Hepatocellular carcinoma treated with transarterial chemoembolization: Dynamic perfusion-CT in the assessment of residual tumor

AIM: To asses the value of computed tomography (CT)-perfusion in the detection of residual hepatocellular carcinoma (HCC) vascularization after transarterial chemoembolization (TACE). METHODS: Thirty-two consecutive patients were pro-spectively included in this study. All patients had liver cirrhosis and a conf irmed HCC lesion which was treated with TACE. One month after treatment, perfusion measurements of treated lesions were carried out. The CTperfusion (CT-p) protocol was performed with 16 slice multidetector computed tomography which included the following parameters: 8 dynamic slices/scan per 40 scans after iv injection of 50 mL of iodinated contrast (350 mg/mL) at a flow rate of 6 mL/s. Treated lesions were evaluated using dedicated perfusion software, which generated a quantitative colour map of perfusion. The following parameters were considered: hepatic perfusion (HP), arterial perfusion (AP), blood volume (BV), hepatic perfusion index (HPI), and time to peak (TTP). Perfusion parameters were described with quartile values of their distribution and statistically analyzed. RESULTS: Perfusion parameters of the treated lesions could be quantitatively assessed using CT-p analysis. The presence of residual tumor tissue was observed in 13 of the 32 patients. The values of the perfusion parameters measured within the relapse tissue were: HP (mL/100 g per minute): median = 44.4 (1stqt = 31.3, 3rdqt = 55.8); BV (mL/100 g): median = 18.7 (1stqt = 11.5, 3rdqt = 22.5); AP (mL/min): median = 39.0 (1stqt = 36.5, 3rdqt = 61.3); HPI (%): median = 34.0 (1stqt = 30.4, 3rdqt = 38.9); TTP (s): median = 17.3 (1stqt = 15.8, 3rdqt = 26.5). With the use of the univariate paired Wilcoxon signed rank test, HP, AP and HPI were shown to be significantly higher (P<0.001) in the relapse site than in the primary lesion. The BV and TTP parameters showed a tendency to be greater and lower, respectively, in the relapse site than in the primary lesion. CONCLUSION: In patients with HCC treated with TACE, CT-p provides measurement of flow parameters related to residual arterial structures in viable tumor, thus helping in the assessment of therapeutic response.

Rectal cancer staging: Multidetector-row computed tomography diagnostic accuracy in assessment of mesorectal fascia invasion

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 m As. 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, as compared to the reference magnetic resonance images. The difference in accuracy was statistically significant(P = 0.02). CONCLUSION: New generation CT scanner, using high resolution MPR images, represents a reliable diagnostic tool in assessment of loco-regional and whole body staging of advanced rectal cancer, especially in patients with MRI contraindications.

Combined value of apparent diffusion coefficient-standardized uptake value max in evaluation of post-treated locally advanced rectal cancer

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;9tumors were classified as non responders(TRG3,4 and5).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 of4.4) and ADC2(1.29 × 10^(-3) mm^2/s) with high sensitivity and specificity.Combining in a single analysis both the obtained median value,the positive predictive value,in predicting the different group category response in related to TRG system,presented R^2 of 0.95.CONCLUSION:The functional imaging combining ADC and SUVmax in a single analysis permits to detect changes in cellular tissue structures useful for the assessment of tumour response after the neoadjuvant therapy in rectal cancer,increasing the sensitivity in correct depiction of treatment response than either method alone.

Role of dynamic perfusion magnetic resonance imaging in patients with local advanced rectal cancer

BACKGROUND The management of rectal cancer patients is mainly based on the use of the magnetic resonance imaging(MRI)technique as a diagnostic tool for both staging and restaging.After treatment,to date,the evaluation of complete response is based on the histopathology assessment by using different tumor regression grade(TRG)features(e.g.,Dworak or Mandard classifications).While from the radiological point of view,the main attention for the prediction of a complete response after chemotherapy treatment focuses on MRI and the potential role of diffusion-weighted images and perfusion imaging represented by dynamiccontrast enhanced MRI.The main aim is to find a reliable tool to predict tumor response in comparison to histopathologic findings.AIM To investigate the value of dynamic contrast-enhanced perfusion-MRI parameters in the evaluation of the healthy rectal wall and tumor response to chemo-radiation therapy in patients with local advanced rectal cancer with histopathologic correlation.METHODS Twenty-eight patients with biopsy-proven rectal adenocarcinoma who underwent a dynamic contrast-enhanced MR study performed on a 1.5 T MRI system(Achieva,Philips),before(MR1)and after chemoradiation therapy(MR2),were enrolled in this study.The protocol included T1 gadolinium enhanced THRIVE sequences acquired on axial planes.A dedicated workstation was used to generate color permeability maps.Region of interest was manually drawn on tumor tissue and normal rectal wall,hence the following parameters were calculated and statistically analyzed:Relative arterial enhancement(RAE),relative venous enhancement(RVE),relative late enhancement(RLE),maximum enhancement(ME),time to peak and area under the curve(AUC).Perfusion parameters were related to pathologic TRG(Mandard’s criteria;TRG1=complete regression,TRG5=no regression).RESULTS Ten tumors(36%)showed complete or subtotal regression(TRG1-2)at histology and classified as responders;18 tumors(64%)were classified as non-responders(TRG3-5).Perfusion MRI parameters were significantly higher in the tumor tissue than in the healthy tissue in MR1(P<0.05).At baseline(MR1),no significant difference in perfusion parameters was found between responders and nonresponders.After chemo-radiation therapy,at MR2,responders showed significantly(P<0.05)lower perfusion values[RAE(%)54±20;RVE(%)73±24;RLE(%):82±29;ME(%):904±429]compared to non-responders[RAE(%):129±45;RVE(%):154±39;RLE(%):164±35;ME(%):1714±427].Moreover,in responders group perfusion values decreased significantly at MR2[RAE(%):54±20;RVE(%):73±24;RLE(%):82±29;ME(%):904±429]compared to the corresponding perfusion values at MR1[RAE(%):115±21;RVE(%):119±21;RLE(%):111±74;ME(%):1060±325];(P<0.05).Concerning the time-intensity curves,the AUC at MR2 showed significant difference(P=0.03)between responders and non-responders[AUC(mm2×10-3)121±50 vs 258±86],with lower AUC values of the tumor tissue in responders compared to nonresponders.In non-responders,there were no significant differences between perfusion values at MR1 and MR2.CONCLUSION Dynamic contrast perfusion-MRI analysis represents a complementary diagnostic tool for identifying vascularity characteristics of tumor tissue in local advanced rectal cancer,useful in the assessment of treatment response.

Radiological findings in non-surgical recurrent hepatocellular carcinoma:From locoregional treatments to immunotherapy

Since hepatocellular carcinoma(HCC)represents an important cause of mortality and morbidity all over the world.Currently,it is fundamental not only to achieve a curative treatment but also to manage in the best way any possible recurrence.Even if the latest update of the Barcelona Clinic Liver Cancer guidelines for HCC treatment has introduced new locoregional techniques and confirmed others as well-established clinical practices,there is still no consensus about the treatment of recurrent HCC(RHCC).Locoregional treatments and medical therapy represent two of the most widely accepted approaches for disease control,especially in the advanced stage of liver disease.Different medical treatments are now approved,and others are under investigation.On this basis,radiology plays a central role in the diagnosis of RHCC and the assessment of response to locoregional treatments and medical therapy for RHCC.This review summarized the actual clinical practice by underlining the importance of the radiological approach both in the diagnosis and treatment of RHCC.

Immune response evaluation criteria in solid tumors for assessment of atypical responses after immunotherapy

In 2017,immune response evaluation criteria in solid tumors(iRECIST)were introduced to validate radiologic and clinical interpretations and to better analyze tumor’s response to immunotherapy,considering the different time of following and response,between this new therapy compared to the standard one.However,even if the iRECIST are worldwide accepted,to date,different aspects should be better underlined and well reported,especially in clinical practice.Clinical experience has demonstrated that in a non-negligible percentage of patients,it is challenging to determine the correct category of response(stable disease,progression disease,partial or complete response),and consequently,to define which is the best management for those patients.Approaching radiological response in patients who underwent immunotherapy,a new uncommon kind of target lesions behavior was found.This phenomenon is mainly due to the different mechanisms of action of immunotherapeutic drug.Therefore,new groups of response have been described in clinical practice,defined as“atypical responses,”and categorized into three new groups:pseudoprogression,hyperprogression,and dissociated response.This review summarizes and reports these patterns,helping clinicians and radiologists get used to atypical responses,in order to identify patients that respond best to treatment.

Low-dose computed tomography with 4th-generation iterative reconstruction algorithm in assessment of oncologic patients

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 m A modulation, and iterative reconstruction algorithm. Standard-dose CT was performed on 16-rows scanner, with 120 kV, 200-400 m As(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 m Gy*cm vs 1429.2 m Gy*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.

Liver involvement in patients with COVID-19 infection:A comprehensive overview of diagnostic imaging features

During the first wave of the pandemic,coronavirus disease 2019(COVID-19)infection has been considered mainly as a pulmonary infection.However,different clinical and radiological manifestations were observed over time,including involvement of abdominal organs.Nowadays,the liver is considered one of the main affected abdominal organs.Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs.After clinical assessment,radiology plays a key role in the evaluation of liver involvement.Ultrasonography(US),computed tomography(CT)and magnetic resonance imaging(MRI)may be used to evaluate liver involvement.US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection,in particular liver steatosis and portal-vein thrombosis.CT and MRI are used as second-and third-line techniques,respectively,considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization.This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage.

Relative volume measured with magnetic resonance imaging is an articular collapse predictor in hematological pediatric patients with femoral head osteonecrosis

AIM To assess the potential value of femoral head(FH) volume measurements to predict joint collapse, as compared to articular surface involvement, in posttreatment osteonecrosis(ON) in pediatric patients affected by lymphoproliferative diseases.METHODS Considering 114 young patients with lymphoproliferative diseases undergone a lower-limbs magnetic resonance imaging(MRI) examination between November 2006 and August 2012 for a suspected post-treatment ON, we finally considered a total of 13 cases(7 males, mean age 15.2 ± 4.8 years), which developed a FH ON lesions(n = 23). The MRI protocol included coronal short tau inversion recovery and T1-weighted sequences, from the hips to the ankles. During the follow-up(elapsed time: 9.2 ± 2 mo), 13/23 FH articular surface(FHS)developed articular deformity. The first MRI studies with diagnosis of ON were retrospectively analyzed, measuring FH volume(FHV), FHS, ON volume(ONV) and the articular surface involved by ON(ONS). The relative involvement of FHS, in terms of volume [relative volume(RV): ONV/FHV] and articular surface [relative surface(RS): ONS/FHS], was then calculated.RESULTS By using receiver operating characteristic curve analysis(threshold of 23% of volume involvement), RV predicted articular deformity in 13/13 FHS [sensitivity 100%, specificity 90%, accuracy 95%, positive predictive value(PPV) 93%, negative predictive value(NPV) 100%]. Considering a threshold of 50% of articular involvement, RS predicted articular deformity in 10/13 femoral heads(sensitivity 77%, specificity 100%, accuracy 87%, PPV 100%, NPV 77%).CONCLUSION RV might be a more reliable parameter than RS in predicting FH deformity and could represent a potential complementary diagnostic tool in the follow-up of femoral heads ON lesions.

Intestinal ischemic manifestations of SARS-CoV-2:Results from the ABDOCOVID multicentre study

BACKGROUND Intestinal ischemia has been described in case reports of patients with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)disease(coronavirus disease 19,COVID-19).AIM To define the clinical and histological,characteristics,as well as the outcome of ischemic gastrointestinal manifestations of SARS-CoV-2 infection.METHODS A structured retrospective collection was promoted among three tertiary referral centres during the first wave of the pandemic in northern Italy.Clinical,radiological,endoscopic and histological data of patients hospitalized for COVID-19 between March 1st and May 30th were reviewed.The diagnosis was established by consecutive analysis of all abdominal computed tomography(CT)scans performed.RESULTS Among 2929 patients,21(0.7%)showed gastrointestinal ischemic manifestations either as presenting symptom or during hospitalization.Abdominal CT showed bowel distention in 6 patients while signs of colitis/enteritis in 12.Three patients presented thrombosis of main abdominal veins.Endoscopy,when feasible,confirmed the diagnosis(6 patients).Surgical resection was necessary in 4/21 patients.Histological tissue examination showed distinctive features of endothelial inflammation in the small bowel and colon.Median hospital stay was 9 d with a mortality rate of 39%.CONCLUSION Gastrointestinal ischemia represents a rare manifestation of COVID-19.A high index of suspicion should lead to investigate this complication by CT scan,in the attempt to reduce its high mortality rate.Histology shows atypical feature of ischemia with important endotheliitis,probably linked to thrombotic microangiopathies.

Developments in diagnosis and management of post-liver transplantation biliary complications:the radiologist’s perspective

Biliary complications are the most common source of morbidity after liver transplantation as they may occur in up to 45%of patients(1).The review by Magro et al.(2)provides comprehensive insights on this topic and offers a cue for in-depth remarks form a radiological perspective regarding both diagnostic and interventional aspects.Ultrasound(US)-based techniques,including B-mode and color-Doppler,are the milestone of post-transplant follow-up.The assessment of graft vascularization is crucial since many biliary complications are supposed to be induced by arterial ischemia.To this regard,however,it must be emphasized that US imaging is hampered by a limited panoramic view,especially in difficult abdomens,therefore it is not possible to rely exclusively on this technique.