Hiroyuki Horikoshi

Magnetic resonance imaging in peripheral lung adenocarcinoma: correlation with histopathologic features.

Objective Magnetic resonance imaging (MRI) with various technologic advancements has generally been used to elevate the accuracy of diagnosis for several malignant tumors. This study retrospectively evaluated the efficacy of newer MRI techniques for differentiating among the different types of invasiveness in lung adenocarcinoma by comparing the MRI findings with the pathologic findings. Materials and Methods From May 2005 to April 2007, 46 patients with lung adenocarcinoma measuring 3 cm or less across the greatest dimension underwent a surgical operation including preoperative MRI study in this hospital. The MR imaging protocol included 3 pulse sequences: (1) respiratory-triggered T2-weighted short TI inversion recovery; (2) respiratory-triggered high b-value diffusion-weighted imaging (DWI); (3) gadolinium-enhanced dynamic MRI studies. Results Of all the tumors, 13 were bronchioloalveolar carcinoma (BAC), 24 were adenocarcinomas with mixed subtypes (advanced BAC), and 9 were other histologic subtypes (non-BAC). Both the moderate and strong signal intensity on DWI was significantly greater in the advanced BAC (79.2%) and the non-BAC (88.9%) than in the BAC (38.5%). In the dynamic study, a strong enhancement on the time-intensity curve was significantly greater in the advanced BAC (95.2%) and the non-BAC (87.5%) than in the BAC (25%). When the lesions demonstrated a strong enhancement in dynamic study or showed strong signal intensity on DWI, they were judged to be positive. Sensitivity, specificity, and accuracy were 97%, 76.9%, and 91.3%, respectively. Conclusions DWI could therefore be a useful diagnostic modality for differentiating the subtypes of lung adenocarcinomas, and the MRI finding may thus provide useful supplementary information before surgery comprising limited resections.

Diffusion-weighted imaging and positron emission tomography in various cytological subtypes of primary lung adenocarcinoma

The purpose of the study was to retrospectively characterize diffusion-weighted magnetic resonance imaging (DWI) and positron emission tomography for differentiating among the various cytological subtypes of primary lung adenocarcinomas. The maximum diffusion signal intensities and the maximum standardized uptake value (SUV max) of 31 lesions were analyzed after delineation of regions of interest on the images. Diffusion intensities were 0.934 for Clara type, 0.938 for type II type, 1.473 for nongoblet type, and 1.617 for poorly differentiated adenocarcinoma type based on Shimosatos cytological classification (P=.020). The SUV max values were 4.926, 5.491, 5.709, and 12.132, respectively (P=.044). DWI might reflect some of the cytological characteristics of the tumor cells for differentiating the subtypes of lung adenocarcinomas.

Diffusion-weighted magnetic resonance imaging in differentiating the invasiveness of small lung adenocarcinoma.

Backgound Magnetic resonance imaging (MRI) with several sequences may provide a valuable additional modality for evaluating the grade of invasiveness lesions. Diffusion-weighted magnetic resonance imaging (DWI) represents the biological characteristics of tissues. Purpose To retrospectively evaluate the usefulness of DWI for evaluating the invasiveness of small lung adenocarcinomas. Material and Methods From May 2005 to June 2008, 46 patients with lung adenocarcinomas measuring 2 cm or less across the greatest dimension underwent a preoperative MRI study followed by surgery at the Gunma Prefectural Cancer Center. Fourteen of the tumors were bronchioloalveolar carcinomas (so-called Noguchis type A+B group), 26 were adenocarcinomas with mixed subtypes (type C group) and six were other histological subtypes of adenocarcinomas (type D+E+F group). The mean signal intensities of a lesion (DWI) and the spinal cord (SC) were analyzed in the region of interests (ROIs), and the mean DWI/SC ratio was then calculated with the value of DWI divided by the value of SC. Results The calculated mean DWI/SC ratio for the lesions were as follows: 0.448±0.261 (mean±standard deviation [SD]) for type A+B group, 0.963±0.465 for type C group, and 0.816±0.291 for type D+E+F group. The mean DWI/SC ratio of type A+B group was significantly lower than that for the type C (P = 0.0005) or type D+E+F groups (P = 0.0117). Conclusion DWI may thus provide useful supplementary information before determining the surgical strategy, including a limited resection.

Partial anomalous pulmonary venous connection in right lung cancer: Report of a case

A partial anomalous pulmonary venous connection (PAPVC) is an uncommon congenital anomaly which is frequently associated with congenital heart disease such as an atrial-level shunt. This report documents the case of an 81-year-old man with PAPVC which was incidentally discovered during a right upper lobectomy for lung cancer. Surgery was performed through a minithoracotomy of an auscultatory triangle using a video-assisted procedure (video-assisted thoracic surgery: VATS). Although the ramus lobi medii was connected normally, the right superior lobe vein was found to drain into the superior vena cava. The surgery was successful, and the patient had an uneventful postoperative course. Asymptomatic PAPVC without an atrial septal defect (ASD) is extremely rare. If the PAPVC is located in a different lobe, a pulmonary resection for lung cancer would precipitate an adverse outcome without a correction of the PAPVC. Surgeons should therefore be cautious regarding the potential existence of a PAPVC when a patient undergoes surgical procedures, especially VATS, for lung cancer.

Immediate cytology improves accuracy and decreases complication rate in real-time computed tomography-guided needle lung biopsy

Computed tomography‐guided percutaneous transthoracic needle biopsy (CTNB) of the lung is a well‐established diagnostic technique for the evaluation of thoracic lesions. At our institution, we have performed real‐time CTNB using automated biopsy needles since 1998 and we introduced immediate cytology in 2004. We evaluate immediate cytology in CTNB to increase the diagnostic accuracy and to reduce the number of inadequate specimens.