Wall suction-assisted image-guided thoracentesis: a safe alternative to evacuated bottles.

AIM: To compare the safety of evacuated bottle-assisted thoracentesis with wall suction-assisted thoracentesis. MATERIALS AND METHODS: An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study of 161 consecutive patients who underwent 191 evacuated bottle-assisted thoracenteses from 1 January 2012 to 30 September 2012, and 188 consecutive patients who underwent 230 wall suction-assisted thoracenteses from 1 January 2013 to 30 September 2013 was conducted. All procedures used imaging guidance. Primary diagnosis, age, gender, total fluid volume removed, and adverse events (AE) up to 30 days post-procedure were recorded and graded using Common Terminology Criteria for Adverse Events 4.0 (CTCAE)2. RESULTS: Overall AE rates were 42.9% (82/191) for the evacuated bottle group and 19.6% (45/230) for the wall suction group (p<0.0001). Grade I AE occurred more commonly in the evacuated bottle group than in the wall suction group, [41.9% (80/191) and 18.3% (42/230)], respectively (p<0.0001). No significant differences were observed in grade 2 [0.5% (1/191) and 0% (0/230), p=0.45] or grade 3 AE [0.5% (1/191) and 1.3% (3/230), p=0.63] between the evacuated bottle and wall suction groups, respectively. No grade 4 or 5 AE occurred. Excluding transient chest pain and cough, there was no statistical difference in overall AE rate between the evacuated bottle and wall suction groups [11% (21/191) and 8.3% (19/230), p=0.4]. CONCLUSION: Image-guided thoracentesis performed with wall suction is safe when compared to evacuated bottles. The use of wall suction, in comparison to evacuated bottles, may decrease the incidence of transient chest pain or cough.

Breath-hold PET/CT-guided tumour ablation under general anaesthesia: accuracy of tumour image registration and projected ablation zone overlap.

AIM: To assess single-breath-hold combined positron-emission tomography/computed tomography (PET/CT) for accuracy of tumour image registration and projected ablation volume overlap in patients undergoing percutaneous PET/CT-guided tumour-ablation procedures under general anaesthesia. MATERIALS AND METHODS: Eight patients underwent 12 PET/CT-guided tumour-ablation procedures to treat 20 tumours in the lung, liver, or adrenal gland. Using breath-hold PET/CT, the centre of the tumour was marked on each PET and CT acquisition by four readers to assess two- (2D) and three-dimensional (3D) spatial misregistration. Overlap of PET and CT projected ablation volumes were compared using the Dice similarity coefficient (DSC). Interobserver differences were assessed with repeated measure analysis of variance (ANOVA). Technical success and local progression rates were noted. RESULTS: Mean tumour 2D PET/CT misregistrations were 1.02 mm (range 0.01-5.02), 1.89 (0.03-7.85), and 3.05 (0-10) in the x, y, and z planes. Mean 3D misregistration was 4.4 mm (0.36-10.74). Mean projected PET/CT ablation volume DSC was 0.72 (±0.19). No significant interobserver differences in 3D misregistration (p=0.73) or DSC (p=0.54) were observed. Technical success of ablations was 100%; one (5.3%) of 19 tumours progressed. CONCLUSION: Accurate spatial registration of tumours and substantial overlap of projected ablation volumes are achievable when comparing PET and CT acquisitions from single-breath-hold PET/CT. The results suggest that tumours visible only at PET could be accurately targeted and ablated using this technique.

PET/CT-guided percutaneous liver mass biopsies and ablations: targeting accuracy of a single 20 s breath-hold PET acquisition.

AIM: To determine whether a single 20 s breath-hold positron-emission tomography (PET) acquisition obtained during combined PET/computed tomography (CT)-guided percutaneous liver biopsy or ablation procedures has the potential to target 2-[(18)F]-fluoro-2-deoxy-d-glucose (FDG)-avid liver masses as accurately as up to 180 s breath-hold PET acquisitions. MATERIALS AND METHODS: This retrospective study included 10 adult patients with 13 liver masses who underwent FDG PET/CT-guided percutaneous biopsies (n = 5) or ablations (n = 5). PET was acquired as nine sequential 20 s, monitored, same-level breath-hold frames and CT was acquired in one monitored breath-hold. Twenty, 40, 60, and 180 s PET datasets were reconstructed. Two blinded readers marked tumour centres on randomized PET and CT datasets. Three-dimensional spatial localization differences between PET datasets and either 180 s PET or CT were analysed using multiple regression analyses. Statistical tests were two-sided and p < 0.05 was considered significant. RESULTS: Targeting differences between 20 s PET and 180 s PET ranged from 0.7-20.3 mm (mean 5.3 ± 4.4 mm; median 4.3) and were not statistically different from 40 or 60 s PET (p = 0.74 and 0.91, respectively). Targeting differences between 20 s PET and CT ranged from 1.4-36 mm (mean 9.6 ± 7.1 mm; median 8.2 mm) and were not statistically different from 40, 60, or 180 s PET (p = 0.84, 0.77, and 0.35, respectively). CONCLUSION: Single 20 s breath-hold PET acquisitions from PET/CT-guided percutaneous liver procedures have the potential to target FDG-avid liver masses with equivalent accuracy to 180 s summed, breath-hold PET acquisitions and may facilitate strategies that improve image registration and shorten procedure times.

Attitudes of patients with metastatic breast cancer toward research biopsies.

BACKGROUND: Research studies involving human tissue are increasingly common. However, patients' attitudes toward research biopsies are not well characterized, particularly when the biopsies are carried out outside the context of therapeutic trials. PATIENTS AND METHODS: One hundred sixty patients with metastatic breast cancer (MBC) from two academic (n = 80) and two community (n = 80) hospitals completed a 29-item self-administered survey to evaluate their willingness to consider providing research purposes only biopsies (RPOBs) (as a stand-alone procedure) and additional biopsies (ABs) (additional needle passes at the time of a clinically indicated biopsy). RESULTS: Eighty-two (51%) of 160 patients would consider having RPOBs, of which 42 (53%) and 40 (50%) patients were from academic and community hospitals, respectively. Patients who had more prior biopsies were less likely to consider RPOBs (RR = 0.6, 95% CI: 0.4-1.0, P = 0.03). Of 160 patients, 115 (72%) patients would consider having ABs. Of these, 64 (80%) and 51 (64%) patients from academic and community hospitals, respectively, would consider ABs (RR = 1.2, 95% CI: 1.0-1.5, P = 0.03). CONCLUSIONS: Many patients with MBC in both academic and community settings report willingness to consider undergoing biopsies for research. Further research is needed to understand ethical, logistical and provider-based barriers to broader participation in such studies.

Virtual unenhanced CT images acquired from dual-energy CT urography: accuracy of attenuation values and variation with contrast material phase.

AIM: To determine how representative virtual unenhanced (VNE) images are of true unenhanced (TNE) images when performing computed tomography (CT) urography on a dual-energy CT (DECT) system, and whether the images are affected by the contrast material phase. MATERIALS AND METHODS: In this retrospective, institutional review board-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant study, TNE were compared with VNE images derived from the nephrographic (VNEn) and excretory (VNEe) phases in 100 consecutive CT urograms. Two readers in consensus measured attenuation values of abdominal organs, fat, and renal lesions (>1 cm). Image noise was correlated with patient thickness. Detectability of renal stones was evaluated. Image quality and acceptability was assessed using a five-point scale. Expected dose saving by removing the TNE phase was calculated. RESULTS: VNE attenuation values of liver, renal parenchyma, and aorta were significantly different to TNE values (p < 0.05); spleen and fat attenuation values showed no significant difference. No significant difference was found between VNEn and VNEe images. Image noise was significantly greater in TNE images (p < 0.0001) and correlated with patient thickness. VNEn and VNEe images had sensitivities of 76.6 and 65.6% for detection of stones, identifying all stones greater than 3 and 4 mm, respectively. Both VNE images received significantly lower image quality scores than TNE images (p < 0.0001); however, the majority of images were deemed acceptable. The mean theoretical dose saving by removing the TNE phase was 35%. CONCLUSION: Although VNE images demonstrate high reader acceptability, accuracy of attenuation values and detection of small stones is limited. The contrast material phase, however, does not affect attenuation values. Further validation of VNE images is recommended prior to clinical implementation.

Noninvasive multidetector computed tomography enterography in patients with small-bowel Crohn's disease: is a 40-second delay better than 70 seconds?

BACKGROUND: Multidetector computed tomography (MDCT) enterography combines neutral enteric contrast with intravenously administered contrast material. The optimal intravenous (IV) contrast material protocol has still not been established. PURPOSE: To determine the optimal delay time to image patients with small-bowel Crohn's disease during MDCT enterography. MATERIAL AND METHODS: After oral administration of 1350 ml of neutral contrast medium, 26 patients with small-bowel Crohn's disease underwent MDCT enterography;scans were obtained 40 s (enteric phase) and 70 s (parenchymal phase) after IV administration of 100 ml of iodinated contrast material. Three radiologists, blinded to clinical and pathological findings, independently and retrospectively evaluated each scan in two separate reading sessions for the presence or absence of CT features of Crohn's disease activity. The interobserver agreement was evaluated, and the efficacy of each phase in detecting active disease in the terminal ileum for each reader was determined. The gold standard was pathology (n=13), endoscopy (n=3), and clinical evaluation (n=10). RESULTS: No statistically significant difference was present between the enteric and the parenchymal phase for each reader in each segment regarding the presence or absence of CT features of Crohn's disease. The interobserver agreement for the presence of five main features of active Crohn's disease in the terminal ileum ranged from poor to excellent.The sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for active Crohn's disease in the terminal ileum ranged from 40 to 90%, 88 to 100%, 70 to 94%, 44 to 100%, and 69 to 96%, respectively. There was no statistical difference between the two phases for each reader. CONCLUSION: MDCT enterography in patients with suspected active Crohn's disease can be obtained at either 40 s or 70 s after IV contrast material.

Abdominal cross-sectional imaging for inpatients with abnormal liver function test results: yield and usefulness.

BACKGROUND: Abdominal cross-sectional imaging is often performed to evaluate abnormal liver function test (LFT) results in hospitalized patients. However, few data are available regarding the yield and usefulness of imaging inpatients for the indication of abnormal LFT results, the process of requesting abdominal imaging studies, or the response to their findings. METHODS: We retrospectively reviewed abdominal imaging scans that were obtained during a 27-month period. We matched the imaging studies done with the indication of abnormal LFT results; all scans were requested using computerized physician order entry. Reports were coded for interpretation and associated process step results. To determine the usefulness of the imaging studies, a random sample of patient charts with positively coded imaging studies were reviewed. Imaging examinations were considered useful if they provided new diagnostic information and/or changed subsequent patient care. RESULTS: Of 6494 abdominal imaging studies, 856 were performed for the indication of abnormal LFT results and matched to both image reports and laboratory results. Report coding judged 37% of interpretations as clinically significant, including 27% with "positive" (abnormal results and explain the abnormal LFT results) examinations. Among the positive examinations, the most common diagnoses were biliary obstruction (25%), cholecystitis (21%), malignancy (20%), and cirrhosis (14%). Positively coded reports provided new clinical information in 63% of these studies and changed patient care in 42% of cases. Process measures assessed provision of additional information to and from radiologists (69% and 8%, respectively) and the frequency with which the findings of current abdominal imaging studies were compared with those of prior studies (59%). CONCLUSION: Abdominal cross-sectional imaging studies performed on inpatients with abnormal LFT results had a high diagnostic yield and frequently changed patient care.

Three-dimensional imaging and display of renal tumors using spiral CT: a potential aid to partial nephrectomy.

OBJECTIVE: A new technique for creating three-dimensional (3D) images of renal tumors using contrast-enhanced spiral computed tomography (CT) is described and preliminarily investigated. METHODS: 3D spiral CT was employed in 2 patients before radical nephrectomy and in 5 patients before partial nephrectomy. Preoperative and postoperative image analyses were conducted to evaluate the ability of the images to depict key anatomic relationships in planning partial nephrectomies. RESULTS: 3D spiral CT defined the tumor's location and relationship to the kidney surface better than the tumor's proximity to renal hilar vessels and collecting system. Negative surgical margins were obtained in all 4 patients with renal cell carcinoma, and post-operative serum creatinine remained less than 2 mg/dL in all 5 patients after partial nephrectomy. CONCLUSIONS: This early experience suggests that 3D spiral CT can help in the planning of partial nephrectomy and in attaining complete resection of renal cell carcinoma while conserving normal renal tissue.

Open-configuration MR imaging, intervention, and surgery of the urinary tract.

The open-configuration MR imaging system provides new applications both in diagnosis and in therapy of conditions in the urinary tract. In addition to conventional imaging, the open configuration permits MR imaging of patients in many positions. This has already been shown to be useful in imaging the pelvis during voiding, where a sitting position allows urodynamic evaluation. The lithotomy position can be used for imaging the prostate, which also permits procedural access. The ultimate purpose of the interventional MR imaging suite is to integrate therapeutic tools and techniques with MR imaging. From surgical planning through specialized imaging systems with minimally invasive surgical applications, new methods are being developed and implemented. This new field of image-guided therapy will require extensive clinical development and evaluation for applications in the urinary tract. This will require a large concentrated interdisciplinary effort of surgeons, radiologists, computer scientists, engineers, and physicists. Successful integration of basic research and clinical work will result in a number of cutting-edge technologies with direct clinical application in the urinary tract. Initial projects have included biopsies, endoscopies, and real-time procedural control of high-temperature and cryogenic ablations. It is anticipated that the current surge in image-guided interventions will motivate even more research activity in this field, and will ultimately define the role of MR imaging guidance in urologic intervention and surgery.

Helical (spiral) CT of the retroperitoneum.

Helical CT promises to improve imaging of the retroperitoneum through the elimination of respiratory misregistration and the minimization of partial volume averaging. The speed of acquisition enables the entire abdomen and pelvis to be imaged in less than 2 minutes with standard collimator widths. This is a distinct advantage in critically ill patients, particularly in the case of trauma. Selective intravenously administered contrast enhancement is made possible with helical CT. Rapid scanning allows imaging in an arterial, renal cortical, renal medullary, or delayed collecting system phase. This property of helical CT enables CT angiography to emerge as a powerful minimally invasive alternative to conventional arteriography for imaging the abdominal aorta and its branches. After 4 years of investigating the use of volumetric CT, the clinical settings described herein remain the only clear indications for using helical CT in the kidney and retroperitoneum. These studies took advantage of the single most important feature of helical CT--the elimination of respiratory misregistration. Two broad diagnostic advantages result: (1) the ability to search and characterize a region thoroughly, such as in the evaluation of a small renal mass, or to search for the needle-tip during an interventional procedure; and (2) the ability to create multiplanar and 3-D images that are of sufficient quality to be useful in clinical practice, such as in imaging the vasculature (CT angiogram), and in surgical planning.

Pleural interventions. Indications, techniques, and clinical applications.

Pleural interventions represent one of the newest frontiers of interventional radiology. Many of the data are preliminary, but it is tempting to postulate that future side-by-side comparisons would prove these innovations superior to unguided techniques. Each procedure utilizes similar principles of pleural intervention yet emphasizes unique issues pertinent to the disease processes involved.

Spiral computed tomography of the liver: contrast agent pharmacokinetics and the potential for improved hepatic enhancement.

RATIONALE AND OBJECTIVES: We conducted a prospective study of 131 patients to evaluate the contrast agent dose-response relationship for liver spiral computed tomography (CT) and to test the hypothesis that spiral CT scanning provides greater enhancement than does dynamic CT scanning. METHODS: Patients were assigned to one of two control groups (dynamic CT) or to one of five experimental groups (spiral CT). Dynamic CT patients received 150 ml and spiral CT patients received either 75, 100, or 150 ml of diatrizoate meglumine. All groups had a monophasic injection rate of 2.5 ml/sec. Hepatic enhancement was compared among experimental and control groups. RESULTS: In the experimental groups, there was a linear dose-response relationship (p < .0001) among the enhancements achieved for the three dosages. The enhancement of the last slice of liver for the spiral CT versus dynamic CT groups receiving 150 ml was significantly greater (p = .002). Peak, first liver slice, and average liver enhancement values were higher with spiral CT scanning, but the difference was not statistically significant (power > .55). CONCLUSION: Using uniphasic injection rates and identical doses of contrast agent, spiral CT scanning has the advantage of improved enhancement of the last part of the liver to be imaged.

Original smooth receiver operating characteristic curve estimation from continuous data: statistical methods for analyzing the predictive value of spiral CT of ureteral stones.

RATIONALE AND OBJECTIVES: Diagnostic studies such as spiral computed tomography (CT) in patients with obstructing ureteral calculi often necessitate the analysis of continuous test data (e.g., stone sizes). The accuracy of a test can be summarized by using a receiver operating characteristic (ROC) curve. The authors developed and compared three methods for constructing a smooth ROC curve from continuous diagnostic data. MATERIALS AND METHODS: Nonparametric, semiparametric, and parametric smooth ROC curve analyses were applied to data from 100 unenhanced spiral CT scans of patients with proved obstructing ureteral stones. Accuracy in using stone size to predict the need for intervention was evaluated by means of these methods. Characteristics and summary measures of the resulting ROC curves were estimated. RESULTS: All methods fit the data well. The nonparametric method followed the details of the empiric data. The semiparametric and parametric methods yielded similar estimates of the ROC curve parameters. Areas under the ROC curves were 0.807, 0.821, and 0.814 for nonparametric, semiparametric, and parametric methods, respectively, in comparison with 0.811 for the empiric method. CONCLUSION: The parametric method is preferred for constructing a smooth ROC curve with available stone-size data derived from spiral CT. The analyses confirm the predictive value of stone size in determining the need for intervention.

Multidisciplinary gastrointestinal cancer clinic: abdominal radiologist as active participant.

RATIONALE AND OBJECTIVES: Abdominal radiologists actively participated and provided subspecialty radiologic expertise in a multidisciplinary gastrointestinal cancer clinic that served a tertiary referral center. The purpose of this study was to evaluate the feasibility and nonradiologists' opinions of this new approach to radiologic consultation. MATERIALS AND METHODS: One of four subspecialty-trained abdominal radiologists joined physicians from four other subspecialties in staffing weekly 4-hour clinic sessions. Images were reviewed, opinions on test selection and interventional options rendered, and patients met with when interventional options were considered. Radiologists were compensated a fixed sum for each session. A survey of nonradiologists' opinions about the radiologists' active participation was conducted after 15 months (61 clinic sessions). RESULTS: Abdominal radiologists' active participation was feasible and highly regarded by nonradiologist physicians. Specific benefits cited in the survey included improved interpretation, more efficient use of nonradiologist physician time, and improved rapport between radiologists and nonradiologists. Nonradiologist physicians believed that patient care was improved and that the radiologists' participation should continue. CONCLUSION: The active participation of abdominal radiologists in a multidisciplinary gastrointestinal cancer clinic is feasible and highly regarded by nonradiologists.

MR-guided therapy. Applications in the abdomen.

This article provides an overview of current abdominal interventional applications that use MR imaging guidance and monitoring for diagnostic biopsies, tumor ablations and--owing to the development of new pulse sequences--monitoring the ablation process, and aspiration and drainage of fluid collections. These applications are optimal for patients with lesions that can be localized only by MR imaging or for lesions in suboptimal locations such as the dome of the liver.

Fine needle aspiration biopsy of idiopathic retroperitoneal fibrosis.

OBJECTIVE: To report three cases of idiopathic retroperitoneal fibrosis (IRF) diagnosed by fine needle aspiration (FNA) biopsy and confirmed by histologic examination. To our knowledge, this is the first report on the FNA findings in IRF. STUDY DESIGN: Specimens were obtained under computed tomographic guidance using the standard technique. Half the smears were ethanol fixed and stained with Papanicolaou stain, and the other half were air dried and stained with Diff-Quik. A cell block was prepared in all cases. RESULTS: Similar findings were seen in all three cases. The predominant elements were fibrous tissue and inflammatory cells, which occasionally occurred together but often were separate. The inflammatory cells were predominantly small lymphocytes, with occasional plasma cells, histiocytes and neutrophils. Smears from one case showed the inflammatory component only, but the cell block in all three cases showed both elements. The diagnosis of IRF was suggested in two of the three cases. All patients underwent laparotomy for diagnostic confirmation, and two had therapeutic resection of the lesion. Histologic material reflected the FNA findings, showing hyalinized fibrous tissue and an inflammatory cell infiltrate consisting of lymphocytes, plasma cells, histiocytes and neutrophils. No infection, arteritis or malignancy was present. CONCLUSION: Although the FNA picture is nonspecific, in combination with clinical and radiologic findings it is highly suggestive of a diagnosis of IRF. A presumptive diagnosis allows a rational approach to further evaluation and therapy, which, in most cases, is an exploratory laparotomy with ureterolysis.

Gastrointestinal tract wall visualization and distention during abdominal and pelvic multidetector CT with a neutral barium sulphate suspension: comparison with positive barium sulphate suspension and with water.

OBJECTIVE: When examining patients with contrast-enhanced multidetector-row CT, we determined if the stomach and small bowel were visualized and distended better with a neutral barium sulphate suspension than with positive barium sulphate suspension or water. MATERIALS AND METHODS: After obtaining approval from our institutional review board, 156 patients (women: 84; mean age: 54 yrs) with no history of gastrointestinal tract disease were randomized prospectively to receive orally either 900 ml of neutral (0.1% w/v) barium sulphate suspension (n = 53), 900 ml of positive (2.1% w/v) barium sulphate suspension (n = 53), or 900 ml of water (n = 50), prior to undergoing contrast-enhanced abdominal and pelvic multidetector-row CT. Two independent radiologists evaluated the stomach, and small bowel, for luminal distension and wall visualization, using a five point scale. Results were compared using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The walls of the stomach, and small bowel were visualized better in patients who were administered neutral barium sulphate suspension than those who were administered either positive barium sulphate suspension (p < 0.01) or water (p < 0.01). In patients who received neutral barium sulphate suspension, the stomach and small bowel were distended better compared to patients administered water (p < 0.01); the stomach, duodenum, and ileum were distended better compared to patients administered positive barium sulphate suspension (p < 0.05). CONCLUSIONS: When examining patients with intravenous contrast-enhanced abdominal and pelvic multidetector-row CT, orally administered neutral barium sulphate suspension allows the gastrointestinal tract to be visualized and distended better than either positive barium sulphate suspension, or water.