Multimodality imaging review of focal renal lesions

Background

Focal lesions of the kidney comprise a spectrum of entities that can be broadly classified as malignant tumors, benign tumors, and non-neoplastic lesions. Malignant tumors include renal cell carcinoma subtypes, urothelial carcinoma, lymphoma, post-transplant lymphoproliferative disease, metastases to the kidney, and rare malignant lesions. Benign tumors include angiomyolipoma (fat-rich and fat-poor) and oncocytoma. Non-neoplastic lesions include infective, inflammatory, and vascular entities. Anatomical variants can also mimic focal masses.

Main body of the abstract

A range of imaging modalities are available to facilitate characterization; ultrasound (US), contrast-enhanced ultrasound (CEUS), computed tomography (CT), magnetic resonance (MR) imaging, and positron emission tomography (PET), each with their own strengths and limitations. Renal lesions are being detected with increasing frequency due to escalating imaging volumes. Accurate diagnosis is central to guiding clinical management and determining prognosis. Certain lesions require intervention, whereas others may be managed conservatively or deemed clinically insignificant. Challenging cases often benefit from a multimodality imaging approach combining the morphology, enhancement and metabolic features.

Short conclusion

Knowledge of the relevant clinical details and key imaging features is crucial for accurate characterization and differentiation of renal lesions.

Predatory Journals- The Power of the Predator Versus the Integrity of the Honest

Over the last few decades, the authenticity and confidence of scientific work from around the world has been systematically corrupted by predatory journals and their affiliated publication houses. These journals predominantly prey on both aspiring and established academics and researchers from around the world, but primarily on individuals from developing countries, by aggressively soliciting manuscripts for a nominal publication fee without providing a robust editorial service or peer review system and ultimately promising fast track publication in a few days to weeks. Such journals may also diminish the opportunity for authors in developing countries from getting their original work published in legitimate journals. A majority of the work published in these pseudo journals aside from being incorrect and mundane, provide no advancement to science. But more importantly, the negative impact of these journals can have direct implications on patient health care and research.

Abdominal and pelvic radiographs of medical devices and materials- part 2: neurologic and genitourinary devices and materials

Radiographs of the abdomen and pelvis are routinely obtained as a standard part of clinical care for the abdomen and pelvis. Brisk advances in technology over the last few decades have resulted in a multitude of medical devices and materials. Recognizing and evaluating these devices on abdominal and pelvic radiographs are critical, yet increasingly a difficult endeavor. In addition, multiple devices serving different purposes may have a similar radiographic appearance and position causing confusion for the interpreting radiologist. The role of the radiologist is to not only identify accurately these medical objects, but also to confirm for their accurate placement and to recognize any complications that could affect patient care, management or even be potentially life threatening. An extensive online search of literature showed our review article to be the most comprehensive work on medical devices and materials of the abdomen and pelvis, and in this second part of our two-part series, we discuss in depth about the neurologic and genitourinary devices seen on abdominal and pelvic radiographs.

Current status quo on COVID-19 including chest imaging

With each day the number coronavirus disease 2019 (COVID-19) cases continue to rise rapidly and our imaging knowledge of this disease is expeditiously evolving. The role of chest computed tomography (CT) in the screening or diagnosis of COVID-19 remains the subject of much debate. Despite several months having passed since identifying the disease, and numerous studies related to it, controversy and concern still exists regarding the widespread use of chest CT in the evaluation and management of COVID-19 suspect patients. Several institutes and organizations around the world have released guidelines, recommendations and statements against the use of CT for diagnosing or screening COVID-19 infection and advocating its use only for those cases with a strong clinical suspicion of complication or an alternate diagnosis. However, these guidelines and recommendations are in disagreement with majority of the widely available literature, which strongly favour CT as a pivotal tool in the early diagnosis, management and even follow-up of COVID-19 infection. This article besides comprehensively reviewing the current status quo on COVID-19 disease in general, also writes upon the current consensus statements/recommendations on the use of diagnostic imaging in COVID-19 as well as highlighting the precautions and various disinfection procedures being employed world-wide at the workplace to prevent the spread of infection.

Abdominal and pelvic radiographs of medical devices and materials-Part 1: gastrointestinal and vascular devices and materials

When compared with chest radiographs, medical devices of the abdomen and pelvis are less frequently seen. However, with recent advances in technology the interpreting radiologists are seeing more medical objects on these radiographs. The identification of these devices and materials are crucial for not only enabling the radiologist to understand the underlying background pathology but also for evaluating any related complications. An online survey of literature showed our review article to be the most detailed. In this first part of our two-part series, we discuss about the various gastrointestinal and vascular devices and materials seen on abdominal and pelvic radiographs.

Fish bone induced bronchial artery pseudoaneurysm in a patient with underlying bronchiectasis—a case report

Background

Fish bones are the most common cause of accidental foreign body ingestion, especially in Asian and Mediterranean nations. In most cases, the fish bones pass through the alimentary tract without any complications and rarely require any intervention. Less than 5% of the patients with accidentally ingested fish bones develop complications. In this report, we present the first documented case of a fish bone induced bronchial artery pseudoaneurysm in an elderly male with underlying bronchiectasis; the latter recognized as a risk factor for developing bronchial artery hypertrophy.

Case presentation

We report a case of a fish bone induced bronchial artery pseudoaneurysm in a patient with underlying bronchiectasis. The vascular complication induced by the fish bone was identified only on intravenous contrast CT and would not have been identified on plain CT alone. The patient underwent bronchial artery embolization, following which the fish bone was dis-impacted endoscopically.

Conclusions

Intravenous post contrast chest CT may have an important role in the evaluation of accidental fish bone ingestion, especially in patients with underlying lung diseases, as vascular complications are most often overt on a non-contrast CT study.

Caution in using 3D-EAUS as the first-line diagnostic tool in the preoperative work up for perianal fistulas

MRI is considered the de facto imaging modality for evaluating perianal fistulas, primarily due to its excellent soft tissue contrast, operator independence, multiplanar capabilities and excellent field of view. Tridimensional endoanal ultrasound (3D-EAUS) is inferior to MRI in identifying and/or evaluating ischiorectal/supralevator tracks/extensions and therefore could end up providing incomplete and even inaccurate information (e.g. misclassification of tracks) to the surgeon, with a missed track potentially leading to recurrence of the disease.

Malignant transformation of hepatic adenoma complicated by rupture and hemorrhage: An extremely rare clinical entity

Hepatic adenomas (HAs) are rare benign tumors of the liver and comprise 2% of all liver tumors with an annual incidence of 3-4/100,000 per year in Europe and North America. These tumors may be clinically silent or present with abdominal pain. Although rare, the most important complications associated with this tumor is haemorrhage and malignant transformation to hepatocellular carcinoma. The reported risk of malignant transformation is believed to be 4.2%. We present an extremely rare case report of a young woman on the oral contraceptive pill (OCP) with malignant transformation of a hepatic adenoma complicated additionally by tumor rupture and intraperitoneal bleed. This article therefore highlights the need to carefully evaluate any liver lesion in a young female on the OCP to be a possible adenoma and if confirmed to be so, to consider the potential risks associated with it as well as the need for follow-up imaging in order to avoid life threatening complications.

Phlebosclerotic Colitis - An Enigma Among Ischemic Colitis

Phlebosclerotic Colitis is a rare, potentially life-threatening condition of unclear etio-pathogenesis seen almost exclusively in Asians and people of Asian descent. The condition predominantly affects the right hemicolon and imaging plays a crucial role in its diagnosis. Here we report the only second documented case of phlebosclerotic colitis in North America in a 60-year-old Canadian resident of Vietnamese descent with a history of consuming herbal medication (sanshishi) in soup for 2-3 decades.

Imaging of Hepatic Fibrosis

PURPOSE OF REVIEW

The purpose of this review is to discuss the current imaging techniques for non-invasive assessment of liver fibrosis (LF).

RECENT FINDINGS

Elastography-based techniques are the most widely used imaging methods for the evaluation of LF. Currently, MR elastography (MRE) is the most accurate non-invasive method for detection and staging of LF. Ultrasound-based vibration-controlled transient elastography (VCTE) is the most widely used as it can be easily performed at the point of care but has technical limitations especially in the obese. Innovations and technical improvements continue to evolve in elastography for improving accuracy and avoiding misinterpretation from confounding factors. Other imaging methods including diffusion-weighted imaging (DWI), hepatocellular contrast-enhanced (HCE) MRI, T1 relaxometry, T1ρ imaging, textural analysis, liver surface nodularity, susceptibility-weighted imaging, and perfusion imaging are promising but need further evaluation and clinical validation. MRE is the most accurate imaging technique for assessment of LF.

Conjoined twins - role of imaging and recent advances

INTRODUCTION

Conjoined twins are identical twins with fused bodies, joined in utero. They are rare complications of monochorionic twinning. The purpose of this study is to describe the various types of conjoined twins, the role of imaging and recent advances aiding in their management.

MATERIAL AND METHODS

This was a twin institutional study involving 3 cases of conjoined twins diagnosed over a period of 6 years from 2010 to 2015. All the 3 cases were identified antenatally by ultrasound. Only one case was further evaluated by MRI.

RESULTS

Three cases of conjoined twins (cephalopagus, thoracopagus and omphalopagus) were accurately diagnosed on antenatal ultrasound. After detailed counseling of the parents and obtaining written consent, all the three cases of pregnancy were terminated. Delivery of the viable conjoined twins was achieved without any complications to the mothers, and all the three conjoined twins died after a few minutes.

CONCLUSION

Ultrasound enables an early and accurate diagnosis of conjoined twins, which is vital for obstetric management. MRI is reserved for better tissue characterization. Termination of pregnancy when opted, should be done at an early stage as later stages are fraught with problems. Recent advances, such as 3D printing, may aid in surgical pre-planning, thereby enabling successful surgical separation of conjoined twins.

CT Perfusion for Early Response Evaluation of Radiofrequency Ablation of Focal Liver Lesions: First Experience

PURPOSE

To investigate the value of perfusion CT (P-CT) for early assessment of treatment response in patients undergoing radiofrequency ablation (RFA) of focal liver lesions.

METHODS AND MATERIALS

20 consecutive patients (14 men; mean age 64 ± 14) undergoing P-CT within 24 h after RFA of liver metastases (n = 10) or HCC (n = 10) were retrospectively included. Two readers determined arterial liver perfusion (ALP, mL/min/100 mL), portal liver perfusion (PLP, mL/min/100 mL), and hepatic perfusion index (HPI, %) in all post-RFA lesions by placing a volume of interest in the necrotic central (CZ), the transition (TZ), and the surrounding parenchymal (PZ) zone. Patients were classified into complete responders (no residual tumor) and incomplete responders (residual/progressive tumor) using imaging follow-up with contrast-enhanced CT or MRI after a mean of 57 ± 30 days. Prediction of treatment response was evaluated using the area under the curve (AUC) from receiver operating characteristic analysis.

RESULTS

Mean ALP/PLP/HPI of both readers were 4.8/15.4/61.2 for the CZ, 9.9/16.8/66.3 for the TZ and 20.7/29.0/61.8 for the PZ. Interreader agreement of HPI was fair for the CZ (intraclass coefficient 0.713), good for the TZ (0.813), and excellent for the PZ (0.920). For both readers, there were significant differences in HPI of the CZ and TZ between responders and nonresponders (both, P < 0.05). HPI of the TZ showed the highest AUC (0.911) for prediction of residual tumor, suggesting a cut-off value of 76 %.

CONCLUSION

Increased HPI of the transition zone assessed with P-CT after RFA might serve as an early quantitative biomarker for residual tumor in patients with focal liver lesions.

Value and Accuracy of Multidetector Computed Tomography in Obstructive Jaundice

BACKGROUND

Objective; To find out the role of MDCT in the evaluation of obstructive jaundice with respect to the cause and level of the obstruction, and its accuracy. To identify the advantages of MDCT with respect to other imaging modalities. To correlate MDCT findings with histopathology/surgical findings/Endoscopic Retrograde CholangioPancreatography (ERCP) findings as applicable.

MATERIAL/METHODS

This was a prospective study conducted over a period of one year from August 2014 to August 2015. Data were collected from 50 patients with clinically suspected obstructive jaundice. CT findings were correlated with histopathology/surgical findings/ERCP findings as applicable.

RESULTS

Among the 50 people studied, males and females were equal in number, and the majority belonged to the 41-60 year age group. The major cause for obstructive jaundice was choledocholithiasis. MDCT with reformatting techniques was very accurate in picking a mass as the cause for biliary obstruction and was able to differentiate a benign mass from a malignant one with high accuracy. There was 100% correlation between the CT diagnosis and the final diagnosis regarding the level and type of obstruction. MDCT was able to determine the cause of obstruction with an accuracy of 96%.

CONCLUSIONS

MDCT with good reformatting techniques has excellent accuracy in the evaluation of obstructive jaundice with regards to the level and cause of obstruction.

A rare case of malignant giant phyllodes tumour with retrosternal extension and pericardial invasion

Phyllodes tumour was first described in 1838 by Johannes Muller. These tumours are uncommon and comprise < 0.5% of all breast neoplasms. Among the three histological subtypes—benign, borderline and malignant—the malignant variety is the most uncommon. Giant phyllodes tumours measure > 10 cm in their largest dimension. Overall prognosis for these lesions is poor, with high recurrence rates. Surgery with post-operative adjuvant chemoradiotherapy is the main treatment for malignant giant phyllodes tumours. We present a rare case of malignant giant phyllodes tumour of the left breast in a 23-year-old female patient with retrosternal extension and invasion of the pericardium.

Rare case of acute dengue encephalitis with correlated MRI findings

Dengue encephalitis is extremely rare, with most patients showing no significant abnormality on neuroimaging (CT/MRI). We report one of the very few documented cases of dengue encephalitis, with abnormal signal intensities on all major sequences on brain MRI.

Analysis of tissue optical coefficients using an approximate equation valid for comparable absorption and scattering

New photosensitizers activated by longer wavelengths than 630 nm light used with Photofrin II are under evaluation by various groups for the treatment of malignancies. Any increase in tumour volume destroyed by these agents as compared to Photofrin II will be partly determined by tissue penetrance at the longer wavelengths. Attenuation coefficients were measured for various tissues at 630 nm and the more penetrative near infrared wavelength of 789 nm. A new model of light propagation in tissue is shown to be accurate for arbitrary ratios of absorption and scattering, by comparison with a rigorous solution to the transport equation. Absorption and transport scattering coefficients of tissues at 630 and 789 nm were obtained by fitting this model to optical attenuation measurements. In vitro tissues included bovine heart, kidney and tongue, pig liver and fat, and chicken muscle; in vivo tissues included Dunning R3327-AT and R3327-H tumours. The penetration depth was found to be 1.35-2.25 times greater at 789 than 630 nm, depending on tissue type. The greatest differences in penetration between the two wavelengths were in the highly pigmented tissues. These substantial increases in penetration in the infrared may be important in future applications of photodynamic therapy.