Ki Jun Kim

Benign tumors of the tracheobronchial tree: CT-pathologic correlation.

OBJECTIVE The purpose of this essay is to illustrate the CT findings of variable benign tumors of the tracheobronchial tree and to correlate the CT and pathologic findings in 17 patients. CONCLUSION The tracheal tumors were eccentric, well-defined, polypoid masses in all cases. The endobronchial tumors were masses confined within the bronchus in all cases, and atelectasis or pneumonia of the distal parenchyma was frequently associated. Of the six hamartomas, one was a fatty mass, and two were nodules with calcification. The others were soft-tissue-density nodules. The lipomas manifested as fat density on CT scans in both cases. The other benign tumors were low-attenuating, soft-tissue-density masses without characteristic findings on CT scans.

Blunt traumatic rupture of the diaphragm: sonographic diagnosis

Ultrasonographic features of seven patients with diaphragmatic rupture due to blunt trauma were analyzed. The ruptures occurred at the left hemidiaphragm in four patients and at the right in three. Direct ultrasonographic findings were as follows: disrupted diaphragm in four patients; nonvisualized diaphragm in three patients; floating diaphragm in two patients; and herniation of the liver or bowel loops through the diaphragmatic defect in three patients. Indirect sonographic findings included pleural effusion or subphrenic fluid collection in five patients and splenic laceration in one. Although the number of patients was limited, ultrasonography was very useful for the diagnosis of diaphragmatic rupture.

Typical and Atypical Manifestations of Intrathoracic Sarcoidosis

Sarcoidosis is a systemic disorder of unknown cause that is characterized by the presence of noncaseating granulomas. The radiological findings associated with sarcoidosis have been well described. The findings include symmetric, bilateral hilar and paratracheal lymphadenopathy, with or without concomitant parenchymal abnormalities (multiple small nodules in a peribronchovascular distribution along with irregular thickening of the interstitium). However, in 25% to 30% of cases, the radiological findings are atypical and unfamiliar to most radiologists, which cause difficulty for making a correct diagnosis. Many atypical forms of intrathoracic sarcoidosis have been described sporadically. We have collected cases with unusual radiological findings associated with pulmonary sarcoidosis (unilateral or asymmetric lymphadenopathy, necrosis or cavitation, large opacity, ground glass opacity, an airway abnormality and pleural involvement) and describe the typical forms of the disorder as well. The understanding of a wide range of the radiological manifestations of sarcoidosis will be very helpful for making a proper diagnosis.

Re-irradiation of unresectable recurrent head and neck cancer: using Helical Tomotherapy as image-guided intensity-modulated radiotherapy

Purpose Re-irradiation (re-RT) is considered a treatment option for inoperable locoregionally recurrent head and neck cancer (HNC) after prior radiotherapy. We evaluated the efficacy and safety of re-RT using Helical Tomotherapy as image-guided intensity-modulated radiotherapy in recurrent HNC. Materials and Methods Patients diagnosed with recurrent HNC and received re-RT were retrospectively reviewed. Primary endpoint was overall survival (OS) and secondary endpoints were locoregional control and toxicities. Results The median follow-up period of total 9 patients was 18.7 months (range, 4.1 to 76 months) and that of 3 alive patients was 49 months (range, 47 to 76 months). Median dose of first radiotherapy and re-RT was 64.8 and 47.5 Gy10. Median cumulative dose of the two courses of radiotherapy was 116.3 Gy10 (range, 91.8 to 128.9 Gy10) while the median interval between the two courses of radiation was 25 months (range, 4 to 137 months). The response rate after re-RT of the evaluated 8 patients was 75% (complete response, 4; partial response, 2). Median locoregional relapse-free survival after re-RT was 11.9 months (range, 3.4 to 75.1 months) and 5 patients eventually presented with treatment failure (in-field failure, 2; in- and out-field failure, 2; out-field failure, 1). Median OS of the 8 patients was 20.3 months (range, 4.1 to 75.1 months). One- and two-year OS rates were 62.5% and 50%, respectively. Grade 3 leucopenia developed in one patient as acute toxicity, and grade 2 osteonecrosis and trismus as chronic toxicity in another patient. Conclusion Re-RT using Helical Tomotherapy for previously irradiated patients with unresectable locoregionally recurrent HNC may be a feasible treatment option with long-term survival and acceptable toxicities.

The effects of human keratinocyte coculture on human adipose-derived stem cells.

The potential for adipose‐derived stem cells to differentiate into keratinocyte‐like cells has recently been receiving attention, stemming from the hypothesis that a bioengineered skin may be manufactured from these readily available mesenchymal stem cells. This study was conducted to evaluate the influence of human keratinocyte non‐contact coculture on hADSCs. Human epidermal keratinocytes and hADSCs obtained by lipoaspiration were cultured in keratinogenic growth media, which were divided into the following groups: human adipose‐derived stem cell (hADSC) monoculture, non‐contact coculture of hADSCs and human keratinocytes and keratinocyte monoculture. Cell proliferation was assessed, and keratogenicity was analysed through immunocytochemistry and polymerase chain reaction of early, intermediate and late keratogenic markers. hADSCs cocultured with keratinocytes displayed enhanced proliferation compared with the monoculture group. After a 7‐day coculture period, immunohistochemistry and polymerase chain reaction findings revealed the presence of specific keratinocyte markers in the coculture group. This study demonstrates that hADSCs cocultured with keratinocytes have the capacity to transdifferentiate into keratinocyte lineage cells, and suggests that adipose tissue may be a source of keratinocytes that may further be used in structuring the bioengineered skin.

Detection of pulmonary embolism using 64-slice multidetector-row computed tomography: accuracy and reproducibility on different image reconstruction parameters

Background Direct comparison of different image reconstruction parameters to detect pulmonary embolism (PE) using 64-slice multidetector-row computed tomography (MDCT) is absent and the most accurate image reconstruction parameters have not yet been proven. Purpose To compare different image reconstruction parameters for detecting PE using 64-slice MDCT in patients suspected of having an acute PE. Material and Methods Forty patients who underwent pulmonary CT angiography with 64-slice MDCT for a suspected PE were included. Different image reconstruction parameters were used for each patient: axial and coronal images with slice thicknesses of 0.625 mm, 1.3 mm, and 2.5 mm and axial maximum intensity projection (MIP) images with slab thicknesses of 1.3 mm, 2.5 mm, and 5 mm. Four experienced radiologists reviewed the images. The diagnosis of a PE was based on consensus review of axial 0.625 mm slice thickness images by two chest radiologists with allowing multiplanar reconstruction. Accuracy and reproducibility (kappa value) were evaluated. Results In 15 of 40 patients, a PE was diagnosed. For detecting lobar PEs, axial images with a slice thickness of 1.25 mm and all coronal re-formatted images showed comparable results to axial images with a slice thickness of 0.625 mm. For detecting segmental PEs, axial images with a slice thickness of 1.25 mm and coronal images with a slice thickness of 0.625 mm re-formatted images showed comparable results to axial images of a slice thickness of 0.625 mm. For detecting subsegmental PEs, axial images with a slice thickness of 0.625 mm showed the highest sensitivity. Better reproducibility was obtained when the thinner slice thickness reconstructions were in axial and coronal images. However, reproducibility of MIP images with slab thicknesses of 2.5 mm and 5 mm was similar for detecting segmental and subsegmental PEs. Conclusion Thin-slice reconstruction of less than 1 mm is mandatory for visualization of PE at the subsegmental level.

Bronchiectasis in active tuberculosis

Background Bronchiectasis in tuberculosis (TB) is usually considered chronic traction bronchiectasis associated with healed scars. However, bronchiectasis can occasionally be seen in active TB. Purpose To evaluate prevalence, appearance, and changes of bronchiectasis associated with active TB on computed tomography (CT). Material and Methods A total of 391 patients with active TB who had undergone CT scans at the time of diagnosis were included in the study. Active TB was diagnosed when the sputum or the sample obtained by bronchoalveolar lavage tested positive using an acid-fast bacillus (AFB) smear test, polymerase chain reaction (PCR) test, or an AFB culture. The CT scans were reviewed focusing on bronchiectasis within consolidations or nodules. Cases with bronchiectasis beyond the consolidation or nodules were excluded from the study to exclude pre-existing traction bronchiectasis. The prevalence and appearance (cylindrical, varicose, cystic, and presence of focal erosion) of bronchiectasis and its time-dependent changes were analyzed. In addition, the presence of the feeding bronchus sign was checked. Here, the feeding bronchus sign was defined as a CT finding where the cavity communicates with the dilated airway. Results In 100 (25%) of the 391 patients, bronchiectasis was present within consolidations or nodules on CT. The shape of the bronchiectasis was cylindrical in all patients and focal erosions were revealed in 75 patients (75%). Nine patients had both cylindrical and varicose forms of the bronchiectasis. The feeding bronchus sign was observed in 42 patients (42%). Follow-up CT was performed on 19 of 100 patients. The bronchiectasis had progressed in 11 patients (58%), improved in four patients (21%), remained unchanged in one patient (5%), and could not be determined in the remaining three patients (16%). In nine patients, CT images prior to diagnosis were available, and in all these cases, bronchiectasis was newly developed. Conclusion Bronchiectasis can be seen within active inflammation in one-fourth of active TB on CT. In association with active inflammation, bronchiectasis is mostly cylindrical with focal erosions, occasionally accompanied by the feeding bronchus sign.

A small Askin’s tumor presenting with early onset of chest pain

Most primitive neuroectodermal tumor of the chest wall destroy the rib, chest wall muscles, diaphragm, and lung or extend into the spinal compartment, resulting in a large-sized tumor and symptoms. In contrast, we recently encountered a rare case of Askin’s tumor presenting with early-onset chest pain despite the small size. After resection of the tumor and adjuvant chemotherapy, the patient remains disease-free over 3 years of follow-up.