Chad J. Fleming

Intravenous Contrast Material–induced Nephropathy: Causal or Coincident Phenomenon?

PURPOSE To determine the causal association and effect of intravenous iodinated contrast material exposure on the incidence of acute kidney injury (AKI), also known as contrast material-induced nephropathy (CIN). MATERIALS AND METHODS This retrospective study was approved by an institutional review board and was HIPAA compliant. Informed consent was waived. All contrast material-enhanced (contrast group) and unenhanced (noncontrast group) abdominal, pelvic, and thoracic CT scans from 2000 to 2010 were identified at a single facility. Scan recipients were sorted into low- (<1.5 mg/dL), medium- (1.5-2.0 mg/dL), and high-risk (>2.0 mg/dL) subgroups of presumed risk for CIN by using baseline serum creatinine (SCr) level. The incidence of AKI (SCr ≥ 0.5 mg/dL above baseline) was compared between contrast and noncontrast groups after propensity score adjustment by stratification, 1:1 matching, inverse weighting, and weighting by the odds methods to reduce intergroup selection bias. Counterfactual analysis was used to evaluate the causal relation between contrast material exposure and AKI by evaluating patients who underwent contrast-enhanced and unenhanced CT scans during the study period with the McNemar test. RESULTS A total of 157,140 scans among 53,439 unique patients associated with 1,510,001 SCr values were identified. AKI risk was not significantly different between contrast and noncontrast groups in any risk subgroup after propensity score adjustment by using reported risk factors of CIN (low risk: odds ratio [OR], 0.93; 95% confidence interval [CI]: 0.76, 1.13; P = .47; medium risk: odds ratio, 0.97; 95% CI: 0.81, 1.16; P = .76; high risk: OR, 0.91; 95% CI: 0.66, 1.24; P = .58). Counterfactual analysis revealed no significant difference in AKI incidence between enhanced and unenhanced CT scans in the same patient (McNemar test: χ(2) = 0.63, P = .43) (OR = 0.92; 95% CI: 0.75, 1.13; P = .46). CONCLUSION Following adjustment for presumed risk factors, the incidence of CIN was not significantly different from contrast material-independent AKI. These two phenomena were clinically indistinguishable with established SCr-defined criteria, suggesting that intravenous iodinated contrast media may not be the causative agent in diminished renal function after contrast material administration. SUPPLEMENTAL MATERIAL http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12121823/-/DC1.

Radioembolisation for liver metastases: Results from a prospective 151 patient multi-institutional phase II study

PURPOSE To investigate the safety, response rate, progression-free and overall survival of patients with liver metastases treated with (90)Y (glass) radioembolisation in a prospective, multicenter phase II study. METHODS 151 patients with liver metastases (colorectal n=61, neuroendocrine n=43 and other tumour types n=47) refractory to standard of care therapies were enrolled in this prospective, multicenter, phase II study under an investigational device exemption. Clinical/laboratory/imaging follow-up were obtained at 30 days followed by 3-month intervals for 1 year and every 6 months thereafter. The primary end-point was progression-free survival (PFS); secondary end-points included safety, hepatic progression-free survival (HPFS), response rate and overall survival. RESULTS Median age was 66 (range 25-88). Grade 3/4 adverse events included pain (12.8%), elevated alkaline phospatase (8.1%), hyperbilirubinemia (5.3%), lymphopaenia (4.1%), ascites (3.4%) and vomiting (3.4%). Treatment parameters including dose delivery were reproducible among centers. Disease control rates were 59%, 93% and 63% for colorectal, neuroendocrine and other primaries, respectively. Median PFS was 2.9 and 2.8 months for colorectal and other primaries, respectively. PFS was not achieved in the neuroendocrine group. Median survival from (90)Y treatment was 8.8 months for colorectal and 10.4 months for other primaries. Median survival for neuroendocrine patients has not been reached. CONCLUSION Patients with liver metastases can be safely treated with (90)Y microspheres. This study is the first to demonstrate technical and dose reproducibility of (90)Y glass microspheres between centers in a prospective setting. Based on these promising data, three international, multicenter, randomised phase III studies in colorectal and hepatocellular carcinoma have been initiated.

Hepatic Artery Embolization for Neuroendocrine Tumors: Postprocedural Management and Complications

BACKGROUND There is scant evidence to guide the management of patients after hepatic artery embolization (HAE). We examined length of stay (LOS), laboratory patterns, medication usage, morbidity, and mortality of patients hospitalized after HAE for metastatic neuroendocrine tumors. METHODS Data were abstracted retrospectively from electronic medical records on LOS, liver function tests (LFTs), i.v. antibiotics, analgesia, peak temperature, bacteremia, hepatic abscess formation, carcinoid crisis, and metastatic burden on cross-sectional imaging. RESULTS In 2005-2009, 72 patients underwent 174 HAEs for carcinoid and islet cell tumors. The median LOS was 4 days (range, 1-8 days). There was no correlation between peak LFTs and tumor burden. Declines in LFTs were not uniform before hospital discharge; 25%, 37%, 30%, 53%, and 67% of patients were discharged before their respective aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and total and direct bilirubin levels began to decline, with no readmissions for acute hepatic failure. The median i.v. analgesia dose was 60 mg oral morphine equivalents (range, 3-1,961 mg). Pre-HAE i.v. antibiotics were administered in 99% of cases; post-HAE fever occurred in 37% of patients, with no documented bacteremia. One patient developed a hepatic abscess after HAE. There were two carcinoid crises. The single in-hospital death was associated with air in the portal veins. CONCLUSIONS The duration and intensity of in-hospital care following HAE should be managed on an individual basis. A downward trend in LFTs is not required before discharge. Modest use of i.v. analgesia suggests that many patients could exclusively receive oral analgesics. Given the rarity of serious complications, hospital stays could be shortened, thereby reducing costs and nosocomial risks.

Hepatic Vein Tumor Thrombus as a Risk Factor for Excessive Pulmonary Deposition of Microspheres during TheraSphere Therapy for Unresectable Hepatocellular Carcinoma

PURPOSE To evaluate the impact of identifiable hepatic vein tumor thrombus on the ability to safely deliver TheraSphere (yttrium 90-containing glass microspheres) for the treatment of hepatocellular carcinoma (HCC). MATERIALS AND METHODS A retrospective review was performed of 87 patients (71 men, 16 women; mean age, 64.5 years; age range, 25-83 y) referred for TheraSphere therapy for HCC during a 2-year period between April 2005 and May 2007. Evaluation included contrast-enhanced computed tomography or magnetic resonance imaging, selective mesenteric angiography, and radionuclide perfusion scintigraphy to measure the arteriovenous shunting through the tumor. RESULTS Of the 87 patients, 83 underwent angiography and perfusion scintigraphy; 53 were ultimately treated with 65 glass microsphere infusions. Twelve of 83 were identified as having tumor thrombus in a hepatic vein or extending into the inferior vena cava. The mean lung shunt for the patients with hepatic vein tumor thrombus was 30% (range, 11%-60%), compared with 8.2% (range, 3%-23%) for patients without identifiable tumor thrombus. Two of the 12 patients were treated with reduced doses of glass microspheres, and the remaining 10 were offered alternative therapies. CONCLUSIONS The presence of hepatic vein tumor thrombus is a risk factor for an increased lung shunt that may prohibit delivery of a therapeutic dose of TheraSphere to hepatic tumor.

Ice Ball Fractures during Percutaneous Renal Cryoablation: Risk Factors and Potential Implications

The authors present two cases of ice ball fractures with associated hemorrhage during percutaneous renal cryoablation procedures. Although this is a rare occurrence, it is important to be able to identify ice ball fractures on monitoring noncontrast computed tomography (CT) scans during cryoablation, because they can result in significant bleeding, and recognition allows prompt intervention. Risk factors for ice ball fractures and potential implications are discussed.

Tube Thoracostomy: A Review for the Interventional Radiologist

Small-caliber tube thoracostomy is a valuable treatment for various pathologic conditions of the pleural space. Smaller caliber tubes placed under image guidance are becoming increasingly useful in numerous situations, are less painful than larger surgical tubes, and provide more accurate positioning when compared with tubes placed without image guidance. Basic anatomy and physiology of the pleural space, indications, and contraindications of small caliber tube thoracostomy, techniques for image-guided placement, complications and management of tube thoracostomy, and fundamental principles of pleurodesis are discussed in this review.

Small Bowel Imaging: Computed Tomography Enterography, Magnetic Resonance Enterography, Angiography, and Nuclear Medicine

Radiology examinations play a major role in the diagnosis, management, and surveillance of small bowel diseases and are complementary to endoscopic techniques. Computed tomography enterography and magnetic resonance enterography are the cross-sectional imaging studies of choice for many small bowel diseases. Angiography still plays an important role for catheter-directed therapies. With the emergence of hybrid imaging techniques, radionuclide imaging has shown promise for the evaluation of small bowel bleeding and Crohn disease and may play a larger role in the future. This article reviews recent advances in technology, diagnosis, and therapeutic options for selected small bowel disorders.

Severe Acute Cardiopulmonary Failure Related to Gadobutrol Magnetic Resonance Imaging Contrast Reaction: Successful Resuscitation with Extracorporeal Membrane Oxygenation

Nonanaphylactic noncardiogenic pulmonary edema leading to cardiorespiratory arrest related to the magnetic resonance imaging contrast agent gadobutrol has rarely been reported in the literature. Rarer is the association of hypokalemia with acidosis. We report 2 patients who had severe pulmonary edema associated with the use of gadobutrol contrast in the absence of other inciting agents or events. These cases were unique not only for their rare and severe presentations but also because they exemplified the increasing role of extracorporeal membrane oxygenation in resuscitation. Emergency extracorporeal membrane oxygenation resuscitation can be rapidly initiated and successful in the setting of a well-organized workflow, and it is a viable alternative and helps improve patient outcome in cases refractory to conventional resuscitative measures.

Percutaneous radiologic gastrostomy catheter placement without gastropexy: a co-axial balloon technique and evaluation of safety and efficacy

Purpose The purpose of this study is to evaluate the short-term safety and efficacy of a co-axial angioplasty balloon technique for percutaneous radiologic gastrostomy catheter placement (PRG).MethodsA total of 65 percutaneous radiologic gastrostomy tube placements were performed with the co-axial angioplasty balloon technique from 10/1999 to 1/2014. This included 19 females and 46 males between the ages of 20–83. Without the use of T-fasteners for gastropexy, the gastrostomy tube was placed over a catheter-shaft angioplasty balloon as a co-axial system. The angioplasty balloon was used to sequentially approximate the stomach wall to the abdominal wall, dilate the tract, and was then used as a dilator to aid gastrostomy tube advancement into the gastric lumen. Technical success, complications, and dislodgements were evaluated by means of retrospective review of patient medical records and imaging.Results There was no procedural failure in any of the 65 placements. 30-day follow-up was available for 56 patients. 7 patients died within 30 days; none of the deaths were recorded as procedure-related. There was 1 major complication (1.5%) consisting of a colocutaneous fistula. There were 4 minor complications (6.2%). There was no occurrence of bleeding or skin infection while using this technique.Conclusions PRG with the co-axial angioplasty-balloon technique is a safe and effective technique for gastrostomy placement.

Polyarteritis Nodosa (PAN)

PAN is a necrotizing vasculitis affecting small and medium sized arteries in most locations in the body. It is the most common type of necrotizing vasculitis encountered at angiography and noninvasive imaging studies. Imaging findings are predominantly occlusive in nature, manifested by luminal irregularities, stenoses and occlusions, and are found in more than 90% of patients. Aneurysms, micro and macro in size, including areas of ectasia, are found in at least 60% of patients and are the most specific finding of PAN, but they may be found in other diseases such as Wegener’s granulomatosis, systemic lupus erythematosus, bacterial endocarditis and necrotizing vasculitis of drug abuse. For some patients, traditional arteriography is more effective as a diagnostic modality because it detects smaller arterial abnormalities than other imaging modalities. However, CTA and MRA have better ability to detect organ infarction and have adequate imaging capacity to identify most patients with aneurysms, especially if rupture occurs. Ultrasound may be helpful if the aneurysms are large enough to evaluate with color Doppler or if rupture has resulted in a hematoma within or adjacent to an abdominal organ. Following treatment, noninvasive imaging modalities are usually preferred to repeat angiography.