Diffusion MRI for rectal cancer staging: ADC measurements before and after ultrasonographic gel lumen distension.

OBJECTIVES: To compare Apparent Diffusion Coefficient (ADC) measurements in rectal neoplastic lesions before and after lumen distension obtained with sonography transmission gel. METHODS: From January 2014 to July 2016, 25 patients (average age 63.7, range 41-85, 18 males) were studied for pre-treatment rectal cancer staging using a 1.5T MRI. Diffusion MRI was obtained using echo-planar imaging with b=800 value; all patients were studied acquiring diffusion sequences with and without rectal lumen distension obtained using sonography transmission gel. In both diffusion sequences, two blinded readers calculated border ADC values and small ADC values, drawing regions of interest respectively along tumour borders and far from tumour borders. Mean ADC values among readers - for each type of ADC measurement - were compared using Wilcoxon matched pairs signed rank test. Correlation was assessed using Pearson analysis. RESULTS: Border ADC mean value for diffusion MR sequences without endorectal contrast was 1.122mm2/sec, with 95% Confidence Interval (CI)=1.02-1.22; using gel lumen distension, higher border ADC mean value of 1.269mm2/s (95% CI=1.16-1.38) was obtained. Wilcoxon matched pairs signed rank test revealed statistical difference (p<0.01); a strong Pearson correlation was reported, with r value of 0.69. Small-ADC mean value was 1.038mm2/s (95% CI=0.91-1.16) for diffusion sequences acquired without endorectal distension and 1.127mm2/s (95% CI=0.98-1.27) for diffusion sequences obtained after endorectal gel lumen distension. Wilcoxon analysis did not show statistical difference (p=0.13). A very strong positive correlation was observed, with r value of 0.81. CONCLUSIONS: ADC measurements are slightly higher using endorectal sonographic transmission gel; ROI should be traced far from tumour borders, to minimize gel filled-pixel along the interface between lumen and lesion. Further studies are needed to investigate better reliability of ADC in rectal cancer MRI using sonographic gel intraluminal distension.

Cystic pancreatic neoplasms: diagnosis and management emphasizing their imaging features.

The incidence of cystic pancreatic neoplasms increased in the past decade, due to the recent advances in multidetector computed tomography and magnetic resonance imaging; several pancreatic cysts are incidentally encountered during diagnostic exams performed for non-pancreatic diseases. Indeed, cystic pancreatic tumors are currently considered relatively rare, accounting for approximately 10% of all pancreatic neoplasms. Serous cystadenoma, mucinous cystadenoma, intraductal papillary mucinous neoplasms and solid-pseudopapillary tumor represent about 90% of all pancreatic primary cystic tumours. The non-optimal diagnostic preoperative accuracy in distinguishing benign from malignant cystic lesions ensures that up till now there are no well-defined guidelines regarding the management of cystic pancreatic neoplasms. Imaging findings often do not allow the diagnosis, because there is a considerable overlap among the cystic lesions; the best pre-operative characterization is obtained by the association of all diagnostic procedures available. For their different histology and behavior, cystic pancreatic neoplasms need to be managed according to various factors. In this review, the main elements necessary for their management are assessed--radiological features, tumour dimensions, patients' characteristics, the mode of clinical presentation and the associated oncologic markers. A multidisciplinary approach--including gastroenterologists, radiologists and surgeons--should be adopted in order to perform a differential diagnosis and a correct management.

Vascular cerebral anomalies associated with Septo-Optic Dysplasia. A case report.

We describe a case of Septo-Optic Dysplasia (SOD) characterized by the presence of anomalous cerebral vessels. In our young patient the classical features of SOD were associated with vascular anomalies including absence of the vein of Galen, right Rosenthal vein leading to the superior petrosal sinus, and anomalous origin of the anterior choroidal arteries. These findings have never been associated with SOD in the literature but their revelation supports the hypothesis of a vascular disruption as a possible cause of the SOD.

Multidetector CT Dentascan evaluation of bone regeneration obtained with deproteinised bovine graft in residual cavity after mandibular cyst enucleation.

PURPOSE: This study compared spontaneous bone healing and regeneration obtained with deproteinised bovine graft in residual cavities after mandibular cyst enucleation using computed tomography (CT) Dentascan. MATERIALS AND METHODS: Eighty patients with a radiological diagnosis of mandibular cyst underwent surgical enucleation. Patients were divided into a control group (spontaneous healing, 40 patients) and a test group (deproteinised bovine graft, 40 patients). All patients underwent follow-up CT Dentascan 12 months after the procedure. For each residual cavity, apical-coronal and mesial-distal distance, average pixel intensity and volume were calculated and results compared between two groups using the t test. RESULTS: The control group showed mean volume, apical-coronal and mesial-distal distance of 703.2 ± 185.3 mm(3), 28.6 ± 9.4 mm and 25 ± 2.84 mm, respectively. In the test group, values were 738.2 ± 189.2 mm(3), 27.5 ± 3.6 mm and 25.3 ± 2.97 mm, respectively. There was no statistically significant difference between groups. Average pixel intensity was 1,102.8 ± 124.3 in the test group and 624.9 ± 133.3 in the control group, with a significant difference between groups (p<0.0001). CONCLUSIONS: The significantly higher average pixel intensity observed in the test group demonstrates the cavalue of treatment with biomaterials to obtain earlier bone regeneration.

Endometrial carcinoma: MR staging and causes of error.

PURPOSE: This study was undertaken to prospectively determine the diagnostic capabilities of magnetic resonance (MR) imaging in detecting myometrial and cervical invasion and lymph node involvement in endometrial carcinoma and to identify the causes of errors in staging endometrial carcinoma. MATERIALS AND METHODS: Twenty consecutive patients with a histological diagnosis of endometrial carcinoma underwent preoperative MR imaging. MR findings were compared with surgical staging, considered as the standard of reference. RESULTS: In assessing myometrial invasion, MR imaging showed 70% accuracy, 80% sensitivity, 40% specificity, 80% positive predictive value (PPV), and 40% negative predictive value (NPV). In detecting cervical invasion, MR imaging had 95% accuracy, 100% sensitivity, 94.4% specificity, 66.7% PPV, and 100% NPV. In evaluating lymph node involvement, MR imaging showed 100% accuracy, sensitivity, specificity, PPV and NPV. Errors in evaluating myometrial invasion were caused by polypoid tumour, adenomyosis and leiomyomas, whereas those in evaluating cervical invasion were caused by dilatation and curettage. CONCLUSIONS: MR imaging is a reliable technique for preoperative evaluation of endometrial carcinoma. Its main limitation is differentiating between stage IA and IB carcinomas, which is not highly important for surgical planning. Cooperation between the gynaecologist and radiologist is mandatory to avoid staging errors.

Pelvic floor imaging: comparison between magnetic resonance imaging and conventional defecography in studying outlet obstruction syndrome.

PURPOSE: This study prospectively compared the diagnostic capabilities of magnetic resonance (MR) imaging with conventional defecography (CD) in outlet obstruction syndrome. MATERIALS AND METHODS: Nineteen consecutive patients with clinical symptoms of outlet obstruction underwent pelvic MR examination. The MR imaging protocol included static T2-weighted fast spin-echo (FSE) images in the sagittal, axial and coronal planes; dynamic midsagittal T2-weighted single-shot (SS)-FSE and fast imaging employing steady-state acquisition (FIESTA) cine images during contraction, rest, straining and defecation. MR images (including and then excluding the evacuation phase) were compared with CD, which is considered the reference standard. RESULTS: Comparison between CD and MR with evacuation phase (MRWEP) showed no significant differences in sphincter hypotonia, dyssynergia, rectocele or rectal prolapse and significant differences in descending perineum. Comparison between CD and MR without evacuation phase (MRWOEP) showed no significant differences in sphincter hypotonia, dyssynergia or enterocele but significant differences in rectocele, rectal prolapse and descending perineum. Comparison between MRWEP and MRWOEP showed no significant differences in sphincter hypotonia, dyssynergia, enterocele or descending perineum but significant differences in rectocele, rectal prolapse, peritoneocele, cervical cystoptosis and hysteroptosis. CONCLUSIONS: MR imaging provides morphological and functional study of pelvic floor structures and may offer an imaging tool complementary to CD in multicompartment evaluation of the pelvis. An evacuation phase is mandatory.

Magnetic resonance with diffusion-weighted imaging in the evaluation of transplanted kidneys: updating results in 35 patients.

BACKGROUND: We compared values of apparent diffusion coefficient (ADC) with renal function indices among a population of kidney transplant recipients who underwent magnetic resonance with diffusion-weighted imaging (DWI) of their grafts. MATERIALS AND METHODS: Thirty-five patients with right iliac transplanted kidneys were studied using 1.5-T magnetic resonance. Diffusion echo-planar sequences with several b-values were acquired to investigate transplanted grafts. Patients were divided into 3 groups according to their creatinine clearances; Group A, clearance >60 mL/min; Group B, clearance >30 and ≤60 mL/min; and Group C, clearance ≤30 mL/min. ADC values between groups were compared using Mann-Whitney U test. Receiver operating characteristic (ROC) curves were used to predict the normal function (Group A) versus renal failure cohorts (Group C). RESULTS: Comparing mean values of ADC between Group A and Group C patients, we observed a significant difference (P = .0003) with higher ADC values among patients with a normal creatinine clearance (>60 mL/min). Comparing Groups B and C did not show a significant difference (P = .05); nor did Group A and Group B reveal a significant difference (P = .38). To predict normal clearance values, the Group A ROC curve showed an area under curve (AUC) of 0.780 with a sensitivity of 92.3% and a specificity of 68.2% at a threshold ADC value of ≥2.08 × 10(-3) mm(2)/sec. In the prediction of low clearance values, the Group C ROC curve showed an AUC of 0.846 with a sensitivity of 83.3% and a specificity of 82.6% using a threshold ADC value of ≤2.07 × 10(-3) mm(2)/sec. CONCLUSIONS: Updating our experience among 35 patients, DWI was confirmed to be a promising noninvasive tool to assess renal function; an ADC ≥2.08 × 10(-3) mm(2)/sec may be used as a threshold to predict a normal clearance. However, an overlap of ADC values between groups is a limit.

E-learning in radiology: an Italian multicentre experience.

OBJECTIVE: The aim of this study was to design, deliver and evaluate an e-learning teaching programme for post-graduate radiodiagnostics training that would involve various post-graduate schools throughout Italy. MATERIALS AND METHODS: All of the Directors of Italian post-graduate schools of radiodiagnostics were sent an e-mail on 27 September 2010 informing them of our willingness to set up an e-learning project for the academic year 2010-2011 in the form of single-subject teaching seminars. The proposed subjects were the semeiotics of the various organs and apparatuses in the context of "Urgent/Emergency Pathology". After having received registrations, a calendar of lessons was planned to be held between 10 November 2010 and 12 October 2011. The validity of the project was tested by means of a multiple-choice questionnaire covering the technical and didactic quality of the entire project, to be completed by the students. RESULTS: Fifty-one percent of the universities in Italy participated in the project: Trieste, Udine, Verona, Milan-Bicocca, Novara, Varese, Genoa, Sassari, Rome Campus, the Catholic University of Rome, Chieti, Foggia, Catania, Modena, Florence, Palermo, Bologna, Pavia, Parma and Ferrara. The lessons were attended by a total of 10,261 post-graduate medical students, for an average of 513.1 students per lesson. Seventy percent of the students judged the didactic content "excellent", 25% "good", and 5% "satisfactory"; none said it was unsatisfactory. In terms of visual quality (particularly the details of the radiological images proposed in the form of slides and/or video clips), 73% judged it "excellent", 20% "good", 6% "satisfactory", and 1% "poor". The audio quality was judged "excellent" by 71%, "good" by 22%, "satisfactory" by 6% and "poor" by 1%. In relation to judgement of audio and video quality, it has to be underlined that this was greatly affected by the hardware/software configuration and the band speed and technology of the Internet connection. CONCLUSIONS: Technological evolution is overcoming all barriers, and technology is also having a positive impact on the approach to teaching. Our multicentre teaching experience merits the following considerations: the quality of the teaching product was certified by the students' judgements of its didactic content and the quality of reception; the economic cost of the teaching had a minimal impact on the post-graduate schools (€ 18 per lesson). In terms of breaking down national barriers, it is to be hoped that the coordination and integration of diagnostic imaging e-learning projects, with the participation of post-graduate schools in different European countries, can be developed not only in a spirit of "cultural sharing" and the exchange of teaching experiences.

Guillain-barré syndrome associated with acute onset bilateral facial nerve palsies. A case report and literature review.

Guillain-Barré syndrome is a post infectious, immune-mediated disease with cranial nerve involvement observed in 45-75% of patients. Bilateral facial nerve palsy is rather uncommon and occurs in 0.3% to 2% of all facial palsies. We describe a rare case of a 29-year-old man with bilateral facial palsy caused by a Guillain-Barré syndrome with an unusual onset and progression of neurological symptoms. Neuroradiological findings in our patient are described and compared with data from literature on bilateral facial palsies to make differential diagnosis easier for neuroradiologists.

Magnetic resonance with diffusion-weighted imaging in the evaluation of transplanted kidneys: preliminary findings.

BACKGROUND: The aim of this study was to compare values of apparent diffusion coefficient (ADC) and diffusion (D) with renal function indexes, in a population of kidney transplant recipients who underwent magnetic resonance with diffusion-weighted imaging (DWI) of the transplanted graft. MATERIALS AND METHODS: We studied 21 patients using a 1.5-Tesla magnetic resonance; DWI sequences were acquired with several b-values. Patients were divided into 3 groups by their creatinine clearance values: group A, clearance >60 mL/min; group B, clearance >30 and ≤60 mL/min; and group C, clearance ≤30 mL/min. ADCs values between groups were compared using the Mann-Whitney U test. Receiver operating characteristic (ROC) curves were created for prediction of normal renal function (group A) and renal failure (group C). RESULTS: Comparing mean values of ADC between groups A and C, we observed a difference (P=0.0012), with higher values in group A. Regarding mean values of D, we observed a difference between groups A and C (P=0.022). In the comparison between contiguous groups, we observed no difference for ADC and D values. In the prediction of normal clearance values (group A), ROC curve showed an area under curve (AUC) of 0.861, with a sensitivity of 88.89% and specificity of 75% using a threshold ADC value ≥2.1 × 10(-3) mm(2)/sec. For prediction of normal clearance values (group A), ROC curve showed an AUC of 0.787, with a sensitivity of 77.8% and specificity of 83.3% using a threshold D value ≥2.3 × 10(-3) mm(2)/sec. CONCLUSION: Although studies with a larger number of patients are needed, DWI represents a promising tool for noninvasive assessment of renal function. An ADC ≥ 2.1 × 10(-3) mm(2)/sec and a D ≥ 2.3 × 10(-3) mm(2)/sec may be used as a threshold for predicting normal clearance.

E-learning in radiology: Italian multicentre experience.

PURPOSE: The aim of our work was to design, implement and evaluate an e-learning programme in favour of trainee radiologists enrolled at the many specialty schools located throughout Italy, in the spirit of "sharing culture". MATERIALS AND METHODS: Once a common educational programme and time slot had been identified and planned, the programme was delivered via Internet-based video conferencing once a week for 2-h lectures. Each lecture was followed by interaction between the teaching staff and trainees at the individual sites. The universities involved were Trieste, Udine, Verona, Milano Bicocca, Novara, Varese, Genova, Sassari, Rome "Campus", Rome "Cattolica", Chieti, Foggia, Catania, Modena and Firenze. The University of Rome "Cattolica" participated in the project with two locations: Rome "Policlinico Gemelli" and Rome "Cattolica Campus of Campobasso". RESULTS: Eighteen lectures were conducted, for a total of 36 h. "Transient" connection interruption occurred 13 times for a total of 33 min over 2,160 min of lessons. Video quality and, in particular, details of radiological images shown in slides or moving pictures, were rated as very good by 71% of trainees, good by 24% and satisfactory by 4.5%; no one gave a rating of unsatisfactory. CONCLUSIONS: Based on our experience, whereas e-learning in radiology has become established and compulsory, there is the need for legislation that on the one hand protects online teaching activity and on the other allows study and continuing medical education (CME) credits to be recognised.

Magnetic resonance cholangiopancreatography and contrast-enhanced magnetic resonance cholangiopancreatography versus endoscopic ultrasonography in the diagnosis of extrahepatic biliary pathology.

PURPOSE: This study compared the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) and endoscopic ultrasonography (EUS) in evaluating the cause of extrahepatic bile duct dilatation. MATERIALS AND METHODS: Forty-five patients (26 men, mean age 57 years) with extrahepatic biliary dilatation, as shown by transabdominal ultrasound, with or without elevated biliary and pancreatic serum indices, were prospectively studied with MRCP and EUS between September 2007 and October 2008. EUS and MRCP were performed within no more than 24 h of each other to reduce the possibility of changes due to stone migration. Image analysis was carried out in a double-blind fashion. RESULTS: MRCP had 88.9% diagnostic accuracy, 91.9% sensitivity and 75% specificity, with 94.4% positive predictive value and 66.7% negative predictive value. EUS had 93.3% diagnostic accuracy, 97.3% sensitivity and 75% specificity; the positive and negative predictive values were 94.7% and 85.7%, respectively. CONCLUSIONS: MRCP and EUS do not show significant statistical differences in diagnostic accuracy. MRCP is an accurate, noninvasive modality in the study of extrahepatic biliary pathology. EUS is especially reliable in patients with extrahepatic biliary obstruction caused by endoluminal sludge.

Evaluation of the biliary and pancreatic system with 2D SSFSE, breathhold 3D FRFSE and respiratory-triggered 3D FRFSE sequences.

PURPOSE: The authors compared biliary and pancreatic imaging obtained through 2D single-shot fast spin-echo (SSFSE), breath-hold 3D fast recovery fast spin-echo (FRFSE) and respiratory-triggered 3D FRFSE sequences. MATERIALS AND METHODS: A total of 106 magnetic resonance cholangiopancreatography (MRCP) examinations performed between December 2007 and September 2008 were evaluated with a comparison of 2D SSFSE (thin section and thick slab), breath-hold 3D FRFSE and respiratory-triggered 3D FRFSE sequences. The biliary tract was divided into seven segments: right hepatic duct, left hepatic duct, common hepatic duct, cystic duct, common bile duct, cystic duct junction and biliary-pancreatic confluence. The main pancreatic duct was divided into three segments (head, body and tail). Visualisation of biliary variants was also compared. Two blinded radiologists evaluated segment visibility using a quantitative scale. The Student's t test for paired samples was used for statistical analysis. RESULTS: Compared with 2D SSFSE, respiratory-triggered 3D FRFSE sequences showed better visibility of the right hepatic duct (p=0.0277), the cystic duct (p=0.0081), the cystic duct junction (p=0.0010), the biliary-pancreatic confluence (p=0.0334) and biliary variants (p=0.0198). In the comparison between breath-hold 3D FRFSE and 2D SSFSE, a significant statistical difference was found in visualisation of the cystic duct (p=0.027), the cystic duct junction (p=0.020), the biliary-pancreatic confluence (p=0.0338) and biliary variants (p=0.0311). CONCLUSIONS: Three-dimensional FRFSE offers a significant benefit over conventional 2D imaging.

Power Doppler ultrasonography with time-signal intensity curves in monitoring hepatocellular carcinoma and liver metastases after intralesional therapy.

PURPOSE: Analysis of time-intensity curves allows evaluation of the patterns of lesion enhancement before and after treatment. The aim of this study was to evaluate the diagnostic accuracy of time-intensity curves in monitoring intralesional therapy of focal hepatic lesions. MATERIALS AND METHODS: Twenty patients underwent intralesional therapy with either radiofrequency thermal ablation or percutaneous ethanol injection. Contrast-enhanced power Doppler ultrasound with analysis of time-intensity curves was performed one day before and one day after treatment. Targeted biopsy was then obtained to confirm the imaging findings. RESULTS: Before treatment, all lesions showed time-intensity curves characterised by high peaks of signal intensity and plateaus. Complete tumour necrosis, confirmed by targeted biopsy, was observed in patients showing no intralesional flow signals and time-intensity curves with low peak of signal intensity and absence of plateau after treatment. Biopsy confirmed the presence of residual neoplastic tissue in one patient exhibiting perilesional vascularity, absence of intralesional flow signals, and a time-intensity curve with high peak of signal intensity and plateau. CONCLUSIONS: According to our findings, time-intensity curves characterised by high peak of signal intensity and plateau might reflect the presence of perilesional or intralesional neoplastic tissue and provide important information on the effectiveness of the treatment.

Poly-L-lactic acid - hydroxyapatite (PLLA-HA) bioabsorbable interference screws for tibial graft fixation in anterior cruciate ligament (ACL) reconstruction surgery: MR evaluation of osteointegration and degradation features.

PURPOSE: We evaluated with magnetic resonance imaging (MRI) the degradation and osteointegration features of a new type of bioabsorbable interference (BioRCI) screw composed of poly-L-lactic acid and hydroxyapatite (PLLA-HA) used for tibial graft fixation in anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: Thirty-one patients underwent arthroscopic surgery for ACL reconstruction using doubled gracilis and semitendinosus tendons fixed to the tibial tunnel with PLLA-HA (BioRCI-HA) screws. Two groups of patients were evaluated, one group 10-13 months after surgery and the other after 30-40 months. The standard knee ligament evaluation form of the International Knee Documentation Committee (IKDC) was used for clinical assessment and MRI for the radiological assessment. RESULTS: MRI after 10-13 months revealed findings referable to healing and integration of the bone-graft-screw system, findings that disappeared at later follow-up examinations. The BioRCI-HA screw remained constantly visible in all patients, although with changes in signal intensity over time. CONCLUSIONS: BioRCI-HA screws allow adequate primary stability and superior osteoconduction and biocompatibility in comparison with plain PLLA screws. The absence of ferromagnetic artefacts allows accurate MRI follow-up and adequate evaluation of ligament synovialisation, screw degradation and graft osteointegration.

Contrast-enhanced colour-Doppler sonography versus pH-metry in the diagnosis of gastro-oesophageal reflux in children.

PURPOSE: The aim of this study was to evaluate the accuracy of contrast-enhanced colour-Doppler ultrasound (CDUS) in the diagnosis of gastro-oesophageal reflux in children. MATERIALS AND METHODS: One hundred and twenty children (68 boys and 52 girls aged between 1 month and two years) with a clinical suspicion of gastro-oesophageal reflux (postprandial vomiting, weight loss, failure to thrive, anaemia, night-time coughing and crying, regurgitation, etc.) were studied by contrast-enhanced CDUS and subsequently by 24-hour pH-metry. Results of the two techniques were compared using the McNemar test. RESULTS: Gastro-oesophageal reflux was detected on CDUS in 84 patients and with 24-h pH-metry in 86. In all cases of reflux, CDUS visualised the passage of contrast material from the stomach into the abdominal and middle and distal third of the thoracic oesophagus, enabling assessment of the segment of oesophagus involved by the reflux. Compared with pH-metry, CDUS had a sensitivity of 98% (p<0.0001 with McNemar's test). CONCLUSIONS: In consideration of the results obtained and particularly of the low level of invasiveness, contrast-enhanced CDUS could be used to monitor children undergoing medical or surgical treatment for the complications of gastro-oesophageal reflux disease.

Jaw osteonecrosis in patients treated with bisphosphonates: MDCT evaluation.

PURPOSE: This study was done to evaluate the use of multidetector computed tomography (MDCT) in the evaluation of jaw osteonecrosis, a recently described medical entity in patients receiving long-term intravenous or oral bisphosphonates, and to help radiologists recognise it to enable early diagnosis and appropriate management. MATERIAL AND METHODS: Thirty-eight patients with a history of neoplasm (breast, prostate, multiple myeloma, pancreas) or osteoporosis and bisphosphonate use and recent oral surgery who presented with pain in the mouth and temporomandibular joints, soft tissue infections, altered taste and numbness were examined with MDCT. RESULTS: In all patients, MDCT revealed the presence of structural bony alterations referable to osteonecrosis associated with orosinusal fistula in four of them and bony intraoral spicules in 25. CONCLUSIONS: Jaw osteonecrosis is an established medical entity discovered in patients who have undergone treatment with bisphosphonates and dental extraction or other oral surgery. MDCT with multiplanar (MPR), volume rendering (VR) and three-dimensional (3D) reconstructions allows accurate assessment of affected bone structures, enabling early diagnosis and suitable treatment planning. Radiologists should be aware of the risk of osteonecrosis in patients treated with bisphosphonates and be able to distinguish it from other bone diseases (osteomyelitis and osteoradionecrosis) with which it enters the differential diagnosis.

Functional study of the transplanted kidney with power Doppler US and time/intensity curves.

PURPOSE: Power Doppler ultrasound (US) with time-intensity curves was used to study renal graft function both in the absence of disease and with complications (acute tubular necrosis and chronic rejection) in an attempt to identify pathognomonic patterns. Time-intensity curves allow representation of the kidneys' wash-in and wash-out phases after intravenous administration of sonographic contrast material. MATERIALS AND METHODS: Fifty-six asymptomatic renal transplant patients (36 men and 20 women), 19 of whom had altered creatinine clearance levels, were studied by power Doppler US with time-intensity curves followed by biopsy. Ten asymptomatic patients with normal creatinine clearance levels were used as controls. RESULTS: Time-intensity curve analysis enabled identification of three groups of patients: group A, consisting of 27 patients showing peak enhancement between 50 and 65 s from intravenous administration of contrast material; group B, consisting of 16 patients with peak enhancement between 135 and 235 s; group C, consisting of three patients with peak enhancement between 100 and 130 s. CONCLUSIONS: Data showed significant variations according to renal graft function (no abnormality, acute tubular necrosis or chronic rejection). Although confirmation by a larger series is required, our findings appear to indicate pathognomonic patterns in patients with chronic rejection and acute tubular necrosis.

Double-contrast MRI (DC-MRI) in the study of the cirrhotic liver: utility of administering Gd-DTPA as a complement to examinations in which SPIO liver uptake and distribution alterations (SPIO-LUDA) are present and in the identification and characterisation of focal lesions.

PURPOSE: The aim of this study was to compare the performance of double-contrast magnetic resonance imaging (DC-MRI) with the sequential use of superparamagnetic iron oxide (SPIO) and gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) contrast agents compared with unenhanced MRI and SPIO-enhanced MRI (SPIO-MRI) in the study of the cirrhotic liver. Special attention was paid to cases in which alterations of liver uptake and distribution of the SPIO contrast medium [SPIO-liver uptake and distribution alterations (SPIO-LUDA)] could lead to diagnostic errors at SPIO-MRI. MATERIALS AND METHODS: We used DC-MRI to study 67 patients suffering from hepatic cirrhosis and on a waiting list for liver transplant. The study was performed with a 1.5-Tesla device and characterised by three phases: the first phase without contrast material (unenhanced MRI), the second after the administration of ferumoxides (SPIO-MRI), and the third, a double-contrast study following the injection of a bolus of paramagnetic contrast material (DC-MRI). The sensitivity of unenhanced MRI, SPIO-MRI and DC-MRI in identifying and characterising hepatic focal lesions was assessed, together with the diagnostic increment of one technique with respect to the others. The gold standard was histological confirmation in 38 cases and clinical-radiological follow-up in all cases. Liver function, kidney function, blood tests and urinalysis were performed in all patients 24-48 h before and after the MRI examination. RESULTS: In 14/67 cases (20.8%), SPIO-LUDA were present, which posed a limitation to the SPIO-MRI examination. Focal lesions were absent in 44 patients, and the action of the ferumoxides was reduced by the presence of SPIO-LUDA in nine cases. There were five cases of confluent fibrosis, two of decompensated cirrhosis, one of vascular thrombosis, and one of scarring in a patient who had undergone hepatic resection for hepatocellular carcinoma (HCC). In all these cases, completion of the MR examination with the DC technique clarified the MR picture, confirming the absence of focal lesions. Twenty-three patients had a total of 68 lesions, which consisted of 37 dysplastic nodules (DN), 19 HCC nodules, two relapses of HCC following chemoembolisation, two HCC associated with portal thrombosis, one cancer-cirrhosis, two angiomas and five small cysts. SPIO-LUDA were present in five patients, thus limiting the identification, characterisation or assessment of the real size of the lesions. SPIO-LUDA were the result of vascular thrombosis in one case and fibrosis in four cases. In all of these cases, DC-MRI proved useful for diagnosis. The sensitivity of unenhanced MRI, SPIO-MRI and DC-MRI for lesion detection was 57.3%, 67.6% and 75%, respectively. The results obtained in the characterisation of the lesions were 20.5%, 63.2% and 73.5% for unenhanced MRI, SPIO-MRI and DC-MRI, respectively. The diagnostic increment of SPIO-MRI over unenhanced MRI for lesion identification and characterisation was 9% and 42.7%, respectively, whereas the diagnostic increment of DC-MRI over SPIO-MRI was 7.4% and 10.3%, respectively. CONCLUSIONS: In our study, the combined use of two contrast agents, negative and positive, provided greater diagnostic confidence and caused no side effects in the patients.

Endovascular treatment of pulmonary and cerebral arteriovenous malformations in patients affected by hereditary haemorrhagic teleangiectasia.

Hereditary Haemorrhagic Teleangiectasia (HHT) is a vascular disorder of angiogenesis transmitted in an autosomal dominant pattern, characterised by heterogeneity in clinical manifestations. One of the most important organ involved is lung, including pulmonary arteriovenous malformations (PAVM). PAVM occur in 20 to 30% of the HHT population and recently are considered a marker of disease. PAVM are direct artery-to-vein connections with low pressure and without an interveining capillary bed. PAVM are classified as simple (supplied by one feeding artery) or complex (receiving blood supply from two or more feeding artery). According to the international reports, treatment it's recommendable for all PAVM with feeding vessels 3mm or larger, in order to reduce the risk of cerebral ischaemia and neurologic manifestations frequently attributed to paradoxical embolisation. Transcatheter embolotherapy of PAVM is a form of treatment based on occlusion of the feeding artery to a PAVM by using platinum coils or detachable balloons. The technique of coil embolisation involves the exact localisation of PAVM by pulmonary angiography followed by superselective percutaneous caheterisation of feeding artery obtained by using a dedicated 7F guiding catheter, which coaxially allocates a 5F hydrophilic catheter advanced in order to perform both superselective angiography of feeding artery and embolisation itself. Inside the 5F catheter the platinum coils are advanced using a .035'' guide-wire and released until an optimal occlusion of feeding artery is achieved. At the end of the procedure angiographic control is performed in order to verify the occlusion of feeding artery. The use of platinum coils is preferable over detachable balloons when feeding artery are greater than 7 mm in diameter and have irregular anatomical configuration. On the other hand, the principal advantage of using detachable balloons is that the balloon itself can be deflated and repositioned if necessary. Transcatheter embolotherapy is technically safe and clinically effective and may represent the primary choice of treatment in HHT patients. On the other hand the most common complications of this treatment (pleurisy and air embolism) can be prevented by using some tips during the embolisation procedure like "anchor technique," "scaffold technique" and "balloon assisted technique." Cerebral arteriovenous malformations (CAVM) are present in 10-20% of patients with HHT and multiple in 50% of cases. Cortical surface is the most frequent localisation. Angiography is needed to diagnose all CAVM and to clarify the angioarchitecture of the lesion. In HHT CAVM are usually either micro-AVM, with a nidus not bigger than 1 cm, or small AVM, with a nidus between 1 and 3 cm. Quite frequently there are lesions characterised by arteriovenous fistulas. In the three patterns of CAVM usually found in HHT, small AVM are the most risky for bleeding although the risk is lower than that associated with sporadic ones. It is estimated from 0.38 to 0.69% per year in spite of the general incidence of bleeding in sporadic CAVM that ranges from 2 to 4% per year. In HHT patients, at present, the precise indications and timing of treatment are not established. Trend is to treat small AVM and AVF and to follow-up micro-AVM with MRI and angiography. As for sporadic CAVM, treatment of small AVM is usually referred to stereotactic radiosurgery. Endovascular embolisation is proposable if the lesion is easily reachable by microcatheterism and the position of the microcatheter is safe. Glue is used for embolisation and the technique is briefly discussed.