Michael D. Beland

Diagnostic yield of 58 consecutive imaging-guided biopsies of solid renal masses: should we biopsy all that are indeterminate?

OBJECTIVE The purpose of our study was to report the diagnostic yield of 58 consecutive imaging-guided biopsies of solid renal masses. MATERIALS AND METHODS We retrospectively reviewed all percutaneous renal biopsies of solid masses performed at our institution over 83 consecutive months from May 1998 to March 2005 through a query of our radiology department procedure database. Fifty-five CT and three sonographic biopsies were performed at our institution during this time. A solid renal mass was documented prior to biopsy by contrast-enhanced CT (n = 48), gadolinium-enhanced MRI (n = 6), or sonography (solid noncystic masses, n = 4). The average maximal mass diameter was 3.1 cm (range, 1.0-11.0 cm). Forty-seven (81%) of the 58 biopsies were performed immediately before percutaneous ablation. Forty-four (76%) of the biopsies were performed using a coaxial technique with side-cutting automated biopsy needles (16-20 gauge), and 14 (24%) were fineneedle aspirations with a Franseen needle (20 gauge) using a tandem technique. In 19 cases, immunohistochemistry or histochemistry (Hale colloidal iron stain) was used to establish or confirm the diagnosis. Medical records and radiology and pathology reports were reviewed for all patients. RESULTS An adequate sample size was obtained in 55 (95%) of 58 renal masses and led to a definitive diagnosis in 52 (90%) of the 58. Renal cell carcinoma accounted for 36 (69%) of 52 diagnostic biopsies. The diagnosis of a benign lesion was made in 14 (27%) of 52 biopsies. Lymphoma (1/58) and metastatic disease (1/58) accounted for the remaining two diagnostic biopsies. Three biopsy samples obtained inadequate sample volumes, and an additional three samples were thought to have adequate sample volume but were not diagnostic. A single false-negative biopsy result was identified after growth was seen on follow-up imaging and subsequent nephrectomy revealed renal cell carcinoma. CONCLUSION Imaging-guided biopsy of a solid enhancing renal mass was diagnostic in 52 (90%) of 58 consecutive biopsies. The diagnosis of a benign lesion was made in 27% of diagnostic biopsies. Because of the advances in biopsy and histology techniques, the role of imaging-guided biopsy should be reconsidered.

Dynamic MDCT for Localization of Occult Parathyroid Adenomas in 26 Patients With Primary Hyperparathyroidism

OBJECTIVE The objective of our study was to evaluate the accuracy of dynamic contrast-enhanced 4D MDCT in the preoperative identification of parathyroid adenomas in patients with primary hyperparathyroidism (PHPT) and a history of failed surgery or unsuccessful localization on standard imaging. MATERIALS AND METHODS Thirty-four patients with PHPT underwent 4D CT. Retrospective blinded review of the 4D CT examinations was performed by three radiologists for the presence and location of a suspected parathyroid adenoma or adenomas. At the time of the study, 25 patients underwent surgical exploration after 4D CT. Twenty patients had solitary parathyroid adenomas, two patients had two adenomas resected, two patients did not have an adenoma, and one patient had mild four-gland hyperplasia. One patient did not have PHPT on repeat serum biochemistry. Surgical and pathology reports, adenoma enhancement, and biochemical and clinical follow-up were reviewed. Data were compared with 4D CT interpretations and interobserver reliability was calculated. RESULTS The mean sensitivity and specificity of the three readers for the precise CT localization of adenomas was 82% (range, 79-88%) and 92% (range, 75-100%), respectively. Overall interobserver reliability was excellent (κ = 0.70; range, κ = 0.60-0.79). All adenomas resected at surgery showed a biochemical response and clinical response. The mean densities of the confirmed adenomas were 41, 128, 138, and 109 HU at 0, 30, 60, and 90 seconds, respectively. Level II lymph nodes identified in 10 patients showed significantly less enhancement at 30 (p = 0.0001) and 60 (p = 0.006) seconds compared with surgically proven adenomas. CONCLUSION Occult parathyroid adenoma shows characteristic early enhancement. In this subset of patients, 4D CT may improve surgical outcomes and decrease morbidity.

ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee

Thyroid nodules are a frequent finding on neck sonography. Most nodules are benign; therefore, many nodules are biopsied to identify the small number that are malignant or require surgery for a definitive diagnosis. Since 2009, many professional societies and investigators have proposed ultrasound-based risk stratification systems to identify nodules that warrant biopsy or sonographic follow-up. Because some of these systems were founded on the BI-RADS® classification that is widely used in breast imaging, their authors chose to apply the acronym TI-RADS, for Thyroid Imaging, Reporting and Data System. In 2012, the ACR convened committees to (1) provide recommendations for reporting incidental thyroid nodules, (2) develop a set of standard terms (lexicon) for ultrasound reporting, and (3) propose a TI-RADS on the basis of the lexicon. The committees published the results of the first two efforts in 2015. In this article, the authors present the ACR TI-RADS Committees recommendations, which provide guidance regarding management of thyroid nodules on the basis of their ultrasound appearance. The authors also describe the committees future directions.

Renal Cortical Thickness Measured at Ultrasound: Is It Better Than Renal Length as an Indicator of Renal Function in Chronic Kidney Disease?

OBJECTIVE The purpose of our study was to determine whether there is a relationship between renal cortical thickness or length measured on ultrasound and the degree of renal impairment in chronic kidney disease (CKD). MATERIALS AND METHODS From October to December 2007, 25 patients (13 men and 12 women, mean age 73 years) were identified who had CKD but were not on dialysis. The patients were from a single institution and had undergone renal ultrasound and at least three serum creatinines within 90 days. The lowest creatinine was used for estimated glomerular filtration rate (eGFR) calculation using both the Cockcroft-Gault (CG) and the Modification of Diet in Renal Disease Study (MDRD) equations. Ultrasounds were consensus reviewed by three radiologists (2 attendings and a resident) blinded to specific renal function. Cortical thickness was measured in the sagittal plane over a medullary pyramid, perpendicular to the capsule. Length was measured pole-to-pole. Linear regression was used for statistical analysis. RESULTS Mean cortical thickness was 5.9 mm (range, 3.2-11.0 mm). Mean length was 10 cm (7.2-12.4 cm). Mean minimum serum creatinine was 2.1 mg/dL (1.1-6.1 mg/dL). Mean eGFR using CG was 34.8 mL/min (10.6-99.4 mL/min) and 36 mL/min (8-66 mL/min) using MDRD. There was a statistically significant relationship between eGFR and cortical thickness using both CG (p < 0.0001) and MDRD (p = 0.005). There was a statistically significant relationship between CG and length (p = 0.003) but not between MDRD and length (p = 0.08). CONCLUSION Cortical thickness measured on ultrasound appears to be more closely related to eGFR than renal length. Reporting cortical thickness in patients with CKD who are not on dialysis should be considered.

Thyroid Ultrasound Reporting Lexicon: White Paper of the ACR Thyroid Imaging, Reporting and Data System (TIRADS) Committee.

Ultrasound is the most commonly used imaging technique for the evaluation of thyroid nodules. Sonographic findings are often not specific, and definitive diagnosis is usually made through fine-needle aspiration biopsy or even surgery. In reviewing the literature, terms used to describe nodules are often poorly defined and inconsistently applied. Several authors have recently described a standardized risk stratification system called the Thyroid Imaging, Reporting and Data System (TIRADS), modeled on the BI-RADS system for breast imaging. However, most of these TIRADS classifications have come from individual institutions, and none has been widely adopted in the United States. Under the auspices of the ACR, a committee was organized to develop TIRADS. The eventual goal is to provide practitioners with evidence-based recommendations for the management of thyroid nodules on the basis of a set of well-defined sonographic features or terms that can be applied to every lesion. Terms were chosen on the basis of demonstration of consistency with regard to performance in the diagnosis of thyroid cancer or, conversely, classifying a nodule as benign and avoiding follow-up. The initial portion of this project was aimed at standardizing the diagnostic approach to thyroid nodules with regard to terminology through the development of a lexicon. This white paper describes the consensus process and the resultant lexicon.

MR enterography correlates highly with colonoscopy and histology for both distal ileal and colonic Crohn's disease in 310 patients

BACKGROUND AND AIMS To evaluate the efficacy of MR enterography (MRE) in patients with known or suspected Crohns disease without the use of anti-peristaltic pharmacologic agents compared to colonoscopy and histology. METHODS A retrospective review of 850 consecutive patients who underwent routine MRE to evaluate known or suspected Crohns disease was performed. Of these, 310 patients also underwent colonoscopy with biopsy(s) within 90 days. The results of the MRE were compared to the colonoscopy and pathology reports to determine the presence or absence of disease in evaluable bowel segments. Individual imaging parameters (including wall thickening, enhancement, T2 signal, mesenteric vascular prominence and adenopathy) were also separately analyzed to determine their independent predictive value. RESULTS In 310 patients, the overall sensitivity and specificity of MRE (using endoscopy as a gold standard) were 85% and 80% respectively (kappa=0.65). The sensitivity of MRE for detection of pathologically severe disease was 87% in the terminal ileum (TI) and 88% in the colon. In the subset of 162 patients who underwent colonoscopy within 30 days of MRE, the overall sensitivity remained 85% but the specificity increased to 85% (kappa=0.69). Wall thickening and abnormal enhancement were sensitive indicators of Crohns disease (75% and 78%), while abnormal T2 signal, mesenteric vascular prominence and adenopathy were specific (86%, 91% and 93%). CONCLUSION MRE compares favorably to colonoscopy for evaluation of known or suspected Crohns disease noninvasively and without the exposure to ionizing radiation associated with CT enterography (CTE).

Complex Abdominal and Pelvic Abscesses: Efficacy of Adjunctive Tissue-Type Plasminogen Activator for Drainage

PURPOSE To retrospectively evaluate the effectiveness and safety of tissue-type plasminogen activator (tPA) for drainage of abdominal and pelvic abscesses refractory to simple catheter drainage. MATERIALS AND METHODS This HIPAA-compliant study was approved by the Institutional Review Board; informed consent was waived. Forty-three patients (17 men, 26 women; mean age, 46 years; age range, 10-89 years) with a total of 46 abscesses underwent percutaneous drainage with 8.5-14-F catheters. Etiology was postoperative in 28 abscesses (60.9%) and varied in 18 (39.1%). Intracavitary tPA was initiated on the basis of viscous contents yielding minimal drainage at initial placement or if follow-up imaging showed a large residual collection despite satisfactory catheter position. A treatment cycle was 4-6 mg of tPA in 0.9% saline administered twice daily for 3 days. Drainage success was defined as evacuation of the abscess without surgery. Safety was evaluated on the basis of complications. Statistical analysis was performed by using the Student t test and Fisher exact test. RESULTS Forty-six abscesses were initially drained by 51 catheters. Complete evacuation was achieved in 41 (89.1%) abscesses, whereas five (10.9%) required surgical drainage. Three (60%) of these five had a documented fistula, a higher (P = .02) percentage than in successfully drained abscesses. Three (6.5%) of the 46 abscesses recurred (12-95 days after catheter removal). There were no tPA-linked bleeding complications despite four patients receiving full systemic anticoagulation and 24 receiving prophylactic anticoagulation. CONCLUSION Intracavitary tPA is safe and effective for draining complex fluid collections, with most patients avoiding surgery.

Magnetic resonance enterography.

Magnetic resonance (MR) enterography is a targeted examination of the gastrointestinal tract, particularly the small intestine, without nasojejunal intubation (in which case it is referred to as MR enteroclysis). Until recently, MR imaging of the small bowel could not reliably compete with the high-quality small bowel images generated by computed tomography (CT). Now, however, MR enterography is not only a feasible alternative to CT, but may provide superior diagnostic information, specifically with regard to differentiating active, inflammatory disease from chronic, fibrostenotic disease. MR enterography is no longer merely adequate and radiation-free; it is an essential part of the imaging armamentarium.

Charlson Comorbidity Index predicts patient outcome, in cases of inoperable non-small cell lung cancer treated with radiofrequency ablation.

PURPOSE The Charlson Comorbidity Index (CCI) has been shown to be a significant prognostic indicator in the treatment of many types of cancer. The aim of this study is to evaluate the degree to which the CCI predicts survival in patients with inoperable non-small cell lung cancer (NSCLC) treated with radiofrequency ablation (RFA). MATERIALS AND METHODS Eighty-two (34 men, 48 women) consecutive RFA treatments for medically inoperable NSCLC were performed at our institution from 1/1/2000 to 1/30/2009. With institutional IRB approval and in full HIPAA compliance, the medical records of these patients were examined for data relating to pre-treatment comorbid conditions, and a retrospective analysis was conducted. Survival curves were estimated by the Kaplan-Meier method. Risk factors for mortality were determined by single-factor comparisons of curves using Wilcoxon-weighted chi-square and multiple Cox regressions. RESULTS The patients ranged in age from 59 to 91 years (mean: 75.5). Eighty-eight percent (72 patients) were tumor stage IA or IB. Patients were followed for a total of five years; three-year overall survival was 50.6%. Hospital mortality was 0%. Gender, stage, histology and CCI score were each associated with significantly impaired survival (p<0.001 in all cases). After covarying for age, tumor stage>IB, squamous histology and gender, multiple Cox regressions showed that an increasing CCI score was significantly associated with an increased risk of death (HR 1.3, 95% CI 25.5, 58.2). CONCLUSIONS The CCI is validated as an important, independent predictor of patient survival, in cases of inoperable NSCLC treated with RFA.

Kidney Neoplasms: Renal Halo Sign after Percutaneous Radiofrequency Ablation—Incidence and Clinical Importance in 101 Consecutive Patients

PURPOSE To describe the incidence and clinical importance of the renal halo sign after percutaneous radiofrequency ablation (RFA) of renal neoplasms. MATERIALS AND METHODS Institutional review board approval was obtained for this HIPAA-compliant retrospective study. The study population consisted of 101 consecutive patients with 106 solid renal neoplasms that were treated with percutaneous RFA. Postablation computed tomographic (CT) and magnetic resonance (MR) images were retrospectively reviewed by three board-certified radiologists to determine the presence of the renal halo sign. Statistical analyses were performed to determine reader agreement and assess the effect that tumor size and location, radiofrequency (RF) applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed had on development of the renal halo sign. RESULTS The renal halo sign developed in 79 (75%) of the 106 ablated tumors. Average imaging follow-up lasted 25 months (range, 1-98 months). The renal halo sign appeared, on average, 6 months (range, 1 month to 3 years) after RFA. The renal halo sign resolved in five (6%) of 79 tumors treated. Interobserver agreement for the presence of the renal halo sign was high. Tumor size and location, RF applicator type, RFA treatment time and success, maximum RFA treatment temperature, and number of RF applications performed were not independent predictors of renal halo sign development. CONCLUSION The renal halo sign is seen in 75% of patients after percutaneous RFA of renal neoplasms. It may decrease in size over time; however, it rarely disappears. It is important to recognize this sign, as it can be mistaken for recurrent tumor or angiomyolipoma by radiologists who are not familiar with RFA.