Assessment of Contrast-Enhanced Ultrasound (CEUS) and Computed Tomography (CT) diagnostic accuracy in the evaluation of challenging cystic renal masses.

PURPOSE: To assess the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) within Bosniak IIF/III categories. METHODS: After cystic renal mass diagnosis by contrast-enhanced CT, all patients with Bosniak score ≥ II also underwent CEUS between March 2017 and March 2019. Their exams were retrospectively analyzed. One experienced uro-radiologist performed every CEUS and reviewed the exams according to the EFSUMB 2020 Position Statement, while blinded to clinical data. CT Bosniak scores were retrospectively given blindly by two uro-radiologists (CT 1 and CT 2). We compared CEUS, CT 1 and CT 2 scores to clinical findings and histological tests. Clinical performance characteristics and area under the receiver operating characteristic (ROC) curves (AUCs) were determined separately for CEUS and CT, and then compared. RESULTS: 101 cystic masses were analyzed. In Bosniak categories IIF and III, the AUCs were 0.854 for CT 1, 0.779 for CT 2, and 0.746 for CEUS. CONCLUSION: Despite some statistical limitations, this study confirms that among cystic renal masses, those classified as Bosniak IIF and III are the most difficult to assess. The diagnostic performances of CEUS and CT are similar within this group. However, in experienced hands, CEUS could be valuable in further evaluation of ambiguous cystic masses, and in more ductile, safer, and cost-effective surveillance of those classified as Bosniak IIF and III. When challenging cystic renal masses occur, CEUS is a useful tool for clinical management and for the follow-up of non-surgical lesions.

Assessment of the workload and financial burden of Bosniak IIF renal cyst surveillance in a tertiary referral hospital.

BACKGROUND: The Bosniak classification is a CT classification which stratifies renal cysts based on imaging appearances and therefore associated risk of malignancy. Bosniak IIf cysts are renal which have complex features and therefore require surveillance. AIMS: The aim of this study is to assess the economic and workload burden of diagnosing and following up Bosniak IIf cysts on the urology service in a tertiary hospital in the West of Ireland. METHODS: All patients with a diagnosis of Bosniak IIf renal cysts attending our urology service between 1st of January 2012 and 31st December 2020 were analysed. The following data were collected: number and modality of follow up scans, number of MDT discussions, number and type of outpatient appointments, surgical intervention, and length of follow up. Financial data were provided by the hospital finance department. RESULTS: One hundred and sixty-two patients were included. Total cost of follow up was €164,056, costing €1,012.7 per patient. Cost of outpatient visits was €77,850. Follow-up length ranged from 1 to 109 months, median follow up time 17.5 months. Overall cost of imaging was €74,518. There were a total of 80 MDT discussions at an overall cost of €11,688. CONCLUSIONS: This study demonstrates that surveillance of patients with Bosniak IIf renal cysts represents a significant burden upon both radiology and urology services. Surveillance for these patients could be streamlined in the future through a number of initiatives such as virtual OPDs and dedicated MDTs.

Cost-effectiveness analysis of multiple imaging modalities in diagnosis and follow-up of intermediate complex cystic renal lesions.

OBJECTIVES: To compare health-economic aspects of multiple imaging modalities used to monitor renal cysts, the present study evaluates costs and outcomes of patients with Bosniak IIF and III renal cysts detected and followed-up by either contrast-enhanced computed tomography (ceCT), contrast-enhanced magnetic resonance imaging (ceMRI), or contrast-enhanced ultrasonography (CEUS). PATIENTS AND METHODS: A simulation using Markov models was implemented and performed with 10 cycles of 1 year each. Proportionate cohorts were allocated to Markov models by a decision tree processing specific incidences of malignancy and levels of diagnostic performance. Costs of imaging and surgical treatment were investigated using internal data of a European university hospital. Multivariate probabilistic sensitivity analysis was performed to confirm results considering input value uncertainties. Patient outcomes were measured in quality-adjusted life years (QALY), and costs as averages per patient including costs of imaging and surgical treatment. RESULTS: Compared to the 'gold standard' of ceCT, ceMRI was more effective but also more expensive, with a resulting incremental cost-effectiveness ratio (ICER) >€70 000 (Euro) per QALY gained. CEUS was dominant compared to ceCT in both Bosniak IIF and III renal cysts in terms of QALYs and costs. Probabilistic sensitivity analysis confirmed these results in the majority of iterations. CONCLUSION: Both ceMRI and CEUS can be used as alternatives to ceCT in the diagnosis and follow-up of intermediately complex cystic renal lesions without compromising effectiveness, while CEUS is clearly cost-effective. The economic results apply to a large university hospital and must be adapted for smaller hospitals.

Multimodality Assessment of Cystic Renal Masses.

Renal cysts are a common imaging finding, often incidental. Ultrasound, CT and MRI are the main modalities responsible for renal cyst detection and characterization. These modalities often play a complementary role in modern radiological practice, each of them with strengths and limitations. In view of a recently proposed 'multimodality' update to the historical Bosniak classification, this article provides a general overview of the current imaging approach to renal cysts, and outlines some of the diverse pathologic entities responsible for renal cyst formation.

What to Do With Renal Cysts in Children?

OBJECTIVE: To explore the current practice patterns for the management of renal cysts internationally among pediatric urologists and nephrologists. MATERIALS AND METHODS: A survey composed of 21 questions and 4 clinical scenarios was distributed to pediatric urologists and nephrologists. Survey questions evaluated optimal imaging modality, management, and follow-up period. Interspecialty comparisons were made using chi-square analysis where appropriate. RESULTS: A total of 183 respondents completed the survey (128 pediatric urologists, 37 pediatric nephrologists, and 19 other specialists). Most (57%) respondents agreed or strongly agreed with using an ultrasound based Bosniak classification to categorize renal cysts in children. The most commonly used follow-up intervals were 6-12 months for pediatric urologists and 1-2 years for pediatric nephrologists. Symptomatic mass effect (80.9%), gross hematuria (79.2%), or family history were the most common reasons for escalating surveillance. Pediatric nephrologists were more likely to increase follow-up with development of bilateral simple renal cysts (P = .008) or chronic kidney disease (P = .027) when compared to pediatric urologists. Laparoscopic marsupialization (39.4%) was the most common treatment for a simple renal cyst in a symptomatic child. Modified Bosniak III cysts had more heterogeneity in treatment based on the physician responses. CONCLUSION: There is currently no consensus on the optimal protocol for the surveillance, imaging, or treatment of renal cysts in children. Most respondents agree that using an ultrasound-based Bosniak classification is reasonable. A call to action is therefore necessary for the development of registries and guidelines on the management of pediatric renal cysts and their associated malignancies.

Comparison of computed tomography and magnetic resonance imaging in the assessment of complex renal cysts by using the Bosniak classification. / Comparación entre tomografía computarizada y resonancia magnética en la evaluación de quistes renales complejos empleando la clasificación de Bosniak.

INTRODUCTION AND OBJECTIVES: The Bosniak classification of cystic renal lesions was first published in 1986 based on computed tomography (CT). In the present study, we aimed to investigate the effect of magnetic resonance imaging (MRI) on Bosniak category compared with CT, and to determine how this effect changed the treatment modality in the evaluation of complex renal cysts. MATERIAL AND METHODS: Data of 144 patients were collected retrospectively. After exclusion criteria, 102 cystic renal lesions with a Bosniak category of at least IIF on CT or MRI between 2013 and 2016 were evaluated by 2abdominal radiologists. The demographic data, Bosniak category, interobserver agreement, and pathologic data of patients who underwent surgery were recorded. RESULTS: The coherence between MRI and CT was 75.5%. The Bosniak classification of 17 patients was upgraded with MRI, and the treatment modality changed in 10 patients, and they underwent surgery. The Bosniak category was downgraded from III to IIF in 6 patients out of 8 whose Bosniak category was downgraded with MRI and the treatment modality changed. Surgery was performed in one patient out of these 6 patients, and the pathology was reported as benign. Progression was detected in the follow-up at month 18 of 1 patient out of 5, and surgery was performed. The pathology was reported as renal cell carcinoma. The pathology result was reported as RCC in 35 (68.6%) patients out of 51 who underwent surgery. Progression was detected in 7 patients out of 51 who were followed up (13.7%), and the pathology results were reported as RCC. The majority of the malignant tumors were low stage and grade. CONCLUSIONS: MRI may be successfully used in the evaluation of renal cystic lesions. In particular, the challenging Bosniak IIF and all Bosniak III lesions must be evaluated using MRI before making the decision for surgery. The upgrading of Bosniak category with MRI is more possible compared with CT due to its high-contrast resolution, therefore further studies are required to identify whether it was the cause of overtreatment of Bosniak III lesions.

Combined Qualitative and Quantitative Assessment of Low-Attenuation Renal Lesions Improves Identification of Renal Malignancy on Noncontrast Computed Tomography.

OBJECTIVE: The objective of this study was to assess renal lesions measuring less than 20 Hounsfield units (HU) on noncontrast computed tomography (NCT). METHODS: Twenty-one (18.1%) of 116 consecutive pathologically proven renal cell carcinomas measured less than 20 HU on NCT and were compared with 40 confirmed benign cysts also measuring less than 20 HU. All lesions were assessed qualitatively (heterogeneous or homogenous) by 3 blinded readers and quantitatively with commercially available textural analysis software. Finally, a combined assessment was performed. RESULTS: Qualitative assessment performed well (sensitivity, 76%-90%; specificity, 70%-88%). Quantitative assessment revealed mean positive pixels as having the highest performance (area under the curve, 0.912; sensitivity, 90%; specificity, 80% at a cutoff value of 21). The combined assessment, using the mean positive pixel cutoff, improved the sensitivity (reader 1, 100%; reader 2, 95%; and reader 3, 95%). CONCLUSION: Qualitative and quantitative assessments have relatively good performance, but the combination can nearly eliminate renal cell carcinomas being missed on NCT.

Imaging Follow-up of Low-Risk Incidental Pancreas and Kidney Findings: Effects of Patient Age and Comorbidity on Projected Life Expectancy.

Purpose To determine the effects of patient age and comorbidity level on life expectancy (LE) benefits associated with imaging follow-up of Bosniak IIF renal cysts and pancreatic side-branch (SB) intraductal papillary mucinous neoplasms (IPMNs). Materials and Methods A decision-analytic Markov model to evaluate LE benefits was developed. Hypothetical cohorts with varied age (60-80 years) and comorbidities (none, mild, moderate, or severe) were evaluated. For each finding, LE projections from two strategies were compared: imaging follow-up and no imaging follow-up. Under follow-up, it was assumed that cancers associated with the incidental finding were successfully treated before they spread. For patients without follow-up, mortality risks from Bosniak IIF cysts (renal cell carcinoma) and SBIPMNs (pancreatic ductal adenocarcinoma) were incorporated. Model assumptions and parameter uncertainty were evaluated in sensitivity analysis. Results In the youngest, healthiest cohorts (age, 60 years; no comorbidities), projected LE benefits from follow-up were as follows: Bosniak IIF cyst, 6.5 months (women) and 5.8 months (men); SBIPMN, 6.4 months (women) and 5.3 months (men). Follow-up of Bosniak IIF cysts in 60-year-old women with severe comorbidities yielded a LE benefit of 3.9 months; in 80-year-old women with no comorbidities, the benefit was 2.8 months, and with severe comorbidities the benefit was 1.5 months. Similar trends were observed in men and for SBIPMN. Results were sensitive to the performance of follow-up for cancer detection; malignancy risks; and stage at presentation of malignant, unfollowed Bosniak IIF cysts. Conclusion With progression of age and comorbidity level, follow-up of low-risk incidental findings yields increasingly limited benefits for patients. © RSNA, 2018 Online supplemental material is available for this article.

Diagnostic performance of contrast-enhanced ultrasonography and magnetic resonance imaging for the assessment of complex renal cysts: A prospective study.

OBJECTIVES: To compare the diagnostic performance of computed tomography, magnetic resonance imaging and contrast enhanced ultrasonography for the assessment of complex renal cysts. METHODS: We carried out a prospective single-center study from January 2012 to December 2013. We included patients with Bosniak category 2F or 3 renal cysts found on computed tomography and reviewed by two expert radiologists. Magnetic resonance imaging and contrast-enhanced ultrasonography were then carried out. Patients with a Bosniak ≥3 cyst on magnetic resonance imaging, as well as those upgraded as appearing malignant on contrast-enhanced ultrasonography, were surgically managed. Imaging results were compared with histological data. For patients without surgery, imaging examinations were compared with follow-up data. For each imaging examination, diagnostic performance and Cohen's kappa coefficient were assessed. RESULTS: A total of 47 patients were included. The median follow up was 36 months (range 17-48 months). At initial computed tomography, cysts were classified as Bosniak 2F and Bosniak ≥3 in 34 and 13 patients, respectively. Magnetic resonance imaging found 13 Bosniak ≥3 cysts, and contrast-enhanced ultrasonography upgraded six more patients with cysts that appeared malignant. A total of 19 patients had surgery. Histological analysis reported 14 malignant tumors. No tumor progression was found in followed-up patients. Computed tomography showed poor sensitivity (36%) and specificity (76%; κ = 0.11). Magnetic resonance imaging showed 71% sensitivity and 91% specificity (κ = 0.64). Contrast-enhanced ultrasonography showed high sensitivity (100%) and specificity (97%), and a negative predictive value at 100% (κ = 0.95). CONCLUSIONS: The present results suggested that contrast-enhanced ultrasonography could be useful in improving the assessment of complex renal cysts. Indeed, computed tomography accuracy might be limited in this indication requiring further investigations to determine the best treatment strategy.

Visual Assessment of the Intensity and Pattern of T1 Hyperintensity on MRI to Differentiate Hemorrhagic Renal Cysts From Renal Cell Carcinoma.

OBJECTIVE: The purpose of this study was to apply a visual assessment of the intensity and pattern of T1 hyperintensity at MRI to differentiate hemorrhagic renal cysts from renal cell carcinoma (RCC). MATERIALS AND METHODS: A total of 144 T1-hyperintense renal lesions (62 cysts, all showing no enhancement on subtracted contrast-enhanced images and either 2-year stability or unenhanced CT density > 70 HU, and 82 histologically confirmed RCCs) in 144 patients were included. Two radiologists independently characterized qualitative features of the T1 hyperintensity in each lesion on unenhanced T1-weighted images. An additional radiologist placed ROIs to measure lesions' T1 signal intensity normalized to that of the psoas muscle. Chi-square and unpaired t tests were performed to compare the pattern of T1 hyperintensity between groups. RESULTS: The T1 hyperintensity was considered marked in 62.9% of cysts and 17.1% of RCCs for reader 1 and in 46.8% of cysts and 8.5% of RCCs for reader 2 (p < 0.001). The T1 hyperintensity exhibited a diffusely homogeneous distribution in 88.7% of cysts and 7.3% of RCCs for reader 1 and in 72.6% of cysts and 4.9% of RCCs for reader 2 (p < 0.001). The combination of both diffusely homogeneous distribution and marked degree of T1 hyperintensity achieved sensitivities of 40.3-56.5%, specificities of 97.6-98.8%, and accuracies of 73.6-79.9% for the diagnosis of T1-hyperintense cysts. The two cases of RCC exhibiting this imaging pattern for at least one reader were both papillary RCCs. Normalized signal intensity was 2.39 ± 0.99 in T1-hyperintense cysts versus 2.12 ± 0.84 in T1-hyperintense RCCs (p = 0.088). CONCLUSION: Diffuse T1 hyperintensity, particularly when marked, strongly indicates a hemorrhagic cyst rather than an RCC. Deferral of follow-up imaging may be considered when this imaging appearance is encountered at unenhanced MRI.

Role of US Contrast Agents in the Assessment of Indeterminate Solid and Cystic Lesions in Native and Transplant Kidneys.

Ultrasonography (US) is often the initial imaging modality employed in the evaluation of renal diseases. Despite improvements in B-mode and Doppler imaging, US still faces limitations in the assessment of focal renal masses and complex cysts as well as the microcirculation. The applications of contrast-enhanced US (CEUS) in the kidneys have dramatically increased to overcome these shortcomings with guidelines underlining their importance. This article describes microbubble contrast agents and their role in renal imaging. Microbubble contrast agents consist of a low solubility complex gas surrounded by a phospholipid shell. Microbubbles are extremely safe and well-tolerated pure intravascular agents that can be used in renal failure and obstruction, where computed tomographic (CT) and magnetic resonance (MR) imaging contrast agents may have deleterious effects. Their intravascular distribution allows for quantitative perfusion analysis of the microcirculation, diagnosis of vascular problems, and qualitative assessment of tumor vascularity and enhancement patterns. Low acoustic power real-time prolonged imaging can be performed without exposure to ionizing radiation and at lower cost than CT or MR imaging. CEUS can accurately distinguish pseudotumors from true tumors. CEUS has been shown to be more accurate than unenhanced US and rivals contrast material-enhanced CT in the diagnosis of malignancy in complex cystic renal lesions and can upstage the Bosniak category. CEUS can demonstrate specific enhancement patterns allowing the differentiation of benign and malignant solid tumors as well as focal inflammatory lesions. In conclusion, CEUS is useful in the characterization of indeterminate renal masses and cysts.

Perinatal assessment of hereditary cystic renal diseases: the contribution of sonography.

The aims of this review article were to clarify the steps that may lead to a proper diagnosis of fetal and neonatal renal cystic diseases. All the hereditary cystic diseases are reviewed and a classification is proposed. The various sonographic patterns that can be used to ascertain the diagnosis are also reviewed. Finally, tables with differential diagnoses are presented to help the reader in the work-up of such pathologies.

Percutaneous treatment of simple renal cysts with sclerotherapy and extended drainage.

PURPOSE: To present the long-term results of sclerotherapy of symptomatic simple renal cysts with alcohol and aethoxysclerol followed by protracted seven-day drainage and to compare the efficacy of the two sclerosing agents used in the therapy. MATERIALS AND METHODS: Sixty-six symptomatic patients underwent percutaneous treatment with drainage and sclerotherapy of 72 simple renal cysts in a day hospital setting. The cysts were divided into two groups according to size (Group I and Group II with cyst volume smaller or larger than 600 ml respectively) for a better comparison of the results. The cysts were punctured directly under local anaesthesia with a 7 French Trocar catheter using the ''one-shot'' technique and ultrasound guidance; a pig tail catheter was then left in the cyst for the complete evacuation of the cyst fluid. Sclerotherapy was performed by injection of 95% alcohol or 3% aethoxysclerol for 40 minutes, followed by seven-day drainage. On the basis of dimensional criteria, response to treatment was defined as: recovery, partial recurrence or recurrence. RESULTS: The procedure was successful in 97.2% of the cases with regard to cyst drainage, with clinical recovery in 95.3% of the cases. Group I had 14 recoveries and no complete recurrence after either alcohol or aethoxysclerol, 2 partial recurrences with alcohol and 4 partial recurrences with aethoxysclerol; Group II had 15 recoveries, 14 partial recurrences and one complete recurrence with alcohol, and 5 recoveries, 8 partial recurrences and 2 complete recurrences with aethoxysclerol. CONCLUSIONS: The one-shot technique under ultrasound guidance prevents the risk of major complications, reduces the likelihood of failure and is inexpensive; furthermore, it significantly reduces procedure time and is better tolerated by patients. On the basis of the clinical and dimensional results obtained, percutaneous sclerotherapy of renal cysts can be recommended as the treatment of choice and as a valid alternative to laparoscopy. As for the comparison between the two sclerosing agents, alcohol has a higher cost and negative side effects, but is more effective for the treatment of larger cysts. Aethoxysclerol is less expensive and has no side effects, but tends to lead to septic complications. On the basis of our experience, we therefore recommend the use of aethoxysclerol for sclerotherapy of smaller cysts followed by a 4-day drainage. For larger cysts, we recommend repeated alcoholization and the removal of the drainage catheter after seven days.

Radiologic assessment of renal masses: implications for patient care.

The relationships between the gross pathologic features of neoplastic and nonneoplastic renal masses and their radiologic analogues, described above, establish specific guidelines for the influence of radiologic studies on clinical management. A tumor that contains fat, as determined with CT or MR imaging, can be confidently diagnosed as an angiomyolipoma without further diagnostic intervention. The size of the lesion should be used to influence clinical decisions related to the fact that angiomyolipomas larger than 4 cm in diameter are more apt to hemorrhage than those smaller than that size. High confidence can also be assigned to those renal masses that exhibit the radiologic analogues for hemangioma with use of imaging modalities that document their vascular nature. These findings should be sufficient for therapeutic decisions directed toward embolization or surgical excision when clinically warranted. If a mass can be characterized as a simple cyst by satisfying all of the required CT or sonographic criteria, no further diagnostic interventions are required. This includes the radiologic findings of thin rim of peripheral calcification and thin septa with or without calcification. An equally high level of confidence is associated with the broad range of CT, sonographic, or MR imaging findings that indicate malignant tumor. These militate for radical surgery. However, the same findings are also encountered in hemorrhagic and infected renal cyst, abscess, benign neoplasms, and inflammatory mass. Therefore, surgical excision, the nature of which will vary according to individual circumstances, is usually required to establish these diagnoses. Exceptions to the need for a tissue diagnosis might be considered in the patient in whom a renal mass is detected in the clinical setting of infection and in the patient with either a small asymptomatic renal mass or a small hyperattenuating mass that meets the other criteria of a simple cyst. Here again, individual circumstances may lead to such alternatives as aspiration of the mass for culture, interval follow-up to seek evidence of growth, or dismissal.

[Percutaneous echo-guided drainage and sclerotherapy of symptomatic renal cysts: critical comparison with laparoscopic treatment]. / Drenaggio percutaneo ecoguidato e sclerotizzazione delle cisti renali sintomatiche: confronto critico con il trattamento laparoscopico.

Nowadays, the minimally invasive treatment of symptomatic renal cyst has been progressively gaining wide acceptance while classic open surgery has been almost abandoned. It is a still controversial which minimally invasive approach provides the major advantages and results. Fifty-two patients with symptomatic simple renal cyst underwent ultrasound guided percutaneous drainage and sclerotherapy (ethanol 95 degrees) and 20 patients underwent laparoscopic unroofing of simple renal cysts in our department. No major complication was recorded with both the techniques. Even if we reported a higher recurrence rate (82%) with sclerotherapy than that with laparoscopic treatment (5%) we consider the percutaneous drainage a valid approach because it is a safe, easy and at low cost procedure.

The outcome of renal ultrasound in the assessment of 556 consecutive patients with benign prostatic hyperplasia.

PURPOSE: We determined the additional value of renal ultrasonography in the assessment of patients with benign prostatic hyperplasia. MATERIALS AND METHODS: Renal ultrasound was performed in 556 consecutive patients with benign prostatic hyperplasia and the results were correlated with other clinical parameters. RESULTS: Of the patients 14 (2.5%) had dilatation of the renal pelvis, 65 (11.7%) had renal cysts and 1 (0.18%) had renal cell carcinoma. The serum creatinine level appeared to be correlated with dilatation of the renal pelvis. To predict dilatation additional information can be obtained by including the results of the post-void residual measurements. CONCLUSIONS: Renal ultrasound is indicated only in patients with a specific serum creatinine level and/or post-void residual volume.

Evaluation of renal masses detected by excretory urography: cost-effectiveness of sonography versus CT.

OBJECTIVE: The purpose of this study was to compare the cost-effectiveness of sonography and CT for the evaluation of renal masses discovered at excretory urography. MATERIALS AND METHODS: The records of 225 patients with a renal mass shown by urography who then had either sonography or CT within 3 months were reviewed retrospectively. The number, location, and size of lesions; initial and subsequent imaging tests; and final diagnoses were determined. Using the current Medicare reimbursements for sonography and CT, we calculated the economic implications of using sonography or CT as the initial examination. Any effect of the location or size of the lesion on the most cost-effective examination was also determined. RESULTS: Twenty-one percent of patients had both initial sonography and follow-up CT because of indeterminate findings or detection of a solid mass that required further staging. When CT was done first, CT findings were equivocal in 12%, necessitating follow-up sonography. At the prevailing charges, CT would have to be needed in 70% of patients initially imaged with sonography to justify the use of CT as the initial examination. The location and size of the lesion did not affect the need for CT at a rate (greater than 70%) that would economically justify use of CT as the first imaging test. Eighty-six percent of patients with a mass detected by urography had either a simple cyst or no evidence of a mass on sonography or CT. CONCLUSION: Sonography is the most cost-effective imaging method for the workup of a renal mass detected at urography. The number of sonographic examinations in which findings are indeterminate or positive (for a solid mass) is not sufficiently high to warrant replacement of sonography by CT, regardless of the size and location of the lesion. CT should be reserved for a limited number of specific indications.

Noncardiac clinical applications of seven-pinhole tomography.

Clinical examples of various noncardiac seven-pinhole tomographic scans are shown. In many cases, this method of emission tomography can provide a very useful extension of standard planar nuclear medicine images. Major advantages of seven-pinhole tomography include reasonable cost and improved lesion detectability due to increased image contrast. Disadvantages include rather difficult patient positioning, nonuniform plane spacing with depth, and sometimes rather long data processing times because the presently available computer algorithms are maximized for cardiac scans.