Intravenous Contrast Enhancement Research Articles

Proton Beam Therapy for Unresectable Cholangiocarcinoma

To evaluate the treatment outcome and patterns of failure in patients with unresectable cholangiocarcinoma undergoing proton beam therapy (PBT). We retrospectively analyzed 22 patients with pathologically confirmed cholangiocarcinoma who were treated with definitive PBT from November 2015 to August 2017. Four-dimensional computer tomography (4D-CT) with and without intravenous contrast-enhancement was acquired with 2.5 mm slide thickness. A clinical target volume expansion of 5-10 mm was used. The internal target volume was generated based on the 4D-CT images, and respiratory gaiting was adopted in patients with tumor motion >10 mm. Treatment-related toxicities were recorded according to Common Terminology Criteria for Adverse Event version 4.0 (CTCAE v4.0). The study included 11 male and 11 female participants, with a median age of 68 years (range, 46-88 years). Intrahepatic, perihilar and distal extrahepatic, and gallbladder tumors were recorded in 12 (54%), 7 (32%), 1 (5%) and 2 (9%), respectively. The median tumor dimension was 7.0 cm (range, 3.8-18.2 cm). Stage IV, III and II was documented in 15 (68%), 5 (23%) and 2 (9%) patients, respectively. Tumor vascular invasion was observed in 5 (23%) patients, and 19 (86%) patients demonstrated biliary tract obstruction. The median PBT dose was 72.6 cobalt gray equivalent (CGE) (range, 39.6-72.6 CGE). Gemcitabine-based concomitant chemotherapy was administered in 15 (68%) patients. After a median follow-up of 14.3 months, the 1-year overall survival rate was 75%. Fifteen (68%) patients developed disease progression. Among them, one (5%) patients experienced in-field local failure, whereas 4 (18%) patients developed intrahepatic out-field recurrence. Distant metastasis (N = 10, 45%) was the predominant form of treatment failure. The 1-year local control and progression-free survival rates were 100% and 42%, respectively. Among the 19 patients who presented obstructive jaundice, normalization of total bilirubin level was recorded in 14 (74%) patients after PBT with or without biliary drainage. Grade 3 dermatitis and grade 4 duodenal ulcer occurred in 2 (9%) and 2 (9%) patients, respectively. PBT could lead to an excellent local control probability, sustainable relief of biliary tract obstruction and a favorable survival outcome in patients with unresectable cholangiocarcinoma. However, distant recurrence remains the primary reason of failure after PBT.

Technical Note: Enhancing soft tissue contrast and radiation-induced image changes with dual-energy CT for radiation therapy.

The purpose of this work is to investigate the use of low-energy monoenergetic decompositions obtained from dual-energy CT (DECT) to enhance image contrast and the detection of radiation-induced changes of CT textures in pancreatic cancer. The DECT data acquired for 10 consecutive pancreatic cancer patients during routine nongated CT-guided radiation therapy (RT) using an in-room CT (Definition AS Open, Siemens Healthcare, Malvern, PA) were analyzed. With a sequential DE protocol, the scanner rapidly performs two helical acquisitions, the first at a tube voltage of 80 kVp and the second at a tube voltage of 140 kVp. Virtual monoenergetic images across a range of energies from 40 to 140 keV were reconstructed using an image-based material decomposition. Intravenous (IV) bolus-free contrast enhancement in pancreas patient tumors was measured across a spectrum of monoenergies. For treatment response assessment, the changes in CT histogram features (including mean CT number (MCTN), entropy, kurtosis) in pancreas tumors were measured during treatment. The results from the monoenergetic decompositions were compared to those obtained from the standard 120 kVp CT protocol for the same subjects. Data of monoenergetic decompositions of the 10 patients confirmed the expected enhancement of soft tissue contrast as the energy is decreased. The changes in the selected CT histogram features in the pancreas during RT delivery were amplified with the low-energy monoenergetic decompositions, as compared to the changes measured from the 120 kVp CTs. For the patients studied, the average reduction in the MCTN in pancreas from the first to the last (the 28th) treatment fraction was 4.09 HU for the standard 120 kVp and 11.15 HU for the 40 keV monoenergetic decomposition. Low-energy monoenergetic decompositions from DECT substantially increase soft tissue contrast and increase the magnitude of radiation-induced changes in CT histogram textures during RT delivery for pancreatic cancer. Therefore, quantitative DECT may assist the detection of early RT response.

THE ROLE OF RADIATION METHODS IN DIAGNOSIS AND STAGING OF COLORECTAL CANCER

Purpose: assessment of complex radiation diagnosis in the recognition and staging of rectal cancer. Material and methods. From 2016 for 2017 are examined 66 patients with rectum cancer. X-ray methods (irrigoscopy), MSCT and (or) MRI in combination with intravenous contrast enhancement were used as radiation methods. Results. Rectal cancer was detected in 66 patients. In the study, the upper ampullar part of the rectum was affected in 14 (21%) patients, the upper-middle-ampullar part in 2 (3%), the middle ampullar one in 26 (39%), the middle- lowera mpullar one in 3 (5%), the lower ampullary in 21 (32%). Results of inspection have allowed not only to establish defeat process, but also to specify his stage in compliance with TNM system. Stage I of the disease was established in 2 (3%) patients, stage II in 22 (33%), stage III in 25 (38%) and stage IV in 17 (26%). Subsequently, 39 (59%) patients were operated on. Conclusion. Complex radiation diagnosis made it possible to accurately diagnose and localize the tumor process, to establish intra – and extra organ distribution with the defeat of surrounding structures and organs. And finally, to make a choice in favor of this or that surgical intervention, and also to determine the necessity of its combination with chemoradiotherapy.

Orbital hemangiomas: capabilities of modern neuroradiological diagnostics

In the period from 2010 to 2016. 14 patients with cavernous hemangioma (CH) and 2 patients with capillary hemangioma (CapH) of the orbit were examined. The age of CH patients varied from 17 to 67 years (median, 53 years); 8 females and 6 males. The age of CapH patients was 35 and 54 years. All patients underwent surgery with subsequent histological verification. CT-perfusion was performed in 10 CH patients and 2 CapH patients according to a developed low-dose protocol (80 kV, 200 mAs, tscan=40 s) with allowance for a target localizer (80 kV, 120 mAs) and at a maximum radiation dose of not more than 4.0 mZv. Neoplasm microcirculation was quantitatively assessed by calculating hemodynamic parameters: blood flow velocity (BFV), blood volume (BV), and mean transit time (MTT). MRI without and with contrast enhancement was performed in 11 CH patients and 2 CapH patients according to the ophthalmologic protocol (Signa GE, 3.0 T) accepted at the Institute: without contrast enhancement - T1, T2, and T2-FLAIR modes, T1 and T2 with a Fat Sat technique at a scan thickness of 3 mm, and DWI MRI; contrast enhancement - T1 (three projections) mode, including the Fat Sat technique. SWAN (n=2) and non-contrast MR perfusion ASL (n=3) were also used. Diffusion-weighted images (DWI) were processed with calculation of the apparent diffusion coefficient (ACD). In all CH patients, CT-perfusion revealed low perfusion parameters of blood flow: BVCH=0.86±0.37 mL/100 g, BFVCH= 4.89±2.01 mL/100 g/min with a high mean transit time MTTCH=10.13±3.05 s compared to the same parameters of blood flow in the normal white matter: CBVNormWM=1.63±2.22 mL/100 g, CBFVNormWM=9.72±3.13 mL/100 g/min, and MTTNormWM=6.76±2.78 s. In CapH cases, significantly increased blood flow velocity and volume values and a low MTT value in the tumor were observed: BVCapH=10.30±4.10 mL/100 g, BFVCapH=119.72±53.13 mL/100 g/min, and MTTCapH=4.35±1.79 s. In the case of orbital hemangiomas, optimal MRI modes were T1 and T2 with the Fat Sat technique, a scan thickness of 3 mm, and intravenous contrast enhancement. The revealed pattern of contrast agent accumulation by CH, initially in the central part and then in the periphery, may be a useful radiographic sign in the differential diagnosis with other orbital tumors. Modern CT- and MRI-based diagnostics of orbital hemangiomas provides not only the exact location, size, and spread of the lesion but also reveals the characteristic structural features of these tumors, and the use of perfusion techniques visualizes hemodynamics of the tumors. CT-perfusion-based hemodynamic parameters of cavernous hemangiomas typical of this type of hemangiomas may be used in the differential diagnosis with other tumors of this location. The use of contrast enhancement and the Fat Sat technique with a scan thickness of not more than 3 mm is optimal for MRI diagnostics of orbital hemangiomas.

Magnetic-Resonance Tomography for Anthropometric Value of Kidneys and Adrenals in Prognosis Efficiency of Renal Sympathetic Denervation in Patients with Treatment-Resistant Hypertension

Aim: to evaluate the possible role of contrast-enhanced MRI studies of the kidneys in prognosis of clinical effect of the renal denervation treatment of the resistant hypertension.Material and methods. 24 patients (57.8 ± 8.75 years) with resistant hypertension were included, in everybody the radiofrequency ablation (RFA) of the sympathetic nerves of renal arteries was carried out. The average 24-h monitor of the arterial pressure was as 137–210/57–148 mm Hg. The MRI studies were performed using MRI scanner “Titan Vantage” (by “Toshiba Medical Ltd”, with the field induction 1.5 Т). After this the intravenous contrast enhancement has been carried out (with 0.5 М solution, 0.2 ml/Kg), with repeat acquisition of Т1-weighted spin-echo images in3–5 min after contrast injection.Results.MRI was employed for quantitative calculation of renal volumes of cortex, medulla and of kidney as total, as well as of suprarenal’s volume. Significant negative correlation of postoperation decrease of arterial pressure has been detected with both volume of renal cortex, as {Decrease in AP = 42.7–0.35 • (V left kidney)}, and also with mass of the right suprarenal gland as {Decrease in SAP = 16.5–6.78 • • (V right suprarenal)}.Conclusion.The anatomic quantitative data of the preoperativeMRI studies of the kidneys can be employed as prognostic tool in patients referred to the renal denervation treatment of the resistant hypertension.

Cranial Ct Scan Findings In Patients With Headache

Objectives : 140 patients with non specific headache referred from neurology and medical outpatient clinics were studied to review the cranial computerized tomography findings and check if there were any significant lesion detected by CT scan.Methods : The patients were assessed using CT apparatusSiemens Somatom Emotion soft ware version A40A at Aldiwanyia teaching hospital during the period from July 2008 to September 2009 CT images were taken with 5 mm slices , intravenous contrast enhancement were done to confirm the diagnosis in patients with cerebral tumors .Results : The patients divided into two main groups on the basis of imaging findings: Group 1: No abnormality detected in cranial CT scan examination of 107 patients ( 76.4 %) . Group 2 : 33 patients ( 23.6 %) with abnormal cranial CT scan examination . Abnormal CT findings divided into : 12 patients with sinusitis or sclerotic mastoid air cells, 10 patients with intracranial space occupying lesion ( SOLs) , 8 patients with cerebral atrophy , 3 patients with cerebral infarction .Conclusion : patients with intracranial SOLs in our study confirms that significant lesions can be detected by CT scan in patients with non specific headache not completely fulfilling international headache society criteria.

THE SIGNIFICANCE OF THE METHOD OF ULTRASONIC RESEARCH OF A THYROID GLAND WITH CONTRAST ENHANCEMENT IN THE DIFFERENTIAL DIAGNOSIS OF FOCAL NODULAR FORMATIONS

Introduction . Currently thyroid nodules are a widespread problem in clinical oncology and head and neck cancer, malignant focal lesions constitute more than 15–20 %. Accurate diagnosis is very important and determines treatment, as well as the volume of surgical intervention. Objective – determination of the diagnostic value of the method of contrast-enhanced ultrasound in the diagnosis of thyroid cancer. Reference materials were the results of the histological study of surgical specimens. Method. Performed a retrospective analysis of medical records of 42 patients who underwent surgery at the surgical department of head and neck tumors on the verified thyroid cancer in the N.N. Petrov Research Institute of Oncology at the Ministry of Health of Russia. The number of female patients was 36 persons (85.5 %), the number of men was 6 people (14.5 %). The average age of patients among men was 55.5 years, women – 46 years. All patients underwent surgical treatment in the amount of extirpation of the thyroid gland – 16 patients (37.5 %), hemithyroidectomy – 26 patients (62.5 %). Results. The sensitivity of ultrasound with contrast in the diagnosis of cancer of the thyroid gland was 94.11 %, specificity was 87.5 %, diagnostic accuracy – 92.8 %. Conclusions. The technique of ultrasound nodules thyroid with intravenous contrast enhancement has an excellent diagnostic properties, allowing to identify and verify thyroid cancer is 8 % more accurately in comparison with standard ultrasound technique.

EVALUATION OF THE INFLUENCE OF RENAL CYSTS ON THE LEVEL OF ARTERIAL PRESSURE REDUCTION AFTER RENAL DENERVATION IN PATIENTS WITH RESISTANT HYPERTENSION. THE BIENNIAL INSPECTION

Aim. We evaluated the influence of renal cysts on the efficiency of reduction of arterial pressure in patients with treatment-resistant hypertension after renal denervation. Materials and Methods. A total of 33 patients (aged 57.8±8.75 years) with treatment-resistant hypertension were included. All patients underwent radiofrequency ablation (RFA) of the sympathetic nerves of renal arteries. The average level of arterial pressure was as high as 137–210/57–148 mm Hg according to 24-h monitoring. MRI studies were performed using MRI scanner “Titan Vantage” (by Toshiba Medical Ltd., 1.5 Т) in T1-W and T2-W spin-echo models. After this, the intravenous contrast enhancement was carried out (with 0.5 М solution, 0.2 ml/Kg), with subsequently repeated acquisition of Т1-weighted spin-echo images 3-5 min after contrast injection, employing exactly the same protocols as before enhancement. Results. Preoperative images demonstrated cysts in kidneys in half of patients (16 individuals). Positive effect (the arterial pressure decreased by 10 mm Hg) was observed in 70% of them. However, in 30% of population, the arterial pressure increased. Among the patients without cysts in the kidneys, negative effect was observed in 8% only, and positive effect was found in 77% of patients (arterial pressure decreased by over 20 mm Hg). Conclusion. There is a statistically significant trend towards a greater antihypertensive effect of renal denervation in patients without cystic changes in the renal parenchyma (cortex). Thus, MRI is of prognostic value for prediction of renal denervation efficacy.

The potential of radiologic procedures in the diagnosis of inflammatory bowel disease

At present, there is no golden standard of diagnosis of inflammatory bowel disease. Each and every individual case requires a thorough analysis of clinical symptoms in their association with endoscopic, histological, radiological and laboratory data. This review paper analyzes both conventional and novel methods of radiological investigations. Some of them have changed their significance from the golden standard to rare and limited application and from promising, then frequent and currently sporadic use of small bowel enema. Traditional ileocolonoscopy maintains its diagnostic potential, especially as a tool for follow up of patients with colonic and ileac disorders. The state-of-the-art non-invasive (ultrasound examination) and limitedly non-invasive (computerized tomography and magnetic resonance imaging) procedures are considered to be the most accurate methods for assessment of inflammatory bowel disorders in patient with already confirmed diagnosis and those with suspected cases of Crohn's disease and ulcerative colitis. The paper describes preparation of patient for each method, assessment technique, advantages and limitations for use, diagnostic criteria for intestinal wall thickness, accuracy of methods and discusses the perspectives of their use. The main sign of inflammatory bowel disease is thickening of intestinal wall. Usually its mean thickness in Crohn's disease (11 to 13 mm) is higher than that in ulcerative colitis (7 to 8 mm). This may provide a diagnostic key during differential diagnosis of an isolated colon disease. The amount of the contrast cumulated by the intestinal wall directly correlates with inflammation activity. Intensive contract cumulation in the intestinal wall after intravenous contrast enhancement is a symptom of active inflammatory process. However, despite progression in the technologies, initial signs of inflammatory bowel diseases are quite superficial and remain hardly visible, being below the resolution ability of any diagnostic investigation.

CURRENT CAPABILITIES OF COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING FOR THE DETECTION OF COMPLICATIONS AFTER COMBINED PANCREAS AND KIDNEY TRANSPLANTATION

Objective: to give computed tomography (CT)- and magnetic resonance imaging (MRI)-based new anatomic-topographic relationships in patients after combined pancreas and kidney transplantation and to describe main visualization tasks and the types and frequency of various complications occurring in different periods after transplantation. Material and methods. Spiral CT and MRI images were analyzed in 45 patients after pancreas and kidney transplantation. A total of 51 studies (35 CTs and 16 MRIs) using intravenous contrast enhancement (n=34 (66%)) were performed. Results. A total of 55 complications, among which pancreatitis after pancreas transplantation was most common (55%), were found. Necrotizing pancreatitis following pancreas transplantation, which required open operative or percutaneous intervention, was diagnosed in 6.6%. Vascular complications were detected in 22%. Conclusion. The current capabilities of CT and MRI enable us to quickly obtain objective information on the status of transplanted organs, their vascular architectonics, as well as on the presence and type of occurred complications. Timely correction of identified complications positively affects the survival of transplanted organs and quality of life in a recipient.

The diagnostic value of contrast-enhanced computed tomography imaging for detection of colorectal tumors: A meta-analysis.

To evaluate the application usage of contrast-enhanced computer tomography imaging for colorectal tumors diagnosis. By searching the Medline and CNKI databases, we collected all diagnostic tests about contrast-enhanced CT imaging for colorectal tumors. Sensitivity and specificity were calculated to evaluate the usage of individual diagnostic tests. The data were analyzed using statistic software Meta-DiSc 1.4. Nine trials that included a total of 4797 patients were analyzed in this study. The summary diagnosis sensitivity and specificity of contrast-enhanced CT were 0.74 (95% confidence interval [CI]: 0.71-0.77) and 0.86 (0.85-0.87), respectively. The pooled area under the receiver operating characteristic curve was 0.90. Subgroup analysis: for intravenous contrast enhancement technology, the pooled diagnosis sensitivity and specificity were 0.63 (95% CI: 0.56-0.69) and 0.89 (95% CI: 0.86-0.92); for oral contrast enhancement technology, the pooled diagnosis sensitivity and specificity were 0.78 (95% CI: 0.74-0.81) and 0.86 (95% CI: 0.84-0.87). Contrast-enhanced CT imaging can be regarded as an effective and feasible method for detection of the colorectal tumors.

PATIENT SAFETY MANAGEMENT TOOLS FOR INTRAVENOUS ADMINISTRATION OF RADIOGRAPHIC CONTRAST MEDIA

The number of CT-examinations in Russia, like all over the world, is constantly increasing. Nevertheless, the analysis of routine practice in our country demonstrates the insufficient usage of intravenous contrast enhancement. One of the main factors defining this situation is poor awareness of radiologists about practical safety aspects of contrast media administration. This article represents a review of risk management plan to be applied in connection with the intravenous administration of contrast agents.

Intravenous C-Arm Conebeam CT Angiography following Long-Term Flow-Diverter Implantation: Technologic Evaluation and Preliminary Results.

A noninvasive investigation with high spatial resolution and without metal artifacts is necessary for long-term imaging follow-up after flow-diverter implantation. We aimed to evaluate the diagnostic value of conebeam CT angiography with intravenous contrast enhancement in the assessment of vascular status following implantation of the Pipeline Embolization Device and to analyze the preliminary results of vascular status following long-term Pipeline Embolization Device implantation. This was an ongoing prospective study of consecutive patients with intracranial aneurysms treated with the Pipeline Embolization Device. Patients with a modified Rankin Scale score of 4-5 were excluded. The median and interquartile range of the time interval of Pipeline Embolization Device implantation to conebeam CT angiography with intravenous contrast enhancement were 56.6 and 42.9-62.4 months, respectively. Conebeam CT angiography with intravenous contrast enhancement was performed with the patient fully conscious, by using a C-arm CT with a flat panel detector. There were 34 patients and 34 vascular segments. In all 34 cases, contrast effect and image quality were good and not substantially different from those of intra-arterial conebeam CTA. Metal artifacts occurred in all 14 cases with coil masses; the Pipeline Embolization Device was obscured in 3 cases. In all 34 cases, there was no residual aneurysm, no vascular occlusion, 1 vascular stenosis (50%), good Pipeline Embolization Device apposition to the vessel, and no Pipeline Embolization Device-induced calcification. All 28 Pipeline Embolization Device-covered side branches were patent. Conebeam CT angiography with intravenous contrast enhancement is potentially promising and useful for effective evaluation of the vascular status following intracranial flow diverters. The Pipeline Embolization Device for intracranial aneurysms is probably safe and promising for long-term placement, with favorable morphologic outcome and without delayed complications.

Impact of intravenous contrast enhancement phase on target definition for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC): Observations from patients enrolled on a prospective phase 2 trial

BackgroundThe safety and efficacy of radiation therapy for hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC) depend on accurate definition of gross tumor volume (GTV), but GTV often varies between phases of multiphasic computed tomography (CT) imaging. MethodsWe contoured GTVs on arterial, portal venous, and delayed phases of multiphasic CT scans for 32 patients treated on an institutional review board–approved prospective trial of proton therapy for primary liver tumors and determined which phase provided optimal GTV visualization. We assessed agreement between individual phase GTVs to determine if GTV for each phase was encompassed in a 5-mm expansion of either the smallest or the best-visualized GTV. ResultsThere were 19 HCC lesions and 14 IHC lesions. HCC lesions were best identified on the arterial phase in 42% (n = 8), portal venous phase in 32% (n = 6), and delayed phase in 26% (n = 5). IHC lesions were best identified on portal venous phase in 64% (n = 9) and the arterial phase in 29% (n = 4), with 1 case equally visualized on arterial and portal venous phases. In all 33 lesions, a 5-mm expansion around the smallest GTV failed to cover GTVs defined on other available phases. A 5-mm expansion around the best-visualized GTV provided satisfactory coverage of all available phases’ GTVs in 6/18 HCC cases and 2/9 IHC cases. ConclusionsVariability between GTVs on multiphasic CT scans could not be overcome with a 5-mm expansion of either the smallest GTV or the best-visualized GTV. Assessment of all available intravenous contrast phases is essential to accurately define the GTV.

Impact of Intravenous Contrast Enhancement Phase on Target Definition for Hepatocellular Carcinoma (HCC) and Intrahepatic Cholangiocarcinoma (IHC): Observations From Patients Enrolled on a Prospective Phase 2 Trial

Impact of Intravenous Contrast Enhancement Phase on Target Definition for Hepatocellular Carcinoma (HCC) and Intrahepatic Cholangiocarcinoma (IHC): Observations From Patients Enrolled on a Prospective Phase 2 Trial

Surgical management of peritonitis secondary to acute superior mesenteric artery occlusion.

Diagnosis of acute arterial mesenteric ischemia in the early stages is now possible using modern computed tomography with intravenous contrast enhancement and imaging in the arterial and/or portal phase. Most patients have acute superior mesenteric artery (SMA) occlusion, and a large proportion of these patients will develop peritonitis prior to mesenteric revascularization, and explorative laparotomy will therefore be necessary to evaluate the extent and severity of intestinal ischemia, and to perform bowel resections. The establishment of a hybrid operating room in vascular units in hospitals is most important to be able to perform successful intestinal revascularization. This review outlines current frontline surgical strategies to improve survival and minimize bowel morbidity in patients with peritonitis secondary to acute SMA occlusion. Explorative laparotomy needs to be performed first. Curative treatment is based upon intestinal revascularization followed by bowel resection. If no vascular imaging has been carried out, SMA angiography is performed. In case of embolic occlusion of the SMA, open embolectomy is performed followed by angiography. In case of thrombotic occlusion, the occlusive lesion can be recanalized retrograde from an exposed SMA, the guidewire snared from either the femoral or brachial artery, and stented with standard devices from these access sites. Bowel resections and sometimes gall bladder removal due to transmural infarctions are performed at initial laparotomy, leaving definitive bowel reconstructions to a planned second look laparotomy, according to the principles of damage control surgery. Patients with peritonitis secondary to acute SMA occlusion should be managed by both the general and vascular surgeon, and a hybrid revascularization approach is of utmost importance to improve outcomes.

Modern treatment of acute mesenteric ischaemia

Diagnosis of acute mesenteric ischaemia in the early stages is now possible with modern computed tomography (CT), using intravenous contrast enhancement and imaging in the arterial and/or portal venous phase. The availability of CT around the clock means that more patients with acute mesenteric ischaemia may be treated with urgent intestinal revascularization. This was a review of modern treatment strategies for acute mesenteric ischaemia. Endovascular therapy has become an important alternative, especially in patients with acute thrombotic superior mesenteric artery (SMA) occlusion, where the occlusive lesion can be recanalized either antegradely from the femoral or brachial artery, or retrogradely from an exposed SMA after laparotomy, and stented. Aspiration embolectomy, thrombolysis and open surgical embolectomy, followed by on-table angiography, are the treatment options for embolic SMA occlusion. Endovascular therapy may be an option in the few patients with mesenteric venous thrombosis who do not respond to anticoagulation therapy. Laparotomy is needed to evaluate the extent and severity of visceral organ ischaemia, which is treated according to the principles of damage control surgery. Modern treatment of acute mesenteric ischaemia involves a specialized approach that considers surgical and, increasingly, endovascular options for best outcomes.

The Role Of 18F-FDG PET/CT For Staging and Response Assessment To Chemotherapy In Marginal Zone Lymphoma.

IntroductionMarginal Zone Lymphoma (MZL) is an indolent lymphoma in which the use of PET/CT is poorly explored and also controversial due to the heterogeneous 18F- FDG avidity described in these types of lymphoma. Our aim in the present study is to evaluate the role of 18F-FDG-PET/ CT (PET/CT) in comparison to CT with intravenous contrast enhancement at initial staging and response assessment to chemotherapy in these patients. Methods and MaterialsA retrospective single-center study that included 34 patients, diagnosed of MZL between 1998 and 2012, with at least one PET/CT available. A total of 55 PET/ CT were performed: 25 at initial diagnosis, 19 for first- line response assessment, 6 in relapse and 5 after relapse- treatment. Locations of involved areas were registered comparing staging CT and PET/CT and were classified as discrepancy or not. ResultsPatients´ baseline characteristics are shown in table 1. At diagnosis, all patients presented with at least one abnormal focal FDG uptake except for one, which reflected a sensitivity of 96%. Median SUVmax was higher in nodal marginal zone lymphoma (NMZL) and extranodal marginal zone lymphoma (ENMZL): 6,1 (4- 8,4) and 6,9 (2- 13,8) respectively, in comparison to splenic marginal zone lymphoma (SMZL) 3,4 (3,2- 3,6) p=0,3. SUVmax was much higher in a patient with histological transformation to a DLBCL (SUVmax 37). Among 17 patients with both radiological imaging at the time of diagnosis, there were 8 patients (47%) with more involved areas demonstrated by PET/ CT than by CT alone, 75% of them were extranodal lesions. PET/CT upstaged 5 patients but in only 2 of them entailed a change in therapeutic management. Four patients did not show FDG avidity by PET/CT in some areas suspected to be involved by CT, what generated a CT sensitivity of 76%.Table 1Patients´ baseline characteristics (N=33). CR: complete remission; PR: partial remission; NA: not assessed; PD: progressive disease.Patient: n/n available (%)Age (mean-range)61 +/-13'5SexManWoman.N=17(51%)N=16(48%)WHO diagnosisENMZLNMZLSMZL.N=22(66.7%)N=6(18.2%)N=5(15.2%)Imaging techniques at diagnosisCT alonePET/CT aloneBothUnknown.N=6(18.1%)N=7(21.2%)N=18(54.5%)N=2(6.2%)Stage at diagnosisIIIIIIIV.N=6/33(18.1%)N=5/33(15.1%)N=6/33(18.1%)N=16/33(48.4%)Bone Marrow involvementN=9/33(27%)Bulky massesN=3/33(9%)Extranodal diseaseN=26/33(78.7%)LDH (median, range)N=28; 292U/ml (186'5-397'75)Hemoglobine (median, range)N=29; 118gr/dl (100-134)B2 microglobulin (median, range)N=24; 3'14mg/dl (2'3-5'1)IPI01234.N=3/25(12%)N=8/25(32%)N=8/25(32%)N=4/25(16%)N=2/25(8%)First line treatmentFCRR-CHOPRituximab monotherapyRadiotherapySurgerySpleenectomy.N=13/33(39.3%)N=5/33(15.1%)N=5/33(15.1%)N=2/33(6%)N=5/33(15.1%)N=3/3 (9%)ResponseCRPRNAPD.N=21(63%)N=4(12.1%)N=3(9%)N=5(15.1%)Overall, CR was attained in 24 patients (66%) with 5-y OS 78%. Among 19 patients with a PET/CT available for first-line response assessment, responses were: 12 CR, 2 PR, 1PD and isolated residual lesions in 4 patients. Progression was documented in 2 of the 4 patients with residual lesions which were considered positive, and in 2 patients who maintained remission, the image was interpreted as a false positive (FP). The response assessment was performed by both radiological imaging in 13 patients. Discrepancies were found in 4 cases: CT showed CR in 3 patients while PET/CT detected localized residual disease and in another patient, CT showed stable disease whereas PET/CT demonstrated CR.Overall, none of the patients in CR by PET/CT relapsed. Five-year OS was 100% in contrast to 64% for those patients with a positive PET/CT after completing treatment (p=0,2), with a mean follow-up of 50 months (10-152). The NPV was 100% and PPV was 71% (5/7).Relapse was detected in 9 patients (37.5%). Six patients had PET/CT for re-staging and 5 for response assessment. All re-staging PET/CT had FDG-avidity with a median SUVmax of 9.9 (4.6-17.2). PET/CT for response after salvage treatment demonstrated 3 CR and 2 localized residual lesions. The NPV and PPV was 100% and 50%, respectively. ConclusionsMZL shows higher 18F- FDG avidity in NMZL y ENMZL subtypes. PET/CT is more sensitive than CT at initial staging, chiefly in identifying extranodal involvement. Response assessment PET/CT had a NPV of 100% and PPV of 71 and 50% after first and second-line treatment, respectively. Disclosures:No relevant conflicts of interest to declare.

Bevacizumab for refractory adverse radiation effects after stereotactic radiosurgery

To retrospectively evaluate the clinical benefit and imaging response of bevacizumab when used to treat refractory adverse radiation effects (ARE) after stereotactic radiosurgery. Twenty-nine patients with brain tumors or vascular malformations developed clinical and/or imaging evidence of ARE after SRS and were treated using bevacizumab. Patients received an average dose of 7.4 mg/kg over a mean of 5.7 weeks at a median of 16 months following SRS. Initial diagnosis, SRS dose, bevacizumab treatment protocols, magnetic resonance imaging T2/FLAIR and T1 paramagnetic contrast enhanced edema volumes were compared before and after bevacizumab administration. Ninety percent (18/20) with clinically symptomatic ARE had neurological improvement after bevacizumab therapy. Twenty-six patients had a decrease of 62 % of T2/FLAIR volumes and a 50 % decrease in magnetic resonance imaging intravenous contrast enhancement volumes. Two patients showed progression of the T2/FLAIR and contrast enhancement volumes. One patient had progression of post-Gd-enhancement but regression of T2/FLAIR volume. Symptoms recurred in 11 of the 20 patients after discontinuing therapy. Patients who experienced a return of enhancement received a lower marginal dose during SRS. Our experience provides additional evidence that bevacizumab reduces both symptoms and reactive imaging changes in patients with ARE. After SRS, refractory ARE unresponsive to initial corticosteroids or other agents may benefit from a bevacizumab trial. The necessary duration and optimum dose of therapy is unknown and provides a further impetus to conduct a prospective trial.

Isolated cerebral susceptibility artefacts in patients with malignant melanoma: metastasis or not?

While staging patients with malignant melanoma, cerebral susceptibility artefacts on T2*-weighted/susceptibility-weighted imaging (SWI) sequences without a correlate on contrast-enhanced T1-weighted images can be confusing. Without intravenous contrast enhancement, cavernomas, microhaemorrhages and melanin-containing metastases represent possible differential diagnoses for these findings. The purpose of this study was to find out, how often such lesions correspond to metastases. Brain MR images (1.5T) of 408 patients with malignant melanoma but without cerebral metastases in the initial staging by MRI were reviewed retrospectively. Eighteen patients (5 female, 13 male) with malignant melanoma and signal intensity loss on T2*/SWI were included in our study. The average observation period was 19.6months (6-46months, 2006-2009). In each of these 18 patients between one and seven hypointense lesions on T2*/SWI were found. None of these lesions developed into metastasis. Focal areas of susceptibility artefacts in the brain parenchyma without corresponding abnormalities in contrast-enhanced T1 weighted images are unlikely to represent brain metastases. • In melanoma patients early diagnosis of metastatic brain lesions is mandatory. • Melanin content and haemorrhage are potential reasons for MRI characteristics of melanoma metastases. • Susceptibility-weighted MRI visualises melanin and blood products. • Isolated cerebral susceptibility artefacts do not convert into melanoma metastases. • SWI/T2* sequences cannot replace Gd-enhanced sequences.