[en] The objective of this study was to introduce the technical utility of micro-computed tomography (CT) with 27-μm resolution by cone-beam CT algorithm. Whole-body micro-CT scans were performed to honeybee. Two- and three-dimensional image analyses were performed by originally developed and available open-source software for acquired images. The original contribution of this work is to describe the technical characteristics of the X-ray micro-CT system, keeping a small experimental insect in a unique condition. Micro-CT may be used as a rapid prototyping tool to research and understand the high-resolution system with Feldkamp cone-beam reconstruction. (author)

[en] Local bone pain and osseous scintigraphic findings were evaluated in patients with cancer of the lung, breast or prostate. (1) In 77-92% out of the patients with local pain, metastatic bone lesions were detected. (2) The sacrum and scapulae were the frequent sites of pain as estimated from the metastatic bone lesions. On the other hand, the incidence of pain was low in the ribs, cervical vertebrae, skull and femurs. (3) When calculated by the weight of red bone marrow, the most likely sites for bone metastases consisted of the scapulae, clavicles, sternum, humeri, ribs and cervical vertebrae, somewhat different from previous reports. Those bones involved were all proximate to the heart. (4) Extensive bone metastases were already detected in more than 50% of patients who complain of pain in the metastatic bone lesion. On the other hand, extensive bone metastases occurred in less than 6% of patients who didn't complain of pain. (5) The appearance of pain in the metastatic bone lesion was earlier in only 3% and was later in 71% than the detection of abnormal radioisotope accumulation on scintigram. (6) Majority of the patients with pain in the metastatic bone lesion showed a high degree of abnormal radioisotope accumulation which measured more than 5 cm in diameter on scintigram. On the other hand, the abnormal radioisotope accumulation in most of patients without pain was mild and mostly measured less than 5 cm in diameter. (7) The positive rate of bone metastasis amounted to 29% by plain X-ray and 41% by local bone pain as compaired to positive bone scintigram. (author)

[en] A prospective study on male sexual and urinary functions after mesorectal excision (ME) or ME plus extended lateral pelvic lymph node dissection (LD) for rectal cancer showed that the patients undergoing ME alone had excellent sexual and urinary functions. The functional results of the patients with ME plus LD were worse than those of the patients with ME alone. Degrees of sexual and urinary dysfunctions depend on the degrees of both autonomic nerve preservation (ANP) and LD. Thus, ideally, ANP and LD should be individualized according to tumor extent. Another prospective study assessing accuracy of thin-section MRI (TSMRI) with a phased-array coil in rectal cancer staging demonstrated that TSMRI is very accurate in detection of mesorectal fascia invasion and lateral pelvic lymph node metastasis, and TSMRI is moderately accurate in prediction of transmural invasion depth and mesorectal lymph node metastasis. In conclusion, individualization of ANP and LD seems possible if it depends on TSMRI findings. (author)

[en] We conducted a study of 90 patients with soft tissue tumor in their arms or legs, in order to determine the usefulness of scintigraphy with gallium-67 citrate as a diagnostic means. All patients had adequate scan images, and tumor tissues had been histologically confirmed by surgical resection. The subjects consisted of 19 patients with malignant tumors, 55 patients with benign tumors, and 16 patients with other disorders in which soft tissue tumor-like lesions occurred. When the activity of the tumor was more than the activity of the normal region of the contralateral extremity, it was estimated to be positive. The positive rate was found in 78% (15/19) of patients with malignant tumors, in 25% (14/55) of patients with benign tumors and in 31% (5/16) of patients with other disorders. Classified by diseases, high positive rates were observed in liposarcoma, leiomyosarcoma, malignant lymphoma, neurinoma, extra-abdominal desmoid and sarcoidosis. Out of 7 patients in which the activity of the tumor was equal to, or higher than that of the liver, 6 patients had malignant tumors and one patient was diagnosed as having an abscess. It seemed possible to distinguish between liposarcoma and lipoma by means of a gallium-67 scan. Furthermore, the gallium-67 scan was useful in detecting lesions of sarcoidosis as well as in evaluating the response to treatment. (author)

[en] The objective of this study was to evaluate the detection of early invasive colorectal cancers (EICC) with submucosal invasion on CT colonography (CTC) using the primary interpretation of virtual colon dissection (VCD) by radiologic technologists. A total of 22 patients (11 males, 11 females; mean age, 57 years) with 23 EICCs (12 elevated lesions and 11 flat type lesions, average size 25.0 mm) underwent 64-multi detector row CT (MDCT) for evaluation of preoperative staging. CT examinations were performed soon after the preoperative colonoscopy. All scan data was transferred to a ZIOstation (Amin, Tokyo, Japan) imaging workstation. The interpretation method was as follows. Radiologic technologists made a primary interpretation by analysis of VCD images picking up lesions. Then, these lesions were verified on fly through 3D images and then again in 2D depictions of axial and multi-planar reformatted images. Four radiologic technologists independently evaluated six colorectal segments per case for the presence or absence of EICCs. The sensitivity, specificity and accuracy of detection were all assessed. The interpretation times for each case were recorded. The inter-observer difference on sensitivity, specificity and accuracy of detection of EICC was evaluated using a z test. Overall average sensitivity, specificity and accuracy of detection on EICCs were 84.1%, 96.9% and 94.5% respectively. Average interpretation time per case was 9 minutes 54 seconds. There was no inter-observer difference between 4 radiologic technologists on sensitivity, specificity and accuracy in detection of EICCs. Radiological technologists can detect the presence of EICCs on CTC on primary interpretation of VCD with high accuracy of detection and relatively short evaluation time. This study shows that primary interpretation of VCD is useful in the detection of EICCs by not only radiologists but also radiologic technologists. (author)

[en] We have applied multi-detector row CT (MDCT) to preoperative staging of colorectal cancer patients. Our data shows that the usefulness of virtual endoluminal images were clearly demonstrated for detecting small invasive colorectal cancers, furthermore, the use of multi-planar reconstruction (MPR) views was also an excellent method for recognizing small lymph node metastasis in MDCT colonography. Both virtual endoluminal images and MPR views can be acquired from the same 3D volumetric data generated by helical scanning in MDCT colonography. Each has a great potential of being a modality for computer-aided diagnosis. (author)

[en] We evaluated the usefulness of computer-aided detection (CAD) software in the diagnosis of 92 patients with early invasive colorectal cancer, using 64-row multislice CT colonography (CTC), immediately after preoperative endoscopy. Sensitivity of protruded lesion was 100% and that of flat or depressed lesion was 71.4%. CAD may be effective for detection of early invasive colorectal cancers, especially protruded lesions. Further improvement of the CAD algorithm to depict flat or depressed lesions may be needed. (author)

[en] 

Purpose

To test the tagging efficacy, patient acceptability, and accuracy of computed tomographic colonography (CTC) with a reduced dose of laxative using a novel barium sulfate (BaSO₄) contrast agent.

Materials and methods

CTC followed by optical colonoscopy (OC) was performed on 73 patients with positive results in fecal occult blood tests. They were administrated a BaSO₄ suspension and a magnesium citrate solution for bowel preparation. Patients completed a questionnaire about the acceptability of bowel preparation. Tagging efficacy was estimated using a novel categorization system, which classified all segments into 8 categories. The accuracy of detecting protruded lesions ≥ 6 mm was calculated from the comparison of CTC and OC results, using the latter as a reference standard.

Results

Tagging efficacy was good in 77.3% of colonic segments where residue was observed. The acceptability of bowel preparation for CTC was significantly higher than that for OC. The sensitivity, specificity, and positive and negative predictive values were 0.778, 0.945, 0.824, and 0.929, respectively. All lesions ≥ 7 mm were successfully detected by CTC.

Conclusion

CTC with a reduced dose of laxative using a novel BaSO₄ contrast agent has a favorable tagging efficacy, patient acceptability, and accuracy.

[en] The aim of this study was to evaluate the usefulness of computer-aided detection (CAD) in diagnosing early colorectal cancer using computed tomography colonography (CTC). A total of 30 CTC data sets for 30 early colorectal cancers in 30 patients were retrospectively reviewed by three radiologists. After primary evaluation, a second reading was performed using CAD findings. The readers evaluated each colorectal segment for the presence or absence of colorectal cancer using five confidence rating levels. To compare the assessment results, the sensitivity and specificity with and without CAD were calculated on the basis of the confidence rating, and differences in these variables were analyzed by receiver operating characteristic (ROC) analysis. The average sensitivities for the detection without and with CAD for the three readers were 81.6% and 75.6%, respectively. Among the three readers, only one reader improved sensitivity with CAD compared to that without. CAD decreased specificity in all three readers. CAD detected 100% of protruding lesions but only 69.2% of flat lesions. On ROC analysis, the diagnostic performance of all three readers was decreased by use of CAD. Currently available CAD with CTC does not improve diagnostic performance for detecting early colorectal cancer. An improved CAD algorithm is required for detecting fiat lesions and reducing the false-positive rate. (author)

[en] The purpose was to evaluate the ability of computer-aided detection (CAD) software to detect morphologically flat early colonic carcinoma using CT colonography (CTC). Twenty-four stage T1 colonic carcinomas endoscopically classified as flat (width over twice height) were accrued from patients undergoing staging CTC. Tumor location was annotated by three experienced radiologists in consensus aided by the endosocpic report. CAD software was then applied at three settings of sphericity (0, 0.75, and 1). Computer prompts were categorized as either true positive (overlapping tumour boundary) or false positive. True positives were subclassified as focal or non focal. The 24 cancers were endoscopically classified as type IIa (n=11) and type IIa+IIc (n=13). Mean size (range) was 27 mm (7-70 mm). CAD detected 20 (83.3%), 17 (70.8%), and 13 (54.1%) of the 24 cancers at filter settings of 0, 0.75, and 1, respectively with 3, 4, and 8 missed cancers of type IIa, respectively. The mean total number of false-positive CAD marks per patient at each filter setting was 36.5, 21.1, and 9.5, respectively, excluding polyps. At all settings, >96.1% of CAD true positives were classified as focal. CAD may be effective for the detection of morphologically flat cancer, although minimally raised laterally spreading tumors remain problematic. (orig.)