Air bubble artifact: why postmortem brain MRI should always be combined with postmortem CT

Forensic pathology increasingly uses postmortem magnetic resonance imaging (PMMRI), particularly in pediatric cases. It should be noted that each (sudden and unexpected) death of an infant or child should have a forensic approach as well. Current postmortem imaging protocols do not focus adequately on forensic queries. First, it is important to demonstrate or rule out bleeding, especially in the brain. Thus, when incorporating PMMRI, a blood sensitive sequence (T2* and/or susceptibility weighted imaging (SWI)) should always be included. Secondly, as intracranial air might mimic small focal intracerebral hemorrhages, PMMRI should be preceded by postmortem CT (PMCT) since air is easily recognizable on CT. This will be illustrated by a case of a deceased 3-week-old baby. Finally, note that postmortem scans will often be interpreted by clinical radiologists, sometimes with no specific training, which makes this case report relevant for a broader audience.

An Incidental Finding of Congenital Pulmonary Airway Malformation Type 3 During a Forensic Autopsy for a Sudden Infant Death: A Case Report With a Brief Literature Review

ABSTRACT

Congenital pulmonary airway malformation (CPAM), previously known as congenital cystic airway malformation, is a developmental disorder of the lower respiratory tract. It is subdivided into 5 types based on clinical and pathologic features. Type 3, an adenomatoid type of CPAM, is the second rarest form of CPAM, occurring in approximately 5% of all CPAM cases. This article reports an autopsy of a nearly 11-week-old male infant, found unresponsive in bed with his mother. She had fallen asleep after breastfeeding a few hours prior. Although the autopsy and additional technical examinations did not uncover the exact cause of death, CPAM type 3 was eventually identified on histological examination. Taking into account the context of this case, in which accidental asphyxia/neglect could not be ruled out, it is thought that the presence of CPAM might have contributed to the demise of the infant. As CPAM is a rare congenital disorder, the diagnosis could easily be missed. Therefore, this article aims to raise awareness of this diagnosis and points out the clinical and pathologic features of this disorder.

Lesion measurement on a combined "all-in-one" window for chest CT: effect on intra- and interobserver variability

PURPOSE

A newly developed image processing technique fuses conventional windows into a single 'All-In-One' (AIO) window. This study aims to evaluate variability of CT measurement of lesions in thoracic oncology patients on this novel AIO-window.

METHODS

Six radiologists with different levels of expertise measured 368 lesions of various size, origin and sharpness. All lesions were measured twice on the AIO-window and twice on the conventional window settings. Intraclass correlation coefficients and Bland-Altman plots were used to assess intra- and interobserver variability.

RESULTS

Overall intra-observer agreement for lesion diameters on the AIO-window and conventional window settings was 0.986 (95% Confidence interval (CI): 0.983-0.989) and 0.991 (95% CI 0.989-0.993) respectively. For interobserver agreement this was 0.982 (95% CI 0.979-0.985) (AIO) and 0.979 (95% CI 0.957-0.982) (conventional). For both the AIO and conventional windows, intra- and interobserver agreement were dependent on size, sharpness and reader experience. Measurement variability decreased with increasing lesion size. Regarding sharpness, inter- and intra-observer agreement ranged from 0.986-0.989 (AIO) and 0.985-0.992 (conventional) for well-defined lesions and from 0.978-0.983 (AIO) and 0.974-0.991 (conventional) for ill-defined lesions.

CONCLUSIONS

Lesion diameters were consistently smaller on the AIO-window compared to conventional window settings. Overall intra- and interobserver variability rates were similar for the AIO-window and conventional window settings. We conclude that the AIO-window offers a reliable and reproducible alternative for measurement of thoracic lesions.

Diagnostic and clinical features of lung cancer associated with cystic airspaces

"Lung cancer associated with cystic airspaces" is an uncommon manifestation, in which lung cancer presents on imaging studies with a cystic area with associated consolidation and/or ground glass. With the widespread use of computed tomography (CT), both in clinical practice and for lung cancer screening, these tumors are being more frequently recognized. An association of this entity with smoking has been established with the majority of cases reported being in former and current smokers. The true pathogenesis of the cystic airspace is not yet fully understood. Different causes of this cystic airspace have been described, including a check-valve mechanism obstructing the small airways, lepidic growth of adenocarcinoma on emphysematous lung parenchyma, cyst formation of tumor and tumor growth along the wall of a pre-existing bulla. Adenocarcinoma is the commonest histological type, followed by squamous cell carcinoma. Two classification systems have been described, based on morphological features of the lesion, taking into account both the cystic airspace as well as the morphology of the surrounding consolidation or ground glass. The cystic component may mislead radiologists to a benign etiology and the many different faces on imaging can make early diagnosis challenging. Special attention should be made to focal or diffuse wall thickening and consolidation or ground glass abutting or interspersed with cystic airspaces. Despite their atypical morphology, staging and management currently are still similar to that of other lung cancer types. Although the rarity of this entity will hamper larger studies, numerous aspects regarding this particular lung cancer type still need to be unraveled. This manuscript reviews the CT-imaging findings and gives an overview of available data in the English literature on pathogenesis, histopathology and clinical findings. Differential diagnosis and pitfalls are discussed as well as future directions regarding staging and management.