Early Arterial Phase Research Articles

Carotid-cavernous fistula initially presented with persistent daily headache with promptly neurological progression. Case report

Carotid cavernous fistulas (CCF) are a dural arteriovenous fistulas which include pathological communications between the arterial system and the venous cavernous sinus situated at the wall of the cavernous sinus (CS). It can be demonstrated by wide range clinical presentations, like ophthalmic signs and symptoms (proptosis, chemosis, and visual loss), cranial nerve pareses, bleeding from the cranial structures and intracranial hemorrhage. We report a case of a patient which has diagnosed with CCF initially presented with persistent daily headache followed with promptly neurological progression. Case report: Twenty eight years old women has presented with 3 months history of daily left side headache, predominantly localized in left eye profound, without free after analgotherapy. Parallel with headache development she described sensation as a heart sound in pain area. Her mother died since some brain AV malformations. On examination, she had no ophthalmoplegia, proptosis and chemosis with normal neurological status. Auscultation under her left eye has found a whir. Digital subtraction angiography was performed and revealed a left side ophthalmic and facial venous dilatation with CS dilatation during all the time beginning from early arterial phase. As a result of panangiography detected a direct fast flow CCF, without presentation of left ICA intracranial parts with promptly retrograde venous swelling into the ophthalmic and facial venous and petrous sinus. During three days in neurological examination have occurred fully left side ophtalmoplegia with diplopia, left side ptosis and hypestesis in V1 area. The patient was scheduled for endovascular therapy (performed stent assisted coil embolization with complete occlusion of the fistula).

Quantitative low mechanical index contrast-enhanced endoscopic ultrasound for the differential diagnosis of chronic pseudotumoral pancreatitis and pancreatic cancer

BackgroundSecond-generation intravenous blood-pool ultrasound contrast agents are increasingly used in endoscopic ultrasound (EUS) for characterization of microvascularization, differential diagnosis of benign and malignant focal lesions, as well as improved staging and guidance of therapeutic procedures.MethodsThe aim of our study was to prospectively compare the vascularisation patterns in chronic pseudotumoral pancreatitis and pancreatic cancer using quantitative low mechanical index (MI) contrast-enhanced EUS. We included 51 patients with chronic pseudotumoral pancreatitis (n = 19) and pancreatic cancer (n = 32). Perfusion imaging started with a bolus injection of Sonovue (2.4 ml), followed by analysis in the early arterial (wash-in) and late venous (wash-out) phase. Perfusion analysis was performed by post-processing of the raw data (time intensity curve [TIC] analysis). TIC analysis was performed inside the tumor and the pancreatic parenchyma, with depiction of the dynamic vascular pattern generated by specific software. Statistical analysis was performed on raw data extracted from the TIC analysis. Final diagnosis was based on a combination of EUS-FNA, surgery and follow-up of minimum 6 months in negative cases.ResultsThe sensitivity and specificity of low MI contrast enhanced EUS using TIC were sensitivity and specificity of low MI contrast enhanced EUS using TIC analysis were 93.75% (95% CI = 77.77 - 98.91%) and 89.47% (95% CI = 65.46 - 98.15%), respectively. Pseudotumoral chronic pancreatitis showed in the majority of cases a hypervascular appearance in the early arterial phase of contrast-enhancement, with a dynamic enhancement pattern similar with the rest of the parenchyma. Statistical analysis of the resulting series of individual intensities revealed no statistically relevant differences (p = .78). Pancreatic adenocarcinoma was usually a hypovascular lesion, showing low contrast-enhancement during the early arterial and also during the late venous phase of contrast-enhancement, also lower than the normal surrounding parenchyma. We found statistically significant differences in values during TIC analysis (p < .001).ConclusionsLow MI contrast enhanced EUS technique is expected to improve the differential diagnosis of focal pancreatic lesions. However, further multicentric randomized studies will confirm the exact role of the technique and its place in imaging assessment of focal pancreatic lesions.

Adenosquamous Carcinoma of the Pancreas

The purpose of this article was to present the adenosquamous carcinoma (ASqC) of the pancreas: multidetector-row computed tomographic (CT) features and tumor characteristics. The clinical data and CT studies of 12 patients with pathologically proven ASqC of the pancreas between the dates February 2001 and February 2010 were retrospectively analyzed. The presenting symptoms of ASqC of the pancreas were nonspecific. Elevated serum levels of carbohydrate antigen 19-9, carbohydrate antigen 12-5, and carcinoembryonic antigen were noted. The tumor was most commonly involved in the pancreatic head in 6 patients, with the dilation of the common bile duct and the upstream main pancreatic duct. All ASqCs exhibited invasive growth. No calcification and intratumoral hemorrhage were noted in ASqCs. Ten tumors showed enhancement in the early arterial phase and persistent enhancement in the portal vein phase. The typical CT appearance of ASqC was solitary oval or round without any capsule and a defined margin. The dilation of the main pancreatic duct and/or the common bile duct was always discovered. The huge infiltrative lesion outside the pancreas was detected in the tail and/or the body of the pancreas. Not only the elevation of carbohydrate antigen 19-9 is common, but also Ca12-5 and CEA, whereas human alpha fetoprotein elevation is not observed. The enhancement pattern of tumor showed persistence in the portal vein phase.

Pulmonary Arteriovenous Malformations and Hepatic Involvement in a Patient With Osler-Rendu-Weber Disease

A 55-year-old woman presented to the emergency department with a 3-week history of progressive fatigue and dyspnea and recurrent hemoptysis. A contrast-enhanced computed tomographic (CT) image of her chest showed multiple arteriovenous malformations (AVMs), with the largest in the posterior left upper lobe (Figs 1A, 1B; * = pulmonary AVMs; FA = feeding artery; DV = drainage vein; AO = aorta; PT = pulmonary trunk). In the CT scan of the patient's liver, axial early arterial phase image showed abnormal perfusion as a result of the AVM (Fig 2A; AO = aorta; IVC = inferior vena cava; the AVM in the falciform ligament between the braces; arrows show the focal telangiectasis).

Image Fusion of Preprocedural CTA with Real-time Fluoroscopy to Guide Proper Hepatic Artery Catheterization During Transarterial Chemoembolization of Hepatocellular Carcinoma: A Feasibility Study

To assess feasibility of proper hepatic artery catheterization using a 3D model obtained from preprocedural computed tomographic angiography (CTA), fused with real-time fluoroscopy, during transarterial chemoembolization of hepatocellular carcinoma. Twenty consecutive cirrhotic patients with hepatocellular carcinoma undergoing transarterial chemoembolization were prospectively enrolled onto the study. The early arterial phase axial images of the preprocedural CTA were postprocessed on an independent workstation connected to the angiographic system (Innova 4100; GE Healthcare, Milwaukee, WI), obtaining a 3D volume rendering image (VR) that included abdominal aorta, splanchnic arteries, and first and second lumbar vertebrae. The VR image was manually registered to the real-time X-ray fluoroscopy, with the lumbar spine used as the reference. The VR image was then used as guidance to selectively catheterize the proper hepatic artery. The procedure was considered successful when performed with no need for intraarterial contrast injections or angiographic acquisitions. The procedure was successful in 19 (95 %) of 20 patients. In one patient, celiac trunk angiography was required for the presence of a significant ostial stenosis that was underestimated at computed tomography. Time for image reconstruction and registration was <10 min in all cases. The use of preprocedural CTA model with fluoroscopy enables confident and direct catheterization of the proper hepatic artery with no need for preliminary celiac trunk angiography, thus reducing radiation exposure and contrast media administration.

P3-041 - Necrolytic Migratory Erythema Associated with Pancreatic Glucagonoma

ABSTRACT Glucagonoma, a rare tumor derived from the a-cells of the pancreas, has an estimated incidence of approximately one in 20 million people per year. This glucagogenesis results in clinical manifestations including necrolytic migratory erythema (NME), cheilitis, diabetes mellitus, anemia, weight loss, among others. Of these, NME is a well-known paraneoplastic symptom observed in patients with glucagonoma. However, NME is often missed at initial investigation, and the correct diagnosis of glucagonoma tends to be delayed.We report a 46-year-old Japanese woman with glucagonoma who presented with mucocutaneous manifestations 1 year before the diagnosis of the pancreatic neoplasm with multiple liver metastases. Contrast-enhanced dynamic CT of the abdomen revealed multiple tumors in the pancreatic tail and liver, which were enhanced during the early arterial phase and washed out in the delayed phase. Liver biopsy showed well-differentiated neuroendocrine tumor. These histopathologic features in skin biopsy were suggestive of NME. Serum glucagon concentration was 8,400 pg/ml (normal range 70-160 pg/ml). Based on these findings, the diagnosis of glucagonoma with NME was confirmed. Because she had unresectable metastatic disease, she was treated with octreotide, a somatostatin analog. NME was dramatically improved within 2 weeks after initiation of octreotide. The rarity of glucagonoma has hampered a closer understanding of its pathophysiological mechanisms, which together with its non-specific clinical manifestations means that diagnosis is often relatively late in the course of the disease. Though several novel agents such as octreotide, sunitinib and everolimus provide clinical benefits for patients with advanced glucagonoma, complete resection still represents the only potentially curative treatment. Earlier recognition of NME, the characteristic skin lesion of glucagonoma syndrome, will facilitate the correct diagnosis of this condition.

Value of contrast-enhanced ultrasound and enhancement patterns in the diagnosis of adrenal tumors

Objective To explore the value of real time contrast-enhanced ultrasound (CEUS) in differential diagnosis of benign and malignant adrenal lesions.Methods Totally,57 adrenal lesions (26malignant and 31 benign) underwent conventional ultrasound and real-time CEUS.The enhancement patterns including types of time-intensity curve,centripetal fill-in,homogeneity and intensity of enhancement were analyzed.Results The enhancement pattern of normal adrenal gland was homogeneous,centrifugal and rapid perfusion from the medulla to the cortex.Four enhancement patterns were significantly different between benign and malignant adrenal lesions (P ＜0.05).If enhancement in the early arterial phase and rapid washout was suggestive of malignancy,the sensitivity and specificity of CEUS were 96.2％ and 77.4％,respectively.If peripheral to central filling was suggestive of malignancy,the sensitivity and specificity of CEUS were 76.9 ％ and 80.7 ％,respectively.Conclusions The patterns of real-time CEUS are helpful in differential diagnosis of malignant and benign adrenal lesions. Key words: Ultrasonography; Microbubbles; Adrenal gland neoplasms

Prediction of tumor stage and lymph node involvement with dynamic contrast-enhanced MRI after chemoradiotherapy for locally advanced rectal cancer

The usefulness of restaging by magnetic resonance imaging (MRI) after chemoradiotherapy (CTx/RTx) in patients with locally advanced rectal cancer has not yet been established, mostly due to the difficult differentiation between viable tumor and fibrosis. MRI with dynamic contrast-enhanced (DCE) sequences may be of additional value in distinguishing malignant from nonmalignant tissue. The aim of this study was to assess the accuracy of tumor, nodal staging, and circumferential resection margin (CRM) involvement by MRI with DCE sequences after CTx/RTx. The accuracies were assessed by MRI on T2-weighted magnetic resonance (MR) images with DCE sequences in patients with locally advanced rectal cancer after a long course of CTx/RTx. MR images were assessed by two independent radiologists. For tumor staging and CRM involvement, MRI with DCE sequences had an accuracy of 45 and 60 %, respectively. The accuracy for nodal staging was 93 %. On MRI, malignant lymph nodes had a median diameter of 8 mm (range, 4-18) and benign lymph nodes a median diameter of 4 mm (range, 3-11). A significant indicator for benign nodes was hypointensity on T2-weighted images (p < 0.001) and early complete arterial phase enhancement on DCE-weighted images (p < 0.001). A significant indicator for malignant nodes was heterogeneity on T2-weighted images (χ (2), p < 0.000) and early incomplete arterial phase enhancement on DCE (p < 0.001). MRI with DCE is a useful tool for nodal staging after CTx/RTx. The addition of DCE sequences did not improve the accuracy of determining the tumor stage, CRM involvement, and in detecting complete response.

Prediction and monitoring of treatment effect using T1-weighted dynamic contrast-enhanced magnetic resonance imaging in colorectal liver metastases: Potential of whole tumour ROI and selective ROI analysis

PurposeTo evaluate dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for prediction and early monitoring of treatment in colorectal liver metastases. Materials and methodsTen patients were included. Baseline and follow-up DCE-MRI examinations were evaluated by whole tumour and selected ROI placements calculating Kep-values. Selective ROIs, concentric-like and hot spot, were drawn on early arterial phase images. Monitoring of treatment was performed comparing RECIST1.1 criteria with whole tumour and selected ROI placement. To evaluate treatment effect between responders and non-responders, independent samples t-test was used on Kep-values. ResultsIn each patient largest lesion was evaluated totalling 10 target lesions. At baseline, for whole tumour ROI placements mean Kep-values in responders were significantly higher than mean Kep-values in non-responders (t=7.481, p<0.001). Selective ROI placement comparison of mean Kep-values at baseline and after 6 weeks of treatment (first follow-up measurement) showed significant decrease in responding patients (t=4.706, p=0.003) whereas increase in Kep-values in non-responding patients was not statistically significant. ConclusionThis preliminary study shows that baseline Kep for whole tumour ROI is a predictor for treatment outcome. Decrease of Kep using selective ROIs allows early identification of response after 6 weeks of treatment.

Preoperative evaluation of myometrial invasion in endometrial carcinoma: diagnostic performance of 3T MRI

To evaluate the diagnostic accuracy of 3T MRI in preoperative staging of myometrial invasion. Twenty-eight women with histological diagnosis of endometrial carcinoma were included in this prospective study. After T2-W SS-TSE and DWI, dynamic series of T1-W THRIVE images were obtained (0-180 s) followed by a T1-W THRIVE sequence in the late phase (5th min). For detection of deep myometrial infiltration: sensitivity, specificity, PPV, NPV, and accuracy were calculated on T2-W, postcontrast early arterial and late phase T1-W, and DWI. For the quantitative analysis of DWI, ADC values of the tumor were calculated and correlated with histologic grade. For the quantitative evaluation of dynamic series, SI-time curves were obtained and the maximum relative enhancement, wash-in rate, time-to-peak, and wash-out rate of masses and myometrium were compared. T2-W and early phase contrast-enhanced sequences obtained sensitivity 100 %, specificity 76 %, PPV 58 %, NPV 100 %, and accuracy 82 %; late-phase contrast-enhanced images obtained sensitivity 100 %, specificity 81 %, PPV 64 %, NPV 100 %, and accuracy 86 %; DWI obtained lower accuracy [sensitivity 71 %, specificity 62 %, PPV 38 %, NPV 87 %, and accuary 57 %] than T2-W and postcontrast images. The MRE of carcinomas were significantly lower than those of the myometrium. This analysis showed a significant improvement in tumor versus myometrium contrast during the late phase. On DWI, the mean ADC value of tumor was 1.02 ± 0.48 × 10(-3). There was no statistically significant correlation between tumor grades and ADCs. As the 3T MRI scanner allows high-resolution images, accurate assessment of myometrial infiltration can be done especially with postcontrast late phase images.

Dynamic CT Angiography after Abdominal Aortic Endovascular Aneurysm Repair: Differences in Contrast Agent Dynamics in the Aorta and Endoleaks—Preliminary Results

PurposeTo assess differences in aortic and endoleak enhancement in patients after endovascular aneurysm repair (EVAR) with dynamic computed tomography (CT) angiography. Materials and MethodsTwenty-one consecutive patients (mean age, 74.5 y ± 6; range, 61–88 y) with endoleaks after EVAR of the abdominal aorta were examined on a second-generation dual-source CT unit with 10 unidirectional scan phases (temporal resolution, 5 s; 80 kV; 120 reference-mAs; z-axis field of view, 283 mm), followed by a venous scan phase. Enhancement was assessed in aorta and endoleaks for all phases by density measurements. The diagnostic reliability of endoleak detection was assessed on a five-point confidence scale. ResultsIn total, 26 endoleaks (type I, n = 1; type II, n = 25) were detected. The highest detection rate was found in phase 5 (22 s after threshold; P < .01 vs other dynamic phases). Mean peak aortic enhancement (560 HU ± 96) was present in an early arterial phase (phase 3, 12 s after threshold), whereas the mean peak endoleak enhancement (398 HU ± 174) for type II endoleaks was present later, in phase 4 (17 s after threshold). Despite perceived high diagnostic confidence in phases 1 and 2 (ie, typical arterial phase of biphasic CT protocol), only 23% and 62% of endoleaks were detected, respectively, whereas peak diagnostic confidence (phases 4 and 5) corresponded well with the maximum endoleak detection rate but decreased significantly in later phases (ie, 6–10). ConclusionsPreliminary dynamic CT angiography results in post-EVAR follow-up revealed notably different peaks of endoleak and aortic enhancement, which are not covered sufficiently by conventional biphasic CT protocols. Phase 5 demonstrated the highest type II endoleak detection rate, with high diagnostic confidence.

Solid Pseudopapillary Tumors of the Pancreas

The aims of this study were to determine the features of solid pseudopapillary tumors of the pancreas on contrast-enhanced sonography and correlate them with pathologic findings. Five patients with solid pseudopapillary tumors of the pancreas underwent conventional sonographic, color Doppler flow imaging, and contrast-enhanced sonographic examinations. Time-intensity curves were used to calculate the contrast enhancement times, wash-out times, and enhancement patterns of the lesions. Three of the 5 patients also underwent contrast-enhanced computed tomography. All cases were confirmed by surgery and pathologic examination. The study included 3 women and 2 men. Tumor diameters ranged from 4.4 to 13.0 cm. Sonography revealed round well-defined encapsulated tumors. Two appeared as mixed cystic-solid and 3 as solid masses on conventional sonography. One mass had a macrocalcification. Some areas of blood flow were seen in 3 of the masses on color Doppler flow imaging. On contrast-enhanced sonography, the peripheral rims of the tumors showed isoenhancement during the early arterial phase, and the interiors of the masses showed heterogeneous enhancement consisting of regions of isoenhancement, hypoenhancement, and nonenhancement. Progressive wash-out of the contrast agent during venous phases revealed hypoenhancement compared with normal adjacent pancreatic parenchyma. Pathologic findings showed that each tumor was completely encapsulated and had varying degrees of internal hemorrhage and necrosis. Solid pseudopapillary tumors of the pancreas have characteristic findings on contrast-enhanced sonography, including peripheral rim isoenhancement and internal heterogeneous enhancement with nonenhanced portions; these features may help differentiate solid pseudopapillary tumors from other pancreatic neoplasms.

Recurrent Pulmonary Capillary Hemangioma: Dynamic Contrast-Enhanced CT and Histopathologic Findings

We report the dynamic contrast-enhanced CT and histopathologic findings of a rare case of recurrent pulmonary capillary hemangiomas. The findings consisted of peripheral nodular enhancement at the early arterial phase and a subsequent "central filling-in" enhancement pattern on the delayed scans, which was identical to the well-known enhancement pattern of hemangiomas of the liver. Although there was no evidence of histological malignancy, pulmonary capillary hemangiomas manifested as multiple nodular lesions and showed postoperative recurrence.

CT and MRI Findings of Hepatic Involvement in Rendu-Osler-Weber Disease

Rendu-Osler-Weber disease is a rare autosomal dominant disorder. Hepatic involvement manifests itself as vascular, parenchymal, and biliary lesions with characteristic telangiectasias and vascular shunts. In a 37-year-old female patient, dynamic contrast-enhanced upper abdominal CT and MRI were performed. CT and MRI revealed dilated celiac trunk and hepatic artery. On early arterial phase, dilated hepatic veins showed significant enhancement. On arterial and portal venous phases, liver showed significantly heterogeneous contrast enhancement and showed homogenous enhancement in the hepatic parenchymal phase. On the magnetic resonance cholangiopancreatography, irregular biliary ducts with strictures and dilatation were seen.

Assessment of Carotid Plaque Stability Based on the Dynamic Enhancement Pattern in Plaque Components With Multidetector CT Angiography

Recent studies have investigated plaque morphology to determine patients who are at high risk of carotid atherosclerosis. In this study, we investigated whether a difference in dynamic enhancement pattern in plaque components could be useful to assess plaque stability with multidetector CT angiography. Fifty-nine lesions with moderate to severe carotid atherosclerosis in 51 patients (33 symptomatic, 18 asymptomatic) were consecutively included. Early- and delayed-phase images were obtained in 3 equivalent axial slices with multidetector CT angiography. Hounsfield units (HU) in the early phase were subtracted from those in the delayed phase in plaques (ΔHU) and compared with clinical features, MRI-based plaque characteristics, and histological findings with 20 surgical specimens acquired from carotid endarterectomy. The ΔHU was significantly higher in asymptomatic than that in symptomatic presentation (P=0.02). With MRI, a higher ΔHU was negatively correlated with signal intensity on T1-weighted imaging (r=-0.56, P<0.0001). Histology confirmed that ΔHU was positively correlated with fibrous tissue (r=0.67, P=0.001) and negatively correlated with a lipid-rich necrotic core with hemorrhage (r=-0.70, P<0.001). Moreover, less neovascularization and inflammation was found in plaques with a higher ΔHU. Delayed-phase images provide information regarding the dynamic change in contrast media from the early arterial phase. An increase in HU from the early phase on multidetector CT angiography indicates plaque stability with more fibrous tissue and a less lipid-rich necrotic core, intraplaque hemorrhage, and neovascularization.

Successful management of severe blunt hepatic trauma by angiographic embolization

We present the case of an 18-year-old female with severe liver trauma after a motorcycle accident. Due to initial hemodynamic instability, fluid resuscitation and transfusion of two units of red packed cells was required. After stabilization, a CT scan was performed, showing grade V liver injuries according to the American Association for the Surgery of Trauma grading system. Angiography revealed multiple extravasations during the early arterial phase, as well as active extravasation from the proximal left hepatic artery in the late arterial phase. The patient was successfully treated by arterial embolization using metal microcoils, after which no further need for blood transfusion ensued. This report highlights that, in carefully selected cases, arterial embolization can improve the clinical condition of patients, reduce the need for blood transfusion and lessen the possibility of an operation, even if severe liver trauma has ensued.

Arteriovenous malformation: a rare cause of trigeminal neuralgia identified by magnetic resonance imaging with constructive interference in steady state sequences

A 64-year-old female presented with a 4-year history of right-sided facial pain. She described an ‘electric shock-type’ pain starting on the right side of her chin that radiated along the lower lip, upper lip and into the lower cheek, in the mandibular division of the trigeminal nerve. The pain was triggered by speaking, eating, drinking, brushing her teeth or touching her chin. These attacks occurred daily and lasted for 3 months before resolving spontaneously, consistent with classical trigeminal neuralgia (TN). Systemic and neurological examinations were normal. In particular, trigeminal sensation was intact bilaterally and trigeminal reflexes were normal. A diagnosis of right-sided, mandibular division TN was made. She had four similar episodes of pain over the following 4 years, each lasting ∼3 months, with each episode becoming more severe. She did not want any analgesic medication for the first two episodes. However, during the most recent episode, carbamazepine (300 mg twice a day) and, subsequently, adjunctive amitriptyline (10 mg at night) were prescribed, although these failed to control the symptoms. Therefore the patient underwent investigation to assess for a structural cause amenable to neurosurgical intervention. The patient underwent a cranial MRI with constructive interference in steady state (CISS) sequences, which demonstrated several small blood vessels surrounding the right trigeminal nerve and a very large mass, thought likely to be a venous aneurysm, lying just behind the root entry zone into the trigeminal nerve (Figure 1). A contrast-enhanced computed tomography angiogram (CTA) confirmed the previous MRI findings and was highly suggestive of an underlying arteriovenous malformation (AVM) (Figure 2). For the pre-surgical work-up a digital subtraction angiogram was organized. This demonstrated a definite AVM during contrast injection in the right vertebral artery with rapid filling of the straight sinus during the early arterial phase (Figure …

Diagnostic value of high spatial and temporal resolution time-resolved MR angiography in the workup of peripheral high-flow vascular malformations at 1.5 Tesla

To evaluate the feasibility and diagnostic impact of time-resolved MR angiography (TR-MRA) combined with parallel imaging and low contrast dose for the assessment of peripheral high-flow vascular malformations (VM) at 1.5 Tesla (T). Twelve consecutive patients (7 female, 5 male, mean age 24.7 ± 11.1 years) with known or suspected high-flow VM underwent time-resolved MRA. Two readers individually assessed image quality, diagnostic confidence as well as hemodynamic features. Digital subtraction angiography (DSA) correlation was available in 9 patients. TR-MRA provided a comprehensive assessment of all VMs with good quality images, allowing reliable differentiation of the early and main arterial phases and of at least the early venous phase. Based on hemodynamic features VM were classified as predominantly arterial malformations in 5 cases (42%), or arteriovenous malformations in the remaining 7 cases (58%). The high-flow component of a VM was confirmed by DSA in 9/9 (100%) cases during the interventional treatment procedure. TR-MRA of peripheral VMs with temporal interpolation and stochastic spiral trajectories is feasible, allowing the assessment of dynamic inflow and vessel-specific information similar to conventional DSA. Therefore, TR-MRA represents a reasonable alternative imaging technique for the pre-treatment evaluation of high-flow VMs.

Teaching Neuro Images : Dual-phase 3D multislice CT angiography for the detection of intracranial pseudoaneurysm

A 45-year-old woman was diagnosed with a subarachnoid hemorrhage. Dual-phase 3-dimensional CT angiography (12 and 23 seconds) showed no aneurysm in the early arterial phase (figure, A), but revealed a dorsal-wall aneurysm in the …

Optimising the scan delay for arterial phase imaging of the liver using the bolus tracking technique.

Objective:To optimize the delay time before the initiation of arterial phase scan in the detection of focal liver lesions in contrast enhanced 5 phase liver CT using the bolus tracking technique.Patients and Methods:Delay - the interval between threshold enhancement of 100 hounsfield unit (HU) in the abdominal aorta and commencement of the first arterial phase scan. Using a 16 slice CT scanner, a plain CT of the liver was done followed by an intravenous bolus of 120 ml nonionic iodinated contrast media (370 mg I/ml) at the rate of 4 mL/s. The second phase scan started immediately after the first phase scan. The portal venous and delay phases were obtained at a fixed delay of 60 s and 90 s from the beginning of contrast injection. Contrast enhancement index (CEI) and subjective visual conspicuity scores for each lesion were compared among the three groups.Results:84 lesions (11 hepatocellular carcinomas, 17 hemangiomas, 39 other hypervascular lesions and 45 cysts) were evaluated. CEI for hepatocellular carcinomas appears to be higher during the first arterial phase in the 6 seconds delay group. No significant difference in CEI and mean conspicuity scores among the three groups for hemangioma, other hypervascular lesions and cysts.Conclusion:The conspicuity of hepatocellular carcinomas appeared better during the early arterial phase using a bolus tracking technique with a scan delay of 6 seconds from the 100 HU threshold in the abdominal aorta.