What is the optimum post treatment surveillance imaging protocol for low grade appendiceal mucinous neoplasms and pseudomyxoma peritoneii?

Appendiceal mucinous neoplasms are rare and can be associated with the development of disseminated peritoneal disease known as pseudomyxoma peritonei (PMP). Mucinous tumours identified on appendicectomy are therefore followed up to assess for recurrence and the development of PMP. In additional, individuals who initially present with PMP who are treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) are followed up to assess for recurrence. However, despite the concerted efforts of multiple expert groups, the optimal imaging follow-up protocol is yet to be established. The purpose of this paper is to review the available evidence for imaging surveillance in these populations to identify the optimum post-resection imaging follow-up protocol.

A comparison of transient elastography with acoustic radiation force impulse elastography for the assessment of liver health in patients with chronic hepatitis C: Baseline results from the TRACER study.

Background: Liver stiffness measurements can be used to assess liver fibrosis and can be acquired by transient elastography using FibroScan® and with Acoustic Radiation Force Impulse imaging. The study aimed to establish liver stiffness measurement scores using FibroScan® and Acoustic Radiation Force Impulse in a chronic hepatitis C cohort and to explore the correlation and agreement between the scores and the factors influencing agreement. Methods: Patients had liver stiffness measurements acquired with FibroScan® (right lobe of liver) and Acoustic Radiation Force Impulse (right and left lobe of liver). We used Spearman's correlation to explore the relationship between FibroScan® and Acoustic Radiation Force Impulse scores. A Bland-Altman plot was used to evaluate bias between the mean percentage differences of FibroScan® and Acoustic Radiation Force Impulse scores. Univariable and multivariable analyses were used to assess how factors such as body mass index, age and gender influenced the agreement between liver stiffness measurements. Results: Bland-Altman showed the average (95% CI) percentage difference between FibroScan® and Acoustic Radiation Force Impulse scores was 27.5% (17.8, 37.2), p < 0.001. There was a negative correlation between the average and percentage difference of the FibroScan® and Acoustic Radiation Force Impulse scores ( r (95% CI) = -0.41 (-0.57, -0.21), p < 0.001), thus showing that percentage difference gets smaller for greater FibroScan® and Acoustic Radiation Force Impulse scores. Body mass index was the biggest influencing factor on differences between FibroScan® and Acoustic Radiation Force Impulse (r = 0.12 (0.01, 0.23), p = 0.05). Acoustic Radiation Force Impulse scores at segment 5/8 and the left lobe showed good correlation (r (95% CI) = 0.83 (0.75, 0.89), p < 0.001). Conclusion: FibroScan® and Acoustic Radiation Force Impulse had similar predictive values for the assessment of liver stiffness in patients with chronic hepatitis C infection; however, the level of agreement varied across lower and higher scores.

MRI remains highly accurate in the diagnosis of appendicitis in pregnancy when read by radiologists of mixed specialty training and experience.

PURPOSE: To audit the accuracy of magnetic resonance imaging (MRI) abdominal studies performed in the diagnosis of appendicitis in pregnant patients when read by radiologists of mixed experience. METHODS: MRI reports from 45 pregnant women presenting to our emergency department for the investigation of appendicitis between 2009 and 2020 were retrospectively reviewed. Where available, these reports were correlated with surgical and pathology reports as well as follow-up clinical information. Following a review of literature, accuracy targets were set. Statistical analyses including sensitivity, specificity, positive, and negative predictive values were calculated. RESULTS: A total of 18 radiology consultants read 45 MRI abdominal studies in the assessment of appendicitis during pregnancy with 62% (n = 28) of these read by specialist radiologists and the remainder by general radiologists. This yielded an accuracy in diagnosis of 99.8%, sensitivity of 80% (95% CI: 49-94.3%), and specificity of 100% (95% CI: 90-100%). The calculated negative predictive value was 94.6% (95% CI: 82.3-98.5%), and positive predictive value was 100% (95% CI: 90-100%). The appendix was not identified in 19 patients (42%). A statistically significant relationship between the presence of right iliac fossa stranding of the fat OR free fluid was associated with appendicitis (p = 0.01). Alternate diagnoses were identified in 8% (n = 4) of cases. CONCLUSION: MRI is a highly accurate imaging modality for the assessment of appendicitis in pregnancy. Even with variable reader MRI experience, MRI demonstrates an accuracy of 99.8% and a positive predictive value for acute appendicitis of 100%. Double reading and the possible inclusion of DWI may help further improve accuracy and minimise false-negative rates.

The role of radiology in addressing the challenge of lung cancer after lung transplantation.

The importance of lung cancer as a complication of lung transplantation is increasingly recognised. It may become an important survival-limiting factor in lung transplant patients as management of other complications continues to improve and utilisation of extended criteria donors grows. Radiology can play a key role in tackling this issue at multiple stages in the transplantation pathway and follow-up process. Routine chest CT as part of pre-transplant recipient assessment (and donor assessment if available) can identify suspicious lung lesions with high sensitivity and detect chronic structural lung diseases such as pulmonary fibrosis associated with an increased risk of malignancy post-transplant. Pre-transplant CT also provides a comparison for later CT studies in the assessment of nodules or masses. The potential role of regular chest CT for lung cancer screening after transplantation is less certain due to limited available evidence on its efficacy. Radiologists should be cognisant of how the causes of pulmonary nodules in lung transplant patients may differ from the general population, vary with time since transplantation and require specific recommendations for further investigation/follow-up as general guidelines are not applicable. As part of the multidisciplinary team, radiology is involved in an aggressive diagnostic and therapeutic management approach for nodular lung lesions after transplant both through follow-up imaging and image-guided tissue sampling. This review provides a comprehensive overview of available clinical data and evidence on lung cancer in lung transplant recipients, and in particular an assessment of the current and potential roles of pre- and post-transplant imaging. KEY POINTS: • Lung cancer after lung transplantation may become an increasingly important survival-limiting factor as mortality from other complications declines. • There are a number of important roles for radiology in tackling the issue which include pre-transplant CT and supporting an aggressive multidisciplinary management strategy where lung nodules are detected in transplant patients. • The introduction of routine surveillance chest CT after transplant in addition to standard clinical follow-up as a means of lung cancer screening should be considered.

Transperineal ultrasound-guided prostate biopsy: what the radiologist needs to know.

Transperineal ultrasound-guided (TP) prostate biopsy has been shown to significantly decrease the risk of post-procedural sepsis when compared to transrectal ultrasound-guided (TRUS) prostate biopsy. With guidance from the European Urology Association favouring adoption of a TP biopsy route, it is clear that, despite being a more technically challenging procedure, TP biopsy in an outpatient setting will replace TRUS biopsy. This paper gives the reader a succinct summary of outpatient transperineal prostate biopsy under local anaesthetic utilising a free-hand ultrasound technique. Patient preparation and consent process is outlined. A comprehensive pictorial review of the procedure, pitfalls and common post-procedural outcomes is presented. This paper provides a framework and guide for those wishing to adopt the transperineal approach under local anaesthetic.

Peritoneal malignancy: anatomy, pathophysiology and an update on modern day imaging.

With increasing subspecialised experience in radical cytoreductive surgery and intra-abdominal chemotherapy for peritoneal malignancy, outcomes have improved significantly in selected patients. The surgery and the treatment regimens are radical and therefore correct patient selection is critical. The radiologist plays a central role in this process by estimating, as precisely as possible, the pre-treatment disease burden. Because of the nature of the disease process, accurate staging is not an easy task. Tumour deposits may be very small and in locations where they are very difficult to detect. It must be acknowledged that no form of modern day imaging has the capability of detecting the smallest peritoneal nodules, which may only be visible to direct inspection or histopathological evaluation. Nonetheless, it behoves the radiologist to be as exact and precise as possible in the reporting of this disease process. This is both to select patients who are likely to benefit from radical treatment, and just as importantly, to identify patients who are unlikely to achieve adequate cytoreductive outcomes. In this review, we outline the patterns of spread of disease and the anatomic basis for this, as well as the essential aspects of reporting abdominal studies in this patient group. We provide an evidence-based update on the relative strengths and limitations of our available multimodality imaging techniques namely CT, MRI and positron emission tomography/CT.

Pragmatic use of short-course radiotherapy, chemotherapy and surgery for stage IV rectal cancer with locally advanced or symptomatic primary tumours.

INTRODUCTION: We assessed management of patients with de novo metastatic rectal cancer, referred for radiotherapy to the rectum, who were candidates for short-course radiotherapy (SCRT) and chemotherapy, followed by resection of all disease. We assessed surgical outcomes, overall survival (OS) and progression-free survival (PFS). METHODS: Retrospective review of patients meeting criteria: (i) treatment with SCRT to rectum; (ii) locally advanced primary rectal cancer; and (iii) resectable distant metastases at diagnosis. Data were collected from charts, correspondence and electronic patient records. OS and PFS were calculated using the Kaplan-Meier method. RESULTS: Between 2016 and 2020, 48 patients with stage IV rectal cancer at diagnosis were treated with SCRT. Only 15 patients (31%) had resectable metastatic disease and were intended for SCRT (25 Gy/5#), then chemotherapy, followed by resection of all sites of disease and are included in our study. 12 of the 15 surgical candidates (80%) had rectal surgery as planned, and 11 of the 15 (73%) had resection of the rectal primary and all metastatic disease. One patient had a pathological complete response (pCR), and 50% of surgical patients had a Mandard TRG of 1 or 2. Median PFS and OS for the 15 surgical candidates were 12.6 and 25.2 months, respectively, with a median FU of 21.2 months. CONCLUSION: For this cohort of patients, our treatment paradigm is pragmatic and results in excellent pathological response. However, the effectiveness of this approach should be the subject of future prospective studies.

An abbreviated MRI protocol for surveillance of cystic pancreatic lesions.

PURPOSE: Cystic pancreatic lesions (CPLs) are common and increasingly encountered in clinical radiology practice. The appropriate imaging surveillance strategy for lower-risk CPLs (branch duct-intraductal papillary mucinous neoplasms and indeterminant small cystic lesions) has been a topic of intense study and debate in recent years. MRI is considered the investigation of choice for initial characterisation and follow-up of CPLs. Follow-up intervals for CPLs vary from 6 months to 2 years and surveillance may be lifelong or until the patient is no longer considered fit for potential surgical intervention. This creates a significant burden on MRI resources as a standard protocol pancreatic MRI may have an acquisition time of up to 35-50 min. However, the necessity of contrast-enhanced sequences and diffusion weighted imaging (DWI) for routine follow-up of CPLs has been questioned in recent years. METHODS: We reviewed the available evidence to determine whether an abbreviated MRI (A-MRI) protocol may be safely adopted for surveillance of CPLs, as has been implemented in other clinical scenarios. RESULTS: A number of recent retrospective studies have indicated that an A-MRI, omitting contrast-enhanced and DWI, may be used for CPL surveillance without any suspicious features or cases of malignancy being missed. Although small number of cases may need to be recalled for additional MR sequences based on the A-MRI findings, there is still a significant overall timesaving. CONCLUSION: The best available evidence currently suggests that an A-MRI protocol should be considered for routine surveillance of CPLs. Prospective studies are required to ensure the findings reported in these retrospective case studies are backed up in ongoing clinical practice.

Integrated multimodality and multi-disciplinary team approach to pre-sacral lesions.

The purpose of this article is to describe the clinical and radiological features of presacral lesions. CT and MRI are the diagnostic modalities of choice and are complimentary in the assessment of presacral lesions. Imaging findings of presacral lesions on CT and MRI are described with the use of examples. Preoperative biopsy, surgical and non-surgical managements are outlined. While the general radiologist cannot be familiar with every rare presacral condition, characterisation of a presacral lesion based on anatomy, demographics and imaging features can guide us in making a sound differential.

What the Radiologist Should Know About Treatment of Peritoneal Malignancy.

OBJECTIVE: The purpose of this article is to discuss the role of the radiologist in the treatment of peritoneal cancer, with focus placed on advanced treatment options and selection of patients with resectable disease for whom complete cytoreduction can be achieved. CONCLUSION: Peritoneal cancers traditionally have been associated with significant morbidity and universal mortality; however, the management of such cancers has evolved substantially. Advanced treatment options, including cytoreductive surgery and intraperitoneal chemotherapy, are associated with significantly improved long-term patient survival. To ensure that patients benefit from aggressive multimodality treatments, the radiologist plays a pivotal role in the multidisciplinary team to ensure careful patient selection, identifying individuals with resectable disease for whom complete cytoreduction can be achieved.

Advanced multimodality imaging of inflammatory bowel disease in 2015: An update.

The diagnosis and effective management of inflammatory bowel disease (IBD) requires a combination clinical, endoscopic, histological, biological, and imaging data. While endoscopy and biopsy remains the gold standard for diagnosis of IBD, imaging plays a central role in the assessment of extra mural disease, in disease surveillance and in the assessment of response to medical treatments, which are often expensive. Imaging is also vital in the detection and diagnosis of disease related complications, both acute and chronic. In this review, we will describe, with illustrative images, the imaging features of IBD in adults, with emphasis on up-to-date imaging techniques focusing predominantly on cross sectional imaging and new magnetic resonance imaging techniques.

Renal Cell Carcinoma: Accuracy of Multidetector Computed Tomography in the Assessment of Renal Sinus Fat Invasion.

PURPOSE: The purpose of this study was to evaluate the accuracy of multidetector computed tomography (MDCT) in the preoperative assessment of renal sinus fat invasion (RSFI) in patients with renal cell carcinoma (RCC) and to assess imaging features that improve detection of RSFI on CT. METHODS: This is a single-institution retrospective review of 53 consecutive patients with histologically proven RCC who underwent triple-phase preoperative contrast MDCT prior to partial or radical nephrectomy. Two experienced radiologists (R1 and R2), blinded to the final histology result, independently reviewed the preoperative MDCT studies to assess for RSFI. Histopathology was used as the gold standard for the presence of RSFI. RESULTS: Of 55 surgically resected RCCs that were evaluated with contrast-enhanced MDCT, 34.5% (19/55) of RCCs had RSFI on final histopathology. Multidetector CT demonstrated high sensitivity (R1, 100%; R2, 93.7%) for the detection of RSFI, but a low positive predictive value (R1, 40%; R2, 53%) and specificity (R1, 38.4%; R2, 66.6%). Interreader agreement for RSFI was moderate (κ = 0.56). Renal tumors were significantly larger in cases with RSFI (6.3 ± 3.219 cm) than tumors without RSFI (4.1 ± 2.9 cm) (P = 0.0275). Renal sinus fat invasion was more commonly associated to an irregular tumor margin at the tumor renal sinus fat interface (P < 0.001). CONCLUSIONS: Multidetector computed tomography demonstrates a high sensitivity but low positive predictive value in diagnosing RSFI with implications for prognosis and treatment planning. Tumor size, location, irregular tumor margin at the tumor/renal sinus interface, and invasion into pelvicaliceal structures can aid in the diagnosis of RSFI on preoperative MDCT.

Imaging of bone metastasis: An update.

Early detection of skeletal metastasis is critical for accurate staging and optimal treatment. This paper briefly reviews our current understanding of the biological mechanisms through which tumours metastasise to bone and describes the available imaging methods to diagnose bone metastasis and monitor response to treatment. Among the various imaging modalities currently available for imaging skeletal metastasis, hybrid techniques which fuse morphological and functional data are the most sensitive and specific, and positron emission tomography (PET)/computed tomography and PET/magnetic resonance imaging will almost certainly continue to evolve and become increasingly important in this regard.

Evaluation of imaging quality of pulmonary 64-MDCT angiography in pregnancy and puerperium.

OBJECTIVE: The aim of this study was to quantitatively and qualitatively evaluate pulmonary 64-MDCT angiography image quality in pregnancy and puerperium, compared with female nonpregnant control subjects. MATERIALS AND METHODS: The study group comprised 124 consecutive pregnant and postpartum women and 124 female nonpregnant control subjects who presented with suspected pulmonary embolism. The individual studies were evaluated for subjective and objective diagnostic quality. RESULTS: Objective measurements of the arterial enhancement in the pulmonary trunk and left and right pulmonary arteries found that there was no statistically significant difference in attenuation values between the pregnant and puerperium group and the control group for pulmonary artery opacification. The mean attenuation in the pulmonary trunk was 270.54 HU in the pregnant group, 277.53 HU in the puerperium group, and 293.90 HU in the control group. CONCLUSION: We found no significant difference in diagnostic quality of pulmonary CT angiography using MDCT between the study and control groups. The use of MDCT acquisition, faster injection rates, higher contrast medium concentration, and higher trigger levels may decrease the number of nondiagnostic studies in this population. MDCT may be a worthwhile investigation in the majority of pregnant patients with suspected pulmonary embolism.

PET/CT in the imaging of ovarian Cancer.

Ovarian cancer is responsible for the largest proportion of deaths among patients with gynecologic cancer. This paper discusses fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in the imaging of ovarian cancer. We discuss and demonstrate how FDG PET/CT can be used to appropriately guide clinical management decisions in patients with ovarian cancer. In particular, FDG PET/CT shows great promise for the preoperative evaluation of women with primary ovarian cancer and for subsequent postoperative assessment for recurrence.

Incidental pulmonary nodules detected on abdominal computed tomography.

OBJECTIVES: To review the characteristics and outcome of incidental pulmonary nodules reported on abdominal computed tomography (CT). METHODS: A database search of abdominal CTs from January 1, 2004, to December 31, 2006, revealed 413 patients with incidental pulmonary nodules and at least one follow-up chest CT. Demographic information, nodule characteristics, and eventual outcome of the nodules were analyzed. RESULTS: Of the 413 patients, 56% had benign nodules, 11% had malignant nodules, and the remaining 33% had insufficient follow-up. There was a statistically significant difference (P < 0.05) in the age of the patients, history of malignancy, and size of the incidental nodule between benign and malignant groups. No malignant nodules were found in patients younger than 59 years who did not have a known or suspected malignancy. CONCLUSION: Small pulmonary nodules (<8 mm) on abdominal CT in patients younger than 50 years with no history of malignancy are unlikely to be malignant.

Brown fat at PET/CT: correlation with patient characteristics.

PURPOSES: To assess the prevalence of brown fat in patients with cancer, compare demographic characteristics of those with and those without brown fat, and correlate these characteristics with the mean and maximum standardized uptake values of brown fat. MATERIALS AND METHODS: This case-control study was institutional review board approved and HIPAA compliant. Informed consent was waived. Reports of 12 195 consecutive positron emission tomography/computed tomography examinations performed in 6867 patients between January 2004 and November 2008 were reviewed for documented fluorodeoxyglucose (FDG) uptake in brown fat (n = 298). Control patients (n = 298) without brown fat were chosen and matched for age, sex, and month and year of examination. Age, sex, weight, body mass index, ethnicity, and examination stage (initial vs restaging) were compared between groups. Paired Student t test, χ(2) test, Pearson correlation coefficient, and analysis of variance were used for statistical analysis. RESULTS: Uptake of FDG in brown fat was demonstrated in 298 of 6867 (4.33%) patients. Prevalence of brown fat was significantly higher in female (5.9% [211 of 3587]) than in male patients (2.65% [87 of 3280]; P < .001). Those with brown fat had significantly lower body weight (147.5 lb ± 3.8 vs 168.61 lb ± 5.0; P < .001) and body mass index (24.3 ± 0.54 vs 27.6 ± 0.77; P < .001) than control patients. There was no significant difference in the prevalence of brown fat among ethnic groups. The maximum standardized uptake value of brown fat had a significant inverse correlation with age (r = -0.3, P < .001). CONCLUSION: Patients with brown fat were more likely to be female and thinner than those without brown fat. Younger patients were more likely to have higher maximum standardized uptake values of brown fat.