Iodine Extravasation Quantification on Dual-Energy CT of the Brain Performed after Mechanical Thrombectomy for Acute Ischemic Stroke Can Predict Hemorrhagic Complications.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage represents a potentially severe complication of revascularization of acute ischemic stroke. The aim of our study was to assess the capability of iodine extravasation quantification on dual-energy CT performed immediately after mechanical thrombectomy to predict hemorrhagic complications. MATERIALS AND METHODS: Because this was a retrospective study, the need for informed consent was waived. Eighty-five consecutive patients who underwent brain dual-energy CT immediately after mechanical thrombectomy for acute ischemic stroke between August 2013 and January 2017 were included. Two radiologists independently evaluated dual-energy CT images for the presence of parenchymal hyperdensity, iodine extravasation, and hemorrhage. Maximum iodine concentration was measured. Follow-up CT examinations performed until patient discharge were reviewed for intracerebral hemorrhage development. The correlation between dual-energy CT parameters and intracerebral hemorrhage development was analyzed by the Mann-Whitney U test and Fisher exact test. Receiver operating characteristic curves were generated for continuous variables. RESULTS: Thirteen of 85 patients (15.3%) developed hemorrhage. On postoperative dual-energy CT, parenchymal hyperdensities and iodine extravasation were present in 100% of the patients who developed intracerebral hemorrhage and in 56.3% of the patients who did not (P = .002 for both). Signs of bleeding were present in 35.7% of the patients who developed intracerebral hemorrhage and in none of the patients who did not (P < .001). Median maximum iodine concentration was 2.63 mg/mL in the patients who developed intracerebral hemorrhage and 1.4 mg/mL in the patients who did not (P < .001). Maximum iodine concentration showed an area under the curve of 0.89 for identifying patients developing intracerebral hemorrhage. CONCLUSIONS: The presence of parenchymal hyperdensity with a maximum iodine concentration of >1.35 mg/mL may identify patients developing intracerebral hemorrhage with 100% sensitivity and 67.6% specificity.

Uric acid versus non-uric acid renal stones: in vivo differentiation with spectral CT.

AIM: To differentiate uric acid from non-uric acid renal stones based on their spectral attenuation values. MATERIALS AND METHODS: The present study was approved by the institutional review board and the need for informed consent was waived. Thirty-three consecutive patients (21 men, 12 women; mean age 55 years) with symptomatic urolithiasis underwent dual-energy computed tomography (DECT) using a second-generation dual-source CT system. Stone composition was assessed by means of chemical analysis after extraction or spontaneous expulsion. The composition of one stone was considered to represent all remaining stones in patients presenting with more than one stone. Image-domain virtual monoenergetic images were generated from the dual-energy datasets. One radiologist evaluated stone attenuation values from 40 to 190 keV; attenuation curves were created and 40/190 keV attenuation ratios calculated. Qualitative evaluation of the spectral attenuation curves was also performed. Imaging findings were compared with laboratory results. RESULTS: Sixty-two stones were considered in 33 patients (mean diameter 6.5 mm). Fifteen of the 62 stones were mainly composed of uric acid and 47/62 of cysteine or calcium oxalates/phosphates. Forty to 190 keV attenuation ratios were significantly lower for uric acid stones (mean 0.87±0.3) than for non-uric acid stones (mean 3.80±0.6; p<0.0001). Accuracy was 100% with a cut-off value of 1.76. Qualitative analysis of spectral attenuation curves showed unique shapes for uric acid and non-uric acid stones. CONCLUSIONS: Spectral CT quantitatively and qualitatively differentiates uric acid from non-uric acid stones.

Computed tomography after nephron-sparing surgery.

The increased use of abdominal cross-sectional imaging has contributed to a greater detection of incidental small renal masses. Treatment options for localized disease renal cell carcinoma include radical nephrectomy or partial nephrectomy (PN), the former being preferred for treatment of early-stage tumors. The most adopted technique for follow-up imaging is contrast-enhanced computed tomography (CT), whose findings can cause uncertainty and unnecessary repetition of examinations. Our purpose is to describe CT findings after PN and to describe evolution in time of such images.

MDCT of blunt renal trauma: imaging findings and therapeutic implications.

OBJECTIVES: To show the wide spectrum of computed tomography (CT) findings in blunt renal trauma and to correlate them with consequent therapeutic implications. METHODS: This article is the result of a literature review and our personal experience in a level II trauma centre. Here we describe, discuss and illustrate the possible CT findings in blunt renal trauma, and we correlate them with the American Association for the Surgery of Trauma (AAST) classification and their therapeutic implications. RESULTS: CT findings following blunt renal trauma can be grouped into 15 main categories, 12 of them directly correlated with the AAST classification and 3 of them not mentioned in it. Non-operative management, which includes the "watchful waiting" approach, endourological treatments and endovascular treatments, is nowadays widely adopted in blunt renal trauma, and surgery is limited to haemodynamically unstable patients and a minority of haemodynamically stable patients. CONCLUSIONS: The interpretation of CT findings in blunt renal trauma may be improved and made faster by the knowledge of their therapeutic consequences. TEACHING POINTS: • The majority of blunt renal injuries do not require surgical treatment. • CT findings in blunt renal injury must be evaluated considering their therapeutic consequences. • Some CT findings in blunt renal trauma are not included in the AAST classification.

Is HCMV vaccine an unmet need? The state of art of vaccine development.

Congenital HCMV infection is the most frequent congenital infection, with an incidence of 0.2- 2.5 percent among all live births. About 11 percent of infected newborns show symptoms at birth, including hepato-splenomegaly, thrombocytopenia, neurologic involvement, hearing impairment and visual deficit. Moreover, 5-25 percent of the asymptomatic congenital HCMV-infected neonates will develop sequelae over months or even years. The relevant social burden, the economic costs of pre-natal screening, post-natal diagnosis, follow-up and possible therapy, although still limited, are the major factors to be considered. Several types of vaccines have been explored in order to develop an effective and safe HCMV vaccine: live attenuated, subunit, vectored, peptide, DNA, and subviral ones, but none are available for use. This review illustrates the different vaccine types studied to date, focusing on the possible vaccination strategy to be implemented once the HCMV vaccine is available, in terms of target population.

Anticoagulation therapy for postoperative deep vein thrombosis coupled with pulmonary embolism: a potential trigger for delayed popliteal artery injury presentation after total knee arthroplasty.

OBJECTIVES: A case of delayed popliteal artery injury (PA-INJ) onset after total knee arthroplasty (TKA) in a patient under postoperative anticoagulation therapy is reported. The role of anticoagulation both in late PA-INJ presentation and in PA-INJ management is discussed. REPORT: An obese 76-year-old woman was presented with a common femoral vein thrombosis coupled with pulmonary embolism five days after TKA. She was immediately placed under anticoagulation therapy. Four days later, during physiotherapy-supervised mobilization, she developed a calf haematoma and large retro-articular pseudoaneurysm. Angiography revealed a minor PA-INJ successively treated with a covered stent-graft. CONCLUSIONS: In cases of initially undetected and staunched TKA-related PA-INJs, postoperative anticoagulation therapy may act as a potential trigger for final arterial rupture during mobilization exercises, followed by acute bleeding; in these cases, endovascular management represents an excellent treatment option. Close clinical and instrumental monitoring is strongly recommended after TKA, in patients who imperatively require full-dose anticoagulation therapy.

Basilar artery thrombosis: imaging and endovascular therapy.

PURPOSE: Basilar artery thrombosis represents a rare type of ischaemic stroke with a mortality rate of 80%-90% if not promptly treated. The aim of our study was to review our experience with computed tomography angiography (CTA) in the diagnosis of basilar artery thrombosis and its treatment with endovascular procedures. MATERIALS AND METHODS: Our retrospective study is based upon 59 nontrauma patients with episodes of sudden loss of consciousness. Patients were investigated using unenhanced brain CT followed by intracranial CTA (16-slice CT) when no parenchymal haemorrhage was detected. Patients with a CTA diagnosis of basilar artery thrombosis were considered for endovascular treatment. CTA accuracy was evaluated by considering the 12 patients who underwent endovascular angiography (the gold standard). The success of endovascular therapy was evaluated by considering the degree of microcirculatory reperfusion. RESULTS: After the exclusion of 33 patients affected by parenchymal or subarachnoid haemorrhage, the final study consisted of 26 patients who underwent CTA. Basilar artery thrombosis was diagnosed in 15 of them, and 12 were treated at our institution. The comparison between CTA and endovascular angiography showed 100% agreement in evaluating occlusion site and extension. Seven patients underwent intra-arterial lysis, and five underwent mechanical clot removal. CONCLUSIONS: CTA, with its wide availability and rapid execution times, is the most indicated examination in the case of suspected basilar artery thrombosis. Although there is a lack of randomised controlled prospective studies suggesting the most appropriate therapeutic approach to basilar artery thrombosis, our study lends weight to the role of interventional neuroradiology in the treatment of this condition.

Detection of cerebral aneurysms in nontraumatic subarachnoid haemorrhage: role of multislice CT angiography in 130 consecutive patients.

PURPOSE: The leading cause of a nontraumatic subarachnoid haemorrhage is rupture of an intracranial aneurysm. The aim of this study was to assess the usefulness of multislice computed tomography angiography (CTA) in identifying and evaluating cerebral aneurysms by comparing it with intra-arterial digital subtraction angiography (DSA) and intraoperative findings. MATERIALS AND METHODS: During a 20-month period (June 2004 and February 2006), 130 patients with a CT diagnosis of nontraumatic acute subarachnoid haemorrhage were prospectively recruited to this study and underwent 16-detector CTA and DSA (57 men, 73 women; mean age 59.5 years). Twenty-five patients who underwent DSA alone postclipping were excluded. CTA and DSA were evaluated by the performing radiologist to assess the presence of one or more aneurysms and their morphological characteristics. RESULTS: CTA detected 133 aneurysms, whereas DSA identified 134: the aneurysm missed by CTA was 2 mm in size. CONCLUSIONS: CTA is fast and relatively noninvasive, and its sensitivity appears similar to that of DSA in detecting and evaluating intracranial aneurysms, even those smaller than 3 mm. This study confirms the value of CTA as the primary imaging technique in subarachnoid haemorrhage, with DSA reserved for selected patients.

[Symptomatic angiomyolipoma of the kidney: report of 2 cases]. / Agiomiolipoma sintomatico del rene: descrizione di due casi.

Renal angiomyolipoma is an uncommon benign tumor composed of adipose tissue, dysplastic blood vessels and smooth muscle. The tumor may occur as a distinct entity or in association with tuberous sclerosis. The diagnosis is usually easy but a malignant neoplasm can not always be excluded. Tumors smaller than 4 cm are mostly asymptomatic and usually do not need to be treated. For larger lesions a treatment is advisable especially in case of symptoms because of the risk of a severe hemorrhage. The treatment should be as conservative as possible and nephrectomy preformed only when a malignant tumor can not be excluded or in cases of life-threatening hemorrhage or widespread infiltration or complete destruction of the kidney. Today the treatment of choice should be embolisation and on second line resection of the lesion. Two cases of symptomatic angiomyolipoma are presented. Both cases are treated by radical nephrectomy.

Preoperative staging of rectal cancer by endoluminal ultrasound vs. magnetic resonance imaging. Preliminary results of a prospective, comparative study.

PURPOSE: The aim of this study was to compare the value of endoluminal ultrasonography (ELUS) with magnetic resonance imaging (MRI) for preoperative staging of rectal carcinoma. METHODS: Thirty-seven consecutive patients were examined by ELUS and MRI. Imaging results were compared with pathohistologic studies. A tumor extending beyond the bowel wall was considered to be "positive" and one within the bowel wall was considered "negative." Lymph node involvement was considered present if nodes equal to or greater than 5 mm in diameter were found in the perirectal tissue. For evaluating the differences between the two methods, the Mc Nemar test was performed. RESULTS: T-Staging was correct in 88.2 percent (30/34) of patients by ELUS and in 82.3 percent (28/34) by MRI (difference not significant). N-Staging was correct in 80 percent (20/25) by ELUS and in 60 percent (15/25) by MRI (difference of borderline significance). A comprehensive preoperative staging (T + N) was made correctly in 68 percent (17/25) by ELUS and in 48 percent only (12/25) by MRI (difference not significant). CONCLUSIONS: We suggest that ELUS and MRI must be evaluated within the framework of established parameters when treatment modalities such as preoperative radiation therapy and local or radical surgical approach must be decided.

[The value of nuclear magnetic resonance tomography in evaluating the patency of aortocoronary bypass grafts]. / Die Wertigkeit der Kernspintomographie bei der Beurteilung der Durchgängigkeit von aortokoronaren Grafts.

BACKGROUND: Patients with previous coronary artery bypass graft surgery often present with pain of unknown origin. Noninvasive documentation of graft patency is of obvious clinical importance. METHODS: In order to assess the efficacy of magnetic resonance imaging (MRI) in evaluating graft patency, 44 patient with prior coronary artery bypass graft surgery and a history of chest pain were studied by coronarography and MRI. MRI was performed within 2.1 +/- 3.8 days from coronarography using a 0.5 Tesla magnet, Spin-Echo T1 technique, cardiac and respiratory gating and scannings in transaxial plans. A graft was defined as patent, if a signal void was identified in at least two different slices in a position consistent with a bypass graft. Images were analyzed by two different observers aware of the type of surgery but not the result of the coronarography. RESULTS: Eighty-nine out of 100 grafts were classified correctly by MRI. Sixty-three grafts were patent as shown by coronarography; 59 of them were classified correctly by MRI. Thirty-seven grafts were shown as occluded; 30 of them were classified correctly by MRI. In particular, 43 out of 45 grafts to the left anterior descending artery, 18 of them using the internal mammary artery, 23 out of 30 graft to the left circumflex artery and 23 out 25 grafts to the right coronary artery were classified correctly. CONCLUSIONS: This study demonstrates the capability of MRI to evaluate coronary artery bypass graft patency with a sensitivity of 94% and specificity of 81%; this technique has significantly clinical limitations because resolution is not adequate to evaluate the presence of graft stenosis.

[Magnetic resonance with the spin-echo technic in the noninvasive evaluation of the patency of aortocoronary bypasses: preliminary data]. / La risonanza magnetica con tecnica spin-echo nella valutazione non invasiva della pervietà dei bypass aorto-coronarici: dati preliminari.

BACKGROUND: Patients with previous coronary artery bypass graft surgery often develop chest pain due to ischemic or nonischemic causes. Noninvasive evaluation of graft patency is thus of obvious potential importance. METHODS: In order to assess the efficacy of magnetic resonance imaging (MRI) in evaluating graft patency after coronary artery bypass graft surgery, 16 patients with prior surgery and history of chest pain were studied prospectively by coronarography and MRI. These 16 patients with a total of 40 grafts were evaluated, using MRI with Spin-Echo T1 technique within 3.6 +/- 4.4 days from coronarography with a 0.5 Tesla magnet, cardiac and respiratory gating and scannings in transaxial planes. A graft was defined as patent if a signal void was identified in at least two different slices in a position consistent with a bypass graft. Images were analyzed by two different observers aware of the type of surgery but not the result of the coronarography. RESULTS: Thirty-six out of the 40 grafts were classified correctly by MRI. Twenty-eight grafts were patent as shown by coronarography; 26 of them were classified correctly by MRI. Twelve grafts were shown as occluded; 10 of them were classified correctly by MRI. In particular, all of the 14 grafts to the left anterior descending artery (3 of them using the internal mammary artery), 13/16 of the grafts to the left circumflex artery and 9/10 of the grafts to the right coronary artery were classified correctly. CONCLUSIONS: This study demonstrates the capability of MRI to evaluate coronary artery bypass graft patency with a sensitivity of 92.8% and specificity of 83.3%; this technique has significant clinical limitations because resolution is not adequate to evaluate the presence of graft stenosis.

[CT after myelography in complete spinal cord blocks]. / La TC post mielografia nei blocchi midollari totali.

In each patient (two meningiomas, two lymphomas, one spine fracture) myelography demonstrated only the lower level of the block, but not enough contrast medium leaked past the block to allow myelographic identification of the upper level. On the contrary, thanks to its high power of contrast resolution, CT immediately after myelography clearly outlined the subarachnoid space both below and above the level of the block. Descending myelography was therefore not necessary. Moreover, CT also revealed associated bone and soft tissue lesions, in two cases, providing a more accurate diagnosis. It is therefore concluded that combined myelography+CT can provide complete diagnosis of spinal blocks and any associated lesions.