Outcomes of Patients Treated With Upfront Cholecystostomy for Severe Acute Cholecystitis.

INTRODUCTION: Percutaneous cholecystostomy tube (PCT) placement is a treatment method for acute cholecystitis, both in adult patients unsuitable for surgery and those failing to improve with conservative management. The purpose of this study was to assess the outcomes of patients undergoing cholecystostomy. MATERIALS AND METHODS: A review of consecutive patients who underwent PCT insertion over a 10-year period was performed. Outcomes assessed included cholecystostomy dwell time, tubogram requirement, cholecystostomy reinsertion, cholecystectomy, bile leaks, and mortality. RESULTS: One hundred eight patients (77 male individuals, 31 female individuals) were included. The mean age was 70 years (range: 29 to 93 y). A total of 89 transhepatic and 19 transperitoneal PCTs were inserted. Fifty-nine patients (55%) had a subsequent tubogram to assess cystic duct patency or catheter position. Mean catheter dwell time was 17 days (range: 1 to 154 d). Eleven (10%) required PCT reinsertion. Time to reinsertion ranged from 2 to 163 days (mean=38 d). Fifty-three patients (50%) had no further biliary intervention after removal of the cholecystostomy catheter. One patient required subsequent drainage of a hepatic abscess, and another developed a biloma. Thirty-two patients (30%) underwent cholecystectomy (66% laparoscopic, 34% open). Thirty-day mortality after PCT insertion was 8.3%. Twenty patients (19%) died of non-cholecystostomy-related illness during the 10-year follow-up period. CONCLUSIONS: Cholecystostomy is an important treatment method of acute cholecystitis as a bridge to cholecystectomy or as an alternative definitive treatment option in those unsuitable for surgery. A tubogram is not always necessary before tube removal. Cholecystostomy tubes can be removed safely with little risk of bile leak if patients are clinically well, and clean-appearing bile is draining.

Single-institution experience with selective internal radiation therapy (SIRT) for the treatment of unresectable colorectal liver metastases.

BACKGROUND: Liver metastases are the commonest cause of death for patients with colorectal cancer. Growing evidence supports the use of selective internal radiation therapy (SIRT) in combination with conventional chemotherapy regimens for liver-only or liver-dominant unresectable metastatic colorectal cancer. AIMS: To measure and evaluate outcomes of the first 20 consecutive patients with unresectable colorectal liver metastasis selected for SIRT in addition to their chemotherapy at a single Irish institution. METHODS: Retrospective case series was performed. Patient charts and medical records were reviewed. RESULTS: All 20 patients (100%) selected for angiographic workup were subsequently successfully treated with radioembolization. All patients were discharged 1 day post-SIRT. At initial imaging evaluation, 12 (60%) had a partial response in their liver, 2 (10%) had stable disease, and 6 (30%) had liver-specific progressive disease. Median follow up was 10 months (range 6-26). At last follow up, 14 (70%) patients were alive and 6 (30%) deceased. Most recent imaging demonstrated 2 (10%) with a complete response, 7 (35%) had a partial response, 2 (10%) had stable disease, and 9 (45%) had progressive disease within their liver. One patient was downstaged to hepatic resection, and one with a complete hepatic response had his primary sigmoid tumor resected 11 months post-SIRT. CONCLUSIONS: SIRT is a safe and effective therapy for certain patients with unresectable colorectal liver metastases. This case series supports our opinion that selected patients should be offered SIRT in concert with their medical oncologist, concomitant with their chemotherapy. Larger multi-center studies are required to more clearly define the patient groups that will derive most benefit from SIRT.

What Are the Indications for Prophylactic Embolization of Renal Angiomyolipomas? A Review of the Current Evidence in the Literature.

Renal angiomyolipomas (AMLs) are benign tumours that may occur sporadically in the general population or in patients with tuberous sclerosis complex. The concern with AMLs is that of retroperitoneal hemorrhage, which can be fatal. Classically the trigger for prophylactic intervention was thought to be an AML diameter of ≥4 cm. However, this value is largely based on data from case series and heterogeneous retrospective studies. The PICO (patient, intervention, comparison, outcome) paradigm was used to systematically search the Cochrane database, TRIP database, and PubMed. The quality of evidence in the literature is poor regarding the indications for prophylactic embolization of AMLs (level 4). There are no prospective studies that adequately assess embolization vs other treatment modalities. However, using the available evidence we have produced recommendations for when intervention should be considered. We have also made recommendations regarding the direction of future research.

Novel Use of a Pneumatic Compression Device for Haemostasis of Haemodialysis Fistula Access Catheterisation Sites.

PURPOSE: Transradial pneumatic compression devices can be used to achieve haemostasis following radial artery puncture. This article describes a novel technique for acquiring haemostasis of arterio-venous haemodialysis fistula access sites without the need for suture placement using one such compression device. MATERIALS AND METHODS: A retrospective review of fistulograms with or without angioplasty/thrombectomy in a single institution was performed. 20 procedures performed on 12 patients who underwent percutaneous intervention of failing or thrombosed arterio-venous fistulas (AVF) had 27 puncture sites. Haemostasis was achieved using a pneumatic compression device at all access sites. Procedure details including size of access sheath, heparin administration and complications were recorded. RESULTS: Two diagnostic fistulograms, 14 fistulograms and angioplasties and four thrombectomies were performed via access sheaths with an average size (±SD) of 6 Fr (±1.12). IV unfractionated heparin was administered in 11 of 20 procedures. Haemostasis was achieved in 26 of 27 access sites following 15-20 min of compression using the pneumatic compression device. One case experienced limited bleeding from an inflow access site that was successfully treated with reinflation of the device for a further 5 min. No other complication was recorded. CONCLUSIONS: Haemostasis of arterio-venous haemodialysis fistula access sites can be safely and effectively achieved using a pneumatic compression device. This is a technically simple, safe and sutureless technique for acquiring haemostasis after AVF intervention.

Asymptomatic Renal Pseudoaneurysm Following Laparoscopic Partial Nephrectomy.

A 66-year-old-woman underwent a laparoscopic left partial nephrectomy for a 3 cm partially exophytic tumor arising from the posterior interpolar region of the left kidney. Follow-up surveillance computed tomography 6 months following the surgery found an incidental 4 cm lesion in the left kidney that is avidly enhanced in the arterial phase, consistent with a renal pseudoaneurysm. She was completely asymptomatic. Renal pseudoaneurysm is a rare complication following minimally invasive nephron-sparing surgery and typically presents in the early postoperative period with gross hematuria. However, a large renal pseudoaneurysm may also present as an asymptomatic incidental finding and is amenable to angioembolization.

Correlation of Peripheral Vein Tumour Marker Levels, Internal Iliac Vein Tumour Marker Levels and Radical Prostatectomy Specimens in Patients with Prostate Cancer and Borderline High Prostate-Specific Antigen: A Pilot Study.

PURPOSE: To correlate prostate-specific antigen (PSA), free to total PSA percentage (fPSA%) and prostatic acid phosphatase (PAP) levels from peripheral and pelvic venous samples with prostatectomy specimens in patients with prostate adenocarcinoma and borderline elevation of PSA. MATERIALS AND METHODS: In this prospective institutional review board approved study, 7 patients with biopsy proven prostate cancer had a venous sampling procedure prior to prostatectomy (mean 3.2 days, range 1-7). Venous samples were taken from a peripheral vein (PVS), the right internal iliac vein, a deep right internal iliac vein branch, left internal iliac vein and a deep left internal iliac vein branch. Venous sampling results were compared to tumour volume, laterality, stage and grade in prostatectomy surgical specimens. RESULTS: Mean PVS PSA was 4.29, range 2.3-6 ng/ml. PSA and PAP values in PVS did not differ significantly from internal iliac or deep internal iliac vein samples (p > 0.05). fPSA% was significantly higher in internal iliac (p = 0.004) and deep internal iliac (p = 0.003) vein samples compared to PVS. One of 7 patients had unilateral tumour only. This patient, with left-sided tumour, had a fPSA% of 6, 6, 6, 14 and 12 in his peripheral, right internal iliac, deep right internal iliac branch, left internal iliac and deep left internal iliac branch samples respectively. There were no adverse events. CONCLUSION: fPSA%, unlike total PSA or PAP, is significantly higher in pelvic vein compared to peripheral vein samples when prostate cancer is present. Larger studies including patients with higher PSA values are warranted to further investigate this counterintuitive finding.

Medical emergencies and cardiopulmonary arrests in interventional radiology.

PURPOSE: To evaluate the circumstances and determine the outcomes of medical emergencies (MEs) and cardiopulmonary arrests (CPAs) in patients undergoing interventional radiology (IR) procedures. MATERIALS AND METHODS: Retrospective review of all MEs and CPAs that occurred between July 2006 and December 2011 was performed. Procedure type, technical outcome, complications, etiology and location of ME/CPA, event outcome, and postevent mortality were collected. RESULTS: A total of 58 events occurred during 38,927 procedures (0.15%). Complete records were available for 55 events (43 MEs, 12 CPAs) in 53 patients (mean age, 63 y; 58.5% male) during 37 inpatient (27 MEs, 10 CPAs) and 18 outpatient (16 MEs, two CPAs) encounters. Seven events (13%; six MEs, one CPA) occurred before the start of the procedure, and 18 (33%; 16 MEs, two CPAs) occurred in the periprocedural holding area. Thirty-five procedures (64%) were completed successfully. Forty-two patients (76%) were alive at discharge, 37 (67%) at 1 month, 26 (47%) at 3 months, and 23 (42%) at 1 year. Procedural complications were attributed as the main cause of 22 MEs (51%) and one CPA (8%; P = .018). The relative risk (RR) of an ME or CPA occurring during a hemodialysis access case versus all other cases was 5.2 (95% confidence interval = 3.02-8.95; P < .0001). CONCLUSIONS: Although the incidence of MEs/CPAs in patients undergoing IR procedures is low, the 1-year mortality rate following these events is high. MEs are significantly more likely than CPAs to be directly attributed to a procedural complication. The RR of MEs/CPAs is significantly higher in hemodialysis access interventions.

Chest radiograph-based algorithm for managing malfunctioning ports.

PURPOSE: To evaluate a chest x-ray-based algorithm for managing malfunctioning ports. MATERIALS AND METHODS: A review of interventional radiology procedures on malfunctioning ports during the period 2000-2012 was performed. Events were divided into two periods: before and after implementation of an algorithm beginning with tip position evaluation using a chest x-ray. Time to return to usability, frequency of interventions to restore function, and frequency of malfunctioning ports remaining in use after the procedure were calculated. RESULTS: The review included 303 procedures before implementation of the algorithm on 237 access sites in 227 patients (mean age, 56 y; 38% male) and 155 procedures after implementation of the algorithm on 131 access sites in 130 patients (mean age, 55 y; 35% male). Implementation of the algorithm was associated with significantly fewer repeat checks on the same access (27% before algorithm, 9% after algorithm, P < .001) and reduced frequency of a malfunctioning port remaining in use after the interventional radiology procedure (43% before algorithm to 14% after algorithm, P < .001). Median time from consultation to revision was significantly less after implementing the algorithm (13 days before algorithm, 1 day after algorithm, P < .001). Median time from consultation to port usability was also less after implementing the algorithm (2.7 days before algorithm, 1 day after algorithm, P < .001). CONCLUSIONS: Implementation of the algorithm was associated with significantly less frequent repeat procedures on the same port and a lower frequency of malfunctioning ports remaining in place. Use of the algorithm was associated with significantly reduced time from consultation to revision and to return to usability. These findings suggest the algorithm allows triage of patients with malfunctioning ports to the appropriate intervention before undergoing a procedure.

Translumbar hemodialysis catheters in patients with limited central venous access: does patient size matter?

PURPOSE: To describe a single institutional experience with translumbar tunneled dialysis catheters (TDC) and compare outcomes between patients with normal and abnormal body mass index (BMI). MATERIALS AND METHODS: Translumbar TDCs placed between January 2002 and July 2011 were reviewed retrospectively. There were 33 patients; 18 had a normal BMI<25, and 15 had an abnormal BMI>25. Technical outcome, complications, indications for exchange or removal, and BMI were recorded. Catheter dwell time, catheter occlusion rate, frequency of malposition, and infection rates were collected. RESULTS: There were 92 procedures (33 initial placements) with 7,825 catheter days. The technical success rate was 100%. Two minor (2.2%) and three major (3.3%) complications occurred. The complication rate did not differ significantly between patients with a normal BMI and patients with an abnormal BMI. Median catheter time in situ (interquartile range) for all patients was 61 (113) days, for patients with normal BMI was 66 (114) days, and for patients with abnormal BMI was 56 (105) days (P = .9). Primary device service intervals for all patients, patients with normal BMI, and patients with abnormal BMI were 47 (96) days, 63 (98) days, and 39 (55) days (P = .1). Secondary device service intervals for all patients, patients with normal BMI, and patients with abnormal BMI were 147 (386) days, 109 (124) days, and 409 (503) days (P = .23). Catheter-related central venous thrombosis rate was 0.01 per 100 catheter days (n = 1). CONCLUSIONS: Translumbar TDC placement can provide effective hemodialysis in patients with limited venous reserve regardless of the patient's BMI. An abnormal BMI (>25) does not significantly affect complication rate, median catheter time in situ, or primary or secondary device service interval of translumbar TDCs.

Catheter-based intraaccess blood flow measurement as a problem-solving tool in hemodialysis access intervention.

PURPOSE: To investigate retrospectively the use of catheter-based intraaccess blood flow measurements as an adjunct to physical examination and fistulography in hemodialysis access interventions. MATERIALS AND METHODS: Among 1,540 dialysis interventions performed at a single institution in a 2.5-year period, 104 qualifying catheter-based flow measurements were made in 70 mature native fistula interventions in 55 patients and 34 graft interventions in 31 patients. The flow rate threshold prompting intervention was generally 600 mL/min, but some variation existed depending on the clinical setting. RESULTS: The most common indication for measurement of blood flow was to determine the hemodynamic significance of a fistula inflow stenosis (n = 25), of which only four had subsequent intervention. Other common indications included decision-making resulting in further angioplasty or stent implantation of noninflow lesions (fistulas, n = 10; grafts, n = 23) versus termination of the procedure (n = 23), problem-solving in cases in which there was no visible lesion to explain the clinical indicator of access failure (n = 17), evaluation for high-flow-related cardiac risk in aneurysmal fistulas (n = 13), suboptimal evaluation of the inflow (n = 8), and suboptimal physical examination (n = 6). Overall, flow measurements supported a decision to perform angioplasty (n = 11) or stent placement (n = 3) in 17% of fistula interventions and 35% of graft interventions. CONCLUSIONS: The major benefit of flow measurement was to support a decision to withhold further angioplasty or stent placement.

Clinical correlates of size and number of collateral vessels in peripheral artery disease.

We studied associations of the number and size of magnetic resonance angiography (MRA)-assessed lower extremity collateral vessels with the ankle-brachial index (ABI), severity of superficial femoral artery (SFA) plaque, and leg symptoms in participants with peripheral artery disease (PAD). A total of 303 participants with PAD underwent time-resolved MRA at the thigh station. Collaterals were categorized by number (Category 1: 0-3 collaterals; Category 2: 4-7 collaterals; Category 3: ≥ 8 collateral vessels) and size (Grade 1: ≤ 5 small collaterals; Grade 2: > 5 small vessels; Grade 3: ≤ 5 large collaterals; Grade 4: > 5 large collaterals). Adjusting for age, sex, race, comorbidities and other covariates, more numerous collateral vessels were associated with lower ABI values (Category 1: 0.79; Category 2: 0.67; Category 3: 0.60; p trend < 0.001). Similarly, larger collateral vessels were associated with lower ABI values (Grade 1: 0.75; Grade 2: 0.65; Grade 3: 0.62; Grade 4: 0.59; p trend < 0.001). More numerous (p < 0.001) and larger (p < 0.001) collateral vessels were associated with greater mean SFA plaque area (p trend < 0.001). More numerous (p trend = 0.007) and larger (p trend = 0.017) collateral vessels were associated with a lower prevalence of asymptomatic PAD. In conclusion, among participants with PAD, larger and more numerous collaterals, measured by MRA, were associated with lower ABI values, greater plaque area in the SFA, and a lower prevalence of asymptomatic PAD. Further study is needed to determine the role of collateral vessels in maintaining functional performance in PAD.

ECG-gated multiecho Dixon fat-water separation in cardiac MRI: advantages over conventional fat-saturated imaging.

OBJECTIVE: The purpose of this pictorial essay is to explore the advantages of multiecho Dixon fat-water separation techniques in cardiac MRI. The clinical indications, potential artifacts, and imaging findings with this technique are reviewed. CONCLUSION: Multiecho Dixon fat-water separation can be used to help characterize cardiac masses, evaluate for myocardial lipomatous infiltration, and diagnose pericarditis. Advantages over conventional fat-saturation techniques include fewer artifacts from background inhomogeneity, improved contrast of microscopic fat, and capability for use in combination with cine and contrast-enhanced imaging.

MDCT bolus tracking data as an adjunct for predicting the diagnosis of pulmonary hypertension and concomitant right-heart failure.

OBJECTIVE: The purpose of this study was to investigate the utility of bolus-triggering data from pulmonary CT angiography for predicting the diagnosis of pulmonary hypertension (PH) and right ventricular dysfunction (RVD) and to test its performance against previously established CT signs of PH. MATERIALS AND METHODS: Automated bolus-triggering data from pulmonary CT angiograms of 101 patients were correlated with echocardiographic findings and a variety of CT-derived indexes of PH and RVD, including right and left ventricular minor axis diameter; pulmonary artery (PA), aortic, and superior vena caval diameters; right ventricular thickness; contrast reflux; and configuration of the interventricular septum. For bolus triggering, a region of interest was placed in the main PA. Time to threshold, defined as the time from the beginning of contrast injection to the time attenuation exceeded the threshold (100 HU), was measured. On the basis of results of two consecutive echocardiographic studies, subjects were divided into control and PH groups. The latter group was subdivided into PH without RVD and PH with RVD. Time to threshold values were compared between groups and correlated with standard CT-derived parameters. RESULTS: Significant differences between groups were found in time to threshold, PA and right ventricular diameters, and PA-to-aorta and right ventricular-to-left ventricular ratios. Time to threshold had an incremental pattern from the control group (6.6 ± 1.0 seconds) to PH without RVD (9.2 ± 2.4 seconds) and PH with RVD (12.1 ± 3.4 seconds) (p < 0.001). The optimal diagnostic performance of time to threshold for revealing the presence of PH and RVD was at cutoff values of 7.75 and 8.75 seconds, respectively. Time to threshold had a strong direct correlation with PA diameter. In multivariable analyses, time to threshold was identified as a significant predictor of PH and RVD. The specificity of time to threshold and PA diameter together was higher than that of PA diameter alone. CONCLUSION: Measurement of time to threshold of contrast enhancement derived from bolus-timing data at MDCT may be a useful adjunctive tool for diagnosing PH and consequent RVD.

Transcatheter arterial embolization of spontaneous life-threatening extraperitoneal hemorrhage.

PURPOSE: To determine the outcomes of patients with spontaneous extraperitoneal hemorrhage (SEH) referred for endovascular therapy. MATERIALS AND METHODS: A retrospective analysis included 25 patients (13 male) with 28 spontaneous bleeding events that occurred during the period 1998-2009. All patients had a computed tomography (CT) scan showing extraperitoneal hematoma before angiography. Hematoma location, presence of contrast extravasation or hematocrit level on CT, angiographic findings, vessels that received embolization, angiographic outcome, transfusion requirements, and mortality were recorded. Patients' medications, lowest measured hemoglobin levels, serologic coagulation parameters, and comorbidities were also noted. Mean follow-up was 37.4 months (range 2-132 mo). RESULTS: Patients had received anticoagulation therapy before 20 of 28 bleeding events. Angiography showed contrast extravasation in 22 (79%) of 28 cases. Angiographic cessation of bleeding with embolization was achieved in all 22 cases. There was extravasation from more than one site in 17 (61%) of 28 cases. There was bleeding in more than one vascular territory in eight (29%) cases. Empiric embolization was performed in three cases. In the 48 hours following angiography, transfusion requirements decreased in 27 (96%) of 28 cases, and there were no deaths. All-cause mortality at 30 days was 29%, at 90 days was 32%, and at 12 months was 43%. CONCLUSIONS: Multiple bleeding sites are typical in SEH. Transcatheter embolization is a safe and effective treatment; however, mortality is high in the time around angiography.

Coronary multidetector computed tomographic angiography to evaluate coronary artery disease in liver transplant candidates: methods, feasibility and initial experience.

AIMS: In patients undergoing orthotopic liver transplantation (OLT), coronary artery disease (CAD), obstructive and nonobstructive, is associated with high morbidity and mortality. In OLT candidates, stress testing for detecting ischemia is often inaccurate, and this patient population often has relative contraindications for cardiac catheterization. The objective of this study was to describe the methods, assess the feasibility and determine the extent and severity of CAD in OLT candidates without a prior history of CAD using coronary multidetector computer tomographic angiography (MDCTA). METHODS: Sixty-five OLT candidates without known CAD underwent coronary MDCTA with dual source cardiac computed tomography (Siemens Definition). Coronary arteries were divided into 17 segments based on American Heart Association guidelines and evaluated independently by two blinded reviewers. Image quality of coronary MDCTA was assessed on a four-point Likert scale (0 = poor, 1 = fair, 2 = good, and 3 = excellent). Atherosclerotic lesions were evaluated for severity [mild (0-50%), moderate (51-70%), and severe (71-100%)], morphology, extent, location and consistency. RESULTS: Image quality was graded as good or excellent in 73.8%. In this cohort of OLT candidates without known CAD, 9% had normal coronary arteries, 58% had mild CAD and 34% had moderate to severe CAD. Plaque severity and burden scores were high. CONCLUSION: The prevalence of asymptomatic CAD is high in OLT candidates. Coronary MDCTA is feasible in OLT candidates and appears to be a useful technique to diagnose occult CAD in this patient population.

Improved detection of subendocardial hyperenhancement in myocardial infarction using dark blood-pool delayed enhancement MRI.

OBJECTIVE: Delayed enhancement MRI using fast segmented k-space inversion recovery (IR) gradient-echo imaging is a well established "bright-blood" technique for identifying myocardial infarction and is used as the reference standard sequence in this study. The purpose of this study was to validate a recently developed dark blood-pool delayed enhancement technique in a porcine animal model, evaluate its performance in human patients, and quantify its performance compared with the reference standard in both. SUBJECTS AND METHODS: In an animal study, the reference standard and dark blood-pool delayed enhancement were assessed in three pigs with induced myocardial infarction. In a human study, 26 patients, 31-81 years old (19 men and seven women), with a known history of myocardial infarction were imaged using the reference standard and dark blood-pool delayed enhancement. Contrast-to-noise ratio (CNR), signal intensity ratio, signal-to-noise ratio (SNR), and qualitative scores of hyperenhancement were recorded. Measurements were compared using paired samples t test and Wilcoxon's signed rank test. RESULTS: In the animal study, the mean CNR of infarct to blood pool was 11 times higher for dark blood-pool delayed enhancement than for the reference standard. The mean SNR was 4.4 times higher for the reference standard. In the human study, the mean CNR and signal intensity ratio of hyperenhancing myocardium to the blood pool were 1.9 (p = 0.04) and 5.5 (p < 0.01) times higher, respectively, for dark blood-pool delayed enhancement compared with reference standard. The mean CNR and signal intensity ratio of hyperenhancing myocardium to normal myocardium and SNR were 2.8 (p < 0.01), 1.3 (p = 0.07), and 2.8 (p < 0.01) higher, respectively, for the reference standard. Qualitative analysis identified seven extra segments with grade 1 scars using dark blood-pool delayed enhancement (p < 0.01). CONCLUSION: Dark blood-pool delayed enhancement is complementary to the reference standard. It can detect more subendocardial foci of hyperenhancement, thus potentially identifying more infarcts and changing patient management.

Assessment of left ventricular myocardial scar in infiltrative and non-ischemic cardiac diseases by free breathing three dimensional phase sensitive inversion recovery (PSIR) TurboFLASH.

The purpose of this study was to compare a navigator gated free breathing 3D Phase Sensitive Inversion Recovery (PSIR) TurboFLASH to an established 2D PSIR TurboFLASH method for detecting myocardial late gadolinium hyperenhanced lesions caused by infiltrative and non-ischemic cardiomyopathy. Under an IRB approved protocol; patients with suspected non-ischemic infiltrative myocardial heart disease were examined on a 1.5T MR scanner for late enhancement after the administration of gadolinium using a segmented 2D PSIR TurboFLASH sequence followed by a navigator-gated 3D PSIR TurboFLASH sequence. Two independent readers analyzed image quality using a four point Likert scale for qualitative analysis (0 = poor, non diagnostic; 1 = fair, diagnostic may be impaired; 2 = good, some artifacts but not interfering in diagnostics, 3 = excellent, no artifacts) and also reported presence or absence of scar. Detected scars were classified based on area and location and also compared quantitatively in volume. Twenty-seven patients were scanned using both protocols. Image quality score did not differ significantly (p = 0.358, Wilcoxon signed rank test) for both technique. Scars were detected in 24 patients. Larger numbers of hyperenhanced scars were detected with 3D PSIR (200) compared to 2D PSIR (167) and scar volume were significant larger in 3D PSIR (p = 0.004). The mean scar volume over all cases was 49.95 cm(3) for 2D PSIR and 70.02 cm(3) for 3D PSIR. The navigator gated free breathing 3D PSIR approach is a suitable method for detecting myocardial late gadolinium hyperenhanced lesions caused by non-ischemic cardiomyopathy due to its complete isotropic coverage of the left ventricle, improving detection of scar lesions compared to 2D PSIR imaging.

Technical considerations for lower limb multidetector computed tomographic angiography.

Multidetector computed tomography (MDCT) enables imaging of the entire arterial tree non-invasively. Optimal technical considerations for performing MDCT angiography (MDCTA) are essential for accurate diagnosis and atherosclerotic disease stratification. This review article focuses on the various technical aspects necessary for peripheral computed tomographic angiography (CTA) acquisition. Common clinical indications for peripheral MDCTA and the latest scan protocols are described. The essential issue of radiation dose reduction is discussed, along with methods of optimal contrast bolus detection and delivery. Post-processing techniques are also presented. Previously, digital subtraction angiography was the only established reliable imaging technique to quantify atherosclerotic disease load; however, MDCTA may now challenge this old gold standard, along with other non-invasive techniques such as magnetic resonance angiography (MRA).