Torsion of the upper lobe in pneumothorax

Is dual-energy absorptiometry accurate in the assessment of bone status of patients with chronic kidney disease?

Several patients with chronic kidney disease (CKD) have deteriorated bone status. Estimation of bone status using DXA has limitations especially in patients with CKD accompanying aortic calcifications. Quantitative CT and the trabecular bone score could be more accurate methods to estimate bone status for patients with CKD and vascular calcifications.

INTRODUCTION

It remains unclear whether dual-energy absorptiometry (DXA) is appropriate for the assessment of bone status in patients with chronic kidney disease (CKD), a disease that impacts bone health. The aims of this study were to compare DXA and central quantitative computed tomography (cQCT) and to evaluate bone status in patients with pre-dialysis CKD.

METHODS

This retrospective study included 363 healthy control subjects whose bone mineral density (BMD) was evaluated with DXA and 117 CKD patients whose BMD was evaluated using both cQCT and DXA. Diagnostic discordance was assessed between the lumbar spine (LS) and femur neck (FN) from DXA or between two modalities. The trabecular bone score (TBS) was extracted from DXA images. The volume of abdominal aortic calcification (AAC) was calculated using CT images from cQCT.

RESULTS

Using LS DXA T-score, osteoporosis was less common in the CKD group than in controls. Patients with normal LS BMD using DXA were reclassified into osteopenia or osteoporosis using cQCT in CKD patients. Among discordant subjects between FN and LS in DXA, a higher BMD of LS was more common in CKD patients than in controls. CKD patients had lower TBS than controls despite having the same diagnosis using DXA. AAC volume negatively correlated with BMD from cQCT and with TBS but not with BMD from DXA.

CONCLUSIONS

TBS and cQCT could accurately assess bone status in CKD patients since DXA may overestimate LS BMD, likely due to an increased AAC volume.

Pulmonary lobar torsion: a rare complication following pulmonary resection, but one not to miss

Lobar torsion is an uncommon phenomenon but a crucial diagnosis to consider in any patient undergoing lobectomy, as the clinical findings and radiographic appearances are non-specific. This case report documents the clinical and radiological evolution of middle lobe torsion in a patient who underwent right upper lobectomy for Stage 1 adenocarcinoma of the lung. The diagnosis of lobar torsion is most often made on CT scanning of the chest, which is frequently performed in order to distinguish this from multiple other more frequently encountered post-operative complications. Contrast-enhanced CT scan is the recommended imaging modality in suspected cases. If features of lobar torsion are identified, the findings must be communicated immediately to cardiothoracic surgeons owing to the potentially life-threatening consequences of delay. Management of lobar torsion is predominantly surgical, with several techniques currently in use; however, video-assisted thoracoscopic surgery is emerging as an increasingly favoured approach.

Right cranial lung lobe torsion after a diaphragmatic rupture repair in a Jack Russell terrier

A seven-year-old male Jack Russell terrier was presented with a history of coughing, generalised weakness and lethargy 10 days after an abdominal coeliotomy to repair a large diaphragmatic rupture. Thoracic radiographs demonstrated a soft tissue mass in the midcaudal right thoracic cavity. Ultrasonographic studies, bronchoscopy and subsequent exploratory thoracotomy confirmed a diagnosis of a right cranial lung lobe torsion (LLT), with an anomalous caudodorsal displacement of the affected lobe. LLT should be considered as a differential diagnosis for respiratory tract disease following diaphragmatic rupture repair.

Radiographic and CT findings in complications following pulmonary resection

A variety of pulmonary resection techniques are currently available, including pneumonectomy (intrapleural, extrapleural, intrapericardial, and sleeve pneumonectomy), lobectomy, and limited resection (sleeve lobectomy, segmentectomy, nonanatomic parenchyma-sparing resection). However, pulmonary resection is often followed by postoperative complications that differ according to the type of surgery and the time elapsed since surgery was performed. The most common complications are bleeding, pulmonary edema, atelectasis, pneumonia, persistent air leak, bronchopleural fistula, and empyema. Other, less frequent complications include cardiac herniation, lung torsion, chylothorax, anastomotic dehiscence, wound infection, esophagopleural fistula, and recurrent tumor. The radiologist plays a major role in the diagnosis of various complications following pulmonary resection. Unfortunately, chest radiography has a relatively low diagnostic accuracy in the detection of these complications. When radiographic findings are subtle or equivocal, computed tomography frequently allows more accurate identification of the disease process. Several complications that follow pulmonary resection are life-threatening and require prompt management. Therefore, knowledge of the diverse radiologic appearances of these complications as well as familiarity with the clinical settings in which specific complications are likely to occur are vital for prompt, effective treatment.

Migrating lobar atelectasis of the right lung: radiologic findings in six patients

OBJECTIVE

To describe the radiologic findings of migrating lobar atelectasis of the right lung.

MATERIALS AND METHODS

Chest radiographs (n = 6) and CT scans (n = 5) of six patients with migrating lobar atelectasis of the right lung were analyzed retrospectively. The underlying diseases associated with lobar atelectasis were bronchogenic carcinoma (n = 4), bronchial tuberculosis (n = 1), and tracheobronchial amyloidosis (n = 1).

RESULTS

Atelectasis involved the right upper lobe (RUL) (n = 3) and both the RUL and right middle lobe (RML) (n = 3). On supine anteroposterior radiographs (n = 5) and on an erect posteroanterior radiograph (n = 1), the atelectatic lobe(s) occupied the right upper lung zone, with a wedge shape abutting onto the right mediastinal border. On erect posteroanterior radiographs (n = 6), the heavy atelectatic lobe(s) migrated downward, forming a peri- or infrahilar area of increased opacity and obscuring the right cardiac margin. Erect lateral radiographs (n = 4) showed inferior shift of the anterosuperiorly located atelectatic lobe(s) to the anteroinferior portion of the hemithorax.

CONCLUSION

Atelectatic lobe(s) can move within the hemithorax according to changes in a patient's position. This process involves the RUL or both the RUL and RML.

Pneumothorax during fluoroscopic biopsy: effect on nodule depth

Transthoracic needle aspiration biopsy of lung nodules is often performed under fluoroscopic guidance after measurement of lesion depth on preliminary computed tomography (CT) scans is obtained. We evaluated the change in depth of nodules in 10 patients in whom pneumothorax developed during CT-guided biopsy. We observed that nodule depth changed by an amount equal to the size of the pneumothorax. Awareness of the potential effect of pneumothorax on lesion depth should be helpful in reducing the likelihood of false-negative results with CT-assisted fluoroscopic biopsy when only single-plane fluoroscopy is available.