Risk management in radiology.

Recent US nationwide research on malpractice lawsuits shows that the most common cause of medical malpractice suits against radiologists was error in diagnosis (mainly failure to diagnose instead of delay); the category next in frequency was procedural complications, followed by inadequate communication with either patient or referring physician. Risk management is a fundamental instrument to prevent and limit errors and adverse events. This article analyzes risk management in radiology addressing the most common ethical-legal issues on appropriateness of prescriptions, informed consent, and management of adverse events. Effective remedial actions are proposed to avoid malpractice claims that would help physicians in preventing malpractice stress syndrome, leading to defensive medicine.

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.

Malpractice in radiology: what should you worry about?

Over recent years the professional role of the radiologist has been evolved due to the increasing involvement in the clinical management of the patient. Radiologists have thus been increasingly charged by new duties and liabilities, exposing them to higher risks of legal claims made against them. Malpractice lawsuits in radiology are commonly related to inappropriate medical care or to the poor physician-patient relationship. In the present paper, we provide overview of the basic principles of the medical malpractice law and the main legal issues and causes of legal actions against diagnostic and interventional radiologists. We also address some issues to help radiologists to reduce risks and consequences of malpractice lawsuits. These include (1) following the standard of care to the best of their ability, (2) cautious use of off-label devices, (3) better communication skills among healthcare workers and with the patient, and (4) ensuring being covered by adequate malpractice insurance. Lastly, we described definitions of some medicolegal terms and concepts that are thought to be useful for radiologists to know.

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.

Use of multiparametric MR with neurovascular bundle evaluation to optimize the oncological and functional management of patients considered for nerve-sparing radical prostatectomy.

INTRODUCTION: To obtain the best results with radical prostatectomy, either from an oncological or a functional point of view, a correct selection of cases and planning of surgery are crucial. Multiparametric magnetic resonance imaging (MRI) promises to make it a successful imaging tool for improving many aspects of prostate cancer management. AIM: The aim of this study is to evaluate whether a modern multiparametric MRI can help either to better select prostate cancer cases for a nerve-sparing radical prostatectomy or to improve the functional evaluation related to neurovascular bundles preservation. MAIN OUTCOME MEASURES: The effect of preoperative MRI on neurovascular bundle management was examined for the frequency and the appropriateness of changes of the surgical plane on the basis of MRI indications. METHODS: In a prospective study, 125 consecutive patients with biopsy proven prostate cancer who were scheduled to undergo bilateral nerve-sparing surgery. All patients included into the study were submitted to a preoperative multiparametric MRI. On the basis of MRI evaluation, patients were divided into two groups. Patients in group A were then submitted to a bilateral nerve-sparing (NS) radical prostatectomy (RP), whereas patients in group B were submitted to unilateral NS or non-NS RP. RESULTS: In group A, the confirmation from the MRI study to perform a bilateral NS procedure was appropriate in 70 of 73 cases (95.9%), whereas in group B, the surgical plan was appropriate in 28 of 32 cases (87.5%). On the contrary, MRI findings suggested a change in the initial surgical plan (group B) for 32 of 105 cases (30.5%). Of these 32 cases in group B, MRI suggested to perform a unilateral NS procedure in 21 of 32 cases (65.6%) and a non-NS procedure in 11 of 32 cases (34.4%). CONCLUSIONS: Multiparametric MRI analysis can significantly improve the standard selection and management of prostate carcinoma cases considered for an NS RP.

Comparative analysis of multiparametric magnetic resonance and PET-CT in the management of local recurrence after radical prostatectomy for prostate cancer.

PURPOSE: Our aim was to assess whether multiparametric magnetic resonance and PET-CT can have a role in detecting local recurrence in patients with biochemical recurrence after radical prostatectomy. METHODS: We reviewed the recent international literature by carrying out a PUBMED search. RESULTS: We critically reviewed 11 recent original studies about the use of PET-CT and 5 recent studies about the use of multiparametric magnetic resonance. PET-CT has not shown significant results in terms of detection rate for local recurrence in patients with low level of PSA. Multiparametric magnetic resonance showed encouraging results to detect local recurrence in patients with low PSA and with small diameter lesions. CONCLUSIONS: Currently, most important urological societies do not consider multiparametric magnetic resonance and PET-CT in the follow-up of patients with suspected local recurrence after radical prostatectomy. We can assert that multiparametric magnetic resonance seems to have excellent results in detecting local recurrence in patients submitted to radical prostatectomy and PSA<1.5 ng/ml.

MR enterography: relationship between intestinal fold pattern and the clinical presentation of adult celiac disease.

PURPOSE: To correlate the clinical presentation of adult celiac disease with various intestinal fold patterns using MR-enterography. MATERIALS AND METHODS: Fifty-four consecutive adult celiac patients (34 female, 20 male, 18 to 62 years) were studied by MR-enterography. Two radiologists blinded to the patients' clinical history evaluated in consensus MR studies, classifying the intestinal fold pattern into four categories: (a) no fold abnormalities, (b) isolated loss of folds in the duodenum, (c) jejunization of ileum, and (d) jejuno-ileal fold pattern reversal. Patients presented with the varying clinical forms of Celiac disease, classified as: (i) typical disease, (ii) atypical disease, and (iii) silent form. RESULTS: Twenty-three patients showed no intestinal fold abnormalities; 11 patients had isolated loss of duodenal folds; 9 patients showed jejunization of ileum and 11 had jejuno-ileal fold pattern reversal. 18/23 (78%) patients with MRI normal fold pattern had the silent clinical form of Celiac disease (Sensitivity 78%; specificity 100%; PPV = 1, NPV = 0.78); 9/11 (82%) patients with the isolated loss of duodenal folds had the atypical clinical form (sensitivity 82%; and specificity 100%; PPV = 1; NPV = 0.82). All 20 patients with the jejunization of ileum and jejuno-ileal fold pattern reversal had typical celiac disease (sensitivity and specificity of 100%; PPV and NPV = 1). CONCLUSION: MR-enterography findings in patients with celiac disease, demonstrates good correlation between MR findings and clinical severity.

Imaging of the carotid artery.

In the study of carotid arteries, modern techniques of imaging allow to analyze various alterations beyond simple luminal narrowing, including the morphology of atherosclerotic plaques, the arterial wall and the surrounding structures. By using CTA and MRI it is possible to obtain three-dimensional rendering of anatomic structures with excellent detail for treatment planning. This paper will detail the role of various imaging methods for the assessment of carotid artery pathology with emphasis on the detection, analysis and characterization of carotid atherosclerosis.

Effect of preoperative breast magnetic resonance imaging on surgical decision making and cancer recurrence rates.

PURPOSE: To evaluate breast magnetic resonance imaging (MRI) for cancer staging and surgical planning in patients with known breast cancer, and to evaluate recurrence rates at long-term follow-up. METHODS AND MATERIALS: Institutional review board approval and patient consent were obtained. Preoperative MRI with 0.1 mmol/kg gadobenate dimeglumine (MultiHance) was performed in 203/274 women with confirmed breast cancer. The sensitivity, accuracy, and positive predictive value of MRI compared with mammography/ultrasound for malignant lesion detection were calculated, and the effect of MRI on surgical decision making evaluated. The cancer recurrence rate was determined for 172 patients with available 2- to 8-year follow-up data. RESULTS: Mammography/ultrasound detected 229 suspicious lesions. Breast MRI detected 159 additional lesions in 48/203 (23.6%) patients; of which 110/110 were correctly classified as malignant and 28/49 as benign, giving sensitivity, accuracy, and positive predictive values for malignant lesion detection of 100% (110/110), 86.8% (138/159), and 84.0% (110/131), respectively. MRI revealed unsuspected multifocal, multicentric, and synchronous contralateral lesions in 7/48, 16/48, and 16/48 patients, respectively, and pectoralis muscle infiltration in 3/38 patients. In 6/48 women, MRI revealed lesions not seen on conventional imaging (n = 5) or discounted suspected multifocal disease (n = 1). Therapy was changed for 50/203 (24.6%) patients: 38 patients underwent more extensive surgery and 12 less extensive surgery. Six (3.5%) recurrences occurred, in all cases at >4 years. CONCLUSION: Breast MRI positively affects patient management and is recommended for mapping tumor extent in patients with newly diagnosed cancer. The cancer recurrence rate at long-term follow-up after MRI is low.

Determination of the time for maximal response to neoadjuvant hormone therapy for prostate cancer using magnetic resonance with spectroscopy (MRSI) and dynamic contrast enhancement (DCEMR).

PURPOSE: To determine the time-dependent metabolic and angiogenic changes that occur in prostate cancer (CaP) during neoadjuvant hormone therapy (HT), using a combination of MRSI and DCEMR analysis. MATERIALS AND METHODS: This is a prospective study on a population of non-metastatic CaP submitted to neoadjuvant HT prior to radiation therapy. All cases homogeneously received a 6-month period of neoadjuvant HT using leuprorelin acetate 7.5 mg every 28 days. In all cases, a MRSI/DCEMR study was performed at baseline (pretreatment) and at regular intervals (4, 12, 24 weeks) during HT. Serum PSA was measured at baseline and at the same intervals (4, 12, 24 weeks). All MRI examinations were performed on a commercially available 3 T scanner. RESULTS: There was a significant ( P < 0.01) time-dependent loss of all prostate metabolites during HT. In regions of CaP no significant variation in the absolute value of metabolites was reported at 1-month interval and a higher variation was observed at 24-week compared with 12-week interval. A complete metabolic atrophy was a common feature (30%) at a 24-week interval of HT, but not at short (4-week 0%), and lower at an intermediate interval (12-week 10%). At DCEMR, onset time and time to peak parameters significantly (P < 0.05) increased at 12- and 24-week intervals. CONCLUSIONS: To individualize neoadjuvant HT courses prior to definitive treatment, the combination of MRSI and DCEMR may represent a valid noninvasive method, and the addition to PSA data could be used to better assess the time-dependent efficacy of HT in our patients.

Prostate cancer: 1HMRS-DCEMR at 3T versus [(18)F]choline PET/CT in the detection of local prostate cancer recurrence in men with biochemical progression after radical retropubic prostatectomy (RRP).

OBJECTIVES: This study compares proton magnetic resonancespectroscopic imaging (1H-MRSI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) combined techniques at 3T magnet versus [(18)F]choline PET/computed tomography (CT) in the detection of local prostate cancer recurrence in patients with biochemical progression after radical retropubic prostatectomy (RRP). MATERIALS AND METHODS: 84 consecutive patients at high risk of local recurrence underwent combined 1HMRSI-DCEMR and 18-Fcholine- PET/CT. MR scan protocol included turbo spin echo (TSE) T2-weighted sequences in the axial, sagittal and coronal planes; three-dimensional (3D) chemical shift imaging (CSI) sequences with spectral/spatial pulses optimized for quantitative detection of choline and citrate; dynamic contrast enhanced gradient-echo (GRE) T1-weighted sequence. The population was divided into two groups. Group A included 28 patients with a lesion size ranging between 5.00mm and 7.2mm and PSA reduction following radiation therapy. Group B included 56 patients with a lesion size between 7.6mm and 19.4mm. Sensitivity, specificity, positive predictive value (PPV) and accuracy were evaluated and receiver operating characteristic (ROC) curves were performed. RESULTS: In Group A combined 1H-MRSI and DCE-MRI showed a sensitivity of 92%, a specificity of 75% (PPV 96%) while PET-CT examination showed a sensitivity of 62% and a specificity of 50% (PPV 88%) in identifying local recurrence. The accuracy of MRI was 89% while PET-CT showed an accuracy of 60%. Areas under the ROC curve (AUC) values for MR and PET-CT were 0.833 and 0.562, respectively. In Group B combined 1H-MRSI and DCEMR showed a sensitivity of 94% and a specificity of 100% (PPV 100%) with accuracy of 94%. PET-CT had a sensitivity of 92% and a specificity of 33% (PPV 98%) with accuracy of 91%. The AUCs for MR and PET-CT values were 0.971 and 0.837, respectively. CONCLUSION: The diagnostic accuracy of combined 1HMRSI-DCEMR was higher than PET/CT to identify local prostate cancer recurrence, mostly in patients with low biochemical progression after RRP (0.2-2ng/mL).

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 (), 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.

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.

Retrograde popliteal access in the supine patient for recanalization of the superficial femoral artery: initial results.

PURPOSE: To report an initial experience of superficial femoral artery (SFA) recanalization performed with a dual femoral-popliteal approach in the supine patient. METHODS: From May 2008 to April 2010, 26 patients (16 men; mean age 68 ± 6.3 years) with intermittent claudication and chronic SFA occlusion (mean length 97.4 ± 3.8 mm, range 35-220) underwent percutaneous recanalization from a retrograde popliteal access. The common femoral artery was punctured with an antegrade (n = 9) or retrograde contralateral (n = 17) approach, then with the patient still supine and the knee gently flexed and medially rotated, the popliteal artery was punctured using an 18-G needle under ultrasound (10, 38.4%) or fluoroscopic (16, 61.5%) guidance with a roadmap technique. Once the SFA was recanalized, the procedure was completed with angioplasty and stenting from the femoral approach. At the end of the procedure, hemostasis at the popliteal access was obtained with manual compression (5-10 minutes). RESULTS: Technical success (puncture of the popliteal artery and SFA recanalization) was achieved in all cases. In the majority of patients (24, 91.6%), endoluminal recanalization was possible from the popliteal access; SFA recanalization in the other 2 cases was obtained through the subintimal space. Two small hematomas were found in the popliteal region, but no pseudoaneurysm or arteriovenous fistulas were seen on duplex examinations during a mean 12.5-month follow-up (range 6-28). Twenty (76.9%) SFAs were patent; in-stent restenosis occurred in the remaining 6 (23%). Primary patency was 80.7% at 6 months and 76.9% at 1 year. No stent fracture was observed. CONCLUSION: The retrograde popliteal approach with the patient in the supine position can be considered a "first choice" method for safe and effective SFA recanalization, especially in occlusions located at the distal and mid portion SFA.

Adolescent Kawasaki disease: usefulness of 64-slice CT coronary angiography for follow-up investigation.

BACKGROUND: Kawasaki disease (KD) is a systemic vasculitis that mainly affects coronary arteries in children, and requires regular follow-up from the time of diagnosis. OBJECTIVE: To evaluate the feasibility of 64-slice CT angiography (CTA) for follow-up of patients with KD using previously performed invasive catheter coronary angiography (CCA) as reference standard. MATERIALS AND METHODS: The study group comprised 12 patients (age 17.6 ± 2.9 years, mean ± SD) with a diagnosis of KD and a previously performed CCA (interval, 32.6 ± 13.5 months) who underwent 64-slice cardiac CTA. The quality of the images for establishing the presence of coronary abnormalities was determined by two observers. The CTA findings were compared with those from the prior CCA. RESULTS: Adequate image quality was obtained in all patients. Mean effective dose for CTA was 6.56 ± 0.95 mSv. CTA allowed accurate identification, characterization and measurement of all coronary aneurysms (n = 32), stenoses (n = 3) and occlusions (n = 9) previously demonstrated by CCA. One patient with disease progression went on to have percutaneous coronary intervention. CONCLUSION: Coronary lesions were reliably evaluated by 64-slice CTA in the follow-up of compliant patients with KD, reducing the need for repeated diagnostic invasive CCA. Hence, in an adequately selected patient population, the role of CCA could be limited almost only to therapeutic procedures.

Investigation of the longitudinal relaxation rate of blood after gadobenate dimeglumine administration: sequence optimization, dynamic acquisition, and clinical impact for contrast-enhanced MR angiography of the carotid arteries.

OBJECTIVES: To optimize the image acquisition parameters for improved steady-state (SS) contrast-enhanced magnetic resonance angiography (CE-MRA) of the carotid arteries with gadobenate dimeglumine. MATERIALS AND METHODS: An inversion recovery fast low-angle shot (IR-FLASH) sequence for ultrafast determination of the longitudinal relaxation rate R1 was first optimized on phantoms and tested against a routine variable repetition time (TR) spin echo sequence used as reference standard. Different combinations of flip angle (FA, between 6 and 14 degrees) and inversion time (between 134 and 9000 milliseconds) were evaluated to achieve the best trade off between speed and accuracy. The optimized sequence was thereafter used in vivo in 5 subjects to determine the time evolution of blood R1 at 1.5 T after administration of gadobenate dimeglumine at 0.1 mmol/kg bodyweight. An optimal FA for angiographic measurement was thereafter derived from the Ernst equation based on experimental values of R1 previously determined in vivo. Finally, steady-state CE-MRA examinations were performed in 20 subjects to evaluate the improved contrast achieved after optimization of the FA for maximal blood signal enhancement. RESULTS: An ultrafast IR-FLASH sequence with a flip angle of 8 degrees and a properly defined set of inversion time values was shown to give in vitro R1 determinations that were in good agreement with those obtained using a routine, time consuming, variable-TR spin echo sequence. The use of this ultrafast IR-FLASH sequence in vivo allowed the blood signal behavior in the carotid arteries after gadobenate dimeglumine administration to be monitored. Using this sequence, the R1 decreased from 8.7±0.96 s⁻¹ at 30 seconds after injection to 3.8±0.24 s⁻¹ at 10 minutes after injection. Based on these data for R1, the optimal FA for SS CE-MRA was calculated to be 18 degrees for a gradient echo acquisition protocol with TR=7.5 milliseconds, when gadobenate dimeglumine is used. Significantly higher blood signal to noise ratio was achieved on SS images acquired using a three-dimensional spoiled gradient echo sequence with a FA of 18 degrees than on corresponding images acquired with a FA of 35 degrees as used typically for intravascular blood pool contrast agents (52.5±8.3 vs. 29.5±6.0; P<0.05, Mann-Whitney U test). CONCLUSION: Detailed experimental knowledge of the in vivo R1 behavior of blood after gadobenate dimeglumine injection and appropriate modification of the acquisition parameters enables improved signal intensity enhancement on steady-state CE-MRA of the carotid arteries.

64-section multidetector CT of the upper abdomen: optimization of a saline chaser injection protocol for improved vascular and parenchymal contrast enhancement.

OBJECTIVES: To prospectively investigate the effect of varying the injection flow rates of a saline chaser on vascular and parenchymal contrast enhancement during abdominal MDCT. METHODS: 100 consecutive patients were randomly assigned to four injection protocols. A fixed dose of contrast medium was administered followed by no saline (Protocol A) or 50 mL of saline at 2, 4, or 8 mL/s (Protocols B, C, and D). Peak, time-to-peak, and duration of 90% peak enhancement were determined for aorta, pancreas, and liver. RESULTS: Aortic peak enhancement was significantly higher for Protocol D (369.5 HU) compared with Protocols A and B (332.9 HU and 326.0 HU, respectively; P < 0.05). Pancreatic peak enhancement was significantly higher for Protocols C and D (110.6 HU and 110.9 HU, respectively) compared to Protocol A (92.5 HU; P < 0.05). Aortic and pancreatic time-to-peak enhancement occurred significantly later for Protocol D compared with Protocol A (42.8 s vs. 36.1 s [P < 0.001] and 49.7 s vs. 45.3 s [P = 0.003]). CONCLUSIONS: Injecting a saline chaser at high flow rates yields significantly higher peak aortic and pancreatic enhancement, with a slight longer time-to-peak enhancement.

PCA3 urinary test versus 1H-MRSI and DCEMR in the detection of prostate cancer foci in patients with biochemical alterations.

AIM: To compare the prostate antigen 3 (PCA3) test with (1)H-magnetic resonance spectroscopic imaging ((1)H-MRSI) and dynamic contrast-enhanced magnetic resonance imaging (DCEMR) combined examination in the detection of prostate tumor foci in patients with persistently elevated prostate-specific antigen (PSA) levels and prior negative random transrectal ultrasound (TRUS)-guided biopsy. PATIENTS AND METHODS: Forty-three patients with a first random biopsy negative for prostate adenocarcinoma, persistent elevated PSA and negative digital rectal examination were recruited. All the patients were submitted to MRSI examination (MRSI-DCEMR) and were submitted to an attentive prostate massage in order to perform PCA3 assay. Afterwards, 10-core laterally-directed random TRUS-guided prostate biopsy was performed. RESULTS: The overall sensitivity and specificity of a PCA3 score ≥35 for positive biopsy were 76.9% and 66.6%, respectively, with a positive predictive value (PPV) of 80% and a negative predictive value (NPV) of 62.5%; as for MRSI sensitivity and specificity were, respectively, 92.8% and 86.6% with a PPV of 92.8% and a NPV of 86.6%. Receiver operating characteristic (ROC) analysis rates were 0.755 for PCA3 and 0.864 for MRSI. CONCLUSION: Combined MRSI/DCEMR can better improve the cancer detection rate in patients with prior negative TRUS-guided biopsy and altered PSA serum levels than PCA3. Optimization of MRSI will allow more precise diagnosis of local invasion and improved bioptical procedures.

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.