Colm J. McMahon

MR Imaging of Scrotal Tumors and Pseudotumors

Magnetic resonance (MR) imaging is an important imaging technique in the evaluation of scrotal masses, providing a useful adjunct to ultrasonography (US). Although US is the modality of choice for initial evaluation of scrotal pathologic conditions because of its wide availability, low cost, and high sensitivity for detection of testicular and paratesticular disease processes, US findings may occasionally be inconclusive. MR imaging may provide additional information in these cases, often affecting patient management. This article reviews and illustrates the MR imaging features of solid extratesticular and intratesticular benign and malignant scrotal tumors, as well as nonneoplastic lesions that can mimic neoplasia. Normal scrotal MR anatomic features and optimal MR imaging technique are also presented.

Cystic Fibrosis below the Diaphragm: Abdominal Findings in Adult Patients

Cystic fibrosis (CF) is the most common lethal autosomal recessive disease in the white population. Mutation of the CF transmembrane conductance regulator gene on chromosome 7 results in production of abnormally viscous mucus and secretions in the lungs of patients with CF. A similar pathologic process occurs in the gastrointestinal tract, pancreas, and hepatobiliary system. Inspissated mucus causes luminal obstruction and resultant clinical and radiologic complications associated with the disease process. Pancreatic involvement can result in exocrine and endocrine insufficiency, pancreatic atrophy, fatty replacement, or lipomatous pseudohypertrophy. Acute and chronic pancreatitis, pancreatic calcification, cysts, and cystosis also occur. Hepatic manifestations include hepatic steatosis, focal biliary and multilobular cirrhosis, and portal hypertension. Biliary complications include cholelithiasis, microgallbladder, and sclerosing cholangitis. The entire digestive tract can be involved. Distal ileal obstruction syndrome, intussusception, appendicitis, chronic constipation, colonic wall thickening, fibrosing colonopathy, pneumatosis intestinalis, gastroesophageal reflux, and peptic ulcer disease have been described. Renal manifestations include nephrolithiasis and secondary amyloidosis. The educational objectives of this review are to reveal the abdominal manifestations of CF to facilitate focused analysis of cross-sectional imaging in adult patients. Life expectancy in patients with CF continues to improve because of a combination of aggressive antibiotic treatment, improved emphasis on nutrition and physiotherapy, and development of promising new CF transmembrane conductance regulator modulators. As lung function and survival improve, extrapulmonary conditions, including hepatic and gastrointestinal malignancy, will be an increasing cause of morbidity and mortality. Awareness of the expected abdominal manifestations of CF may assist radiologists in identifying acute inflammatory or neoplastic conditions. (©)RSNA, 2015.

Predictive value of PI-RADS classification in MRI-directed transrectal ultrasound guided prostate biopsy.

AIM To correlate the results of transrectal ultrasound (TRUS)-guided targeted prostate biopsies (performed in the setting of at least one previous negative biopsy) with the Prostate Imaging Reporting and Data System (PI-RADS). MATERIAL AND METHODS Fifty-two patients (mean age 64 years, range 52-76 years), with previous negative prostate biopsy underwent magnetic resonance imaging (MRI)-directed TRUS-guided targeted and sectoral biopsy. A retrospective review of MRI examinations was carried out, blinded to biopsy results. PI-RADS scores (T2, diffusion-weighted imaging [DWI] and overall) were assigned on a per lesion basis, and localised to sextants. The scores were correlated with biopsy results, and the positive predictive values (PPV) of PIRADS scores for positive biopsies were calculated. RESULTS Overall, biopsies were positive in 23/52 (44.2%) patients. Eighty-one areas were targeted in 52 patients. On a per lesion basis, there was significant correlation between positive targeted biopsy and both T2 and overall PI-RADS score (p<0.001). The correlation between biopsy and DWI score was significant for peripheral zone tumours only, not for transitional zone tumours. The PPV of overall PI-RADS scores of 3, 4, and 5 were 10.6%, 44%, and 100%, respectively. The PPV of T2 PI-RADS scores of 3, 4, and 5 were 19.6%, 60%, and 100%, respectively. The PPV of DWI PI-RADS scores of 3, 4, and 5 were 50%, 27.3%, and 33%, respectively. When transitional tumours were excluded, the PPV of DWI PI-RADS 3, 4, and 5 were 40%, 43%, and 78%. CONCLUSION The PIRADS score provides an effective framework for determining the likelihood of prostate cancer on MRI. The DWI PI-RADS score correlates well with the presence of peripheral zone tumour on targeted biopsy, but not with transitional zone tumours.

Comparison of Battery-Powered and Manual Bone Biopsy Systems for Core Needle Biopsy of Sclerotic Bone Lesions.

OBJECTIVE The purpose of this study was to compare manual and battery-powered bone biopsy systems for diagnostic yield and procedural factors during core needle biopsy of sclerotic bone lesions. MATERIALS AND METHODS A total of 155 consecutive CT-guided core needle biopsies of sclerotic bone lesions were performed at one institution from January 2006 to November 2014. Before March 2012, lesions were biopsied with manual bone drill systems. After March 2012, most biopsies were performed with a battery-powered system and either noncoaxial or coaxial biopsy needles. Diagnostic yield, crush artifact, CT procedure time, procedure radiation dose, conscious sedation dose, and complications were compared between the manual and battery-powered core needle biopsy systems by Fisher exact test and t test. One-way ANOVA was used for subgroup analysis of the two battery-powered systems for procedure time and radiation dose. RESULTS The diagnostic yield for all sclerotic lesions was 60.0% (93/155) and was significantly higher with the battery-powered system (73.0% [27/37]) than with the manual systems (55.9% [66/118]) (p = 0.047). There was no significant difference between the two systems in terms of crush artifact, procedure time, radiation dose, conscious sedation administered, or complications. In subgroup analysis, the coaxial battery-powered biopsies had shorter procedure times (p = 0.01) and lower radiation doses (p = 0.002) than the coaxial manual systems, but the noncoaxial battery-powered biopsies had longer average procedure times and higher radiation doses than the coaxial manual systems. CONCLUSION In biopsy of sclerotic bone lesions, use of a battery-powered bone drill system improves diagnostic yield over use of a manual system.

Taking blood pressure -- no laughing matter!

BackgroundHumour is used commonly to relax subjects when their blood pressure is being measured. However the short-term effect of laughter on blood pressure is not described. MethodsSixteen normotensive volunteers had blood pressure measured using a validated automated oscillometric sphygmomanometric device (Omron 705 CP) as control and during three episodes of laughter while viewing a humorous sit-com video. ResultsBlood pressure was stable in the control period. There was a significant rise (P<0.01) in systolic blood pressure from 115 mmHg (108–121, mean 95% confidence interval) to 127 mmHg (120–135) during laughing. The increase in diastolic pressure 71 (67–74) to 73 (69–77) mmHg was not significant. ConclusionLaughing has an acute effect on systolic blood pressure. Patients should not be encouraged to laugh when their blood pressure is being measured.

Femoral head avascular necrosis: a frequently missed incidental finding on multidetector CT

AIM To determine the incidence of missed femoral head avascular necrosis (AVN) on pelvic computed tomography (CT) performed for clinical indications other than assessment for AVN. MATERIALS AND METHODS The study was a Health Insurance Portability and Accountability Act (HIPAA)-compliant retrospective study. The picture archiving and communication system (PACS) database was queried for patients with diagnosis of femoral head AVN on magnetic resonance imaging (MRI), who also underwent pelvic multidetector CT after or <30 days before the MRI examination. The MRI and CT images of 144 hips of 72 patients (39 patients with reported AVN on MRI and 33 age-matched controls; mean age = 60 years, 28 male, 44 female), were reviewed in consensus by two readers in a randomized, blinded manner. Using MRI-proven CT-visible AVN as a reference standard, the incidence of missed AVN on initial CT interpretation was determined. RESULTS Readers confirmed AVN in 33 patients on the MRI images. Nine hips with AVN underwent joint replacement of the affected joint(s) prior to subsequent CT and were excluded. Forty-three MRI-proven AVN cases in 28 patients (15 bilateral, 13 unilateral) were available for analysis. The study readers diagnosed 35/43 (81%) MRI-proven AVN cases in 22/28 (79%) patients. Four of the 35 (11%) cases of MRI-proven, CT-visible AVN were prospectively reported in 3/22 (14%) patients at initial clinical interpretation, with a miss rate of 89% per hip and 86% per patient. CONCLUSION Multidetector CT has high accuracy for detection of AVN; however, this is frequently missed as an incidental finding (89% missed in the present study). Assessment for signs of femoral AVN should be part of routine search pattern in interpretation of pelvic CT.

Elevated tumour marker: an indication for imaging?

Introduction The purpose of this study was to evaluate the utility of imaging examinations in patients with elevated tumour markers when (a) the tumour marker is not validated for as a primary diagnostic test; (b) the patient had no personal history of cancer and (c) the patient had no other imaging indication. Materials and methods Patients without known cancer who had abnormal carcinoembryonic antigen, CA19-9, CA125 and/or CA15-3 serology over a one-year period were included. A retrospective medical record review was performed to assess the number of these cases who underwent imaging because of ‘elevated tumour marker’ in the absence of a clinical indication for imaging. The number and result of these imaging studies were evaluated. Results Eight hundred and nineteen patients were included. Of those, 25 patients (mean age: 67.8 [range 41–91] y), were imaged to evaluate: ‘elevated tumour marker’. They underwent 29 imaging studies (mean [±standard deviation (SD)] per patient = 1.2 [±0.4]), and had 42 elevated tumour marker serology tests (mean [±SD] per patient = 1.7 [±0.7]). Four patients had >1 imaging test. No patient had an imaging study which diagnosed a malignancy or explained the elevated tumour marker. Conclusion The non-judicious use of tumour markers can prompt further unnecessary investigations including imaging. In this study, there was no positive diagnostic yield for imaging performed for investigation of ‘elevated tumour marker’. ‘Elevated tumour marker’, in the absence of a known underlying malignancy, should not be considered an independent indication for imaging.

Case Report: Longitudinal Stress Fracture of the Humerus: Imaging Features and Pitfalls

Longitudinal stress fractures are an uncommon injury in which a diaphyseal fracture line occurs parallel to the long axis of a bone in the absence of direct trauma. They have been described in the tibia and less commonly in the femur but apparently not in the upper limb. We report a longitudinal stress fracture occurring in the humerus of a 62-year-old woman who had a history of osteoporosis and had undergone recent surgery of the contralateral wrist. We present the radiographic, MRI, and CT features of the case and emphasize the difficulties in diagnosis caused by negative findings on early radiographs and by nonspecific bone marrow edema pattern on MRI. The risk of a contralateral upper extremity stress fracture from activities of daily living in a patient with osteoporosis whose other upper extremity is immobilized also is highlighted.

Progressive Sarcopenia in Patients With Colorectal Cancer Predicts Survival

OBJECTIVE The purpose of this study was to evaluate the relationship between sarcopenia and overall and progression-free survival in patients with colorectal cancer. MATERIALS AND METHODS This study was retrospective and complied with HIPAA. Patients with colorectal cancer who underwent CT at the time of and 6-18 months after diagnosis were included. Patients were followed for at least 5 years after diagnosis. Skeletal muscle index (SMI) and mean muscle attenuation of the psoas and paraspinal muscles at the L4 level determined the degree of sarcopenia. Composite measurements combining psoas and paraspinal muscles (total muscle) were also obtained. Univariate and multivariate Cox proportional hazard analysis was performed to evaluate the association between survival and changes in SMI and changes in attenuation. Kaplan-Meier analysis was also performed. RESULTS A total of 101 patients were included (mean age ± SD, 63.7 ± 13.7 years; 68 men, 33 women). The hazard ratios for overall survival were 2.27, 1.68, and 1.54 for changes in SMI of the psoas muscle, paraspinal muscle, and total muscle (all p < 0.05). The hazard ratios for overall survival were 1.14, 1.18, and 1.24 for changes in attenuation of the psoas muscle, paraspinal muscle, and total muscle, respectively (all p < 0.05). The hazard ratios for progression-free survival were 1.33, 1.41, and 1.23 for changes in SMI of the psoas muscle, paraspinal muscle, and total muscle (not statistically significant). The hazard ratios for progression-free survival were 1.10, 1.21, and 1.23 for changes in attenuation of the psoas muscle, paraspinal muscle, and total muscle, respectively (p < 0.05). Kaplan-Meier analysis showed significant differences in overall and progression-free survival based on sex-specific quartiles of muscle quantity and quality. CONCLUSION Progressive sarcopenia after diagnosis of colorectal cancer has a significant negative prognostic association with overall and progression-free survival.

The Extensor Mechanism: Imaging and Intervention

&NA; We present an overview of imaging and intervention of the extensor mechanism of the knee. Particular focus is placed on the evaluation of patellofemoral tracking disorders, patellar and quadriceps tendinosis and tears, patellar fracture, lateral patellar condyle patellar friction syndrome, and prepatellar bursitis. Anatomical and biomechanical factors contributing to these disorders are considered. Imaging evaluation is presented in a clinical context, and therapeutic options for these disorders are discussed. Image‐guided therapy options for symptomatic patellar tendinosis are also described and illustrated.