Image quality in abdominal CT using an iodine contrast reduction algorithm employing patient size and weight and low kV CT technique.

BACKGROUND: Low tube potential-high tube current computed tomography (CT) imaging allows reduction in iodine-based contrast dose and may extend the benefit of routine contrast-enhanced CT exams to patients at risk of nephrotoxicity. PURPOSE: To determine the ability of an iodine contrast reduction algorithm to maintain diagnostic image quality for contrast-enhanced abdominal CT. MATERIAL AND METHODS: CT exams with iodine contrast reduction were prescribed for patients at risk for renal dysfunction. The iodine contrast reduction algorithm combines weight-based contrast volume reduction with patient width-based low tube potential selection and bolus-tracking. Control exams with routine iodine dose were selected based on weight, width, and scan protocol. Three radiologists evaluated image quality and diagnostic confidence using a 4-point scale (<2 acceptable). Another radiologist assessed contrast reduction indications and measured portal vein and liver contrast-to-noise ratios. RESULTS: Forty-six contrast reduction algorithm and control exams were compared (mean creatinine 1.6 vs. 1.2 mg/dL, P ≤ 0.0001). Thirty-nine contrast reduction patients had an eGFR <60 mL/min/1.73m2 and 15 had single or transplanted kidney. Mean iodine contrast dose was lower in the contrast reduction group (20.9 vs. 39.4 g/mL, P < 0.0001). Diagnostic confidence was rated as acceptable in 95% (131/138) of contrast reduction and 100% of control exams (1.18-1.28 vs. 1.02-1.13, respectively; P > 0.06). Liver attenuation and contrast-to-noise ratio (CNR) were similar (P = 0.08), but portal vein attenuation and CNR were lower with contrast-reduction (mean 176 vs. 198 HU, P = 0.02; 13 vs. 16, P = 0.0002). CONCLUSION: This size-based contrast reduction algorithm using low kV and bolus tracking reduced iodine contrast dose by 50%, while achieving acceptable image quality in 95% of exams.

Procedure-Related Pain During Image-Guided Percutaneous Biopsies: A Retrospective Study of Prevalence and Predictive Factors.

OBJECTIVE. The purpose of this study was to evaluate the prevalence and severity of pain reported during image-guided percutaneous biopsies and to identify factors associated with increased reported pain. MATERIALS AND METHODS. In this retrospective study, a database of adult patients who underwent CT- or ultrasound-guided percutaneous core needle biopsy between July 22, 2013, and February 1, 2018, was reviewed. Data collected included patient age and sex, biopsy site, biopsy type (lesion or parenchymal), needle gauge, number of passes, use of sedation, and whether it was the patient's first recorded biopsy. The maximum procedure-related pain reported on a 0-10 numeric rating scale was recorded. Multivariable logistic regression with generalized estimating equations was used to assess the association between covariates and patient-reported pain. RESULTS. A total of 13,344 biopsy procedures were performed in 10,474 patients. Patients reported no pain (0 of 10 scale) during 9765 (73.2%) procedures. Female sex, younger age at biopsy, undergoing IV sedation, and larger needle diameter were all associated with increases in patient-reported pain. Biopsies of renal allografts were the least likely to be painful, followed by hepatic allografts. CONCLUSION. Patients typically report mild or no pain from image-guided biopsy performed by radiologists. Younger patients and women report greater pain. This information can assist preprocedural counseling and reassurance of patients and may help them predict procedure-related patient needs.

Retrospective cohort study of portacaval lymphadenopathy identified on multidetector CT and implications for follow-up.

PURPOSE: Portacaval lymphadenopathy (PCLA) is common in cirrhosis and chronic viral hepatitis and is frequently an incidental finding on abdominal CT scans. We aimed to detect the incidence of malignancy in organs drained by portacaval nodes in patients with PCLA associated with cirrhosis or chronic viral hepatitis, or incidentally detected PCLA. METHODS: We searched CT reports from 2005 to 2007 for the phrases "periportal node" and "portacaval node." MDCTs of patients with portacaval nodes ≥10 mm in maximal short-axis size on contrast-enhanced MDCTs, were included. Records were reviewed for presence of malignancy, liver metastases, chronic viral hepatitis, and cirrhosis. Clinical or imaging follow-up ≥6 months was performed to detect if malignancy developed in organs drained by portacaval nodes in patients with incidental PCLA, cirrhosis, or chronic viral hepatitis. RESULTS: 479 patients met inclusion criteria [298 males (62%), mean age 61.4 years]. In 285 (59.5%) patients, PCLA was explained by local pathology or systemic lymphadenopathy. PCLA was incidental in 146 (30.5%) patients. Of these, 112 (76.7%) had ≥6 months of follow-up (median 26 months). No patient with incidental PCLA developed malignancy in organs drained by these nodes. Cirrhosis or chronic viral hepatitis was present in 48 (10.0%) patients. Of these, 42 (87.5%) had ≥6 months follow-up (median 28 months), and only 1 patient developed cholangiocarcinoma (positive predictive value 2.4%). CONCLUSIONS: Development of malignancy is rare in patients with PCLA, either incidental or secondary to cirrhosis or chronic viral hepatitis. Our study suggests that no follow-up of PCLA is required in these settings.

Optic nerve glioma: an update.

Optic nerve glioma is the most common optic nerve tumour. However, it has an unpredictable natural history. The treatment of optic nerve gliomas has changed considerably over the past few years. Chemotherapy and radiation therapy can now stabilize and in some cases improve the vision of patients with optic nerve gliomas. The treatment of optic nerve glioma requires a multi-disciplinary approach where all treatment options may have to be implemented in a highly individualized manner. The aim of this review article is to present current diagnostic and treatment protocols for optic nerve glioma.

MR imaging of malignancies arising in endometriomas and extraovarian endometriosis.

Cancers that arise in ovarian or extraovarian endometriosis are a distinct disease category with a histologic profile different from that of the more common epithelial ovarian cancers and with a better prognosis. Because the malignant transformation of endometriomas is rarely associated with lymphadenopathy or peritoneal carcinomatosis, a high index of suspicion on the part of the radiologist is necessary to establish a timely diagnosis of endometriosis-related ovarian cancers and allow appropriate oncologic management. Although imaging is not currently performed for surveillance of endometriosis, magnetic resonance (MR) imaging is often performed when surgical treatment is under consideration. An optimal MR imaging protocol for the detection of cancer arising in an endometrioma includes a review of subtraction images derived from unenhanced and contrast material-enhanced T1-weighted datasets. Subtraction images provide improved conspicuity of enhancing mural nodules--which are the most sensitive MR imaging sign of malignancy in ovarian endometriosis--against the background of the high-signal-intensity endometriotic cyst. Cancers arising in extraovarian endometriosis typically manifest as solid lesions with intermediate signal intensity on T1- and T2-weighted images, enhancement after the intravenous administration of a gadolinium-based contrast material, and restricted diffusion on diffusion-weighted images and apparent diffusion coefficient (ADC) maps. The signal intensity of myometrium, or, if the uterus is absent, that of the small bowel wall, is used as an internal reference standard for lesion signal intensity. Lesions are considered to have restricted diffusion if they show signal hyperintensity relative to the reference structure on diffusion-weighted images and hypointensity or isointensity relative to that structure on ADC maps. For definitive diagnosis, histopathologic analysis is required.

Palindromic rheumatism.

We present the case of a 56-year-old woman with a one-month history of recurrent, migratory oligoarthritis. Laboratory tests were normal except for positive antinuclear antibody (ANA) titers. Imaging studies were normal. Palindromic rheumatism (PR) was considered as a diagnosis. In this brief report, we discuss the etiopathogenesis, clinical presentation, prognosis and treatment of this entity. We also elaborate on the factors associated with progression to chronic joint disease. It is important for the primary care physician to be aware of this relatively uncommon diagnosis in patients presenting with joint pains and to distinguish it from other causes of recurrent arthritis, especially rheumatoid arthritis (RA).

MRI, CT, and PET/CT for ovarian cancer detection and adnexal lesion characterization.

OBJECTIVE: The purpose of this article is to describe the role of MR, CT, and PET/CT in the detection of ovarian cancer and the evaluation of adnexal lesions. CONCLUSION: The goal of imaging in ovarian cancer detection is to expeditiously distinguish benign adnexal lesions from those requiring further pathologic evaluation for malignancy. For lesions indeterminate on ultrasound, MRI increases the specificity of imaging evaluation, thus decreasing benign resections. CT is useful in diagnosis and treatment planning of advanced cancer. Although (18)F-FDG-avid ovarian lesions in postmenopausal women are considered suspicious for malignancy, PET/CT is not recommended for primary cancer detection because of high false-positive rates.

Bilateral anterior cerebral artery infarction following viper bite.

The viper is one of India's most commonly encountered poisonous snakes and envenomation following viper bite usually leads to consumption coagulopathy. Clinical manifestations most frequently include external and internal bleeding. In the setting of viper envenomation, large-vessel thrombosis is a very rare occurrence. Also, bilateral anterior cerebral artery infarction, when unrelated to anatomical abnormalities, subarachnoid haemorrhage, surgery or trauma, itself is an exceedingly rare event. We report a case of a 24-year-old previously healthy man who presented with bilateral anterior cerebral artery infarction following a viper bite. We also present hypotheses that may explain this unusual occurrence.

Comparison of two small bowel distending agents for enterography in pediatric small bowel imaging.

OBJECTIVE: To evaluate the ability of pediatric patients with known or suspected inflammatory bowel disease to ingest a new oral distending agent at CT or MR enterography (CTE/MRE), and to determine the impact on small bowel (SB) distension and diagnostic confidence. MATERIALS AND METHODS: The study design is that of retrospective review of pediatric patients who underwent CTE or MRE from January 2014 to June 2016. Patients ingested low-concentration barium suspension or flavored beverage containing sorbitol and mannitol. The need for nasogastric tube (NGT) administration, amount ingested, emesis, distal extent of contrast, SB distension, terminal ileum (TI) transverse dimension, and diagnostic confidence in TI disease were assessed. Three radiologists each blindly reviewed a subset of the studies. RESULTS: Of the total 591 scans in 504 patients, 316 scans used low-concentration barium suspension and 275 scans flavored beverage. Nearly all consumed the entire amount (97% vs. 96%). Low-concentration barium suspension exams required NGT more often (7% [23/316] vs. 1% [3/275]; p < 0.0003), and tended to have more emesis (3% [9/316] vs. 1% [3/275]; p = 0.13). Diagnostic confidence score was nearly identical (p = 0.94). Qualitative and quantitative analyses showed no difference in SB distension, except for distension of mid-ileum (flavored beverage > low-concentration barium suspension; p = 0.02). Flavored beverage exams demonstrated a slight increase in distal extent of luminal distension (p = 0.02). CONCLUSIONS: A new flavored beverage distends small bowel as well as low-concentration barium suspension, with decreased requirement for NGT insertion and improved distal extent of luminal distension, and without any decrease in diagnostic confidence in the presence or the absence of TI disease.

Mucinous appendiceal neoplasms: classification, imaging, and HIPEC.

Recent advances, specifically cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC), offer advantages compared to the traditional therapeutic approach of systemic chemotherapy in the treatment of peritoneal carcinomatosis from mucinous appendiceal neoplasms (MAN). This review provides an up-to-date, comprehensive summary of the histologic classification of MAN, reviews common imaging findings of mucoceles and pseudomyxoma peritonei, and describes the radiologist's role in the multidisciplinary care team in quantifying disease and in helping select patients for definitive surgery.

Reproducible imaging features of biologically aggressive gastrointestinal stromal tumors of the small bowel.

PURPOSE: To identify reproducible CT imaging features of small bowel gastrointestinal stromal tumors (GIST) that are associated with biologic aggressiveness. METHODS: Patients with histologically proven small bowel GISTs and CT enterography or abdominopelvic CT were included. Biologic aggressiveness was established based on initial histologic grading (very low risk to malignant), with "malignant" assigned if recurrence or metastases developed subsequently. CT exams were independently evaluated by three gastrointestinal radiologists for tumor size, growth pattern, enhancement, tumor borders, necrosis, calcification, ulceration, multiplicity, internal air or enteric contrast, nodal metastasis, liver metastasis, peritoneal metastasis, ascites, and draining vein size. Inter-observer variability and imaging features associated with high-grade and malignant small bowel GISTs were determined. RESULTS: Of 78 patients with small bowel GISTs, 10/78 (13%) were high grade and 18/78 (23%) were malignant. There was moderate to substantial inter-observer agreement (Kappa > 0.4) for all findings except tumor border, ulceration, and nodal metastases. Tumor size, irregular or invasive tumor border, necrosis, liver metastasis, ascites, and iso-enhancement were associated with high-grade/malignant small bowel GISTs (p < 0.04). Internal air or enteric contrast and peritoneal metastases additionally predicted malignant behavior (p < 0.03). When imaging features predicting malignant small bowel GISTs were absent and size was ≤ 3 cm, 0% (0/16), 5% (1/19), and 5% (1/17) of patients had high grade, and 0% (0/16, 0/19, and 0/17) had malignant tumors for the three readers, respectively. CONCLUSION: Multiple, reproducibly identified, small bowel GIST imaging features suggest biologic aggressiveness. The absence of these imaging features may identify small tumors that can be followed in asymptomatic or high-risk patients.

Utility of coronal contrast-enhanced fat-suppressed FLAIR in the evaluation of optic neuropathy and atrophy.

BACKGROUND AND PURPOSE: Evaluating chronic sequelae of optic neuritis, such as optic neuropathy with or without optic nerve atrophy, can be challenging on whole brain MRI. This study evaluated the utility of dedicated coronal contrast-enhanced fat-suppressed FLAIR (CE-FS-FLAIR) MR imaging to detect optic neuropathy and optic nerve atrophy. MATERIALS AND METHODS: Over 4.5 years, a 3 mm coronal CE-FS-FLAIR sequence at 1.5T was added to the routine brain MRIs of 124 consecutive patients, 102 of whom had suspected or known demyelinating disease. Retrospective record reviews confirmed that 28 of these 102 had documented onset of optic neuritis >4 weeks prior to the brain MRI. These 28 were compared to the other 22 ("controls") of the 124 patients who lacked a history of demyelinating disease or visual symptoms. Using coronal CE-FS-FLAIR, two neuroradiologists separately graded each optic nerve (n = 50 patients, 100 total nerves) as either negative, equivocal, or positive for optic neuropathy or atrophy. The scoring was later repeated. RESULTS: The mean time from acute optic neuritis onset to MRI was 4.1 ± 4.6 years (range 34 days-17.4 years). Per individual nerve grading, the range of sensitivity, specificity, and accuracy of coronal CE-FS-FLAIR in detecting optic neuropathy was 71.4-77.1%, 93.8-95.4%, and 85.5-89.0%, respectively, with strong interobserver (k = 0.667 - 0.678, p < 0.0001), and intraobserver (k = 0.706 - 0.763, p < 0.0001) agreement. For optic atrophy, interobserver agreement was moderate (k = 0.437 - 0.484, p < 0.0001), while intraobserver agreement was moderate-strong (k = 0.491 - 0.596, p < 0.0001). CONCLUSION: Coronal CE-FS-FLAIR is quite specific in detecting optic neuropathy years after the onset of acute optic neuritis, but is less useful in detecting optic nerve atrophy.

Malignant brachial plexopathy: A pictorial essay of MRI findings.

For imaging, the brachial plexus is a technically and anatomically challenging region of the peripheral nervous system. MRI has a central role in the identification and accurate characterization of malignant lesions arising here, as also in defining their extent and the status of the adjacent structures. The purpose of this pictorial essay is to describe the MRI features of primary and secondary malignant brachial plexopathies and radiation-induced brachial nerve damage.

Added value of selected images embedded into radiology reports to referring clinicians.

PURPOSE: The aim of this study was to evaluate the added utility of embedding images for findings described in radiology text reports to referring clinicians. METHODS: Thirty-five cases referred for abdominal CT scans in 2007 and 2008 were included. Referring physicians were asked to view text-only reports, followed by the same reports with pertinent images embedded. For each pair of reports, a questionnaire was administered. A 5-point, Likert-type scale was used to assess if the clinical query was satisfactorily answered by the text-only report. A "yes-or-no" question was used to assess whether the report with images answered the clinical query better; a positive answer to this question generated "yes-or-no" queries to examine whether the report with images helped in making a more confident decision on management, whether it reduced time spent in forming the plan, and whether it altered management. The questionnaire asked whether a radiologist would be contacted with queries on reading the text-only report and the report with images. RESULTS: In 32 of 35 cases, the text-only reports satisfactorily answered the clinical queries. In these 32 cases, the reports with attached images helped in making more confident management decisions and reduced time in planning management. Attached images altered management in 2 cases. Radiologists would have been consulted for clarifications in 21 and 10 cases on reading the text-only reports and the reports with embedded images, respectively. CONCLUSIONS: Providing relevant images with reports saves time, increases physicians' confidence in deciding treatment plans, and can alter management.

Three distinct co-existent primary brain tumors in a patient.

A rare case of simultaneous occurrence of three entirely distinct intracranial tumors is described. A 55-year-old male with no evidence of phacomatoses or history of radiation therapy presented with complaints of increased drowsiness, headaches, and dysarthria. Investigations revealed an olfactory groove meningioma, a glioblastoma multiforme in the left medial temporal lobe, and a diffuse glioma in the brain stem. Occurrence of multiple varieties of tumors at the same time is extremely rare. Theories that explain their occurrences including the role of common carcinogens, autocrine growth factors, and tumor suppressor genes are discussed.

MRI features of tuberculosis of the knee.

OBJECTIVE: The objective of this study was to describe the magnetic resonance imaging (MRI) features of tuberculosis (TB) of the knee joint. MATERIALS AND METHODS: The MRI features in 15 patients with TB of the knee, as confirmed by histology of the biopsied joint synovium, were reviewed retrospectively. The images were assessed for intra-articular and peri-articular abnormalities. RESULTS: All patients had florid synovial proliferation. The proliferating synovium showed intermediate to low T2 signal intensity. In the patients who were administered intravenous contrast, the hypertrophic synovium was intensely enhancing. Marrow edema (n = 9), osteomyelitis (n = 4), cortical erosions (n = 5), myositis (n = 6), cellulitis (n = 2), abscesses (n = 3), and skin ulceration/sinus formation (n = 2) were seen in the adjacent bone and soft tissue. CONCLUSION: Synovial proliferation associated with tuberculous arthritis is typically hypointense on T2-weighted images. This appearance, in conjunction with other peri-articular MRI features described, can help in distinguishing TB arthritis from other proliferating synovial arthropathies.