Michele Anzidei

Real-time magnetic resonance-guided high-intensity focused ultrasound focal therapy for localised prostate cancer: preliminary experience.

Five patients with unifocal, biopsy-proven prostate cancer (PCa) evident on multiparametric magnetic resonance imaging (MRI) were treated with magnetic resonance-guided focused ultrasound (MRgFUS) ablation before radical prostatectomy (RP). An endorectal probe featuring a phased-array focused ultrasound transducer was positioned for lesion ablation under MRI guidance. The tissue temperature and accumulation of thermal damage in the target zone was monitored during the procedure by MRI thermometry. Overlap between the ablation area and the devascularisation of the target lesion was evaluated by contrast-enhanced MRI performed immediately after treatment. The procedure was uneventful, and no adverse events were observed. RP was safely performed without significant surgical difficulties in relation to the previous MRgFUS treatment. The histopathology report showed extensive coagulative necrosis, with no residual tumour in the ablated area. Significant bilateral residual tumour, not evident on pretreatment MRI, was observed outside the treated area in two patients. MRgFUS ablation of focal localised PCa is feasible and, if confirmed in appropriate studies, could represent a valid option for the focal treatment of localised PCa.

MR-Guided High-Intensity Focused Ultrasound: Current Status of an Emerging Technology

The concept of ideal tumor surgery is to remove the neoplastic tissue without damaging adjacent normal structures. High-intensity focused ultrasound (HIFU) was developed in the 1940s as a viable thermal tissue ablation approach. In clinical practice, HIFU has been applied to treat a variety of solid benign and malignant lesions, including pancreas, liver, prostate, and breast carcinomas, soft tissue sarcomas, and uterine fibroids. More recently, magnetic resonance guidance has been applied for treatment monitoring during focused ultrasound procedures (magnetic resonance–guided focused ultrasound, MRgFUS). Intraoperative magnetic resonance imaging provides the best possible tumor extension and dynamic control of energy deposition using real-time magnetic resonance imaging thermometry. We introduce the fundamental principles and clinical indications of the MRgFUS technique; we also report different treatment options and personal outcomes.

Primary pain palliation and local tumor control in bone metastases treated with magnetic resonance-guided focused ultrasound

ObjectivesThe objectives of this study were to evaluate the efficacy in pain management of magnetic resonance (MR)–guided focused ultrasound for the primary treatment of painful bone metastases and to assess its potential for local control of bone metastases. Materials and MethodsThis was a prospective, single-arm research study with approval from the institutional review board. Eighteen consecutive patients (female, 8; male, 10; mean [SD] age, 62.7 [11.5] years) with painful bone metastases were enrolled. The patients were examined clinically for pain severity and pain interference in accordance with the Brief Pain Inventory-Quality of Life criteria before and at each follow-up visit. Computed tomography and MR imaging were performed before and at 1 and 3 months after the magnetic resonance–guided focused ultrasound treatment. The nonperfused volume (NPV) was calculated to correlate the extension of the ablated pathological tissue in the responder and nonresponder patients. ResultsNo treatment-related adverse events were recorded during the study. The evaluation of pain palliation revealed a statistically significant difference between baseline and follow-up values for pain severity and pain interference (P = 0.001, both evaluations). In the evaluation of local tumor control, we observed increased bone density with restoration of cortical borders in 5 of the 18 patients (27.7%). In accordance with the MD Anderson criteria, complete and partial responses were obtained in 2 of the 18 patients (11.1%) and 4 of the 18 patients (22.2%), respectively. Nonperfused volume values ranged between 20% and 93%. Mean NPV values remained substantially stable after the treatment (P = 0.08). There was no difference in the NPV values between the responder and nonresponder patients (46.7% [24.2%] [25%–90%] versus 45% [24.9%] [20%–93%]; P = 0.7). ConclusionsMagnetic resonance–guided focused ultrasound can be safely and effectively used as the primary treatment of pain palliation in patients with bone metastases and has a potential role in local tumor control.

Whole-Tumor Perfusion CT in Patients with Advanced Lung Adenocarcinoma Treated with Conventional and Antiangiogenetic Chemotherapy: Initial Experience

PURPOSE To determine whether wide-volume perfusion computed tomography (CT) performed with a new generation scanner can allow evaluation of the effects of chemotherapy combined with antiangiogenetic treatment on the whole tumor mass in patients with locally advanced lung adenocarcinoma and to determine if changes in CT numbers correlate with the response to therapy as assessed by conventional response evaluation criteria in solid tumors (RECIST). MATERIALS AND METHODS Forty-five patients with unresectable lung adenocarcinoma underwent perfusion CT before and 40 and 90 days after chemotherapy and antiangiogenetic treatment. RECIST measurements and calculations of blood flow, blood volume, time to peak, and permeability were performed by two independent blinded radiologists. Pearson correlation coefficient was used to assess the correlation between baseline CT numbers. Baseline and follow-up perfusion parameters of the neoplastic lesions were tested overall for statistically significant differences by using the repeated-measures analysis of variance and then were also compared on the basis of the therapy response assessed according to the RECIST criteria. RESULTS Pearson correlation coefficient showed a significant correlation between baseline values of blood flow and blood volume (ρ = 0.48; P = .001), time to peak and permeability (ρ = 0.31; P = .04), time to peak and blood flow (ρ = -0.66; P < .001), and time to peak and blood volume (ρ = -0.39; P = .007). Blood flow, blood volume, and permeability values were higher in responding patients than in the other patients, with a significant difference at second follow-up for blood flow (P = .0001), blood volume (P = .02), and permeability (P = .0001); time to peak was higher in nonresponding patients (P = .012). CONCLUSION Perfusion CT imaging may allow evaluation of lung cancer angiogenesis demonstrating alterations in vascularity following treatment.

MR Imaging–guided Focused Ultrasound for Treatment of Bone Metastasis

Magnetic resonance (MR) imaging-guided focused ultrasound is an alternative noninvasive method for reducing the pain in skeletal metastases. MR imaging-guided focused ultrasound ablation offers several key advantages over other noninvasive treatment modalities. This technology enables the performance of three-dimensional treatment planning with MR imaging and continuous temperature mapping of treated tissue by using MR thermometry, thereby enabling real-time monitoring of thermal damage in the target zone. The concentration of acoustic energy on the intact surface of cortical bone produces a rapid temperature increase that mediates critical thermal damage to the adjacent periosteum, the most innervated component of mature bone tissue. Such thermal ablation has been shown to be an extremely effective approach for pain management. Energy delivered during MR imaging-guided focused ultrasound ablation and accumulated inside the pathologic soft tissue of the metastases can create a variable amount of tissue necrosis. This technique has also a potential role in achieving local tumor control, allowing remineralization of trabecular bone or reduction in lesion size. The current report presents a detailed step-by-step guide for performing MR imaging-guided focused ultrasound ablation of bone metastases, including use of MR thermometry for monitoring treatment, protocol selection for simple palliation of pain or for local tumor control, and a description of imaging features of periosteal neurolysis or metastasis ablation. Two case studies are also presented: in the first, the technique provided palliation of pain in bone metastases, and in the second, the technique achieved tumor control as further proof of primary efficacy. MR imaging-guided focused ultrasound ablation is a promising method for successful palliation of bone metastasis pain and tumor control, because of the bony structure remodeling induced by thermo-related coagulative necrosis.

Osteoid Osteoma: MR-guided Focused Ultrasound for Entirely Noninvasive Treatment

PURPOSE To determine the preliminary feasibility, safety, and clinical efficacy of magnetic resonance (MR)-guided focused ultrasound for the treatment of painful osteoid osteoma. MATERIALS AND METHODS This prospective institutional review board-approved study involved six consecutive patients (five males and one female; mean age, 21 years) with a diagnosis of osteoid osteoma based on clinical and imaging findings. All patients underwent MR-guided focused ultrasound ablation after providing informed consent. Lesions located in the vertebral body were excluded. The number of sonications and the energy deposition were recorded. Treatment success was determined at 1, 3, and 6 months after treatment. A visual analog scale (VAS) score for pain was used to assess changes in symptoms. MR imaging features of osteoid osteoma (edema, hyperemia, and nidus vascularization) were considered at baseline and at imaging follow-up. RESULTS Treatment was performed with a mean of 4 sonications ± 1.8 (standard deviation), with a mean energy deposition of 866 J ± 211. No treatment- or anesthesia-related complications occurred. The pre- and posttreatment mean VAS scores significantly differed (7.9 ± 1.4 and 0.0 ± 0.0, respectively). At imaging, the edema and hyperemia associated with osteoid osteoma gradually disappeared in all lesions. However, nidus vascularization still persisted after treatment in four of six patients. CONCLUSION This limited series demonstrated that MR-guided focused ultrasound treatment of osteoid osteoma can be performed safely with a high rate of success and without apparent treatment-related morbidity.

Diagnostic accuracy of colour Doppler ultrasonography, CT angiography and blood-pool-enhanced MR angiography in assessing carotid stenosis: a comparative study with DSA in 170 patients

PurposeThis study was undertaken to prospectively evaluate the diagnostic performance of colour Doppler ultrasonography (CDUS), first-pass (FP) and steady-state (SS) contrast-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) of the carotid arteries using digital subtraction angiography (DSA) as the reference standard.Materials and methodsA total of 170 patients with previous cerebrovascular events and suspected carotid artery stenoses underwent CDUS, blood-pool MRA, CTA and DSA. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CDUS, FP MRA, SS MRA and CTA. The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to determine significant differences (p<0.05) between the diagnostic performances of the four modalities, and the degree of stenosis was compared using linear regression.ResultsA total of 336 carotid bifurcations were studied. The area under the curve (AUC) for degree of stenosis was: CDUS 0.85±0.02, FP MRA 0.982±0.005, SS MRA 0.994±0.002 and CTA 0.997±0.001. AUC analysis showed no statistically significant difference between CTA and MRA (p=0.0174) and a statistically significant difference between CDUS and the other techniques (p<0.001). Plaque morphology analysis showed no significant difference between CTA and SS MRA; a significant difference was seen between CTA and SS MRA versus FP MRA (p=0.04) and CDUS (p=0.038). Plaque ulceration analysis showed a statistically significant difference between MRA and CTA (0.04< p<0.046) versus CDUS (p=0.019).ConclusionsCTA is the most accurate technique for evaluating carotid stenoses, with a slightly better performance than MRA (97% vs. 95% for SS MRA and 92% for FP MRA) and a greater accuracy than CDUS (97% vs. 76%). Blood-pool contrast-enhanced SS sequences offer improved evaluation of degree of stenosis and plaque morphology with accuracy substantially identical to CTA.RiassuntoObiettivoL’obiettivo di questo studio è stato di valutare prospetticamente l’accuratezza dell’eco-color Doppler (ECD), dell’angiografia con risonanza magnetica (angio-RM), ottenuta con sequenze di primo passaggio (PP) ed allo stato stazionario (SS) e dell’angiografia con tomografia computerizzata (angio-TC) nella diagnostica della stenosi carotidea utilizzando l’angiografia con sottrazione digitale (DSA) come metodica di riferimento.Materiali e metodiCentosettanta pazienti sintomatici e con sospetta stenosi carotidea sono stati sottoposti ad ECD, angio-RM, angio-TC e DSA. Accuratezza, sensibilità, specificità, valore predittivo positivo (VPP) e valore predittivo negativo (VPN) sono stati calcolati per ECD, angio-RM ed angio-TC. Le differenze di performance tra le metodiche sono state valutate utilizzando il test di McNemar, il test di Wilcoxon e l’analisi delle curve receiver operating characteristic (ROC) (p<0,05). Inoltre il valore di stenosi attribuito dalla valutazione dell’ECD, dell’angio-RM e dell’angio-TC è stato confrontato con il valore della DSA tramite regressioni lineari.RisultatiSono state valutate 336 biforcazioni carotidee. Per la valutazione del grado di stenosi è stata calcolata l’area sotto la curva (AUC) delle quattro metodiche che è risultata: ECD 0,85±0,02, angio-RM PP=0,982±0,005, angio-RM SS=0,994±0,002 ed angio-TC=0,997±0,001 con sostanziale equivalenza tra angio-TC ed angio-RM (p=0,0174) ed una differenza statisticamente significativatra l’ECD e le altre metodiche (p<0,001). Per la valutazione della morfologia di placca l’analisi delle AUC delle quattro metodiche ha evidenziato una sostanziale equivalenza tra angio-TC ed angio-RM con SS, ma ha evidenziato una lieve differenza di entrambe le metodiche nei confronti dell’angio-RM con PP (p=0,04) e dell’ECD (p=0,038). La valutazione delle ulcere ha evidenziato una differenza statisticamente significativa tra l’angio-RM e l’angio-TC (p=0,04–0,046) e l’ECD (p=0,019).ConclusioniL’angio-TC è la metodica più affidabile con una leggera superiorità diagnostica rispetto all’angio-RM (97% vs. 95% per le sequenze SS e 92% per le sequenze PP) ed una superiorità molto marcata rispetto all’ECD (97% vs. 76%). L’angio-RM con l’utilizzo delle sequenze allo stato stazionario ottenute con mezzo di contrasto intravascolare ad alta relassività tende sostanzialmente ad eguagliare l’accuratezza dell’angio-TC.Purpose. This study was undertaken to prospectively evaluate the diagnostic performance of colour Doppler ultrasonography (CDUS), first-pass (FP) and steady-state (SS) contrast-enhanced magnetic resonance angiography (MRA) and computed tomography angiography (CTA) of the carotid arteries using digital subtraction angiography (DSA) as the reference standard. Materials and methods. A total of 170 patients with previous cerebrovascular events and suspected carotid artery stenoses underwent CDUS, blood-pool MRA, CTA and DSA. Accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for CDUS, FP MRA, SS MRA and CTA. The McNemar and Wilcoxon tests and receiver operating characteristic (ROC) curve analysis were used to determine significant differences (p<0.05) between the diagnostic performances of the four modalities, and the degree of stenosis was compared using linear regression. Results. A total of 336 carotid bifurcations were studied. The area under the curve (AUC) for degree of stenosis was: CDUS 0.85±0.02, FP MRA 0.982±0.005, SS MRA 0.994±0.002 and CTA 0.997±0.001. AUC analysis showed no statistically significant difference between CTA and MRA (p=0.0174) and a statistically significant difference between CDUS and the other techniques (p<0.001). Plaque morphology analysis showed no significant difference between CTA and SS MRA; a significant difference was Riassunto Obiettivo. L’obiettivo di questo studio e stato di valutare prospetticamente l’accuratezza dell’eco-color Doppler (ECD), dell’angiografia con risonanza magnetica (angio-RM), ottenuta con sequenze di primo passaggio (PP) ed allo stato stazionario (SS) e dell’angiografia con tomografia computerizzata (angio-TC) nella diagnostica della stenosi carotidea utilizzando l’angiografia con sottrazione digitale (DSA) come metodica di riferimento. Materiali e metodi. Centosettanta pazienti sintomatici e con sospetta stenosi carotidea sono stati sottoposti ad ECD, angio-RM, angio-TC e DSA. Accuratezza, sensibilita, specificita, valore predittivo positivo (VPP) e valore predittivo negativo (VPN) sono stati calcolati per ECD, angio-RM ed angio-TC. Le differenze di performance tra le metodiche sono state valutate utilizzando il test di McNemar, il test di Wilcoxon e l’analisi delle curve receiver operating characteristic (ROC) (p<0,05). Inoltre il valore di stenosi attribuito dalla valutazione dell’ECD, dell’angio-RM e dell’angio-TC e stato confrontato con il valore della DSA tramite regressioni lineari. Risultati. Sono state valutate 336 biforcazioni carotidee. Per la valutazione del grado di stenosi e stata calcolata l’area sotto la curva (AUC) delle quattro metodiche che e risultata: ECD 0,85±0,02, angio-RM PP=0,982±0,005, angio-RM SS=0,994±0,002 ed angio-TC=0,997±0,001 con sostanziale equivalenza tra angio-TC ed angio-RM (p=0,0174) ed una differenza statisticamente significativa VASCULAR AND INTERVENTIONAL RADIOLOGY RADIOLOGIA VASCOLARE E INTERVENTISTICA Diagnostic accuracy of colour Doppler ultrasonography, CT angiography and blood-pool-enhanced MR angiography in assessing carotid stenosis: a comparative study with DSA in 170 patients Accuratezza diagnostica nella valutazione della stenosi carotidea di eco-color Doppler, angio-TC ed angio-RM con mezzo di contrasto intravascolare: valutazione comparativa dell’accuratezza diagnostica con DSA in 170 pazienti M. Anzidei1 • A. Napoli1 • F. Zaccagna1 • P. Di Paolo1 • L. Saba2 • B. Cavallo Marincola2 • C. Zini1 G. Cartocci1 • L. Di Mare1 • C. Catalano1 • R. Passariello1 1 Department of Radiological Sciences, University of Rome “La Sapienza”, Viale Regina Elena 324, 00161 Rome, Italy 2 Department of Radiology, Azienda Ospedaliera Universitaria (A.O.U.) Cagliari, Polo di Monserrato, Italy Correspondence to: M. Anzidei, Tel.: +39-06-4455602, Fax: +39-06-490243, e-mail: michele.anzidei@gmail.com Received: 27 July 2010 / Accepted: 7 September 2010 / Published online: 19 March 2011

Peripheral Arterial Occlusive Disease: Diagnostic Performance and Effect on Therapeutic Management of 64-Section CT Angiography

PURPOSE To evaluate the diagnostic performance and effect on therapeutic management of 64-section computed tomographic (CT) angiography in the assessment of steno-occlusive disease in patients with peripheral arterial disease (PAD), with conventional digital subtraction angiography (DSA) as the reference standard. MATERIALS AND METHODS The study protocol was approved by the institutional review board, and written informed consent was obtained from all patients. A total of 212 patients with symptomatic PAD underwent CT angiography and subsequent DSA. For stenosis analysis (≥ 70% stenosis), the arterial bed was divided into 35 segments and evaluated by three readers. Interobserver agreement was determined with generalized κ statistics. Accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated. In addition, according to the TransAtlantic Inter-Society Consensus (TASC) Document on Management of Peripheral Arterial Disease guidelines, treatment recommendations based on CT angiographic and DSA findings were compared. McNemar test was used to prove significant differences between CT angiographic and DSA findings. RESULTS A total of 7420 arterial segments were evaluated, with excellent agreement between readers (κ ≥ 0.928). On a segmental basis, both sensitivity and specificity for stenosis of 70% or more were at least 96% (3072 of 3113 segments and 4141 of 4279 segments, respectively), with an accuracy of 98% (7213 of 7392 segments), a PPV of 96% (3072 of 3187 segments), an NPV of 99% (3141 of 3187 segments), a PLR of 36.7, and an NLR of 0.013. There was no significant difference between CT angiographic and DSA findings (P = .62-.87). In accordance with TASC II guidelines, 49 patients were referred for conservative treatment, 87 underwent endovascular procedures, 38 underwent surgery, and 17 received hybrid treatment. Therapy recommendations based on CT angiographic findings alone were identical to those based on DSA findings in all but one patient. CONCLUSION The diagnostic performance of 64-section CT angiography is excellent in patients with clinical symptoms of PAD. The results can be used to effectively guide therapeutic decision making in these patients.

Malignant tumours of the small intestine: a review of histopathology, multidetector CT and MRI aspects.

Small bowel neoplasms, including adenocarcinoma, carcinoid tumour, lymphoma and gastrointestinal stromal tumours, represent a small percentage of gastrointestinal cancers, yet are among those with the poorest prognosis compared with other gastrointestinal malignancies. Unclear clinical scenarios and difficult radiological diagnosis often delay treatment with negative effects on patient survival. Recently, multidetector CT (MDCT) and MRI have been introduced as feasible and accurate diagnostic techniques for the identification and staging of small bowel neoplasms. These techniques are gradually replacing conventional barium radiography as the tool of choice. However, the inherent technical and physiological challenges of small bowel imaging require a familiarity with patient preparation and scan protocols. Adequate knowledge of the histopathology and natural evolution of small bowel neoplasms is also important for differential diagnosis. The aim of this article is to review MDCT and MRI protocols for the evaluation of small bowel tumours and to provide a concise yet comprehensive guide to the most relevant imaging features relative to histopathology.

Liver metastases from colorectal cancer treated with conventional and antiangiogenetic chemotherapy: evaluation with liver computed tomography perfusion and magnetic resonance diffusion-weighted imaging.

Objective The objectives of the study were to determine whether perfusion computed tomography (CT-p) and magnetic resonance diffusion-weighted imaging (MR-DWI) can allow evaluation of the effects of chemotherapy combined with antiangiogenetic treatment on liver metastases in patients with advanced colorectal cancer and to determine if changes in CT-p and MR-DWI correlate with the response to therapy as assessed by conventional Response Evaluation Criteria in Solid Tumors (RECIST). Methods Eighteen patients with liver metastases from colorectal cancer underwent CT-p and MR-DWI before and 6 months after chemotherapy and antiangiogenetic treatment. Lesions were classified according to RECIST criteria (complete response [CR], partial response [PR], stable disease [SD], and progressive disease) and calculations of CT-p parameters including blood flow (BF), blood volume (BV), capillary permeability (CP), and MR-DWI apparent diffusion coefficient (ADC) values were performed; RECIST, CT-p, and MR-DWI measurements at baseline and follow-up were tested for statistically significant differences using the paired-samples t test. Baseline and follow-up perfusion parameters of the lesions were also compared on the basis of therapy response assessed by RECIST criteria using independent-samples t test. P < 0.05 was considered indicative of a statistically significant difference for all statistical test. Results Six patients (6/18; 33.3%) were classified as PR (Fig. 1), and the remaining 12 (12/18; 66.7%) were classified as SD. On a per-lesion basis, 2 (2/32; 6.3%) cannot be identified at follow-up, 6 (6/32; 18.8%) showed a decrease in size of more than 30%, and 24 (24/32; 75%) were substantially stable in size. No cases of progressive disease were demonstrated at follow-up. No statistically significant differences were demonstrated between PR, CR, and SD lesions for BF (P = 0.19), BV (P = 0.14), and ADC (P = 0.68) measurements, whereas CP was significantly higher in CR and PR lesions (P = 0.038). Considering differences between baseline and follow-up values, no statistically significant differences were noted between PR and CR lesions versus SD lesions for CT-p values (BF: P = 0.77; BV: P = 0.15; CP: P = 0.64). A statistically significant difference between PR and CR lesions and SD lesions was noted for ADC values (P = 0.047). Conclusion Both CT-p and MR-DWI can detect therapy-induced modifications in lesion vascularization before significant changes in size are evident.