ESGAR consensus statement on liver MR imaging and clinical use of liver-specific contrast agents.

OBJECTIVES: To develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents. METHODS: The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach's statistics were used to rate levels of agreement and internal reliability of the consensus. RESULTS: Three Delphi rounds were conducted and 76 statements composed on MR technique (n = 17), clinical application of liver-specific contrast agents in benign, focal liver lesions (n = 7), malignant liver lesions in non-cirrhotic (n = 9) and in cirrhotic patients (n = 18), diffuse and vascular liver diseases (n = 12), and bile ducts (n = 13). The overall mean score of agreement was 4.84 (SD ±0.17). Full consensus was reached in 22 % of all statements in all working groups, with no full consensus reached on diffuse and vascular diseases. CONCLUSIONS: The consensus provided updated recommendations on the methodology, and clinical indications, of MRI with liver specific contrast agents in the study of liver diseases. KEY POINTS: • Liver-specific contrast agents are recommended in MRI of the liver. • The hepatobiliary phase improves the detection and characterization of hepatocellular lesions. • Liver-specific contrast agents can improve the detection of HCC.

Randomised controlled trial of doxorubicin-eluting beads vs conventional chemoembolisation for hepatocellular carcinoma.

BACKGROUND: Transcatheter arterial chemoembolisation (TACE) is the treatment of choice for intermediate stage hepatocellular carcinoma (HCC). Doxorubicin-loaded drug-eluting beads (DEB)-TACE is expected to improve the performance of conventional TACE (cTACE). The aim of this study was to compare DEB-TACE with cTACE in terms of time-to-tumour progression (TTP), adverse events (AEs), and 2-year survival. METHODS: Patients were randomised one-to-one to undergo cTACE or DEB-TACE and followed-up for at least 2 years or until death. Transcatheter arterial chemoembolisation was repeated 'on-demand'. RESULTS: We enrolled 177 patients: 89 underwent DEB-TACE and 88 cTACE. The median number of procedures was 2 in each arm, and the in-hospital stay was 3 and 4 days, respectively (P=0.323). No differences were found in local and overall tumour response. The median TTP was 9 months in both arms. The AE incidence and severity did not differ between the arms, except for post-procedural pain, more frequent and severe after cTACE (P<0.001). The 1- and 2-year survival rates were 86.2% and 56.8% after DEB-TACE and 83.5% and 55.4% after cTACE (P=0.949). Eastern Cooperative Oncology Group (ECOG), serum albumin, and tumour number independently predicted survival (P<0.05). CONCLUSIONS: The DEB-TACE and the cTACE are equally effective and safe, with the only advantage of DEB-TACE being less post-procedural abdominal pain.

IERAPSI project: simulation of a canal wall-up mastoidectomy.

Among the various EU research projects concerning the medical application of virtual reality, the project Ist-1999-12175, called IERAPSI (Integrated Environment for the Rehearsal and Planning of Surgical Interventions), specifically addressed the creation of a virtual and interactive surgical field for the temporal bone using three-dimensional images derived from CT data. We report on the experience obtained in the IERAPSI project in simulating a canal wall-up mastoidectomy. A surgeon with extensive experience in surgery of the petrous bone performed the mastoidectomy. The operative field included the mastoid, with its substantial differences in density between the cortex and the pneumatized bone, together with soft tissue structures, both on the border and inside the bone. The simulation is better in the first part of the operation than in the second part, suffering from a lack of haptic feedback from soft tissue and the surgical tool in deeper contexts, and under-representation of the variability inherent in pneumatized bone. This said, the excellent representation of dust production and removal, 3D simulation through color, and very good visual and haptic feedback in the early stage of the procedure are impressive. IERAPSI represents a potential surgical planning theater for the training of students and young surgeons, but is also expected to aid expert surgeons in the preoperative planning of difficult cases.

Hepatocellular adenoma: imaging findings and pathological correlation.

A 45-year-old man presented with a 1-week history of gastrooesophageal reflux, epigastric discomfort and abdominal pain especially in the right hypochondrium. Abdominal ultrasonography, contrast-enhanced spiral computed tomography and magnetic resonance imaging of the abdomen were performed. Eventually, imaging findings were correlated with histopathological analysis, which confirmed the diagnosis of a 18 cm x 16 cm hepatocellular adenoma.

iPad-based primary 2D reading of CT angiography examinations of patients with suspected acute gastrointestinal bleeding: preliminary experience.

OBJECTIVE: To evaluate the effectiveness of the iPad (Apple Inc., Cupertino, CA) for two-dimensional (2D) reading of CT angiography (CTA) studies performed for suspected acute non-variceal gastrointestinal bleeding. METHODS: 24 CTA examinations of patients with suspected acute gastrointestinal bleeding confirmed (19/24, 79.2%) or ruled out (5/24, 20.8%) by digital subtraction angiography (DSA) were retrospectively reviewed by three independent readers on a commercial picture archiving communication system (PACS) workstation and on an iPad with Retina Display® 64 GB (Apple Inc.). The time needed to complete reading of every CTA examination was recorded, as well as the rate of detection of arterial bleeding and identification of suspected bleeding arteries on both devices. RESULTS: Overall, the area under the receiver operating characteristic curve, sensitivity, specificity, positive- and negative-predictive values for bleeding detection were not significantly different while using the iPad and workstation (0.774 vs 0.847, 0.947 vs 0.895, 0.6 vs 0.8, 0.9 vs 0.944 and 0.750 vs 0.667, respectively; p > 0.05). In DSA-positive cases, the iPad and workstation allowed correct identification of the bleeding source in 17/19 cases (89.5%) and 15/19 cases (78.9%), respectively (p > 0.05). Finally, the time needed to complete reading of every CTA study was significantly shorter using the iPad (169 ± 74 vs 222 ± 70 s, respectively; p < 0.01). CONCLUSION: Compared with a conventional PACS workstation, iPad-based preliminary 2D reading of CTA studies has comparable diagnostic accuracy for detection of acute gastrointestinal bleeding and can be significantly faster. ADVANCES IN KNOWLEDGE: The iPad could be used by on-call interventional radiologists for immediate decision on percutaneous embolization in patients with suspected acute gastrointestinal bleeding.

Corticospinal tract degeneration in motor neuron disease.

Long-repetition-time spin-echo MR images showed symmetric hyperintensity of the intracerebral corticospinal tracts in two patients with clinical and neurophysiologic diagnosis of primary lateral sclerosis and amyotrophic lateral sclerosis. In both, axial low-flip-angle gradient-echo images of the cervical spine showed hyperintensity of the lateral columns of the cord consistent with antegrade degeneration of the crossed corticospinal tracts.

MR angiography of spinal vascular malformations.

PURPOSE: To determine the potential and limitations of MR angiography in the evaluation of spinal vascular malformations. METHODS: Eleven consecutive patients with spinal vascular malformations proved with spinal selective arteriography underwent two-dimensional phase-contrast MR angiography. RESULTS: Abnormal vessels within the spinal canal were identified with MR angiography in 10 patients. In 1 patient with a dural arteriovenous fistula no definite vascular abnormality was seen with MR angiography. Correlation of MR angiography with spinal selective arteriography showed that the former allowed identification of the arterial feeder in 3 patients with intramedullary arteriovenous malformations and 2 with perimedullary arteriovenous fistula, whereas the source of intradural draining vein was seen in only 2 of 6 patients with dural arteriovenous fistula. CONCLUSION: MR angiography is a promising complementary tool to MR imaging for detection and characterization of spinal vascular malformations.

Identification of the feeding arteries of spinal vascular lesions via phase-contrast MR angiography with three-dimensional acquisition and phase display.

PURPOSE: To determine whether identification of the feeding arteries of spinal vascular lesions with phase-contrast MR angiography benefits from the higher spatial resolution of three-dimensional (volume) acquisitions and flow-direction information provided by the phase reconstruction of two-dimensional acquisitions. METHODS: Fifteen patients with high- or low-flow spinal vascular lesions proved by spinal arteriography underwent MR angiography with phase-contrast techniques. Arteriographic and MR angiographic studies were reviewed to identify the arterial feeders of spinal vascular lesions. RESULTS: On modulus reconstructions of coronal 2-D or 3-D acquisitions, three of four arteries feeding high-flow lesions and three of 14 arteries feeding low-flow lesions were identified as hypertrophic vessels joining the parent intercostal or cervical arteries. Of 11 intradural veins draining dural arteriovenous fistulas, three were identified on coronal 2-D acquisitions and six on coronal 3-D acquisitions as vessels that coursed from a neural foramen to a midline tangle of vessels. Phase reconstruction showed ascending and descending flow patterns in two patients with intramedullary arteriovenous malformations, and diverging flow in perimedullary veins draining a hemangioblastoma. In nine patients with dural arteriovenous fistulas, phase reconstruction provided information as to the level of the arterial feeders. Phase reconstruction in coronal plane acquisitions also provided evidence of centripetal flow. CONCLUSION: Three-dimensional acquisitions and phase display of 2-D acquisitions improved the visibility of arterial pedicles of spinal vascular lesions at phase-contrast MR angiography.

Tc 99m-Sestamibi scintimammography in the differentiation of benign and malignant breast microcalcifications.

The capability of the mammography-scintimammography combination to distinguish between benign and malignant isolated clusters of breast microcalcifications is discussed. Scintimammography using Tc 99m-Sestamibi was performed in 97 women with an isolated cluster of microcalcifications on mammograms. Seventy-two women had final histopathologic diagnoses (24 cancer and 48 benign pathology). The other 25 patients had follow-up to 3 years. The results of mammography, scintimammography and mammography-scintimammography combination were divided into five groups, based on the suspicion of malignancy. The sensitivity, specificity, false negative fraction, false positive fraction, predictive positive value, predictive negative value and diagnostic accuracy were calculated varying the diagnostic threshold. The Receiver Operating Characteristic (ROC) statistical technique was employed to compare the diagnostic value of mammography to mammography-scintimammography combination. The area under the ROC curves was calculated by the Wilcoxon statistic without any hypothesis on data distribution. The detected difference between areas under the mammography ROC curve (area=0.854, standard error=0.049) and mammography-scintimammography ROC curve (area=0.897, standard error 0.033) was statistically significant (P>0.05, one tail). The area under a ROC curve represents the probability that a randomly chosen diseased or non-diseased subject could be correctly classified. From this point of view this paper demonstrates that, if properly used, scintimammography can add to mammography in the characterization of an isolated cluster of microcalcifications, even if it is not able to replace FNAB and core biopsy.

Color flow Doppler sonography rapidly differentiates type I and type II amiodarone-induced thyrotoxicosis.

Amiodarone-induced thyrotoxicosis (AIT) occurs both in abnormal thyroid glands (nodular goiter, latent Graves' disease) (type I AIT) or in apparently normal thyroid glands (type II AIT). Differentiation of the two forms is crucial, because type I AIT responds well to methimazole and potassium perchlorate combined treatment, whereas type II AIT is effectively managed by glucocorticoids. Differential diagnosis is often difficult, although thyroid radioactive iodine uptake is usually low-to-normal in type I and low-suppressed in type II, and serum interleukin-6 levels are normal/slightly elevated in type I, markedly elevated in type II. Color flow Doppler sonography (CFDS) is a technique that shows intrathyroidal blood flow and provides real-time information on thyroid morphology and hyperfunction. To investigate the usefulness of CFDS in differentiating the two types of AIT, 27 consecutive AIT patients, 11 type I and 16 type II, were evaluated by CFDS before starting antithyroid treatment. Gender, age, severity of thyrotoxicosis, and cumulative amiodarone dose were similar in the two groups. All type II AIT patients had a CFDS pattern 0 (ie, absent vascularity), in agreement with the pathogenesis of the disease, due to thyroid damage. Likewise, nine patients with subacute thyroiditis, another destructive process of the thyroid gland, also had a CFDS pattern 0. Eleven patients with type I AIT had a CFDS pattern ranging from pattern I (presence of parenchymal blood flow with patchy uneven distribution) (7 patients, 64%) to pattern II (ie, mild increase of color flow Doppler signal with patchy distribution) (1 patient, 9%) and pattern III (markedly increased color flow Doppler signal with diffuse homogeneous distribution)(3 patients, 27%), similar to that found in patients with untreated Graves' disease patients, thus indicating a hyper-functioning gland. Control subjects and euthyroid patients under long-term amiodarone treatment had absent thyroid hypervascularity and a CFDS pattern 0. These findings demonstrate that CFDS distinguishes type I and II AIT. Because of its rapidity and noninvasive features, CFDS represents a valuable tool for a quick differentiation between the two types of AIT. This can avoid any delay in initiating the appropriate treatment for a rapid control of thyrotoxicosis in patients whose tachyarrhythmias or other cardiac disorders make thyroid hormone excess extremely deleterious.

Magnetic resonance and echocardiography in the investigation of cardiac tumour in an infant.

An intracardiac tumour in an asymptomatic female infant was diagnosed by means of echocardiography and magnetic resonance. The natural history of this pathology in patients showing no symptoms of cardiac involvement is still unknown. The development of these modern diagnostic techniques, however, has made it easier to carry out longitudinal follow-up studies aimed at obtaining useful information about the prognosis and growth potentialities of these tumours.

Treatment of renovascular disease and of renovascular hypertension.

Treatment of occlusive lesions of renal arteries, defined as renovascular disease (RVD), is aimed both at preventing ischemic renal disease (IRD) and rescuing renal function through revascularization procedures, such as PTRA, endovascular stenting and surgical revascularization, as well as curing or improving hypertension in the presence of renovascular hypertension (RVH), i.e. hypertension caused by these vascular lesions. Preventive treatment of IRD is still an individual decision making process based on the type of renal lesions, degree of renal stenosis and progressive loss of renal mass as well as on immediate and late technical success of revascularization procedures together with their rate of complications. Rescue of renal function and-or prediction of the outcome of renal function after successful revascularization depends not only on the possibility of clarifying whether the decrease in renal function is a functioning-reversible phenomenon linked to renal hypoperfusion but also on the potential risk that the revascularization procedure may induce irreversible kidney damage. The rationale for treating RVH through revascularization procedures derives from the possibility of establishing a pathogenetic link between the occlusive lesions and hypertension, mainly through renal vein renin measurement and captopril renography and possibly their combination. Finally, medical treatment of hypertension is needed in patients who cannot undergo or refuse revascularization and whose blood pressure is not normalized by these procedures.

Effectiveness of the Short TI Inversion Recovery (STIR) sequence in MR imaging of intramedullary spinal lesions.

A Short TI Inversion Recovery (STIR) sequence with spin-echo data collection was compared to a conventional cardiac gated long TR spin-echo (SE) sequence for detecting intramedullary signal abnormalities. The cervical (n = 48), cervico-thoracic (n = 1), and thoraco-lumbar (n = 18) spinal cord was imaged in a sagittal plane with a 0.5 T (n = 61) or 1.5 T (n = 6) MRI unit in 67 patients with clinical evidence of myelopathy of different etiologies (e.g., multiple sclerosis, trauma, herniated intervertebral disk, spondylosis, etc.). In all patients, ungated double or quadruple echo STIR images (TR 1000-1400 msec, TI 100 msec, TE 30-60 or 30-60-90-120 msec) were compared with cardiac gated long TR (1400-2100 msec), double echo (30-100, 50-100, or 50-150 msec) SE images with first order flow compensation for the second echo. Although STIR images appeared "noisier" than long TR SE images, they showed fewer ghost artifacts. In 55 patients, single or multiple, focal or diffuse, hyperintense areas within the spinal cord were observed on both long TR SE and (magnitude reconstructed) STIR images. Lesion conspicuity was better on the STIR images in 25 patients, better on the SE images in 14 patients, and equal in 16. STIR sequence provides a valuable alternative to gated long TR SE sequence for the MRI investigation of intramedullary spinal lesions.

MR virtual endoscopy of the pancreaticobiliary tract.

PURPOSE: To evaluate the feasibility of surface-rendered magnetic resonance virtual endoscopy (MRVE) of magnetic resonance cholangiopancreatography (MRCP) data sets. We retrospectively reviewed MR cholangiopancreatography data sets of 120 patients with biliary stone (n=40), inflammatory ampullary stenosis (n=12), pancreatic tumor (n=8), cholangiocarcinoma (n=7), stenosis of surgical bilio-enteric anastomosis (n=4), extrinsic localized common bile duct stenosis (n=2), ampullary carcinoma (n=2), pancreatic duct stone (n=1), tumor of the gallbladder (n=1), and normal pancreaticobiliary tree (n=43). MRVE views were generated with Navigator software. Segmentation of the acquired data sets was performed with a thresholding technique. Navigation sequences were simulated through the entire biliary tract. MRVE was obtained in 27 (63%) of the 43 normal patients. Endoscopic views were generated in all 77 patients with partial or complete obstruction of the pancreaticobiliary tree. Among these, three groups of patterns were identified: 36 (47%) endoluminal masses (polyp-like masses), 17 (22%) luminal stenoses, 24 (31%) luminal occlusion. In 29 cases, hole artifacts through the internal wall were observed and interpreted as mistakes of segmentation. MRVE proved to show the internal anatomy of the biliary tract and endoluminal changes due to pathological condition. Further investigations are needed to test the usefulness and the potentialities of this technique.

Choledocolithiasis: diagnostic accuracy of MR cholangiopancreatography. Three-year experience.

The purpose of this study was to evaluate the diagnostic accuracy of MR cholangiopancreatography (MRCP) in the detection of common bile duct stones. A series of 286 consecutive patients were referred for MRCP, that was performed with a 1.5 T MR unit, through a non-breath-hold, respiratory-triggered, fat-suppressed, two-dimensional, heavily T2-weighted fast spin-echo sequence in the coronal plane. Axial T1 and T2-weighted sequences were first obtained. Axial, coronal, and Maximum Intensity Projection images were evaluated by three independent readers, who were asked to determine whether stones were present or not inside the biliary tract. The findings of MRCP images were compared with endoscopic retrograde cholangiopancreatography, percutaneous trans-hepatic cholangiography, intra-operative cholangiography, surgical, or imaging follow-up findings. Two-hundred and seventy-eight out of 286 MRCP examinations were judged diagnostic by the three reviewers. Among the 278 patients included in our study group, biliary tract lithiasis was proved in 76 cases (27%). On the basis of reviewers' reading, MRCP had sensitivity 92-93%, specificity 97-98%, positive predictive value 91-93%, negative predictive value 97-98%, and the diagnostic accuracy ranged between 95% and 96% in the detection of calculi. Interobserver agreement was excellent (K = 0.84, kappa statistic). MRCP showed a high diagnostic accuracy and an excellent inter-observer agreement in the detection of common bile duct stones.

Detection of biliary complications after orthotopic liver transplantation with MR cholangiography.

To assess the diagnostic value of magnetic resonance cholangiography (MRC) when evaluating biliary complications in the follow-up of liver transplant patients. One hundred and thirteen patients prospectively underwent MR imaging and MR cholangiography at 1.5-T unit after orthotopic liver transplantation (OLT). After the acquisition of axial T1- and T2-weighted sequences, MRC involved a coronal, non breath-hold, respiratory-triggered, fat-suppressed, two-dimensional, thin-slab, heavily T2-weighted fast spin-echo sequence, and coronal breath-hold, thick-slab, single-shot T2-weighted sequences. The images and maximum intensity projections were evaluated by two readers in order to determine biliary anatomy and the presence of complications, whose final diagnosis was based on endoscopic retrograde cholangiography (ERC) in 50 patients, percutaneous trans-hepatic cholangiography (PTC) in five, and by integrating clinical follow-up with ultrasound and MR findings in 58 cases. MRC had a sensitivity of 93%, a specificity of 92%, a positive predictive value of 86%, a negative predictive value of 96%, and a global diagnostic accuracy of 93% in detecting all types of biliary complications in OLT patients. MRC is a reliable technique for detecting post-OLT biliary complications. We now restrict the use of ERC to patients for whom therapeutic procedures are advocated or whose MRC results are equivocal.

Ex-vivo MR imaging of liver intracellular contrast agents.

The objective is to evaluate whether an ex-vivo model can be used to test intracellular contrast agents for MR imaging of the liver. T1 weighted inversion recovery, proton density spin echo and T2* weighted gradient echo images of the liver were acquired at 0.5 T in 10 rats before and 30 min after intravenous injection of 0.075 mmol/kg Gadolinium benzyloxypropionictetraacetate (Gd-BOPTA, n = 5) or 0.015 mmol/kg dextran magnetite (DM, n = 5), Four additional animals served as controls. After exsanguination and perfusion with saline and formalin, specimens of the liver and brain were embedded in an agar gel and examined with MR imaging one to three weeks later using the same protocol. In-vivo, the mean liver signal enhancement caused by Gd-BOPTA in T1, proton density and T2* weighted images was +23%, +28% and -70%, respectively. The mean liver signal enhancement caused by DM was -71%, -76% and -94%. In-vitro, no signal change was seen in the brain of animals injected with Gd-BOPTA and DM as compared to controls. Liver signal was increased by Gd-BOPTA and decreased by DM. Mean liver enhancement rate induced by Gd-BOPTA was +22%, +5% and +27% for T1, proton density and T2* weighted images, respectively. Mean liver enhancement rate induced by DM was -27%, -19% and -31%. MR imaging signal changes induced by liver intracellular contrast agents are still appreciable in an ex-vivo model. The latter might be useful for for preliminary investigation of intracellular contrast agents for MR imaging of the liver.

The role of ultrasonography and ultrasound guided biopsy in the management of patients with cold nodules of the thyroid.

The histological diagnoses of surgical specimens from 86 patients with cold nodules of the thyroid (55 goitres, 16 adenomas and 15 malignancies) were compared with the clinical data, ultrasonographic appearances and the results of the fine needle biopsy of each patient to evaluate the role of ultrasonography alone and combined with guided biopsy in distinguishing patients with malignancies from patients without malignancies. The Authors suggest that ultrasonography alone cannot be used for distinguishing malignancies from non-malignancies in cold nodules of the thyroid; the combined use of the ultrasonographic appearances with guided biopsy offers a remarkable diagnostic gain in this field. In the Authors' case material the detection of a simple cyst by ultrasound always excluded the possibility of malignancy.

Teleradiology in Europe.

The new concept of teleradiology is centered on the consideration that it involves management of medical information rather than the simple transmission of diagnostic images from one location to another. Teleradiology must therefore be able to contribute to the seamless integration of the digital environment in which medical data are managed throughout and beyond the hospital, generating value added services for the patients as well as prospective economical benefits for the institution. In this perspective the evolution of telecommunication with the spectacular success of mobile telephony and Internet will play and increasingly important role, by allowing further development in the exchange of multimedia medical information on a regional as well as international level. However, new responsibilities are being given to the radiologists, who must take all necessary technical and organizational actions in order to avoid that the digital management of data may endanger the confidentiality and the integrity of patients' data.

Breast MR imaging screening in eight women proved or suspected to be carriers of BRCA1&2 gene mutations.

The aim of this study was to evaluate the efficacy of MR imaging for the early detection of breast tumor in women at high genetic risk compared to conventional strategies such as ultrasonography and mammography. This study included 8 women, 5 of which had undergone surgery for breast cancer. BRCA germ line mutations were detected in 7 women, one patient was enrolled for more than 50% probability to be carrier of BRCA mutation. RM imaging screening was negative in 7 patients and strongly indicative of a malignant lesion in one. The gold standard was surgery for the suspicious cases and follow-up with clinical examination and conventional imaging every six months for the others. MR imaging proved itself to be a reliable technique in familial breast cancer high risk women.