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Purpose: To evaluate the usefulness of compressive ultrasound (CUS) for the diagnosis of deep vein thrombosis (DVT) in patients with SARS-CoV-2-related infection. Methods: 112 hospitalized patients with confirmed SARS-CoV-2 infection were retrospectively enrolled. CUS was performed within 2 days of admission and consisted in the assessment of the proximal and distal deep venous systems. Lack of compressibility, or direct identification of an endoluminal thrombus, were the criteria used for the diagnosis of DVT. Pulmonary embolism (PE) events were investigated at computed tomography pulmonary angiography (CTPA) within 5 days of follow-up. Logistic binary regression was computed to determine which clinical and radiological parameters were independently associated with PE onset. Results: Overall, the incidence of DVT in our cohort was about 43%. The most common district involved was the left lower limb (68.7%) in comparison with the right one (58.3%) while the upper limbs were less frequently involved (4.2% the right one and 2.1% the left one, respectively). On both sides, the distal tract of the popliteal vein was the most common involved (50% right side and 45.8% left side). The presence of DVT in the distal tract of the right popliteal vein (OR = 2.444 95%CIs 1.084–16.624, p = 0.038), in the distal tract of the left popliteal vein (OR = 4.201 95%CIs 1.484–11.885, p = 0.007), and D-dimer values (OR = 2.122 95%CIs 1.030–5.495, p = 0.003) were independently associated with the onset on PE within 5 days. Conclusions: CUS should be considered a useful tool to discriminate which category of patients can develop PE within 5 days from admission.

Objective: The American College of Radiology (ACR) and the European Thyroid Association (EU) have proposed two scoring systems for thyroid nodule classification. Here, we compared the ability of the two systems in triaging thyroid nodules for fine-needle aspiration (FNA) and tested the putative role of an approach that combines ultrasound features and cytology for the detection of malignant nodules. Design and Methods: The scores obtained with the ACR and EU Thyroid Imaging Reporting and Data Systems (TIRADS) from a prospective series of 480 thyroid nodules acquired from 435 subjects were compared to assess their performances in FNA triaging on the final cytological diagnosis. The US features that showed the highest contribution in discriminating benign nodules from malignancies were combined with cytology to improve its diagnostic performance. Results: FNA was recommended on 46.5% and 51.9% of the nodules using the ACR and EU-TIRADS scores, respectively. The ACR system demonstrated a higher specificity as compared to the EU-TIRADS (59.0% vs. 52.4%, p = 0.0012) in predicting >TIR3A/III (SIAPEC/Bethesda) nodules. Moreover, specific radiological features (i.e., echogenic foci and margins), combined with the cytological classes improved the specificity (97.5% vs. 91%, p < 0.0001) and positive predictive values (77.5% vs. 50.7%, p < 0.0001) compared to cytology alone, especially in the setting of indeterminate nodules (TIR3A/III and TIR3B/IV), maintaining an excellent sensitivity and negative predictive value. Conclusions: The ACR-TIRADS system showed a higher specificity compared to the EUTIRADS in triaging thyroid nodules. The use of specific radiological features improved the diagnostic ability of cytology.

Ultrasound scores are used to determine whether thyroid nodules should undergo Fine Needle Aspiration (FNA) or simple clinical follow-up. Different scores have been proposed for this task, with the American College of Radiology (ACR) TIRADS system being one of the most widely used. This study evaluates its ability in triaging thyroid nodules deserving FNA on a large prospective monocentric Italian case series of 493 thyroid nodules from 448 subjects. In ACR 1–2, cytology never prompted a surgical indication. In 59% of cases classified as TIR1c-TIR2, the FNA procedure could be ancillary, according to the ACR-TIRADS score. A subset (37.9%) of cases classified as TIR4-5 would not undergo FNA, according to the dimensional thresholds used by the ACR-TIRADS. Applying the ACR score, a total of 46.5% thyroid nodules should be studied with FNA. The ACR system demonstrated a sensitivity and specificity of 58.9% and 59% in the identification of patients with cytology ≥TIR3A, with a particularly high false negative rate for ACR classes ≥3 (44.8%, 43/96), which would dramatically decrease (7.3%, 7/96) if the dimensional criteria were not taken into account. In ACR 3–4–5, a correspondence with the follow-up occurred in 60.3%, 50.2% and 51.9% of cases. The ACR-TIRADS is a useful risk stratification tool for thyroid nodules, although the current dimensional thresholds could lead to an underestimation of malignant lesions. Their update might be considered in future studies to increase the screening performances of the system.

In oncological surgery, the liver still remain a challenge for surgeons. From the seventies, when liver surgery spread, techniques and strategies to approach parenchymal resection are very changed: from a radical surgery, to the finding of liver regeneration capacity and the concept of minimum remnant size, until now, where new liver regeneration theories and new physiological data are changing our approach. In case of HCC, or in case of metastatic disease, when resection is indicated, there are several diagnostic feature to perform before candidate a patient to surgery. How could be safe a liver resection? Which is the phatophysiological etiology of post-hepatectomy liver failure? How could we expand the safe limits for surgery? All these questions are key-points to better understand liver disease, and, moreover, their treatments. From the first meeting with patient affected by liver cancer, we would like to describe how to manage patients, which kinds of imaging we should prefer, how to assess safe limits for resections, and, in case, how to expand this limit. Then, we will focus on interventional radiologic and surgical strategies to approach liver cancer, and how and why posthepatectomy liver failure could be prevented and diagnosed correctly. Particularly, we would focus on portal vein embolization, two-staged hepatectomy, and ALPPS, always with physiological explanation, from the most up-to-date clinical evidence. Particular attention will be made for liver surgery’s sequel and risks. Comparing the newest data available in literature, we will focus on diagnosing, staging and surgical planning to approach liver resections correctly., In oncological surgery, the liver still remain a challenge for surgeons. From the seventies, when liver surgery spread, techniques and strategies to approach parenchymal resection are very changed: from a radical surgery, to the finding of liver regeneration capacity and the concept of minimum remnant size, until now, where new liver regeneration theories and new physiological data are changing our approach. In case of HCC, or in case of metastatic disease, when resection is indicated, there are several diagnostic feature to perform before candidate a patient to surgery. How could be safe a liver resection? Which is the phatophysiological etiology of post-hepatectomy liver failure? How could we expand the safe limits for surgery? All these questions are key-points to better understand liver disease, and, moreover, their treatments. From the first meeting with patient affected by liver cancer, we would like to describe how to manage patients, which kinds of imaging we should prefer, how to assess safe limits for resections, and, in case, how to expand this limit. Then, we will focus on interventional radiologic and surgical strategies to approach liver cancer, and how and why posthepatectomy liver failure could be prevented and diagnosed correctly. Particularly, we would focus on portal vein embolization, two-staged hepatectomy, and ALPPS, always with physiological explanation, from the most up-to-date clinical evidence. Particular attention will be made for liver surgery’s sequel and risks. Comparing the newest data available in literature, we will focus on diagnosing, staging and surgical planning to approach liver resections correctly

Objective: To evaluate image quality and radiation dose exposure of low-kV (100 kV) and low contrast medium (CM) volume CT angiography (CTA) in patients candidate to Transcatheter Aortic Valve Implantation (TAVI), in comparison with standard CTA protocol. Methods: 79 patients candidate for TAVI were prospectively enrolled in this study and examined with 256-MDCT. 42 patients were evaluated using study-group protocol (100 kV; whole-body retrospective ECG-gating; with 50 ml of CM; iterative reconstruction algorithm) while 37 patients underwent a standard CTA study (120 kV; ECG-gating for chest; 100 ml of CM; FBP reconstruction). Overall image quality was evaluated using a 4-point scale. Vascular enhancement (HU) was then assessed in each patient by manually drawing multiple ROIs in lumen of 7 segments of the whole aorta. The radiation dose exposure of both groups was calculated and all data were compared and statistically analyzed. Results: On low-kV protocol, higher mean attenuation values were achieved in all the measurements as compared to standard protocol. There were no significant differences in the image quality evaluation in both groups. Mean radiation dose value of study group was significantly lower than in control group (reduction of 20%). Conclusion: Low kV and low CM volume CTA protocols allow TAVI planning to be carried out with high quality images and a significant reduction in the radiation dose as compared to the standard CTA protocol. Advances in knowledge: Low-kV CTA for pre-operative assessment of patients candidates for TAVI, permits to achieve a significant reduction of radiation dose exposure and contrast medium volume, reducing the risk of contrast induced nephropathy.

AIM To compare radiation dose and image quality of lowdose computed tomography (CT) protocol combined with hybrid-iterative reconstruction algorithm with standarddose CT examinations for follow-up of oncologic patients. METHODS Fifty-one patients with known malignant diseases which underwent, during clinical follow-up, both standarddose and low-dose whole-body CT scans were enrolled. Low-dose CT was performed on 256-row scanner, with 120 kV and automated mA modulation, and iterative reconstruction algorithm. Standard-dose CT was performed on 16-rows scanner, with 120 kV, 200-400 mAs (depending on patient weight). We evaluated density values and signal-to-noise ratio, along with image noise (SD), sharpness and diagnostic quality with 4-point scale. RESULTS Density values in liver, spleen and aorta were higher in lowdose images (liver 112.55 HU vs 103.90 HU, P < 0.001), as SD values in liver and spleen (liver 16.81 vs 14.41). Volumetric-Computed-Tomographic-Dose-Index (CTDIvol) and Dose-Length-Product (DLP) were significantly lower in low-dose CT as compared to standard-dose (DLP 1025.6 mGy*cm vs 1429.2 mGy*cm, P < 0.001) with overall dose reduction of 28.9%. Qualitative analysis did not reveal significant differences in image noise and diagnostic quality. CONCLUSION Automatic tube-current modulation combined with hybriditerative algorithm allows radiation dose reduction of 28.9% without loss of diagnostic quality, being useful in reducing dose exposure in oncologic patients.

Background: Effective radiation dose in coronary CT angiography (CTCA) for coronary artery bypass graft (CABG) evaluation is remarkably high because of long scan lengths. Prospective electrocardiographic gating with iterative reconstruction can reduce effective radiation dose. Objectives: To evaluate the diagnostic performance of low-kV CT angiography protocol with prospective ecg-gating technique and iterative reconstruction (IR) algorithm in follow-up of CABG patients compared with standard retrospective protocol. Methods: Seventy-four non-obese patients with known coronary disease treated with artery bypass grafting were prospectively enrolled. All the patients underwent 256 MDCT (Brilliance iCT, Philips) CTCA using low-dose protocol (100 kV; 800 mAs; rotation time: 0.275 s) combined with prospective ECG-triggering acquisition and fourth-generation IR technique (iDose4; Philips); all the lengths of the bypass graft were included in the evaluation. A control group of 42 similar patients was evaluated with a standard retrospective ECG-gated CTCA (100 kV; 800 mAs).On both CT examinations, ROIs were placed to calculate standard deviation of pixel values and intra-vessel density. Diagnostic quality was also evaluated using a 4-point quality scale. Results: Despite the statistically significant reduction of radiation dose evaluated with DLP (study group mean DLP: 274 mGy cm; control group mean DLP: 1224 mGy cm; P value < 0.001). No statistical differences were found between PGA group and RGH group regarding intra-vessel density absolute values and SNR. Qualitative analysis, evaluated by two radiologists in “double blind”, did not reveal any significant difference in diagnostic quality of the two groups. Conclusions: The development of high-speed MDCT scans combined with modern IR allows an accurate evaluation of CABG with prospective ECG-gating protocols in a single breath hold, obtaining a significant reduction in radiation dose.

Objectives To evaluate intrareader and inter-reader agreement in CT perfusion (Perf) measurements in cirrhotic patients with hepatocellular carcinoma (HCC) lesions. Methods Sixteen patients with HCC (9 untreated, 5 recurrence/residual disease after transarterial chemoembolization, and 2 after radiofrequency ablation treatment) underwent standard CT examination and a Perf study; a quantitative map of arterial and portal Perf by means of a color scale was generated. With dedicated Perf software, the following parameters were calculated on untreated and treated HCC lesions and on cirrhotic parenchyma: hepatic Perf, tissue blood volume, hepatic perfusion index, arterial perfusion, and time to peak. Intraobserver and interobserver agreements were assessed for 2 readers with Bland-Altman plots, intraclass correlation coefficients (ICCs), coefficients of variation, and repeatability. Results In HCC lesions, agreement analysis demonstrated higher intra-agreement values in comparison with interagreement (range of ICC values, 0.26-0.59 between readers and 0.67-0.94 between readings). Lower interagreement was found for treated HCC lesions in comparison with untreated lesions (range of ICC values, respectively, 0.12-0.54 and 0.31-0.89). Conclusions For all Perf parameters intra-agreement was higher than interagreement, even though a relatively wide range of 95% limits of agreement was found in both cases.

Objective Complication rates after pancreatic resections remain high despite improvement in perioperative management. The effects of body composition and the relationship among different body compartments on surgical morbidity are not comprehensively investigated. The aim of this study was to assess whether the evaluation of different body compartments and their relationship was associated with the development of major postoperative complications after pancreatoduodenectomy (PD) for cancer. Methods We retrospectively analyzed 124 patients who underwent PD and had a staging computed tomography (CT) scan at our center. CT scan was used to measure abdominal skeletal muscle area and volume, as well as visceral fat area (VFA) and volume. The total abdominal muscle area (TAMA) was then normalized for height. The severity of complications was assessed. Univariate and multivariate analyses were performed to investigate correlations between the above variables and postoperative complications. The receiver operating characteristic curve methodology was used to investigate the predictive ability of each parameter. Results Major complications occurred in 42 patients (33.9%). The prevalence of sarcopenia was 24.2%. Regression analyses revealed no correlation between abdominal muscular and adipose tissue areas. Univariate analysis showed that the depletion of muscle area normalized for height was not per se predictive of complications (P = 0.318). Multivariate logistic regression showed that the VFA/TAMA was the only determinant of major complications (odds ratio, 3.20; 95% confidence interval, 1.35–7.60; P = 0.008). The model predictive performance was 0.735 (area under the curve) with a sensitivity of 64.3% and a specificity of 74.4%. Conclusion Sarcopenic obesity is a strong predictor of major complications after PD for cancer.

AIM: To assess the diagnostic accuracy of multidetectorrow computed tomography (MDCT) as compared with conventional magnetic resonance imaging (MRI), in identifying mesorectal fascia (MRF) invasion in rectal cancer patients. METHODS: Ninety-one patients with biopsy proven rectal adenocarcinoma referred for thoracic and abdominal CT staging were enrolled in this study. The contrast-enhanced MDCT scans were performed on a 256 row scanner (ICT, Philips) with the following acquisition parameters: tube voltage 120 KV, tube current 150-300 mAs. Imaging data were reviewed as axial and as multiplanar reconstructions (MPRs) images along the rectal tumor axis. MRI study, performed on 1.5 T with dedicated phased array multicoil, included multiplanar T2 and axial T1 sequences and diffusion weighted images (DWI). Axial and MPR CT images independently were compared to MRI and MRF involvement was determined. Diagnostic accuracy of both modalities was compared and statistically analyzed. RESULTS: According to MRI, the MRF was involved in 51 patients and not involved in 40 patients. DWI allowed to recognize the tumor as a focal mass with high signal intensity on high b-value images, compared with the signal of the normal adjacent rectal wall or with the lower tissue signal intensity background. The number of patients correctly staged by the native axial CT images was 71 out of 91 (41 with involved MRF; 30 with not involved MRF), while by using the MPR 80 patients were correctly staged (45 with involved MRF; 35 with not involved MRF). Local tumor staging suggested by MDCT agreed with those of MRI, obtaining for CT axial images sensitivity and specificity of 80.4% and 75%, positive predictive value (PPV) 80.4%, negative predictive value (NPV) 75% and accuracy 78%; while performing MPR the sensitivity and specificity increased to 88% and 87.5%, PPV was 90%, NPV 85.36% and accuracy 88%. MPR images showed higher diagnostic accuracy, in terms of MRF involvement, than native axial images

Purpose. To assess the diagnostic accuracy of dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSCE-MRI) in differentiation between benign and malignant liver lesions by assessment of tumoral perfusion parameters. Methods Materials. Seventy-three patients with known focal liver lesions, including 45 benign (16 FNH, 27 angiomas, and 2 abscesses) and 28 malignant ones (17 metastases, 9 HCCs, and 2 cholangiocarcinoma) underwent 1.5 T MRI upper abdominal study, with standard protocol that included dynamic contrast-enhanced sequences. On dedicated workstation, time-intensity curves were determined and the following perfusion parameters were calculated: relative arterial, venous and late enhancement (RAE, RVE, RLE), maximum enhancement (ME), relative enhancement (RE), and time to peak (TTP). Results. All diagnoses were established either by histopathology or imaging follow-up. Perfusion mean values calculated in benign lesions were RAE 33.8%, RVE 66.03%, RLE 80.63%, ME 776.00%, MRE 86.27%, and TTP 146.95 sec. Corresponding perfusion values calculated in malignant lesions were RAE 22.47%, RVE 40.54%, RLE 47.52%, ME 448.78%, MRE 49.85%, and TTP 183.79 sec. Statistical difference (p<0.05) was achieved in all the perfusion parameters calculated, obtaining different cluster of perfusion kinetics between benign and malignant lesions. Conclusions. DSCE-MRI depicts kinetic differences in perfusion parameters among the different common liver lesions, related to tumour supply and microvascular characteristics.

Purpose. To assess the diagnostic accuracy of dynamic susceptibility contrast-enhanced magnetic resonance imaging (DSCE-MRI) in differentiation between benign and malignant liver lesions by assessment of tumoral perfusion parameters. Methods Materials. Seventy-three patients with known focal liver lesions, including 45 benign (16 FNH, 27 angiomas, and 2 abscesses) and 28 malignant ones (17 metastases, 9 HCCs, and 2 cholangiocarcinoma) underwent 1.5 T MRI upper abdominal study, with standard protocol that included dynamic contrast-enhanced sequences. On dedicated workstation, time-intensity curves were determined and the following perfusion parameters were calculated: relative arterial, venous and late enhancement (RAE, RVE, RLE), maximum enhancement (ME), relative enhancement (RE), and time to peak (TTP). Results. All diagnoses were established either by histopathology or imaging follow-up. Perfusion mean values calculated in benign lesions were RAE 33.8%, RVE 66.03%, RLE 80.63%, ME 776.00%, MRE 86.27%, and TTP 146.95 sec. Corresponding perfusion values calculated in malignant lesions were RAE 22.47%, RVE 40.54%, RLE 47.52%, ME 448.78%, MRE 49.85%, and TTP 183.79 sec. Statistical difference (p<0.05) was achieved in all the perfusion parameters calculated, obtaining different cluster of perfusion kinetics between benign and malignant lesions. Conclusions. DSCE-MRI depicts kinetic differences in perfusion parameters among the different common liver lesions, related to tumour supply and microvascular characteristics.

Objective: To assess the diagnostic quality of low dose (100kV) CT angiography (CTA), by using ultra-low contrast medium volume (30ml), for thoracic and abdominal aorta evaluation. Methods: 67 patients with thoracic or abdominal vascular disease underwent multidetector CT study using a 256 slice scanner, with low dose radiation protocol (automated tube current modulation, 100kV) and low contrast medium volume (30 ml; 4ml s-1). Density measurements were performed on ascending, arch, descending thoracic aorta, anonymous branch, abdominal aorta, and renal and common iliac arteries. Radiation dose exposure [dose-length product (DLP)] was calculated. A control group of 35 patients with thoracic or abdominal vascular disease were evaluated with standard CTA protocol (automated tube current modulation, 120 kV; contrast medium, 80ml). Results: In all patients, we correctly visualized and evaluated main branches of the thoracic and abdominal aorta. No difference in density measurements was achieved between low tube voltage protocol (mean attenuation value of thoracic aorta, 304HU; abdominal, 343 HU; renal arteries, 331HU) and control group (mean attenuation value of thoracic aorta, 320HU; abdominal, 339; renal arteries, 303 HU). Radiation dose exposure in low tube voltage protocol was significantly different between thoracic and abdominal low tube voltage studies (490 and 324DLP, respectively) and the control group (thoracic DLP, 1032; abdomen, DLP 1078). Conclusion: Low-tube-voltage protocol may provide a diagnostic performance comparable with that of the standard protocol, decreasing radiation dose exposure and contrast material volume amount. Advances in knowledge: Low-tube-voltage-setting protocol combined with ultra-low contrast agent volume (30 ml), by using new multidetector-row CT scanners, represents a feasible diagnostic tool to significantly reduce the radiation dose delivered to patients and to preserve renal function, while also maintaining adequate d

AIM: To assess the clinical diagnostic value of functional imaging, combining quantitative parameters of apparent diffusion coefficient (ADC) and standardized uptake value (SUV) max, before and after chemo-radiation therapy, in prediction of tumor response of patients with rectal cancer, related to tumor regression grade at histology. METHODS: A total of 31 patients with biopsy proven diagnosis of rectal carcinoma were enrolled in our study. All patients underwent a whole body (18)FDG positron emission tomography (PET)/computed tomography (CT) scan and a pelvic magnetic resonance (MR) examination including diffusion weighted (DW) imaging for staging (PET1, RM1) and after completion (6.6 wk) of neoadjuvant treatment (PET2, RM2). Subsequently all patients underwent total mesorectal excision and the histological results were compared with imaging findings. The MR scanning, performed on 1.5 T magnet (Philips, Achieva), included T2-weighted multiplanar imaging and in addition DW images with b-value of 0 and 1000 mm(2) /s. On PET/CT the SUVmax of the rectal lesion were calculated in PET1 and PET2. The percentage decrease of SUVmax (.SUV) and ADC (.ADC) values from baseline to presurgical scan were assessed and correlated with pathologic response classified as tumor regression grade (Mandard's criteria; TRG1 = complete regression, TRG5 = no regression). RESULTS: After completion of therapy, all the patients were submitted to surgery. According to the Mandard's criteria, 22 tumors showed complete (TRG1) or subtotal regression (TRG2) and were classified as responders; 9 tumors were classified as non responders (TRG3, 4 and 5). Considering all patients the mean values of SUVmax in PET 1 was higher than the mean value of SUVmax in PET 2 (P < 0.001), whereas the mean ADC values was lower in RM1 than RM2 (P < 0.001), with a.SUV and.ADC respectively of 60.2% and 66.8%. The best predictors for TRG response were SUV2 (threshold of 4.4) and ADC2 (1.29 x 10-3 mm(2)/s) with high sensi

The aim of this article is to assess whether measures of abdominal fat distribution, visceral density, and antropometric parameters obtained from computed tomography (CT) may predict postoperative pancreatic fistula (POPF) occurrence. We analyzed 117 patients who underwent pancreatoduodenectomy (PD) and had a preoperative CT scan as staging in our center. CT images were processed to obtain measures of total fat volume (TFV), visceral fat volume (VFV), density of spleen, and pancreas, and diameter of pancreatic duct. The predictive ability of each parameter was investigated by receiver-operating characteristic (ROC) curves methodology and assessing optimal cutoff thresholds. A stepwise selection method was used to determine the best predictive model. Clinically relevant (grades B and C) POPF occurred in 24 patients (20.5%). Areas under ROC-curves showed that none of the parameters was per se significantly predictive. The multivariate analysis revealed that a VFV >2334 cm3, TFV >4408 cm3, pancreas/spleen density ratio <0.707, and pancreatic duct diameter <5mm were predictive of POPF. The risk of POPF progressively increased with the number of factors involved and age. It is possible to deduce objective information on the risk of POPF from a simple and routine preoperative radiologic workup.

Background: Aim of the study was to determine the value of perfusion computed tomography in the quantitative assessment of tumour-related neoangiogenesis for the diagnosis and treatment of hepatocellular carcinoma lesions. Methods: Overall, 47 consecutive patients with cirrhotic liver disease, with a high risk of hepatocellular carcinoma, and undergoing standard surveillance (six-month intervals) were eligible for inclusion in this prospective study; based on Barcelona Clinic Liver Cancer guidelines, 27 patients were enrolled. Perfusion computed tomography was performed in 29 biopsy-proven hepatocellular carcinoma lesions before and after treatment with transarterial chemoembolization or radiofrequency ablation. The dynamic study was performed with a 256-slice multidetector-computed tomography scanner; the following parameters were measured: hepatic perfusion, arterial perfusion, blood volume, hepatic perfusion index, and time-to-peak in all patients. Results: Hepatocellular carcinoma lesions had the following median perfusion values: perfusion 46.3. mL/min/100. g; blood volume 20.4. mL/100. mg; arterial perfusion 42.9. mL/min; hepatic perfusion index 92.5%; time to peak 18.7. s. Significantly lower perfusion values were obtained in correctly treated lesions or surrounding parenchyma than in viable hepatocellular carcinoma tissue. Conclusions: In hepatocellular carcinoma, perfusion computed tomography could contribute to a non-invasive quantification of tumour blood supply related to the formation of new arterial structures, and enable the assessment of therapeutic response

Purpose To assess if radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) may influence the evaluation of perfusion parameters obtained with CT-perfusion (CT-p) in HCC treated patients. Materials and methods Thirty-three consecutive cirrhotic patients with biopsy-proven diagnosis of HCC lesions and candidates to TACE or RFA were included. The CT-p study of hepatic parenchyma and of treated lesions was performed about 1 month after treatment on 16 multidetector CT after injection of 50 mL of non ionic contrast agent (350 mg I/mL) at a flow rate of 6 mL/s acquiring 40 dynamic scans. A dedicated perfusion software which generated a quantitative map of arterial and portal perfusion by means of colour scale was employed.The following perfusion parameters were assessed before and after RFA or TACE treatment: hepatic perfusion (HP), arterial perfusion (AP), blood volume (BV), time to peak (TTP), hepatic perfusion index (HPI). Results A complete treatment was obtained in 16 cases and incomplete treatment in the 17 remaining cases. The perfusion data of completely treated lesions were: HP 10.2 ± 6.3; AP 10.4 ± 7; BV 4.05 ± 4.8; TTP 38.9 ± 4.2; HPI 9.9 ± 9.2, whereas in partially treated lesions were: HP 43.2 ± 15.1 mL/s/100 g; AP 38.7 ± 8.8 mL/min; BV 20.7 ± 9.5 mL/100 mg; TTP 24 ± 3.7 s; HPI 61.7 ± 7.5%. In adjacent cirrhotic parenchyma, the parameters of all evaluated patients were: HP 13.2 ± 4; AP 12.3 ± 3.4; BV 11.8 ± 2.8; TTP 43.9 ± 2.9; and HPI 17.1 ± 9.8. A significant difference (P < 0.001) was found for all parameters between residual viable tumor tissue (P < 0.001) compared to successfully treated lesion due to the presence of residual arterial vascular structure in viable portion of treated HCC. Conclusion According to our results, CT-p evaluation is not influenced by TACE or RFA treatments, thus representing a feasible technique that allows a reproducible quantitative evaluation of treatment response in HCC patients. © 2014 Elsevier Ireland Lt