Sachin S. Saboo

Spleen in haematological malignancies: spectrum of imaging findings

Imaging morphology and metabolic activity of splenic lesions is of paramount importance in patients with haematological malignancies; it can alter tumour staging, treatment protocols and overall prognosis. CT, MRI and positron emission tomography (PET)/CT have been shown to be powerful tools for the non-invasive assessment of splenic involvement in various haematological malignancies. Since many haematological malignancies and non-neoplastic conditions can involve the spleen and imaging manifestations can overlap, imaging and clinical findings outside of the spleen should be looked for to narrow the differential diagnosis; confirmation can be obtained by pathological findings. Radiologists should be familiar with the cross-sectional imaging patterns of haematological malignancies involving the spleen as well as non-neoplastic splenic findings common in these patients to facilitate their care and follow-up. This pictorial review provides the common and uncommon imaging appearances and complications of various haematological malignancies involving the spleen on CT, MRI and PET/CT, and common pitfalls in diagnosis.

Anal carcinoma: FDG PET/CT in staging, response evaluation, and follow-up

The role of FDG PET/CT in anal cancer is becoming increasingly important. At the time of initial staging, FDG PET/CT can detect the primary site of disease more frequently than CT, is sensitive for nodal and metastatic spread and alters staging in a significant number of patients. Indeed, the NCCN guidelines for anal cancer published in April 2012 recommend FDG PET/CT for therapy planning. Metabolic activity of primary anal cancer at presentation is a potential biomarker for predicting prognosis, treatment response and survival. More intensely FDG-avid primary malignancy is associated with a higher incidence of disease spread. Metabolic response following chemoradiotherapy is associated with improved survival. The aim of this paper is to provide an up-to-date pictorial review of FDG PET/CT in anal cancer at the time of staging and to illustrate its utility for determining response to therapy and detecting recurrent disease.

Computed tomography and echocardiography in patients with acute pulmonary embolism: part 2: prognostic value.

Purpose: The aim of the study was to compare the prognostic value of right ventricular (RV) dysfunction detected on computed tomography pulmonary angiography (CTPA) and transthoracic echocardiography (TTE) in patients with acute pulmonary embolism (PE). Materials and Methods: From all consecutive CTPAs performed between August 2003 and May 2010 that were positive for acute PE (n=1744), those with TTE performed within 48 hours of CTPA (n=785) were selected as the study cohort. Multivariate logistic regression analysis was performed to assess the association of CTPA RV/left ventricular (LV) diameter ratio and TTE RV strain with PE-related 30-day mortality, including other associated factors as covariates. The predictive ability (area under the curve) was compared between the model including the CT RV/LV diameter ratio and that including TTE RV strain. Test characteristics of the 2 modalities were calculated. Results: Both CT RV/LV diameter ratio and TTE RV strain were independently associated with PE-related 30-day mortality (adjusted odds ratio=1.14, P=0.023 for 0.1 increment of the CT RV/LV diameter ratio; and odds ratio=2.13, P=0.041 for TTE RV strain). History of congestive heart failure and malignancy were independent predictors of PE-related mortality, while there was significantly lower mortality associated with anticoagulation use. The model including TTE RV strain and that including CT RV/LV had similar predictive ability (area under the curve=0.80 vs. 0.81, P=0.50). The sensitivity, specificity, and positive and negative predictive values of TTE RV strain and CT RV/LV diameter ratio at a cutoff of ≥1.0 were similar for PE-related 30-day mortality. Conclusions: Both RV strain on TTE and an increased CT RV/LV diameter ratio are predictors of PE-related 30-day mortality with similar prognostic significance.

Malignant skin and subcutaneous neoplasms in adults: Multimodality imaging with CT, MRI, and 18F-FDG PET/CT

OBJECTIVE The purpose of this article is to enlighten radiologists with the clinical presentation, multimodality imaging features, local recurrence, distant spread, differential diagnosis, and prognosis of skin and subcutaneous malignancies. CONCLUSION Cutaneous and subcutaneous malignancies represent the most common type of cancer and frequently present with overlapping imaging appearances. CT, MRI, and (18)F-FDG PET/CT are commonly used for staging, preoperative planning, and posttreatment assessment. Knowledge of the multimodality imaging features can narrow down the differential diagnosis and elucidate their metastatic pattern.

MDCT of Congenital Coronary Artery Fistulas

OBJECTIVE The purpose of this article is to describe the evaluation of congenital coronary artery fistulas (CAFs) with MDCT angiography with ECG gating (MDCTA), including the clinical manifestations, scanning techniques, differential diagnosis, and other imaging methods that may be used. CONCLUSION Congenital CAFs are rare coronary artery anomalies of termination. MDCTA is a first-line modality for pretreatment planning, and imaging findings should be recognized because CAFs may be detected incidentally.

Gastrointestinal stromal tumors (GIST): lesser known facts

In an era of molecular targeted therapy, patients with advanced gastrointestinal stromal tumor (GIST) are living longer and are often followed with imaging. Therefore, it is important for the radiologists to be aware of the atypical subtypes of GIST, implications of molecular makeup, its behavior, and the uncommon metastatic sites. The aim of this pictorial review is to illustrate the lesser-known aspects of GIST including histological and molecular classifications, syndromes associated with GIST, and uncommon metastatic sites.

Modern imaging techniques: applications in the management of acute aortic pathologies

Acute aortic pathologies include traumatic and non-traumatic life-threatening emergencies of the aorta. Since the clinical manifestation of these entities can be non-specific and may overlap with other conditions presenting with chest pain, non-invasive imaging plays a crucial role in their rapid and accurate evaluation. The early diagnosis and accurate radiological assessment of acute aortic diseases is essential for improved clinical outcomes. Multidetector CT is the imaging modality of choice for evaluation of acute aortic diseases with MRI playing more of a problem-solving role. The management can be medical, endovascular or surgical depending upon pathology, and imaging remains an indispensable management-guiding tool. It is important to understand the pathogenesis, natural history, and imaging principles of acute aortic diseases for appropriate use of advanced imaging modalities. This understanding helps to formulate a more appropriate management and follow-up plan for optimised care of these patients. Imaging reporting pearls for day-to-day radiology as well as treatment options based on latest multidisciplinary guidelines are discussed. With newer techniques of image acquisition and processing, we are hopeful that imaging would further help in predicting aortic disease progression and assessing the haemodynamic parameters based on which decisions on management can be made.

Pneumosinus dilatans: Is it more than an aesthetic concern?

BackgroundPneumosinus dilatans (PD) is a pathologic condition involving the hyperaeration of one or several of the paranasal sinuses that can lead to significant deformation of the overlying bone. Although the presenting complaint of patients with PD is most commonly aesthetic in nature, the condition has also been associated with intracranial tumors and several other serious conditions. Materials and MethodsA meta-analysis of all available clinical publications on the subject of PD was conducted. Patients were categorized on the basis of their sinus involvement. Associated conditions were also identified and categorized. The resulting data were used to further characterize the condition and describe previously unreported associations between PD and other conditions. ResultsTo date, a total of 123 cases of PD have been reported. The frontal sinus was the most commonly involved (63%), followed by the sphenoid sinus (24%), maxillary sinus (20%), and ethmoid sinus (19%). Of patients with symptomatic PD of the frontal sinus, 25% had intracranial pathology (meningioma or arachnoid cyst or orbital tumor). Patients with sphenoid PD had an 83% chance of having associated diagnosis of visual loss, meningioma, or arachnoid cyst, whereas patients with ethmoid PD had 83% chance of having associated diagnosis of exophthalmos, vision loss, or arachnoid cyst. ConclusionsAlthough the presenting complaint of patients with PD is most commonly aesthetic in nature, a significant percentage may have an associated diagnosis. Health care providers must be able to recognize the condition and carry out the appropriate clinical evaluation to avoid missing an associated diagnosis.

Imaging features of primary and secondary adult rhabdomyosarcoma.

OBJECTIVE Rhabdomyosarcomas are rare and aggressive soft-tissue sarcomas in adults. The purpose of this article is to describe the imaging features of primary and secondary adult rhabdomyosarcomas utilizing MRI, CT, and (18)F-FDG PET/CT. CONCLUSION MRI is the imaging technique of choice for the evaluation of primary rhabdomyosarcoma involving most body sites (extremity, pelvis, head, and neck), with the added advantages of diffusion-weighted imaging and whole-body MRI for staging. CT and FDG PET/CT play major roles in the evaluation of metastatic disease. Because the imaging features of adult rhabdomyosarcoma are nonspecific, other parameters, such as clinical findings, age, site, lymphadenopathy, and metastatic disease, should be combined to narrow the differential diagnosis.

Radiologist's perspective for the Meckel's diverticulum and its complications

The Meckels diverticulum is the commonest congenital anomaly of the gastrointestinal tract, often presenting with complications such as gastrointestinal bleeding, intussusception, bowel obstruction and diverticulitis, which are often misdiagnosed. Imaging plays an important role in the early diagnosis and characterization of these conditions and is very helpful in decision making. The Meckels diverticulum and its complications have myriad presentations and appearances on various imaging modalities. Thus, sound knowledge of the anatomy, embryology, clinical presentation, imaging characteristics and complications is crucial to the practice of abdominal imaging. We present a review of the literature and current radiological practices in the diagnosis and management of the Meckels diverticulum and its various complications with special emphasis on the imaging of various complications, mimickers and pathological correlation.