Spinal cord microstructure integrating phase-sensitive inversion recovery and diffusional kurtosis imaging.

PURPOSE: The aim of this prospective study was to determine the feasibility in terms of repeatability and reproducibility of diffusional kurtosis imaging (DKI) for microstructural assessment of the normal cervical spinal cord (cSC) using a phase-sensitive inversion recovery (PSIR) sequence as the anatomical reference for accurately defining white-matter (WM) and gray-matter (GM) regions of interests (ROIs). METHODS: Thirteen young healthy subjects were enrolled to undergo DKI and PSIR sequences in the cSC. The repeatability and reproducibility of kurtosis metrics and fractional anisotropy (FA) were calculated in GM, WM, and cerebral-spinal-fluid (CSF) ROIs drawn by two independent readers on PSIR images of three different levels (C1-C4). The presence of statistically significant differences in DKI metrics for levels, ROIs (GM, WM, and CSF) repeatability, reproducibility, and inter-reader agreement was evaluated. RESULTS: Intra-class correlation coefficients between the two readers ranged from good to excellent (0.75 to 0.90). The inferior level consistently had the highest concordance. The lower values of scan-rescan variability for all DKI parameters were found for the inferior level. Statistically significant differences in kurtosis values were not found in the lateral white-matter bundles of the spinal cord. CONCLUSION: The integration of DKI and PSIR sequences in a clinical MR acquisition to explore the regional microstructure of the cSC in healthy subjects is feasible, and the results obtainable are reproducible. Further investigation will be required to verify the possibility to translate this method to a clinical setting to study patients with SC involvement especially in the absence of MRI abnormalities on standard sequences.

Malpractice claims in interventional radiology: frequency, characteristics and protective measures.

PURPOSE: The use of interventional radiology procedures has considerably increased in recent years, as has the number of related medicolegal litigations. This study aimed to highlight the problems underlying malpractice claims in interventional radiology and to assess the importance of the informed consent process. MATERIALS AND METHODS: The authors examined all insurance claims relating to presumed errors in interventional radiology filed by radiologists over a period of 14 years after isolating them from the insurance database of all radiologists registered with the Italian Society of Medical Radiology (SIRM) between 1 January1993 and 31 December 2006. RESULTS: In the period considered, 98 malpractice claims were filed against radiologists who had performed interventional radiology procedures. In 21 cases (21.4%), the event had caused the patient's death. In >80% of cases, the event occurred in a public facility. The risk of a malpractice claim for a radiologist practising interventional procedures is 47 per 1,000, which corresponds to one malpractice claim for each 231 years of activity. DISCUSSION: Interventional radiology, a discipline with a biological risk profile similar to that of surgery, exposes practitioners to a high risk of medicolegal litigation both because of problems intrinsic to the techniques used and because of the need to operate on severely ill patients with compromised clinical status. CONCLUSIONS: Litigation prevention largely depends on both reducing the rate of medical error and providing the patient with correct and coherent information. Adopting good radiological practices, scrupulous review of procedures and efficiency of the instruments used and audit of organisational and management processes are all factors that can help reduce the likelihood of error. Improving communication techniques while safeguarding the patient's right to autonomy also implies adopting clear and rigorous processes for obtaining the patient's informed consent to the medical procedure.

Endoleaks after endovascular repair of abdominal aortic aneurysm: value of CEUS.

Endovascular repair (EVAR) is playing an increasingly role in the treatment of abdominal aortic aneurysm. A successful procedure depends on the complete sealing of the aneurysm sac from blood flow to achieve general pressure relief and avoid aneurysm rupture, with a shrinkage of the aneurysm sac. The most common complication of EVAR is endoleak that is the persistence of perigraft flow within the aneurysm sac, which has to be considered the major cause of enlargement and rupture of the aneurysm, and the main indication for surgical late conversion. For this reason, strict surveillance of these patients is mandatory for the early detection of endoleaks and the preferred method of follow-up is represented by CT angiography. However, CTA has limitations. The investigation is repeated several times, making radiation exposure a necessary concern. Therefore, it would be useful to have another reliable diagnostic examination during follow-up. Color duplex ultrasound is non-invasive, does not use radiation or contrast medium, is less expensive, easy to perform and widely available. However, this technique obtained poor results in terms of sensitivity in the detection of endoleaks. In the last years, the introduction of ultrasound contrast agents and contrast-specific imaging has, however, rekindled interest in this modality and its potential for replacing of CTA in routine surveillance. The purpose of this review is to highlight the diagnostic value of CEUS in the post-EVAR endoleaks detection.

Prognostic value of pulmonary blood volume by first-pass contrast-enhanced CMR in heart failure outpatients: the PROVE-HF study.

Aims: Pulmonary blood volume (PBV) is a novel clinical application of cardiovascular magnetic resonance (CMR) imaging for the quantitative grading of haemodynamic congestion. In this study, we aimed to assess the prognostic value of PBV in a cohort of outpatients with chronic heart failure (HF). Methods and results: One hundred and twelve consecutive patients (91 men, 67 ± 12 years) and 53 age- and sex-matched healthy controls underwent echocardiography and contrast-enhanced CMR. PBV was calculated as the product of stroke volume and the number of cardiac cycles for an intravenous bolus of gadolinium contrast to pass through the pulmonary circulation determined by first-pass perfusion imaging. Compared with healthy controls, HF outpatients showed significantly higher PBV index (PBVI, 308 ± 92 vs. 373 ± 175, mL/m2, P = 0.012) and pulmonary transit time (6.8 ± 1.8 vs. 9.5 ± 4 s, P ≤0.001). During a median follow-up of 26 ± 17 months, 27 patients (24%) reached the composite end point of cardiovascular death, HF hospitalization, or sustained ventricular arrhythmias/appropriate implantable cardioverter-defibrillator intervention. Using a cut-off point of PBVI >492 mL/m2, corresponding to two standard deviations above the mean of healthy controls, event-free survival was significantly lower in patients with higher PBVI (P < 0.001). At multivariable-adjusted Cox regression analysis, PBVI was an independent predictor of the composite cardiovascular end point (per 10% increase hazard ratio 1.31, 95% confidence interval: 1.02-1.69, P = 0.03). Conclusions: PBVI is a novel application of perfusion CMR potentially useful to quantitatively determine haemodynamic congestion as a surrogate marker of left ventricular diastolic dysfunction. PBVI might prove to be helpful in stratifying the prognosis of asymptomatic or mildly symptomatic patients with left ventricular dysfunction.

Comparing 3T T1-weighted sequences in identifying hyperintense punctate lesions in preterm neonates.

BACKGROUND AND PURPOSE: The loss of contrast on T1-weighted MR images at 3T may affect the detection of hyperintense punctate lesions indicative of periventricular leukomalacia in preterm neonates. The aim of the present study was to determine which 3T T1-weighted sequence identified the highest number of hyperintense punctate lesions and to explore the relationship between the number of hyperintense punctate lesions and clinical outcome. MATERIALS AND METHODS: The presence of hyperintense punctate lesions was retrospectively evaluated in 200 consecutive preterm neonates on 4 axial T1-weighted sequences: 3-mm inversion recovery and spin-echo and 1- and 3-mm reformatted 3D-fast-field echo. Statistically significant differences in the number of hyperintense punctate lesions were evaluated by using a linear mixed-model analysis. Logistic regression analysis was used to assess the relation between the number of hyperintense punctate lesions and neuromotor outcome at 3 months. RESULTS: Thirty-one neonates had at least 1 hyperintense punctate lesion indicative of periventricular leukomalacia in at least 1 of the 4 sequences. The 1-mm axial reformatted 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions (P < .001). No statistically significant differences were found among the 3-mm T1-weighted sequences. The greater number of hyperintense punctate lesions detected by the 1-mm reformatted T1 3D-fast-field echo sequence in the central region of the brain was associated with a worse clinical outcome. CONCLUSIONS: At 3T, the 1-mm axial reformatted T1 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions in the central region of preterm neonate brains, and this number was associated with neuromotor outcome.

Advanced carcinoma of the cervix treated by continuous pelvic arterial infusion with cytostatics and radiation therapy.

Regional chemotherapy by infusion of cytostatic drugs (methotrexate and adriamycin) into the hypogastric arteries has been used in 25 cases of advanced carcinoma of the cervix (IIIB and IV stage). A method for the percutaneous introduction of catheters into these arteries and their permanence for a period of time of 8-12 days is described. After chemotherapy there was such a satisfactory reduction in size of the tumour that patients could then be treated with radiotherapy and/or surgery.

Therapeutic embolization of renal artery to control severe hypertension due to renal trauma.

In a young patient with a post-traumatic renal hematoma, severe systemic hypertension, secondary to the activation of the renin-angiotensin axis, developed. Because of persistent hypertension, after 3 months of drug therapy, selective percutaneous embolization of the damaged vessels was performed. One year after procedure, the patient is normotensive without drugs.

Treatment of intraosseous arteriovenous fistulas of the extremities.

Intraosseous arteriovenous fistulas of the extremities are rare malformations frequently associated with severe systemic hemodynamic alterations. In many cases, it is quite difficult to eliminate these anomalous vascular structures, but the possibilities for successful treatment are much greater when surgery is combined with interventional radiology. Selective embolization of the malformed vessels can be produced with a variety of agents that are injected into afferent arteries, via percutaneous puncture or through direct surgical access. The intraosseous portion of the fistula should be resected at the time of embolization or later. The authors describe the successful treatment of three patients having intraosseous arteriovenous fistulas of the upper extremities, who have had follow-up for 2 to 10 years.

Transvenous sclerotherapy of the gonadal veins for treatment of varicocele: long-term results.

Percutaneous occlusion of the spermatic vein has been performed on 136 consecutive patients with varicocele scroti during the last six years. The authors report their long-term results on the first 119 cases to have a follow-up of at least six months. Occlusion of the insufficient gonadal vein is induced by the selective transcatheter injection of sclerosing agent with local anesthesia. Their patients are always evaluated before and after the procedure by Doppler examination. A spermiogram is done before the procedure and after six months. In this series they registered only 4 recurrences with no major complications.

Carcinoma of the pancreatic head area. Diagnostic imaging. Direct cholangiography: PTC.

The use of Chiba needle and a carefully performed procedure make percutaneous transhepatic cholangiography (PTC) highly diagnostic, with a low incidence of complications. However, because of their anatomy, visualization of pancreatic ducts, mandatory for an accurate diagnostic approach to the carcinomas of the pancreatic head area is impossible and thus this limits the diagnostic indications for PTC. At present it is performed in case of failure of endoscopic retrograde cholangiography (ERCP) or in view of interventional maneuvers. In carcinomas of the pancreatic head area PTC pattern is characterized by a more or less tight stenosis of the distal common bile duct with upward dilatation of biliary tree. The morphological features, the site and extent of stenosis usually permit a differential diagnosis between malignancies and benign forms (pancreatitis) while for definitive differentiation of cholangiocarcinoma from carcinoma of the pancreatic head infiltrating the common bile duct or from ampullary carcinoma, PTC should be combined with other imaging procedures.

Interventional radiology in the treatment of pulmonary embolism.

Percutaneous therapy of pulmonary embolism is performed by local administration of thrombolytic agents or by mechanical canalization. The latter is achieved by fragmentation of the embolus with angiographic catheters, or by aspiration or fragmentation of the thrombus with dedicated devices. The pharmacologic basis of locoregional administration of thrombolytic agents, as in the treatment of deep vein thrombosis, is the possibility of reaching a higher concentration of the drug at the level of the embolus by decreasing the activity of systemic fibrinolysis, thus lowering the incidence of hemorrhagic complications. In recent years, locoregional thrombolytic therapy has been used only combined with mechanical canalization. The easiest way is direct fragmentation of the embolus with an angiographic catheter. The system of aspiration of pulmonary emboli, experimented by Greenfield is based on the use of a flexible catheter the tip of which is equipped with a plastic radiopaque cup. Recently, several rotating devices have been designed. Some have already been used for the peripheral arterial system, others are specific for the venous system (Schmitz-Rode-Gunther device). The clinical effectiveness of these devices is however still to be assessed. Other non conventional possibilities for the mechanical canalization of pulmonary arterial system are represented by metal stents and angioplasty with balloon catheters. At present, interventional radiologic procedures represent an additional tool in the medical or surgical therapy of severe pulmonary embolism, when it is contraindicated or ineffective.

The role of interventional radiology in the treatment of the diabetic foot.

Although the pathologic features of arterial disease in diabetes do not differ from those of simple atheromatous lesions, the plurisegmental involvement, the predominant subpopliteal location of lesions and the association with impaired cardiac and renal function in these patients imply peculiar problems in the selection of an adequate therapy. At present, in interventional radiology a number of procedures are available for intravascular therapy (angioplasty, stent, locoregional fibrinolisis, mechanical atherectomy), particularly suitable for diabetics who are affected by multisystem impairment. These procedures are not in opposition to the conventional ones (surgical and medical) but rather integrate them, allowing to extend the indications and improve the results in the treatment of the vasculogenic diabetic foot. Based on the personal experience the potential of intravascular procedures in this disease, is analyzed.

Treatment of deep vein thrombosis.

At present, most common initial treatment of deep vein thrombosis is anticoagulant therapy with i.v. heparin. Recently, some reports in literature suggest the efficacy of low molecular weight heparin fractions administered also to outpatients. Thrombolytic therapy as compared to heparin seems to be favorable as for the valvular integrity and function with minor postphlebitic sequels. It is however burdened with a higher incidence of hemorrhagic complications. Probably, it should be reserved for those patients with massive phlebothrombosis or phlebothrombosis associated with relevant clinical signs. At present, it has not definitely been proved that one of the commonly used drugs, streptokinase, urokinase and r-TPA affords substantial advantages in terms of efficacy and safety. Locoregional administration by a catheter inserted into the thrombus with the protection of a caval filter enhances the efficacy of thrombolytic agents, even if data on long-term results of this method are still lacking. Discordant opinions exist on the validity of thrombectomy. As a prophylaxis of pulmonary embolism, thrombus removal has been replaced by caval filters. At present it is commonly indicated for phlegmasia coerulea dolens. In the other forms, even if the vascular patency is restored in a good percentage of cases, it is not similarly effective in preventing the postphlebitic syndrome. For these reasons it should be applied in selected cases.

Venous interruption as prophylaxis of pulmonary embolism: vena cava filters.

Interruption of vena cava for prevention of pulmonary embolism (PE) was achieved in the past with surgical ligation or placement of clips outside the infrarenal vena cava. At present, this procedure is performed with percutaneous insertion of vena cava filters. Vena cava filters can be permanent or temporary, catheter-retrievable. Main indications for placement of a vena cava filter are: contraindication for anticoagulant therapy in patients with severe PE in whom a further embolic episode would be fatal or patients with PE (or its recurrence) undergoing adequate anticoagulant therapy. Temporary filters are reserved to patients where the risk of PE is limited in time as in posttraumatic, post-partum or postoperative thromboembolism. The incidence of recurrence after placement of a vena cava filter varies between 0.5 and 7%. Procedure-associated complications are usually mild. However, severe complications as filter migration into the pulmonary artery or vena cava perforation were described. Our experience concerns the insertion of 61 vena cava filters (47 permanent and 14 temporary). Indications were as follows: iliofemoral thrombosis at embolic risk (37 cases), contraindication for anticoagulant therapy in the presence of deep vein thrombosis with embolic risk (7 cases), protection during fibrinolytic therapy (3 cases), PE during anticoagulant therapy (5 cases) complications of anticoagulant therapy which required discontinuation (5 cases), prophylaxis in view of surgery at high risk for PE (2 cases), protection for surgical venous thrombectomy (2 cases). Mortality was nil. Clinically evident PE was not observed in any patient in whom vena cava filter was inserted. Complications were mild and asymptomatic. Vena cava filters represent an effective prevention of PE together with medical and surgical treatment. At present, problems of this procedure are not technical but rather concern correct indications. Interruption of vena cava is effective if planned within a global strategy for prevention of thromboembolism.

Role of angiography in the evaluation of hepatic perfusion.

Angiography was the first method to be used for a morphofunctional study of hepatic perfusion. It can be performed with direct puncture of portal system or indirect opacification after contrast injection into the splenic artery or superior mesenteric artery. At present, direct angiographic procedures have only a historical value in the diagnostic approach while they have a preliminary role in interventional maneuvers on the portal system (TIPSS, embolization of portal branches or left gastric vein). Indirect angiographic procedures allow the study of arteries, parenchymas and portal system. Much of the information on arterial hepatic and portal circulation is now supplied by noninvasive procedures (US,CT,MRI); however in selected cases, angiography can be performed. Furthermore, the knowledge of angiographic findings of hepatic circulation is basic to the interpretation of "functional" information supplied by color-Doppler US, spiral CT and MR angiography.

New perspectives on the clinical applications of functional radiology of the liver.

Preliminary results of "new clinical applications" of functional imaging of the liver are reported. In 20 healthy volunteers portal flow measurement with Doppler US at the level of right, left portal branch and main portal trunk, showed the preferential distribution in baseline conditions of portal flow to the right liver (about 68%) as compared to the left portal branch. This influenced MRI volumetry of right liver as compared to left liver. After meal intake, flow increase was significantly higher at the level of left portal branch suggestive for a "functional reserve" in left liver. Portal flow physiology was examined in preparation of portal imaging before and after portal vein embolization, a procedure performed preoperatively before enlarged hepatectomies.

Carcinoma of the pancreatic head area. Therapy: nonoperative biliary drainage for palliation.

Jaundice is the dominant symptom in patients with biliary obstruction from carcinomas of the pancreatic head area. The many symptoms usually associated to prolonged biliary stasis (malnutrition, coagulopathy, pruritus hepatocellular failure, renal dysfunction, angiocolitis) is commonly resolved or relieved by biliary drainage. Palliation is frequently the only feasible treatment in these patients due to the biological aggressiveness of these tumors characterized by the early infiltration of adjacent tissues. Endoscopic and percutaneous procedures of biliary recanalization are as effective as those of surgical palliation, are more comfortable to the patients and burdened with a lower morbidity and mortality. In selected patients, palliation of jaundice can be combined with intraluminal radiotherapy or pancreatic drainage the latter aimed at the relief of the "obstructive" pain present in some patients with carcinoma of the area of the head of the pancreas.

The diabetic foot: role of color-Doppler US.

Color Doppler US is a first choice instrumental exam for the diagnosis and staging of peripheral arterial occlusive disease in diabetic patients. Normal and pathological findings are analyzed to establish the potential and limitations of the procedure. Color Doppler US is a noninvasive, reproducible and cost-effective procedure. Direct morphologic and flowmetric evaluations of stenotic-occlusive alterations, and indirect evaluations based on the interpretation of velocimetry findings proximal and distal to the lesions, are feasible. The conventional basic exam can be enhanced with the power module. Encouraging experimental results are observed with the use of echographic contrast media. Disadvantages of the procedure are related to the poor panoramic view, subjective (operator-dependent) interpretation and limitations related to the physics of ultrasound.

Angiography and MR-angiography in the diagnosis of peripheral arterial occlusive disease in diabetic patients.

An invasive diagnostic procedure as angiography which involves direct arterial injection of contrast through suitable catheters, is still considered the gold standard in the evaluation of diabetic patients with peripheral arterial occlusive disease. The accuracy of anatomical details is combined on angiography with a pan view, indispensable for correct therapeutic planning. MR-angiography, with the 2D time of flight sequences in particular, supplies images of great anatomical accuracy and very sensitive in the detection of occlusive lesions which compare well with angiography and superior in the assessment of the length of occluded tracts. This noninvasive, cost-effective procedure seems bound to replace angiography in the pretreatment evaluation of diabetic patients with peripheral arterial occlusive disease.

The foot clinic. Multidisciplinary management of the patient with diabetic foot.

Treatment of a complex disease as the diabetic foot requires a multidisciplinary management with the close collaboration of a team for care. The most important members of the team are the diabetologist as coordinator, the vascular surgeon, the orthopedist, the radiologist, the orthopedic technician, the podiatrist and the nurse specialist. The care based on this arrangement should be carried out in dedicated rooms and times to exploit at best the organizational potential in the patient's interest, implemented in the foot clinic.