm of the main renal artery in two (7.4%). Eight patients (29.6%) scheduled for endovascular aneurysm repair (EVAR) of the abdominal aorta underwent prophylactic embolisation of the renal polar branch arising from the aneurysmal sac or the subrenal aortic neck to prevent the possible revascularisation of the sac. Different embolisation agents were used: coils (17 cases), embolisation particles (14 cases), glue (one case), coated stent (two cases) and mechanical occlusion devices (two cases). In 11 cases, two to three different embolisation agents were used together., Results: Technical success was achieved in 26/27 patients (96.3%); in one case, embolisation of a polar artery arising from the aneurysmal sac was not possible. One case of gross haematuria recurred 13 months after the procedure and was re-treated with success. There were no cases of major or minor complications., Conclusions: RAE is an effective and minimally invasive procedure in the treatment of neoplastic/iatrogenic symptomatic gross haematuria and in the palliative treatment of inoperable renal tumours. One possible new indication is the prophylactic exclusion of the polar artery arising from the neck or the sac of an abdominal aortic aneurysm in patients who are candidates for EVAR. In our experience, we observed very low morbidity and a short hospital stay. This procedure requires the availability of various materials for performing embolisation and experience in their use.

Purpose: 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)., Materials and Methods: 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., Results: 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%)., Conclusions: 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.

Purpose: 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., Materials and Methods: 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., Results: 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., Conclusions: 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.

Purpose: 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., Materials and Methods: 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., Results: 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)., Conclusions: 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 x 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.

Purpose: 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., Materials and Methods: 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., Results: 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., Conclusions: 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.

Purpose: This paper describes the different endovascular treatments (cuffs, endografts and embolisation) available for types I, II and III endoleaks occurring after endovascular abdominal aortic aneurysm repair (EVAR)., Materials and Methods: From January 2000 to June 2006, 134 patients (118 men, 16 women; mean age 75.1 years) underwent EVAR. Ten patients (7%) developed significant endoleaks requiring endovascular treatment., Results: Five endoleaks were type I, two were type II and three were type III. Of the five type I endoleaks, four were proximal and one was distal. The proximal endoleaks were treated by cuff deployment, whereas the distal endoleak was treated with a bifurcated graft. Of the two patients with type II endoleak, one was treated by translumbar puncture and coil embolisation, and the other was treated by superselective embolisation of the lumbar feeding vessel with nonresorbable particles. Of the three patients with type III endoleak, two were treated by deploying an aortouniiliac endograft inside the bifurcated graft and the other by implanting a cuff to restore continuity between the graft body and the contralateral limb. Endovascular treatment was successful in 6/10 cases, whereas three cases required surgical conversion. One patient did not undergo surgery owing to poor general condition., Conclusions: The reported incidence of endoleaks after EVAR is 10%-20%. Significant endoleaks should be treated promptly. Endovascular treatment can be done with different techniques, but success in not constant due to adverse anatomical conditions and technical difficulties.

Purpose: The aim of this study was to analyse the costs pertaining to the radiology department of magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA) in the evaluation of arterial disease of the lower limbs., Materials and Methods: The differential cost of the two procedures, i.e. the sum of equipment costs (amortisation and service contract), variable costs (supplies and related services) and personnel costs (radiologist, radiographer and nurse) was determined. The common cost (auxiliary personnel and indirect internal costs) was also calculated. Finally, the full cost of the two procedures was obtained (sum of differential and common costs)., Results: The differential cost of MRA was 186.14 euro (equipment costs: 50.80 euro, variable costs: 75.04 euro, personnel costs: 60.30 euro) while the differential cost of intra-arterial DSA was 238.18 euro (equipment costs: 57.60 euro, variable costs: 90.13 euro, staff costs: 90.45 euro). The estimated common cost was 5.62 euro. Therefore, the full cost of MRA was 191.76 euro and the full cost of intra-arterial DSA was 243.80 euro (27.1% higher)., Discussion and Conclusions: Intra-arterial DSA costs more than MRA, mainly because of the higher costs of supplies used during the procedure and higher personnel costs (as a result of the longer duration of intra-arterial DSA). It should be noted that our evaluation considers costs pertaining to the radiology department only. It is evident that an economic analysis considering hospital costs as well would result in much higher costs for DSA if post-procedure hospitalisation is required. Our results cannot be simply exported to other radiology departments since they refer to the technology and organisation adopted in our department. However, our cost analysis model can be easily applied to other environments. MRA provides good diagnostic accuracy in the evaluation of arteries of the lower extremities, and its biological cost is far lower than that of intra-arterial DSA (MRA is noninvasive, it does not use ionising radiation, and the contrast medium is safe). Its lower cost is another argument in favour of the use of MRA instead of intra-arterial DSA in the evaluation of lower-extremity arterial disease.

Purpose: 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., Materials and Methods: 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., Results: 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., Conclusions: 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.

Purpose: Virtual stenting (VS) is a new tool in the 3D processing work station of rotational angiography (RA) systems. This tool enables the 3D visualization of a stent or stent-graft in the site of a stenotic, obstructive or aneurysmatic lesion to be treated. We report the preliminary results obtained with this software in the treatment of segmental stenotic, obstructive or aneurysmal lesions of the iliac artery., Materials and Methods: Seventeen patients under-went rotational angiography and 3D reformations for one or more stenoses (19 cases), obstructive lesions (2 cases) or aneurysms (2 cases) of the common and/or external iliac artery and were treated with stents in 22/23 of cases. In all cases, the VS tool was applied to the stenotic-obstructive lesion on the identified on the 3D angiogram obtained before the stenting procedure., Results: The measurements of the stents/stents-grafts (length, proximal and distal diameter) provided by the tool were compared to those of the stent deployed. In 22/23 procedures, the measurements of virtual stenting and those of the deployed stent showed a good level of concordance. The system failed to provide correct measurements in only one long and tortuous iliac aneurysm., Conclusions: The ''virtual stenting'' tool proved to be reliable and fast, and enabled a more objective selection of the stent to be deployed on a stenotic-obstructive lesion in almost all cases. In cases of aneurysms of marked tortuosity, the system tends to suggest an inappropriate stent. The possibility of manually defining the optimal stent path within the aneurysmal sac might be useful.

Purpose: The angiographic evaluation of the results of femoropopliteal balloon angioplasty (PTA) is fundamental for monitoring long term success, but, often, the examination is performed only with one or two orthogonal projections. The aim of this study is to report our experience with a new digital angiography system able to perform "rotational" acquisitions to assess the results after femoro-popliteal PTA., Materials and Methods: Twenty-eight patients underwent femoro-popliteal PTA due to steno-obstructive lesions varying in length between 1 and 10 cm. All examinations were performed on a Philips Integris Allura system able to perform "rotational angiography"(RA). The two frames showing the greatest degree of stenosis and the presence of subintimal "flaps" induced by PTA were compared with the frame obtained in the AP projection., Results: RA after PTA was possible in all cases. In 12/28 (42.4%) cases there was no difference between the static AP projection and RA, whereas in 13/28 (46.5%) the static acquisition, compared with RA, underestimated the extent of residual stenosis by 10-30%. In 6 out of these 13 cases a discordance on the presence and extent of subintimal flap between static and rotational acquisition was identified. In three other cases (10.7%) there was substantial agreement on the residual stenosis but not on the PTA-induced dissection which was always better visible on RA., Conclusions: RA allowed optimal analyses of all cases improving the information of the conventional technique based on one projection only. It also proved very useful in demonstrating residual stenosis and PTA-induced dissections. In our experience this information modified our therapeutic approach leading to repeated balloon angioplasty or stenting in about 50% of cases.

Purpose: To compare the long-term patency after the treatment of mild-to-moderate femoropopliteal artery disease by percutaneous transluminal angioplasty (PTA) alone (PTA group) and PTA plus stenting (STENT group) in a non-randomised retrospective study., Materials and Methods: Eighty-six limbs in 64 patients (mean age 67+/-8 years, 47 males and 17 females) with femoropopliteal artery disease and symptomatic for mild-to-moderate intermittent claudication (Rutherford's category 1-2) were treated by percutaneous revascularization. None of the patients had critical lower limb ischaemia. Of the 86 lesions, 63 (40 stenoses and 23 occlusions) were treated by PTA alone and 23 (12 stenoses and 11 occlusions) by PTA plus stent implantation. The success was defined as a maximal = or < 30% residual stenosis of vessel lumen diameter, as defined by biplane angiography. The angiography findings were confirmed by colour-Doppler sonography of the treated segment. A peak systolic velocity = or < 150 cm/sec in the treated segment and an improvement of the ankle/brachial index by gs; 0.15 were considered indications of haemodynamic success. Restenosis at follow-up (mean 21 months, range 1-72 months) was defined by colour-Doppler sonography as a peak systolic velocity gs; 230 cm/sec or a peak systolic velocity ratio gs; 2.5 in the treated area and a gs; 0.15 decrease in ankle/brachial index compared with post-procedure measurements., Results: Treatment by PTA plus stenting enabled correction of residual stenosis in 15/23 limbs, relief of PTA complications in 7/23 limbs and correction of restenosis after a PTA in 1/23. In the PTA group the treatment was successful in 59/86 limbs (68%) versus 21/23 (91%) in the STENT group (chi squared value= 0,04). As a whole, major complications occurred in 5.8% of cases (n=5), 3 in the PTA group and 2 in the STENT group. The primary patency rates at 6, 12, and 24 months were 70%, 66% and 58% in the PTA group versus 74%, 67% and 46% in the STENT group (Gehan p value=0.96). The secondary patency rates at 6, 12, 24 months were 75%, 73%, 65% in the PTA group versus 84%, 76%, 64% in the STENT group (Gehan p value=0,59)., Discussion and Conclusions: In this study, stenting and PTA for the treatment of mild-to-moderate femoropopliteal peripheral artery disease improved the primary technical success of PTA by correcting residual stenosis, elastic recoil and occlusive intimal flaps. Moreover, stenting can prevent delayed constrictive remodelling. However, stenting did not improve long-term outcomes in comparison with PTA alone given that stent implantation increases the risk of restenosis due to myointimal hyperplasia. Our findings regarding the complication rates and long-term outcome agree with those published by other authors. Colour-Doppler US monitoring enabled early detection of restenosis in the treated area and its differentiation from the development of new lesions in other areas.

Purpose: Rotational Angiography (RA), a new modality for performing conventional catheter angiography, enables an accurate evaluation of the artery to be obtained from different points of view by means of the contemporary rotation of the X-ray tube and image intensifier during intrarterial selective injection of contrast media. This paper describes the examination technique and compares the diagnostic accuracy of the RA oblique projections with the data obtained in the antero-posterior (AP) and latero-lateral (LL) projections in the study of the carotid bifurcation., Materials and Methods: Thirty patients underwent RA of the supra-aortic vessels to evaluate the degree of a stenosis at the carotid bifurcation suspected at color Doppler imaging. The angiographic examinations were performed on a Philips Integris Allura system able to rotate the arc at a speed of 55 degrees /s with selective catheterisation of both common carotid arteries., Results: The frame showing the greatest degree of stenosis was compared with the frames obtained in the AP and LL projections. 57/60 carotid bifurcations were assessable (3 cases of internal carotid arteries were obstructed). The degree of stenosis evaluated on the most significant of the oblique projections was superior to that shown in the AP and LL projections for 16/30 cases on the right side and for 14/27 cases on the left side. In 4/57 cases (7%) the degree of stenosis was modified from less than 70% to more than 70%. No adverse event was observed due to catheterisation., Conclusions: RA enables the complete three-dimensional evaluation of the carotid bifurcation, and generally yields more accurate information on the degree of the stenosis in comparison with AP and LL technique. The study was successfully carried out in all cases, however slightly longer examination times due to the setup requirements of the system. This was largely compensated by the quality of the information yielded, which required no additional projections to be performed. Moreover, the high frame rate of 25 frames per second showed the haemodynamic flow through the lesion.

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.

Unlabelled: 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.

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.

Aim: A retrospective study of our experience of CT evaluation and follow-up of 16 solitary and multiple renal abscesses treated successfully with antibiotics alone and evaluated with CT at the onset of symptoms and after therapy., Materials and Methods: Seven patients had a solitary renal abscess, five had multiple renal abscesses and four had renal and perinephric abscess. None of the abscesses were larger than 5 cm., Results: In all 16 patients, the CT examination showed total renal and extrarenal regression of the abscesses. In four patients, scarring of the renal outline was observed on follow-up., Conclusions: The study demonstrates the opportunity to avoid aggressive interventional or surgical treatment of renal and perirenal abscesses of 5-cm diameter or less which can completely regress after antibiotic therapy of at least 4 weeks. The CT examination results are important both in the diagnostic phase to establish the extent of the lesions and in the follow-up to check the results of medical treatment.

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.

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.

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 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.

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.

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.

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.

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.

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.

Parathyroid surgery needs an appropriate diagnosis and a preoperative localization. We conducted a prospective study to compare the efficacy of 4 different imaging modalities in 17 patients: thallium-technetium subtraction scintigraphy, ultrasonography, computed tomography and arteriography. The sensitivity was: scintigraphy 58%, echotomography 86%, Tc 92% and arteriography only 33%. Neck exploration confirmed the imaging results. We found 15 cases of adenomas (2 cases of double adenoma) and 1 case of hyperplasia; in 1 patient, no lesions were found. We conclude that the association of such techniques appears to be the optimal strategy in about 100% of the 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 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.

Acetabular fractures represent a complex variety that are classified in different types. Conventional radiology is often inadequate to demonstrate and classify the fractures. Computed tomography (CT) has already been shown to be superior in this field. A further advantage of CT is represented by the recent availability of three-dimensional (3D) images that are realized from axial CT scans by means of a new software. The Authors report the applications of this new software to the study of the normal acetabulum and in patients with fractures. 3D images allows an effective demonstration of the fracture, its irradiation and the dislocation of bone fragments. The information is contained in one or few images rather than many axial images. Therefore the role of 3D images may be considered complementary to axial CT scans.

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.