Image-guided adrenal and renal biopsy

Clinical indications, safety, and effectiveness of percutaneous image-guided adrenal mass biopsy: an 8-year retrospective analysis in 160 patients

PURPOSE

To assess indications, safety, and effectiveness of percutaneous adrenal mass biopsy in contemporary practice.

METHODS

This institutional review board-approved, retrospective study included all patients undergoing percutaneous image-guided adrenal mass biopsies at an academic health system from January 6, 2015, to January 6, 2023. Patient demographics, biopsy indications, mass size, laboratory data, pathology results, and complications were recorded. Final diagnoses were based on pathology or ≥ 1 year of imaging follow-up when biopsy specimens did not yield malignant tissue. Test performance calculations excluded repeat biopsies. Continuous variables were compared with Student's t test, dichotomous variables with chi-squared test.

RESULTS

A total of 160 patients underwent 186 biopsies. Biopsies were indicated to diagnose metastatic disease (139/186; 74.7%), for oncologic research only (27/186; 14.5%), diagnose metastatic disease and oncologic research (15/186; 8%), and diagnose an incidental adrenal mass (5/186; 2.7%). Biopsy specimens were diagnostic in 154 patients (96.3%) and non-diagnostic in 6 (3.8%). Diagnostic biopsies yielded malignant tissue (n = 136), benign adrenal tissue (n = 12), and benign adrenal neoplasms (n = 6) with sensitivity = 98.6% (136/138), specificity = 100% (16/16), positive predictive value = 100% (136/136), and negative predictive value = 88.9% (16/18). Adverse events followed 11/186 procedures (5.9%) and most minor (7/11, 63.6%). The adverse event rate was similar whether tissue was obtained for clinical or research purposes (10/144; 6.9% vs. 1/42; 2.4%, p = 0.27), despite more specimens obtained for research (5.8 vs. 3.7, p < 0.001).

CONCLUSION

Percutaneous adrenal mass biopsy is safe, accurate, and utilized almost exclusively to diagnose metastatic disease or for oncologic research. The negative predictive value is high when diagnostic tissue samples are obtained. Obtaining specimens for research does not increase adverse event risk.

Adrenalectomy for Metastasis: The Impact of Primary Histology on Survival Outcome

Adrenalectomy is commonly considered a curative treatment in case of adrenal gland as site of metastasis. In the present study, we evaluated the impact of primary tumor histology on survival outcomes after a minimally invasive adrenal mastectomy for a solitary metachronous metastasis. From May 2004 to August 2020, we prospectively collected data on minimally invasive adrenalectomies whose pathological examination showed a metastasis. All patients only received metastasectomies that were performed with curative intent, or to achieve non-evidence of disease status. Adjuvant systemic therapy was not administered in any case. Cancer-specific survival (CSS) was assessed using the Kaplan-Meier method. Univariable and multivariable Cox regression analyses were applied to identify independent predictors of CSS. Out of 235 laparoscopic and robotic adrenalectomies, the pathologic report showed metastases in 60 cases. The primary histologies included 36 (60%) renal cell carcinoma (RCC), 9 (15%) lung cancer, 6 (10%) colon cancer, 4 (6.7%) sarcoma, 3 (5%) melanoma and 2 (3.3%) bladder cancer. RCC displayed significantly longer survival rates with a 5-year CSS of 55.9%, versus 22.8% for other histologies (log-rank p = 0.01). At univariable analysis, disease-free interval (defined as the time from adrenalectomy to evidence of disease progression) < 12 months and histology were predictors of CSS (p = 0.003 and p < 0.001, respectively). At multivariable Cox analysis, the only independent predictor of CSS was primary tumor histology (p = 0.005); patients with adrenal metastasis from colon cancer and bladder cancer showed a 5.3- and 75.5-fold increased risk of cancer death, respectively, compared to patients who had RCC as primary tumor histology. Oncological outcomes of adrenal metastasectomies are strongly influenced by primary tumor histology. A proper discussion of the role of surgery in a multidisciplinary context could provide optimal treatment strategies.

Review of Diagnostic Modalities for Adrenal Incidentaloma

Adrenal incidentalomas are common findings in clinical practice, with a prevalence of up to 4.2% in radiological studies. Due to the large number of focal lesions in the adrenal glands, it can be challenging to make a definitive diagnosis and determine the appropriate management. The purpose of this review is to present current diagnostic modalities used to preoperatively distinguish between adrenocortical adenoma (ACA) and adrenocortical cancer (ACC). Proper management and diagnosis are crucial in avoiding unnecessary adrenalectomies, which occur in over 40% of cases. A literature analysis was conducted to compare ACA and ACC using imaging studies, hormonal evaluation, pathological workup, and liquid biopsy. Before deciding on surgical treatment, the nature of the tumor can be accurately determined using noncontrast CT imaging combined with tumor size and metabolomics. This approach helps to narrow down the group of patients with adrenal tumors who require surgical treatment due to the suspected malignant nature of the lesion.

Atypical Nelson Syndrome Following Right Partial and Left Total Nephrectomy With Incidental Bilateral Total Adrenalectomy of Renal Cell Carcinoma: A Chat Generative Pre-Trained Transformer (ChatGPT)-Assisted Case Report and Literature Review

Nelson syndrome (NS) is a dangerous condition that can sometimes manifest after bilateral adrenalectomy (BA), typically in treating Cushing's disease. It is defined by the collection of systemic signs and symptoms that can arise in a state where there are chronically and massively elevated levels of adrenocorticotropic hormone (ACTH). Traditionally it may manifest from six months to 24 years following the loss of both adrenal glands, with the meantime of development being 15 years following BA. The diagnostic criteria are controversial, with historically many different methods being used, ranging from visual field defects and an enlarged pituitary corticotrophinoma to elevated plasma ACTH levels and skin hyperpigmentation. What remains consistent between criteria is that it is secondary to total BA, traditionally in treating refractory Cushing's disease. We describe here a rare case of a patient diagnosed with bilateral renal cell carcinoma (RCC) treated with right partial and left total nephrectomy, and incidental BA, presenting with the symptoms and signs of NS. Although NS classically presents following total BA for the treatment of Cushing disease, further research is required to look for etiologies of Nelson's-like pathology outside the context of Cushing's disease treatment, thereby necessitating a change to the traditional diagnostic criteria for the syndrome to identify cases that would otherwise go untreated. In addition, this case report's outlining, drafting, and conclusions were written in part by or with the support of Chat Generative Pre-Trained Transformer (ChatGPT), a large language transformer open-source artificial intelligence.

Imaging Recommendations for Diagnosis, Staging, and Management of Adrenal Tumors

Adrenal glands are affected by a wide variety of tumors apart from infective and inflammatory lesions and their noninvasive characterization on imaging is important for the management of these patients. Incidentalomas form the major bulk of adrenal tumors and differentiation of benign adenomas from other malignant lesions, especially in patients with a known malignancy, guide further management. Imaging is an integral part of management along with clinical and biochemical features. The cornerstone of clinical and biochemical evaluation of adrenal tumors is to determine whether the lesion is functional or nonfunctional. Computed tomography (CT) is considered as the workhorse for imaging evaluation of adrenal lesions. CT densitometry and CT contrast washout characteristics are quite reliable in differentiating adenomas from malignant lesions. CT is also the modality of choice for the evaluation of resectability and staging of primary adrenal tumors. Magnetic resonance imaging (MRI) has superior contrast resolution compared to other morphological imaging modalities and is generally used as a problem-solving tool. MRI chemical shift imaging can also be used to reliably detect adrenal adenomas. Ultrasonography (USG) is used as a screening tool that is usually followed by either CT or MRI to better characterize the tumor and it is not routinely used for assessing the resectability, staging, and characterization of adrenal tumors. Another important role of USG is in image-guided sampling of tumors. Fluorodeoxyglucose positron emission tomography-computed tomography and other nuclear medicine modalities are a valuable addition to morphological imaging modalities. Image-guided interventions also play an important role in obtaining tissue samples where diagnostic imaging is not able to characterize adrenal tumors. In the functioning of adrenal tumors, adrenal venous sampling is widely used to accurately lateralize the secreting tumor.

Laparoscopic approach of pediatric adrenal tumors

PURPOSE

To analyze the role of laparoscopic surgery for the management of pediatric adrenal tumors (AT).

METHODS

Retrospective analysis of children diagnosed with AT, operated laparoscopically during 2003-2020. The strategy differed according to tumor extension. AT < 6 cm were resected. Locally advanced tumors (L2) or > 6 cm were biopsied.

RESULTS

N = 28. Complete tumor resection (R0) in 20 (71%), tumor biopsy in 8 (R2). Age (median): 28.8 months (2 months-18 years). 14/28 left-sided, 2 bilateral. Median operating time: 78 min (45-180). Mean tumor size (for resections): 4 cm (2.5-6). Tumor pathology: neuroblastoma (n = 17), Ganglioneuroma (n = 7), Adrenocortical carcinoma (n = 1), Osteosarcoma metastasis (n = 1), Pheochromocytoma (n = 1), Venous malformation (n = 1). Mean hospital stay: 2.5 days (1-3). Mean follow up: 65.5 months (24-192). Overall survival and event-free survival were 86 and 75%, respectively (5 years event-free survival for neuroblastoma: 33% [intermediate risk], 16.6% [high risk]. No surgery-related mortality.

CONCLUSION

Laparoscopic surgery for adrenal tumors is safe. Laparoscopic biopsy is useful for unresectable tumors when a percutaneous approach is not possible. With the proposed selection criteria, the laparoscopic approach should be the first option for resection of small and localized AT in pediatrics.

Imaging and biopsy of HIV-infected individuals undergoing analytic treatment interruption

Background

HIV persistence during antiretroviral therapy (ART) is the principal obstacle to cure. Lymphoid tissue is a compartment for HIV, but mechanisms of persistence during ART and viral rebound when ART is interrupted are inadequately understood. Metabolic activity in lymphoid tissue of patients on long-term ART is relatively low, and increases when ART is stopped. Increases in metabolic activity can be detected by ¹⁸F-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and may represent sites of HIV replication or immune activation in response to HIV replication.

Methods

FDG-PET imaging will be used to identify areas of high and low metabolic uptake in lymphoid tissue of individuals undergoing long-term ART. Baseline tissue samples will be collected. Participants will then be randomized 1:1 to continue or interrupt ART via analytic treatment interruption (ATI). Image-guided biopsy will be repeated 10 days after ATI initiation. After ART restart criteria are met, image-guided biopsy will be repeated once viral suppression is re-achieved. Participants who continued ART will have a second FDG-PET and biopsies 12–16 weeks after the first. Genetic characteristics of HIV populations in areas of high and low FDG uptake will be assesed. Optional assessments of non-lymphoid anatomic compartments may be performed to evaluate HIV populations in distinct anatomic compartments.

Anticipated results

We anticipate that PET standardized uptake values (SUV) will correlate with HIV viral RNA in biopsies of those regions and that lymph nodes with high SUV will have more viral RNA than those with low SUV within a patient. Individuals who undergo ATI are expected to have diverse viral populations upon viral rebound in lymphoid tissue. HIV populations in tissues may initially be phylogenetically diverse after ATI, with emergence of dominant viral species (clone) over time in plasma. Dominant viral species may represent the same HIV population seen before ATI.

Discussion

This study will allow us to explore utility of PET for identification of HIV infected cells and determine whether high FDG uptake respresents areas of HIV replication, immune activation or both. We will also characterize HIV infected cell populations in different anatomic locations. The protocol will represent a platform to investigate persistence and agents that may target HIV populations.

Study protocol registration

Identifier: NCT05419024.

Adrenal Incidentaloma

An adrenal incidentaloma is now established as a common endocrine diagnosis that requires a multidisciplinary approach for effective management. The majority of patients can be reassured and discharged, but a personalized approach based upon image analysis, endocrine workup, and clinical symptoms and signs are required in every case. Adrenocortical carcinoma remains a real concern but is restricted to <2% of all cases. Functional adrenal incidentaloma lesions are commoner (but still probably <10% of total) and the greatest challenge remains the diagnosis and optimum management of autonomous cortisol secretion. Modern-day surgery has improved outcomes and novel radiological and urinary biomarkers will improve early detection and patient stratification in future years to come.

"How We Do It" - A Practical Approach to Percutaneous Adrenal Ablation Techniques

Incidental adrenal masses are common and are found in 4% of the CT scans.¹ While clinical history, laboratory results, and imaging characteristics are typically sufficient for diagnosis of an adrenal lesion, a biopsy is sometimes warranted. In some cases, adrenal mass ablation is subsequently indicated. This article serves as a brief but comprehensive review of preprocedural work-up and planning before an adrenal mass ablation, as well as a discussion on ablation techniques, associated challenges and solutions, and management of expected and unexpected outcomes.

Results of Percutaneous Computed Tomography-Guided Biopsy of Adrenal Lesions and Spectrum of Computed Tomography Findings

Objective

Adrenal enlargement occurs in various conditions such as infections, benign, and malignant neoplasms. Percutaneous computed tomography (CT)-guided adrenal biopsy is a safe method for obtaining tissue specimen in cases where diagnosis cannot be established on imaging and biochemical grounds. The study aims to evaluate diagnostic yield, accuracy, and complications of percutaneous CT-guided adrenal biopsies. Furthermore, CT findings of various adrenal lesions have been described.

Materials and Methods

Data of CT-guided adrenal biopsies performed from September 2009 to May 2019 were analyzed. Biopsies were performed on a 64-slice or a 128-slice multidetector CT scanner using a coaxial technique. Pathological and microbiological reports were retrieved from the hospital information system. Clinical details were obtained from clinical case records.

Results

CT-guided adrenal biopsies were performed in 48 patients, 37 males and 11 females. Adrenal insufficiency was present in 31 (64%) cases and bilateral adrenal glands were affected in 35 (73%). Biopsy yielded a diagnosis in 35 cases (72.9%). The final diagnosis was achieved in 43 (90%) cases. Combined accuracy of CT-guided biopsy for identifying malignancy and infection was 88.3%. Adrenal histoplasmosis (AH) was the most common entity diagnosed (44%). After combining histopathology and microbiology results, the sensitivity for diagnosing AH was 100%. One (2%) patient had a major complication in the form of intra-abdominal hemorrhage requiring transfusion. Local hematoma and mild stable pneumothorax were noted in one patient each.

Conclusion

Percutaneous CT-guided biopsy is a safe procedure for the diagnosis of adrenal lesions. It has good accuracy for diagnosing adrenal conditions such as infections and malignancies. However, the specific diagnosis of benign adrenal lesions was difficult to make. AH, tuberculosis, and metastasis have overlapping imaging findings.

Adrenal cortical carcinoma: pathology, genomics, prognosis, imaging features, and mimics with impact on management

Adrenocortical carcinoma (ACC) is a rare tumor with a poor prognosis. Most tumors are either metastatic or locally invasive at the time of diagnosis. Differentiation between ACC and other adrenal masses depends on clinical, biochemical, and imaging factors. This review will discuss the genetics, pathological, and imaging feature of ACC.

Safety of percutaneous ultrasound-guided fine-needle aspiration of adrenal lesions in dogs: Perception of the procedure by radiologists and presentation of 50 cases

Background

Percutaneous ultrasound (US)‐guided fine‐needle aspiration (FNA) of adrenal gland lesions is controversial in veterinary medicine.

Objective

To evaluate the frequency and radiologists' perception of the risk of the procedure as well as determining the incidence of complications.

Methods

Retrospective study. A first survey was submitted by e‐mail to all board‐certified radiologists of the American College of Veterinary Radiology (ACVR) and European College of Veterinary Diagnostic Imaging (ECVDI). A second survey was sent to radiologists who declared having performed the procedure at least once in their career (observational cross‐sectional case study).

Results

The first survey was sent to 977 diplomates and answered by 138. Of 138 diplomates, 40 currently performed the procedure and 98 did not; 44 of the 98 gave the hypertensive crisis risk in pheochromocytoma as a reason. To the second survey, 12 of 65 responded positively; 50 dogs with 58 lesions were recruited, including 23 pheochromocytomas. Complications were reported in 4 of 50 dogs; 3 hemorrhages (1 mild and 1 moderate) and 1 death from acute respiratory distress syndrome (possibly related to laryngeal paralysis). No hypertensive crisis was reported. There was no relationship between the method of FNA/type of needle used and occurrence of complications. Based on the recollection of these 65 radiologists, who performed approximately 200 FNA of adrenal lesions, a death rate of approximately 1% was estimated.

Conclusions and Clinical Importance

Percutaneous US‐guided FNA of adrenal lesions can be considered a minimally risky procedure, despite the negative perception by radiologists.

Primary adrenal leiomyosarcoma with inferior vena cava extension in a 70-year-old man

Primary adrenal leiomyosarcoma, a malignant soft tissue tumour originating from the smooth muscle of the inferior vena cava and adrenal vein, is rarely described in the literature. Cases are often diagnosed at an advanced stage as the tumour is not hormone-producing. We describe a 70-year-old man who presented with lower extremity swelling and abdominal varices and was subsequently found to have a large adrenal mass on imaging. Our case is among the few reported primary adrenal leiomyosarcomas in which a CT-guided biopsy was used to aid in diagnosis.

Performance characteristics of EUS-FNA biopsy for adrenal lesions: A meta-analysis

Background and Objective:

The role of EUS-FNA biopsy (EUS-FNAB) for detection of metastatic lesions (mets) to adrenals has not been evaluated systematically. Our aim is to systematically evaluate the performance characteristics of EUS-FNAB in detecting metastasis to the adrenal glands.

Materials and Methods:

We performed a systematic search on PubMed and OvidSP from January 1990 to July 2016 using various search terms for EUS and adrenal lesion. Only articles published in English literature were included in the study. Studies with fewer than 10 patients were excluded from the study. Publication bias was assessed using Begg-Mazumdar test and visual inspection of funnel plots.

Results:

Eight studies including 360 adrenal lesions that underwent EUS-FNAB were identified. Of these, 137 FNABs were conclusive for malignancy. Sensitivity of EUS-FNAB in detecting metastasis to the adrenals was 95% (95% confidence interval [CI]: 90%–98%) and specificity was 99% (95% CI: 96%–100%). Pooled positivity of EUS-FNAB in detecting lung cancer metastasis to the adrenals was 44% (95% CI: 31.5%–57.3%). No evidence of publication bias was noted.

Conclusion:

Our study demonstrates that EUS-FNAB is highly sensitive and specific in detecting metastasis to adrenals. It also shows that up to about half of the patients with lung cancer and adrenal lesions on imaging have metastasis, a finding with profound implications on lung cancer staging and treatment.

Adrenal tumor segmentation method for MR images

BACKGROUND AND OBJECTIVE

Adrenal tumors, which occur on adrenal glands, are incidentally determined. The liver, spleen, spinal cord, and kidney surround the adrenal glands. Therefore, tumors on the adrenal glands can be adherent to other organs. This is a problem in adrenal tumor segmentation. In addition, low contrast, non-standardized shape and size, homogeneity, and heterogeneity of the tumors are considered as problems in segmentation.

METHODS

This study proposes a computer-aided diagnosis (CAD) system to segment adrenal tumors by eliminating the above problems. The proposed hybrid method incorporates many image processing methods, which include active contour, adaptive thresholding, contrast limited adaptive histogram equalization (CLAHE), image erosion, and region growing.

RESULTS

The performance of the proposed method was assessed on 113 Magnetic Resonance (MR) images using seven metrics: sensitivity, specificity, accuracy, precision, Dice Coefficient, Jaccard Rate, and structural similarity index (SSIM). The proposed method eliminates some of the discussed problems with success rates of 74.84%, 99.99%, 99.84%, 93.49%, 82.09%, 71.24%, 99.48% for the metrics, respectively.

CONCLUSIONS

This study presents a new method for adrenal tumor segmentation, and avoids some of the problems preventing accurate segmentation, especially for cyst-based tumors.

Image-Guided Renal Interventions

Image-guided renal biopsies have an increasing role in clinical practice. Renal mass and renal parenchymal biopsy indications, techniques, and other clinical considerations are reviewed in this article. Image-guided renal mass ablation shows significant promise and increasing clinical usefulness as more studies demonstrate its safety and efficacy. Renal mass ablation indications, techniques, and other considerations are also reviewed.

Computed tomography-guided percutaneous biopsy of abdominal lesions: indications, techniques, results, and complications

Objective

To evaluate the performance of computed tomography (CT)-guided percutaneous biopsy of abdominal lesions.

Materials and Methods

This retrospective, single-center study evaluated patients submitted to CT-guided percutaneous biopsy of abdominal lesions at a cancer center, between January 2014 and June 2015. The images and patient medical records were reviewed using a standardized data collection form.

Results

We included 225 procedures performed in 212 patients, of whom 143 (63.5%) had a prior diagnosis of cancer. Of the 225 lesions biopsied, 88 (39.1%) had a suspected primary origin and 137 (60.9%) were suspected metastatic lesions. Complications occurred in only 14 (6.2%), the most common being self-limited bleeding, which occurred in 12 (85.7%) of the 14. The occurrence of complications was not found to be significantly associated with the lesion location, age of the patient, presence of comorbidities, use of a supplementary technique, vascularization pattern, or proximity of the lesion to large vessels. The pathology findings were sufficient for making the diagnosis in 202 cases (89.8%), and the diagnosis was consistent with the clinical suspicion in 132 (58.6%).

Conclusion

The procedure demonstrated a high (approximately 90%) rate of providing a sufficient sample for the diagnosis and a low complication rate, the most common complication being self-limiting bleeding.

Interventional radiology of the adrenal glands: current status

As more and more adrenal neoplasms are found incidentally or symptomatically, the need for interventional procedures has being increasing. In recent years these procedures registered continued steady expansion. Interventional radiology of the adrenal glands comprises angiographic and percutaneous procedures. They may be applied both in benign and in malignant pathologies. The present review reports the current status of indications, techniques results and complications of the image-guided procedures.

Endoscopic ultrasound-guided fine-needle aspiration of enlarged adrenals in patients with pyrexia of unknown origin: A single-center experience of 52 cases

BACKGROUND

Fine-needle aspiration (FNA) of adrenals is needed in patients with pyrexia of unknown origin (PUO) and adrenal enlargement in absence of other diagnostic clues. Adrenals are easily accessible by endoscopic ultrasound (EUS) due to proximity; however, there is no systemic study available on FNA of adrenals in patients with PUO. The aim of this study was to evaluate the diagnostic yield and safety of EUS-FNA of enlarged adrenal in patients with PUO.

METHODS

Data was analyzed from October 2010 to September 2016 at a single tertiary care center in northern India. EUS-FNA of enlarged adrenals was done in 52 patients for the etiological diagnosis of PUO in whom a definitive diagnosis could not be made with other means.

RESULTS

The mean age was 48±14 years; 36 were males and 16 were females. EUS-FNA was done from the left adrenal in 50 patients and from the right sample in 2 patients. A technical success was achieved in 100% cases. The 19-G needle was used in the majority (75%) to the presence of necrotic areas in adrenals; median numbers of passes were 2. The cytopathological diagnoses were tuberculosis (n = 36), histoplasmosis (n = 13), lymphoma (n = 2), and metastasis from undiagnosed neuroendocrine tumor of lung (n = 1). Thus, a diagnosis could be made in 52/52 (100%) patients. None of the patients had any procedure-related complications.

CONCLUSIONS

EUS-FNA is a safe and effective method for evaluating etiology of PUO in patients with adrenal enlargement.

Morphologic analysis with computed tomography may help differentiate fat-poor angiomyolipoma from renal cell carcinoma: a retrospective study with 602 patients

PURPOSE

To assess whether morphologic analysis using computed tomography (CT) could differentiate between fat-poor angiomyolipoma (fpAML) and renal cell carcinoma (RCC).

METHODS

A total of 602 patients with a histologically confirmed fpAML (n = 49) or RCC (n = 553) were evaluated. All renal lesions were less than 4 cm in size and had no gross fat on contrast-enhanced CT. For morphologic analysis, overflowing beer sign and angular interface were evaluated. Overflowing beer sign was defined as contact length between bulging-out portion of a mass and the adjacent renal capsule of 3 mm or greater. Angular interface was defined as the angle of parenchymal portion of a mass of 90° or less. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were assessed. Multivariate analysis was conducted to determine which variable is predictive of fpAML.

RESULTS

Sensitivity, specificity, PPV, NPV, and accuracy were 61.2% (30/49), 97.1% (537/553), 65.2% (30/46), 96.6% (537/556), and 94.2% (567/602) with overflowing beer sign, while they were 55.1% (27/49), 81.9% (453/553), 21.3% (27/127), 95.4% (453/475), and 79.7% (480/602) with angular interface for fpAML, respectively. Both CT variables were predictive of fpAML (overflowing beer sign, odds ratio = 132.881, p < 0.001; angular interface, odds ratio = 5.766, p = 0.010). The multivariate model with CT variables showed good performance for predicting fpAML (AUC, 0.871 with angular interface, 0.943 with overflowing beer sign, and 0.949 with both).

CONCLUSION

Morphologic analysis with contrast-enhanced CT may be useful for differentiating fpAML from RCC. Overflowing beer sign has the potential as an imaging biomarker for fpAML.

Ultrasound-guided genitourinary interventions: principles and techniques

Ultrasound (US) is often used to guide various interventional procedures in the genitourinary (GU) tract because it can provide real-time imaging without any radiation hazard. Moreover, US can clearly visualize the pathway of an aspiration or biopsy needle to ensure the safety of the intervention. US guidance also helps clinicians to access lesions via the transabdominal, transhepatic, transvaginal, transrectal, and transperineal routes. Hence, US-guided procedures are useful for radiologists who wish to perform GU interventions. However, US-guided procedures and interventions are difficult for beginners because they involve a steep initial learning curve. The purpose of this review is to describe the basic principles and techniques of US-guided GU interventions.

C-arm cone-beam computed tomography with stereotactic needle guidance for percutaneous adrenal biopsy: initial experience

Background Metastasis to the adrenal glands is frequent in patients with various cancers and adrenal gland biopsy is routinely performed using ultrasound or computed tomographic (CT) guidance. However, this method is technically challenging, especially in the case of small masses. Purpose To determine whether the new real-time stereotactic needle guidance technique C-arm cone-beam CT (CBCT) allows safe and accurate biopsy of adrenal gland masses, especially those in hard-to-reach anatomical locations. Material and Methods CBCT guidance was used to perform 60 stereotactic biopsy procedures of lesions that were inaccessible with ultrasound or CT guidance. The needle path was carefully planned and calculated on the CBCT virtual navigation guidance system, which acquired 3D CT-like cross-sectional images. The adrenal biopsy procedures were performed with fluoroscopic feedback. Technical success rate, sensitivity, specificity, accuracy, and complications were investigated. Results The technical success rate of adrenal biopsy under CBCT virtual navigation was 100%, with a mean total procedure time of 14.6 ± 3.6 min. Of the 60 lesions, 46 were malignant, 11 were benign, and three were non-diagnostic. The three non-diagnostic lesions proved to be malignant. Thus, the sensitivity, specificity, and accuracy were 93.8%, 100%, and 95.0%, respectively. Minor bleeding occurred in two (3.3%) cases. Conclusion CBCT guidance allows safe and accurate biopsy of adrenal gland masses and may be especially useful for hard-to-reach anatomical locations.

CT-guided Native Medical Renal Biopsy: Cortical Tangential versus Non-Tangential Approaches-A Comparison of Efficacy and Safety

Purpose To review a single-center experience with the cortical tangential approach during computed tomography (CT)-guided native medical renal biopsy and to evaluate its efficacy and safety compared with those of a non-cortical tangential approach. Materials and Methods This retrospective study received institutional review board approval, with a waiver of the HIPAA requirement for informed consent. The number of cores, glomeruli, and complications were reviewed in 431 CT-guided medical renal biopsies performed between July 2007 and September 2015. A biopsy followed a cortical tangential approach if the needle path was parallel to the renal cortical surface, at a depth closer to the renal capsule than the renal pelvic fat. A sample was considered adequate if the biopsy yielded at least 10 glomeruli at light microscopy, one glomerulus at immunofluorescence microscopy, and one glomerulus at electron microscopy. The χ² test, the t test, the Mann-Whitney test, and logistic regression modeling of sample adequacy were performed. Results One hundred fifty-six (36%) of 431 biopsies were performed with the cortical tangential approach. More cores were obtained for the cortical tangential group (2.6 vs 2.4, P = .001); biopsy needle gauge was not significantly different (P = .076). More adequate samples were obtained in the cortical tangential group (66.7% vs 49.8%, P = .001), with more glomeruli (23 vs 16, P = .014). Results were significant after controlling for needle gauge and number of cores (P = .008). The cortical tangential group had fewer complications (1.9% vs 7.3%, P = .018). Conclusion The cortical tangential approach, when applied to CT-guided native medical renal biopsies, results in higher rates of sample adequacy and lower rates of postprocedural complications. ^© RSNA, 2016.

Classifying murine glomerulonephritis using optical coherence tomography and optical coherence elastography

Acute glomerulonephritis caused by antiglomerular basement membrane marked by high mortality. The primary reason for this is delayed diagnosis via blood examination, urine analysis, tissue biopsy, or ultrasound and X-ray computed tomography imaging. Blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution, with reduced sensitivity. Optical coherence tomography is a noninvasive and high-resolution imaging technique that provides superior spatial resolution (micrometer scale) as compared to ultrasound and CT. Changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signals, such as optical attenuation and speckle variance. Furthermore, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, OCT has been utilized to quantify the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, its classification accuracy is clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improves from 76% to 95%. These results show that OCT combined with OCE can be a powerful tool for identifying and classifying nephritis. Therefore, the OCT/OCE method could potentially be used as a minimally invasive tool for longitudinal studies during the progression and therapy of glomerulonephritis as well as complement and, perhaps, substitute highly invasive tissue biopsies. Elastic-wave propagation in mouse healthy and nephritic kidneys.

Kidney, Ureter, and Bladder Biopsy

Percutaneous urologic biopsy is a safe and effective technique and can comprise a significant proportion of the daily workload of the interventional radiologist. This article discusses the indications and rationale for the performance of renal, ureter, and bladder biopsy as well as the approach to performing such biopsies, pitfalls, and potential complications.

Endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of adrenal lesions

The use of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) appears to be a safe and feasible means of confirming or excluding malignancy in the adrenal glands. EUS-FNA with biopsy of suspicious masses in either adrenal gland allows for assessment of these lesions while keeping complications relatively rare. The main advantages of EUS-FNA are that it can be done as an outpatient procedure, with good results, minimal morbidity, and a short hospital stay. Nevertheless, EUS-FNA of adrenal masses should be indicated only in selected cases, in which there is potential to either decrease unnecessary treatment or guide therapy in cancer patients by aiding in either staging of malignancy or treatment of recurrence.v.

Imaging of rare medullary adrenal tumours in adults

Although adrenal medullary tumours are rare, they have important clinical implications. They form a heterogeneous group of tumours, ranging from benign, non-secretory, incidental masses to hormonally active tumours presenting acutely, or malignant tumours with disseminated disease and a poor prognosis. Increasingly, benign masses are incidentally detected due to the widespread use of imaging and routine medical check-ups. This review aims to illustrate the multimodality imaging appearances of rare adrenal medullary tumours, excluding the more common phaeochromocytomas, with clues to the diagnosis and to summarise relevant epidemiological and clinical data. Careful correlation of clinical presentation, hormone profile, and various imaging techniques narrow the differential diagnosis. Image-guided percutaneous adrenal biopsy can provide a definitive diagnosis, allowing for conservative management in selected cases. A close collaboration between the radiologist, endocrinologist, and surgeon is of the utmost importance in the management of these tumours.

Work-up of the Incidental Adrenal Mass

CONTEXT

Incidental adrenal masses (or adrenal incidentalomas [AI]) are a common finding during imaging and are present in up to 5% of the computed tomography (CT) scans performed on the general population. The best way to manage these lesions is still under discussion.

OBJECTIVE

To evaluate recent literature and available guidelines regarding the work-up of AIs.

EVIDENCE ACQUISITION

We used a medical search engine to identify studies published in the past 5 yr regarding AIs. We also evaluated current guidelines and the most relevant papers published before 2010.

EVIDENCE SYNTHESIS

Unenhanced and contrast-enhanced CT, with laboratory tests to exclude functional lesions, are the most sensitive and specific methods currently available for the characterisation of adrenal masses. Magnetic resonance imaging, positron emission tomography-CT and fine-needle aspiration biopsy can be used as adjunct diagnostic tools in indeterminate lesions but are rarely indicated. In a relatively high number of indeterminate nodules, follow-up or surgery is suggested, although most of these lesions turn out to be benign.

CONCLUSIONS

Various imaging modalities, with CT being most important, are available to diagnose malignant and functional lesions in AIs. An improved identification of benign lesions is warranted to reduce the number of unnecessary surgeries and follow-up examinations in patients with benign lesions.

PATIENT SUMMARY

We performed a review of the literature on and guidelines for the management of incidental adrenal masses. It is possible to detect the presence of lesions that require surgery in the majority of cases. Follow-up is required for lesions that are not treated surgically.

Role of endoscopic ultrasound fine-needle aspiration evaluating adrenal gland enlargement or mass

AIM: To report the clinical impact of adrenal endoscopic ultrasound fine-needle aspiration (EUS-FNA) in the evaluation of patients with adrenal gland enlargement or mass.

METHODS: In a retrospective single-center case-series, patients undergoing EUS-FNA of either adrenal gland from 1997-2011 in our tertiary care center were included. Medical records were reviewed and results of EUS, cytology, adrenal size change on follow-up imaging ≥ 6 mo after EUS and any repeat EUS or surgery were abstracted. A lesion was considered benign if: (1) EUS-FNA cytology was benign and the lesion remained < 1 cm from its original size on follow-up computed tomography (CT), magnetic resonance imaging or repeat EUS ≥ 6 mo after EUS-FNA; or (2) subsequent adrenalectomy and surgical pathology was benign.

RESULTS: Ninety-four patients had left (n = 90) and/or right (n = 5) adrenal EUS-FNA without adverse events. EUS indications included: cancer staging or suspected recurrence (n = 31), pancreatic (n = 20), mediastinal (n = 10), adrenal (n = 7), lung (n = 7) mass or other indication (n = 19). Diagnoses after adrenal EUS-FNA included metastatic lung (n = 10), esophageal (n= 5), colon (n = 2), or other cancer (n = 8); benign primary adrenal mass or benign tissue (n = 60); or was non-diagnostic (n = 9). Available follow-up confirmed a benign lesion in 5/9 non-diagnostic aspirates and 32/60 benign aspirates. Four of the 60 benign aspirates were later confirmed as malignant by repeat biopsy, follow-up CT, or adrenalectomy. Adrenal EUS-FNA diagnosed metastatic cancer in 24, and ruled out metastasis in 10 patients. For the diagnosis of malignancy, EUS-FNA of either adrenal had sensitivity, specificity, positive predictive value and negative predictive value of 86%, 97%, 96% and 89%, respectively.

CONCLUSION: Adrenal gland EUS-FNA is safe, minimally invasive and a sensitive technique with significant impact in the management of adrenal gland mass or enlargement.

A new method of kidney biopsy using low dose CT-guidance with coaxial trocar and bard biopsy gun

Background

To explore a new method of kidney biopsy with coaxial trocar and bard biopsy gun under low dose computed tomography (CT)-guidance and evaluate its accuracy, safety, and efficacy.

Methods

Sixty patients underwent renal biopsy under CT-guidance. They were randomly divided into two groups: group I, low dose CT-guided (120 kV and 25 or 50 mAs) and group II, standard dose CT-guided (120 kV and 250 mAs). For group I, the coaxial trocar was accurately placed adjacent to the renal capsule of the lower pole, the needle core was removed, and samples were obtained with a bard biopsy gun. For group II, the coaxial trocar was not used. Total number of passes, mean biopsy diameter, mean glomeruli per specimen, mean operation time, mean scanning time, and mean radiation dose were noted. Dose-length product (DLP) was used to calculate the radiation doses. After 24 hours of the biopsy, ultrasound was repeated to identify any subcapsular hematoma.

Results

Success rate of biopsy in group I was 100% while using low dose CT-guidance along with coaxial trocar renal. There was no statistic differences bewteen group I and II in the total number of passes, mean biopsy diameter, mean glomeruli per specimen and mean time of operation and CT scanning. The average DLP of group I was lower as compared to the value of group II (p <0.05).

Conclusions

Kidney biopsy using coaxial trocar and bard biopsy gun under low dose CT was an accurate, simple and safe method for diagnosis and treatment of kidney diseases. It can be used for repeat and multiple biopsies, particularly suitable for obese and renal atrophy patients in whom the kidneys are difficult to image.

Biopsy needle localization using magnetic induction imaging principles: a feasibility study

The accurate navigation and location of a biopsy needle is of main clinical interest in cases of image-guided biopsies for patients with suspected cancerous lesions. Magnetic induction (MI) imaging is a relatively new simple and low-cost noninvasive imaging modality that can be used for measuring the changes of electrical conductivity distribution inside a biological tissue. The feasibility of using MI principles for measuring and imaging the location of a biopsy needle in a tissue with suspected lesion was studied in simulations and with an experimental system. A contactless excitation/sensing unit was designed, and raster scan was performed on a thin tissue slab with an inserted standard 22 gauge stainless steel biopsy needle. A 30-mA, 50-kHz excitation field was employed, and the secondary-induced electromotive force (emf(s)) was measured and plotted on a 2-D plane in order to yield an image of the needle location. The simulations demonstrated the significance of utilizing a ferrimagnetic core for the excitation coil in order to increase induced currents magnitude and scanning resolution. The experimental reconstructed images of the emf(s) spatial distribution revealed the needle position and orientation, with an accuracy of 0.1 mm and a signal-to-background ratio of ~30 dB. High correlation (R(2) = 0.89) between the experimental and simulation results was observed. We conclude that MI principles exhibit a potential alternative to existing imaging modalities for needle biopsy procedures.

3D cone-beam CT guidance, a novel technique in renal biopsy--results in 41 patients with suspected renal masses

Objective

To determine whether 3D cone-beam computed tomography (CBCT) guidance allows safe and accurate biopsy of suspected small renal masses (SRM), especially in hard-to-reach anatomical locations.

Materials and methods

CBCT guidance was used to perform 41 stereotactic biopsy procedures of lesions that were inaccessible for ultrasound guidance or CT guidance. In CBCT guidance, a 3D-volume data set is acquired by rotating a C-arm flat-panel detector angiosystem around the patient. In the data set, a needle trajectory is determined and, after co-registration, a fusion image is created from fluoroscopy and a slice from the data set, enabling the needle to be positioned in real time.

Results

Of the 41 lesions, 22 were malignant, 17 were benign, and 2 were nondiagnostic. The two nondiagnostic lesions proved to be renal cell carcinoma. There was no growth during follow-up imaging of the benign lesions (mean 29 months). This resulted in a sensitivity, specificity, PPV, NPV, and accuracy of 91.7, 100, 100, 89.5, and 95.1%, respectively. Mean dose-area product value was 44.0 Gy·cm² (range 16.5–126.5). There was one minor bleeding complication.

Conclusion

With CBCT guidance, safe and accurate biopsy of a suspected SRM is feasible, especially in hard-to-reach locations of the kidney.

Key Points

• Cone-beam computed tomography has potential advantages over conventional CT for interventional procedures.

• CBCT guidance incorporates 3D CBCT data, fluoroscopy, and guidance software.

• In hard-to-reach renal masses, CBCT guidance offers an alternative biopsy method.

• CBCT guidance offers good outcome and safety and has potential clinical significance.