Radiologists' performance in the detection of benign and malignant masses with 3D automated breast ultrasound (ABUS)

Objectives

To retrospectively evaluate the detection performance of benign and malignant breast masses using 3D volume data obtained by ABUS and to determine lesion variables which affect detectability.

Methods

Between November and December of 2007, bilateral whole breast US images were obtained using ABUS in 67 consecutive women who were scheduled to undergo US-guided needle biopsy due to suspicious breast masses. Twenty-four invasive ductal cancers in 23 breasts, 46 benign breast lesions in 44 breasts and 38 normal breasts were included. Three breast radiologists (experience range, 8-16 years) who did not perform the examinations and were blinded to the histology independently reviewed the ABUS data of the 105 breasts to detect suspicious solid masses with pathology as the standard of reference. Sensitivity and specificity in detecting benign and malignant masses were calculated, and lesion characteristics affecting detectability were analyzed.

Results

Sensitivities for benign and malignant mass detections were 65.2% (30/46), 95.8% (23/24) for reader 1 (p = 0.007), 66.7% (31/46), 87.5% (21/24) for reader 2 (p = 0.087), and 56.3% (24/46), 91.7% (22/24), for reader 3 (p = 0.001), respectively. Logistic analysis showed that mass size (odds ratio, 95% CI; 1.12, 1.02-1.24), surrounding tissue changes (odds ratio, 95% CI; 0.11, 0.02-0.47), and shape of the mass (odds ratio, 95% CI; 3.12, 1.02-9.55) were the variables associated with detectability at ABUS.

Conclusion

In reader studies using ABUS data, significantly higher sensitivity was noted for malignant breast masses than for benign masses.     

The role of ultrasound imaging in the evaluation of peripheral nerve in systemic sclerosis (scleroderma)

Background

Patients affected by scleroderma may complain of sensory disturbances especially in the hands.

Purpose

To study the imaging features of upper limb nerves in patients affected by scleroderma (SSc).

Materials and method

Twenty-five patients affected only by SSc were prospectively evaluated with high-resolution US and magnetic resonance (MRI) or computer tomography (CT) when necessary (2 patients). Median and ulnar nerves were evaluated bilaterally. Nerve conduction studies were performed in the symptomatic patients (n = 10). Results of imaging studies were correlated with disease duration, autoimmunity and immunosuppression. Nerves of SSc patients were compared with a control group of 90 patients matched for age and body mass index.

Results

The prevalence of sensory disturbances revealed by clinical examination was 40%. In symptomatic SSc patients (n = 10) US evaluation revealed nerve abnormalities in 70% of cases (n = 7/10). n = 2 had a carpal tunnel syndrome. n = 5 had cubital tunnel syndrome. In two of them CT and MR were necessary to identify the compressed nerve at the level of the elbow due to the presence of calcifications. There was no association between the presence of an entrapment neuropathy and disease duration, autoantibodies and immunosuppression.

Conclusion

Ultrasound, CT and MR may detect nerve abnormalities in 70% of SSc patients complaining of neurologic disturbances in the hands. The results of imaging studies support the hypothesis of a vascular dependent neuropathy in SSc.     

Positive enteric contrast material for abdominal and pelvic CT with automatic exposure control: what is the effect on patient radiation exposure?

Objective

To assess the effect of positive enteric contrast administration on automatic exposure control (AEC) CT radiation exposure in (1) a CT phantom, and (2) a retrospective review of patients.

Materials and methods

We scanned a CT phantom containing simulated bowel that was sequentially filled with water and positive enteric contrast, and recorded the mean volume CT dose index (CTDIvol). We also identified 17 patients who had undergone 2 technically comparable CT scans of the abdomen and pelvis, one with positive enteric contrast and the other with oral water. Paired Student's t-tests were used to compare the mean CTDIvol between scans performed with and without positive enteric contrast. Both the phantom and patient CT scans were performed using AEC with a fixed noise index.

Results

The mean CTDIvol for the phantom with simulated bowel containing water and positive enteric contrast were 8.2 ± 0.2 mGy, and 8.7 ± 0.1 mGy (6.1% higher than water, p = 0.02), respectively. The mean CTDIvol for patients scanned with oral water and with positive enteric contrast were 11.8 mGy and 13.1 mGy, respectively (p = 0.003). This corresponded to a mean CTDIvol which was 11.0% higher (range: 0.0-20.7% higher) in scans with positive enteric contrast than those with oral water in patients.

Conclusions

When automatic exposure control is utilized for abdominopelvic CT, the radiation exposure, as measured by CTDIvol, is higher for scans performed with positive enteric contrast than those with oral water.     

The value of PET/CT for preoperative staging of advanced gastric cancer: Comparison with contrast-enhanced CT

Aim

To date, no data are available on the use of PET/CT for preoperative staging of gastric cancer. We attempted to evaluate the value of PET/CT for preoperative staging of advanced gastric cancer, and to compare the use of PET/CT with contrast-enhanced CT (CECT).

Materials and methods

We analyzed PET/CT of 78 patients with surgically proven advanced gastric cancer who had undergone preoperative CECT. Qualitative analysis was conducted by assessing the presence of primary tumors and metastases with PET/CT and CECT.

Results

Among 71 patients who underwent a gastrectomy, 69 primary tumors (93%) were diagnosed by PET/CT, while 64 primary tumors (90%) were detected by CECT (p = 0.55). For regional lymph node metastasis, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT vs. CECT were 41% vs. 25% (p = 0.00019), 100% vs. 92% (p = 0.31), 100% vs. 98% (p = 0.46), 26% vs. 42% (p = 0.14), and 51% vs. 72% (p = 0.00089), respectively.

Conclusion

Overall, PET/CT showed comparable diagnostic performance to CECT in diagnosing primary tumors and regional lymph node metastases, though PET/CT was inferior to CECT for the sensitivity and accuracy in diagnosing regional lymph node metastases. Nevertheless, PET/CT would be useful when CECT findings were equivocal due to its high positive predictability.     

Below knee angioplasty in elderly patients: Predictors of major adverse clinical outcomes

Aim

To determine predictors of clinical outcome following percutaneous transluminal angioplasty (PTA) in elderly patients with below knee atherosclerotic lesions causing intermittent claudication (IC) or critical limb ischaemia (CLI).

Materials and methods

Over 7.5 years, 76 patients (CLI 72%, n = 55) underwent below knee PTA. The composite end-point of interest was major adverse clinical outcome (MACO) of the treated limb at follow-up which was defined as clinical failure, need for subsequent endovascular or surgical revascularization or amputation. Actuarial freedom from MACO was assessed using Kaplan-Meier curves and multivariable Cox proportional hazards regression.

Results

IC was improved in 95% at mean 3.4 years (range 0.5-108 months). Successful limb salvage and ulcer healing were seen in 73% with CLI. Most failures were in the CLI group (27% CLI vs. 5% IC), with an amputation rate of 16% for CLI vs. 5% for IC and persistent ulceration in 24% of CLI. Significant independent predictors of MACO were ulceration (hazard ratio 4.02, 95% CI = 1.55-10.38) and family history of atherosclerosis (hazard ratio 2.53, 95% CI = 1.1-5.92).

Conclusion

Primary below knee PTA is a feasible therapeutic option in this elderly population. Limb ulceration and family history of atherosclerosis may be independent predictors of adverse outcome.     

Integrated contrast-enhanced diagnostic whole-body PET/CT as a first-line restaging modality in patients with suspected metastatic recurrence of breast cancer

Objective(s)

Only few information exist about the diagnostic accuracy of PET/CT for restaging patients with metastatic recurrence of breast carcinoma. Therefore, our study hypothesis was to perform diagnostic contrast enhanced CT (ce-CT) and FDG-PET in a one-step investigation, to prove sensitivity of each modality and to determine whether diagnostic PET/CT adds information over PET or contrast enhanced CT alone for restaging of patients with suspected recurrence of breast cancer.

Methods

Fifty-two patients with suspected recurrence of breast cancer were included in our study. All of them were free of metastasis after the first line therapy. Indications for restaging were: Elevated tumor markers n = 32, clinical deterioration n = 16 and/or suspicious findings on other imaging studies n = 48. Integrated PET/CT was performed using contrast-enhanced diagnostic CT for attenuation correction.

Results

PET was correct in 44/52 patients (85%), ce-CT in 38/52 patients (73%) and PET/CT in 50/52 patients (96%). Sensitivity and specificity of lesion detection of PET, CT and PET/CT were 84%, 66% and 93%, and 100%, 92%, and 100%, respectively.

Discussion

PET/CT can improve staging and alter therapeutic options in patients suspected to have breast cancer recurrence and distant metastatic disease, primarily by demonstrating local or distant nodal involvement occult at other imaging studies. The added value of FDG-PET/CT over other diagnostic modalities is mainly expressed by the fact that a noninvasive whole-body evaluation is possible in a single examination.     

Computed tomographic features of 23 sporadic cases with Legionella pneumophila pneumonia

Objective

To describe the chest computed tomographic (CT) findings of Legionella pneumophila pneumonia.

Methods

CT scans obtained from 23 sporadic cases of L. pneumophila pneumonia were retrospectively reviewed. Chest CT findings were analyzed with regard to the patterns and distributions of pulmonary abnormalities. We also analyzed the histopathology of lungs from guinea pigs with experimentally induced L. pneumophila pneumonia.

Results

Consolidation and ground-glass opacity (GGO) were the main findings of CT scans in L. pneumophila pneumonia. The distribution of opacities was categorized as non-segmental (n = 20) and segmental (n = 4). Non-segmental distribution may follow an onset of segmental distribution. Pleural effusion was observed in 14 (58.3%) patients, of which 13 were accompanied with non-segmental distribution. Abscess formation was observed in only one immunocompromised patient. In the animal pneumonia model, the lesions comprised of terminal bronchioles, alveolar spaces, and interstitia. Small bacilli were observed to be contained by many macrophages within the alveoli.

Conclusion

Non-segmental distribution was significantly more frequent than segmental distribution in L. pneumophila pneumonia. It is possible that L. pneumophila infection initially results in segmental pneumonia, which progresses to typical non-segmental distribution.     

Time-of-flight MR angiography at 3T versus digital subtraction angiography in the imaging follow-up of 51 intracranial aneurysms treated with coils

Objective

To compare 3D time-of-flight MR angiography (TOF-MRA) at 3 Tesla (3 T) with digital subtraction angiography (DSA) for the evaluation of intracranial aneurysm occlusion after endovascular coiling.

Methods

In a prospective study, 51 consecutive patients (25 females, 26 males; median age, 51 years) with 51 saccular aneurysms treated with endovascular coiling underwent simultaneous DSA and 3 T TOF-MRA at follow-up. DSA and TOF-MRA images were analyzed independently by two senior neuroradiologists. Findings were assigned to 1 of 3 categories in the Raymond classification: complete obliteration, residual neck or residual aneurysm. Agreement between observers and techniques was evaluated using κ statistics.

Results

DSA images were not interpretable for one patient. Interobserver agreement was determined as excellent for DSA (κ = 0.86) and TOF-MRA (κ = 0.80). After reaching a consensus, DSA follow-up showed 26 (51%) complete obliterations, 20 (39%) residual necks and 4 (8%) residual aneurysms. TOF-MRA showed 23 (45%) complete obliterations, 22 (43%) residual necks and 6 (12%) residual aneurysms. Comparison between TOF-MRA and DSA showed excellent agreement between the techniques (κ = 0.86). In the four cases that were misclassified, TOF-MRA findings were assigned to a higher class than for DSA.

Conclusion

TOF-MRA at 3 T is at least as efficient as DSA for the evaluation of intracranial aneurysm occlusion after endovascular treatment with detachable coils. We suggest that TOF-MRA at 3 T might be used as the primary method for imaging follow-up of coiled intracranial aneurysms.     

CT characteristics of resolving ground-glass opacities in a lung cancer screening programme

Purpose

This study aimed at evaluating the computed tomography (CT) characteristics of resolving localized ground-glass opacities (GGOs) in a screening programme for lung cancer.

Material and methods

280 patients at high-risk for lung cancer (221 men, 59 women; mean age, 58.6 years), divided into four groups (lung cancer history (n = 83), head and neck cancer history (n = 63), symptomatic (n = 88) and asymptomatic (n = 46) cigarette smokers), were included in a prospective trial with annual low-dose CT for lung cancer screening. We retrospectively reviewed all localized GGOs, analyzed the CT characteristics on initial CT scans and changes during follow-up (median 29.1 months). Variables associated with resolution of GGOs were tested using chi-square or Mann-Whitney tests.

Results

A total of 75 GGOs were detected in 37 patients; 54.7% were present at baseline and 45.3% appeared on annual CT. During follow-up, 56.2% persisted and 43.8% disappeared. The resolving localized GGOs were significantly more often lobular GGOs (p = 0.006), polygonal in shape (p = 0.02), mixed (p = 0.003) and larger (p < 0.0001) than non-resolving localized GGOs.

Conclusion

Localized GGOs are frequent and many disappeared on follow-up. CT characteristics of resolving GGOs show significant differences compared to persistent ones. This study emphasizes the importance of short-term CT follow-up in subjects with localized GGOs.     

“One-stop-shop” staging: Should we prefer FDG-PET/CT or MRI for the detection of bone metastases?

Aim

The aim of this study was to compare the diagnostic accuracy of fully diagnostic, contrast-enhanced whole-body FDG-PET/CT and whole-body MRI for detection of bone metastases in patients suffering from newly diagnosed non-small cell lung cancer and malignant melanoma.

Material and Methods

109 consecutive non-small cell lung cancer (n = 54) and malignant melanoma (n = 55) patients underwent whole-body FDG-PET/CT and whole-body MRI for initial tumor staging. All images were evaluated by four experienced physicians (three radiologists, one nuclear medicine physician). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for detection of bone metastases were determined for both modalities. Statistically significant differences between FDG-PET/CT and MRI were calculated with Fisher's Exact test (p < 0.05). Clinical and imaging follow-up data with a mean follow-up time of 434 days served as the reference standard.

Results

According to the reference standard 11 patients (10%) suffered from bone metastases. The sensitivity, specificity, PPV, NPV, and accuracy for the detection of osseous metastases was 45%, 99%, 83%, 94%, and 94% with whole-body FDG-PET/CT and 64%, 94%, 54%, 96%, and 91% with whole-body MRI. The difference was not statistically significant (p = 0.6147).

Conclusions

FDG-PET/CT and MRI seem to be equally suitable for the detection of skeletal metastases in patients suffering from newly diagnosed non-small cell lung cancer and malignant melanoma. Both modalities go along with a substantial rate of false-negative findings requiring a close follow-up of patients who are staged free of bone metastases at initial staging.     

Does tumor type affect local control by radiofrequency ablation in the lungs?

Objective

: To retrospectively evaluate the effect of tumor type on local control by radiofrequency ablation in the lungs.

Materials and methods

: This study included 252 lung tumors (mean size, 13.5 mm) in 105 patients (73 men and 32 women; mean age, 66.6 years) who underwent radiofrequency ablation with a multitined expandable electrode. Those tumors comprised five tumor types: primary lung cancer (n = 35) and pulmonary metastases from colorectal cancer (n = 117), lung cancer (n = 23), renal cell carcinoma (n = 49), and hepatocellular carcinoma (n = 28). Local control was evaluated with contrast-enhanced computed tomography. The overall local control rates were estimated as well as those for each tumor type using the Kaplan-Meier analysis. Local control rates for a given tumor type were compared with those for the four other types. Then, multivariate multilevel analysis was performed using the variables of tumor type, tumor size, contact with a vessel or bronchus, and procedure period.

Results

: The overall local control rates were 97%, 86%, 81%, and 76% at 6, 12, 18, and 24 months, respectively. Local control rates varied among the tumor types, and metastatic colorectal cancer showed significantly (P = .023) higher local control rates than those of the four other types. However, multivariate analysis indicated that the relative risk of local progression for a given tumor type was comparable to the risks for the four other types.

Conclusion

: Tumor type per se did not significantly influence local control.     

Thin-section CT of the mediastinum in preoperative N-staging of non-small cell lung cancer: Comparison with FDG PET

Purpose

To compare diagnostic capability of preoperative N-staging of lung cancer between thin-section CT of the mediastinum and FDG PET, and 5 mm slice thickness CT.

Materials and methods

The subjects were 34 patients with lung carcinoma who were examined by both CT and PET, and subsequently underwent surgery between May 2005 and January 2007. CT was carried out with a 16 detector row helical CT scanner. The raw data were reconstructed into 5 mm slice thickness and 1 mm slice thickness (thin-section CT). A total of 251 lymph node stations were retrospectively assessed for the presence of lymph node metastasis with thin-section CT, 5 mm CT and PET. In the interpretations of thin-section CT and 5 mm CT, we employed multi-criteria as follows: nodular calcification and intranodal fat as benign criteria, and short-axis diameter more than 10 mm (size criterion), focal low density other than fat, surrounding fat infiltration and convex margin in hilar lymph nodes, as malignant criteria. On PET, maximum standardized uptake value (SUVmax) of 2.5 or more was used as the criterion of malignancy. Sensitivity and specificity were compared between these examinations using McNemar test.

Results

Sensitivities and specificities of thin-section CT, 5 mm CT and PET were 25%, 25%, 25%, and 97%, 94%, 98%, respectively. The statistical analysis revealed that the specificity of 5 mm CT was significantly lower than those of thin-section CT (p = 0.039) and PET (p = 0.006), while no difference was present between thin-section CT and PET.

Conclusion

Thin-section CT of the mediastinum using multiple criteria was comparable to PET in preoperative N-staging of lung cancer.     

Imaging features of portal biliopathy: frequency of involvement patterns with emphasis on MRCP

Purpose

To investigate the imaging features of portal biliopathy with emphasis on MR cholangiopancreatography (MRCP). The ancillary vascular findings of portal biliopathy were also evaluated by accompanying MR portography, dynamic contrast-enhanced (CE) CT, and dynamic CE MRI studies.

Materials and methods

Sixteen patients with portal cavernoma were included in the study. Patients had undergone MRCP (n = 16) studies accompanied by MR portography (n = 13), dynamic CE CT (n = 3) or dynamic CE MRI (n = 2) of the liver. Two patients had undergone both dynamic CE CT and dynamic CE MRI. Two radiologists evaluated all the examinations together, retrospectively. MRCP images were analyzed for the presence of biliary stenosis, upstream (prestenotic) dilatation, wavy appearance of the bile ducts, angulation of the common bile duct (CBD), and choledocholithiasis. MR portography, dynamic CE CT and dynamic CE MRI studies were evaluated for the existence of portal cavernomas, and the presence of gall bladder/choledochal varices.

Results

All patients had signs of portal biliopathy on MRCP. Frequencies of the biliary findings on MRCP were as follows: biliary stenosis, 93.7%; upstream dilatation, 68.7%; wavy appearance of the biliary tree, 87.5%; angulation of the CBD, 75%. None of the patients had choledocholithiasis. Frequencies of the ancillary vascular findings detected on CE studies were as follows: gall bladder varices, 100%, choledochal varices, 93.7%.

Conclusion

MRCP features of portal biliopathy in order to their frequencies were as follows: biliary stenosis, wavy appearance of the bile ducts, angulation of the CBD, and upstream dilatation of the bile ducts.     

Diagnostic performance of percutaneous core needle lung biopsy under multi-CT fluoroscopic guidance for ground-glass opacity pulmonary lesions

Objective

The diagnostic performance of percutaneous core needle lung biopsy under multi-CT fluoroscopic guidance for ground-glass opacity (GGO) pulmonary lesions was evaluated.

Materials and methods

Out of 90 patients who underwent CT fluoroscopy-guided core needle biopsy of GGO lesions at our institution, the biopsy results and the final diagnoses were retrospectively compared in 67 patients with available data (one lesion per patient). Diagnostic performance was also compared according to the lesion size (≤10 mm (n = 8) versus 11-20 mm (n = 42) versus >20 mm (n = 17)), the percentage of GGO component (50-90% (n = 31) versus >90% (n = 36)), and the length of needle path (≤7 cm (n = 45) versus >7 cm (n = 22)). Finally, all 90 cases were reviewed for complications.

Results

The overall sensitivity, specificity, and accuracy were 97%, 100%, and 97%, respectively. The diagnostic sensitivity and accuracy tended to be lower in smaller lesions (≤10 mm; 86 and 88%, 11-20 mm; 97 and 98%, >20 mm; 100 and 100%, respectively, p > 0.05), and in lesions with lower percentage of GGO component (50-90%; 93 and 94%, >90%; 100 and 100%, respectively, p = 0.21), but statistical significances were not reached. The sensitivity and accuracy were not significantly affected by the length of needle path (≤7 cm; 98 and 98%, >7 cm; 95 and 96%, respectively, p = 1.00). Fourteen patients (16%) developed pneumothoraces, and 13 patients (14%) experienced mild hemoptysis, all of which resolved conservatively.

Conclusion

The diagnostic performance was satisfactory, and it was considered that the procedure was appropriate for GGO lesions regardless of lesion size, the percentage of GGO component, or the length of needle path. The procedure was also feasible without any major complications.     

Sonography-guided positioning of intravenous long lines in neonates

Objective

In neonates, proper positioning of the tip of intravenous long lines (LL) is essential in order to prevent potential life-threatening complications. The gold standard for the evaluation of LL position in neonates is the chest X-ray with or without contrast.We performed a prospective study to assess the use of transthoracic ultrasonography (US) for the positioning of LL in neonates and to compare it to plain radiography.

Materials and method

Thirty-six consecutive neonates requiring percutaneous LL over a period of 3 months were included in the study. Immediately after LL insertion, the position of its tip was verified using transthoracic US, followed by plain radiography. The two techniques were compared in terms of adequate placement and length of time between insertion and radiographic evaluation of the correct position.

Results

The correlation between positioning by US and plain radiography was very good (r = 0.97, r² = 0.94, p < 0.0001). The time needed to verify LL placement by US was shorter by a mean 15 min compared to plain radiography.

Conclusion

US can accurately guide LL tip positioning. We believe that because of the potential gain of time it offers and its lack of ionising radiation, it to be considered as an interesting tool for the positioning of LL in neonates. Yet more accurate results could be obtained with a better-trained staff.     

Outcomes of patients with hepatocellular carcinoma referred for percutaneous radiofrequency ablation at a tertiary center: analysis focused on the feasibility with the use of ultrasonography guidance

Purpose

This study aimed to assess the feasibility of performing ultrasonography (US)-guided percutaneous radiofrequency (RF) ablation on patients with hepatocellular carcinoma (HCC) and identify causes of procedure infeasibility and its predisposing conditions.

Materials and methods

A total of 109 consecutive patients (male:female = 86:23; mean 59.9 years) with 136 HCCs (mean 1.8 cm) who had been referred for planning US were analyzed. We evaluated overall procedure feasibility as well as specific factors relating to feasibility, including inability to visualize the tumor with US and factors relating to safety of the procedure.

Results

The use of percutaneous RF ablation was concluded as infeasible for 45 tumors (33.1%). Reasons for infeasibility included tumor invisibility (n = 32), a high risk of collateral thermal injury (n = 5), absence of a safe electrode path (n = 5) and a combination of factors (n = 3). Among 136 tumors, 36(26.5%) were invisible due to isoechogenicity (n = 16), indiscrimination from surrounding cirrhotic nodules (n = 10) or an unfavorable location (n = 10). Tumor invisibility was significantly attributed to a small tumor size (P < 0.001, risk ratio = 0.823) and the presence of macronodular cirrhosis (P = 0.006, risk ratio = 4.117). Seven patients with invisible tumors were treated with RF ablation after follow-up (n = 4) or with use of adjacent structures as landmarks (n = 3). Ultimately, 65 of 109 patients were treated with percutaneous RF ablation.

Conclusions

US-guided percutaneous RF ablation for HCC was feasible in about two-thirds of candidates. Infeasibility was mostly due to inability to visualize the tumor with US, especially for patients with smaller tumor and macronodular cirrhosis.     

Macrocystic pancreatic lesions: differentiation of benign from premalignant and malignant cysts by CT

Objective

To assess useful CT features for differentiating benign from premalignant and malignant macrocystic pancreatic lesions.

Methods

Seventy-four patients with pathologically proven macrocystic pancreatic lesions were enrolled: 17 benign cysts (macrocystic serous cystadenoma, n = 12; congenital cyst; n = 5) and 57 premalignant and malignant cysts (mucinous cystic neoplasm, n = 28; intraductal papillary mucinous neoplasm of branch duct type, n = 20; tumor with cystic change, n = 9). Size, location, shape (lobulated, round or oval, or complex cystic with tubular cyst), wall thickness (thin, ≤1 mm; thick, >1 mm), internal surface (smooth or irregular), and other findings were analyzed with multiphasic CT with thin-section (2.5-3 mm) images. CT features between two groups were compared using univariate and multivariate stepwise logistic regression analyses.

Results

On univariate analysis, the differences for the shape (p = 0.007), wall thickness (p = 0.011), and internal surface (p = 0.012) between benign and premalignant and malignant cysts were significant. A lobulated shape, a thin wall and a smooth internal surface were more frequent in benign cysts, whereas a round or oval shape or a complex cystic shape with tubular cyst, a thick wall and an irregular internal surface were more frequent in premalignant and malignant cysts. On multivariate analysis, the shape (p = 0.002) and wall thickness (p = 0.025) were significant CT features for differentiating benign from premalignant and malignant cysts.

Conclusion

Shape and wall thickness are the main CT features for differentiating benign from premalignant and malignant macrocystic pancreatic lesions.     

Diagnostic performance of radiographers as compared to radiologists in magnetic resonance colonography

Purpose

To evaluate the diagnostic performance of radiographers compared to radiologists in the detection of colorectal lesions in MR colonography.

Material and methods

159 patients at increased risk of colorectal cancer were included. Four different experienced observers, one MR radiologist, one radiologist in training and two radiographers evaluated all MR colonography examinations. The protocol included T1-weighted and T2-weighted sequences in prone and supine position. Colonoscopy was used as reference standard. Mean sensitivity rates with 95% confidence intervals (CIs) were determined on a per-patient and per-polyp basis, segmented by size (≥6 mm and ≥10 mm). Specificity was calculated on a per-patient basis. The McNemar and chi-square (χ²) test was used to determine significant differences.

Results

At colonoscopy 74 patients (47%) had normal findings; 23 patients had 40 polyps with a size ≥6 mm. In 10 patients at least 1 polyp ≥10 mm was found (20 polyps in total). Similar sensitivities for patients with lesions ≥10 mm were found for radiologists and radiographers (65% (95%CI: 44-86%) vs. 50% (95%CI: 28-72%)) (p = n.s.). For lesions ≥10 mm combined per-patient specificity for radiologists and radiographers was 96% (95%CI: 94-98%) and 73% (95%CI: 68-79%) (p < 0.0001). Combined per-patient sensitivity for lesions ≥6 mm differed significantly between both groups of observers (57% (95%CI: 42-71%) vs. 33% (95%CI: 19-46%)) (p = 0.03).

Conclusion

Radiographers have comparable sensitivity but lower specificity relative to radiologists in the detection of colorectal lesions ≥10 mm at MR colonography. Adequate training in evaluating MR colonography is necessary, especially for readers with no prior experience with colonography.     

Change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy: an early predictor of final treatment response

Background

The purpose of this study was to evaluate the change in contrast enhancement of HCC on 1-month follow-up CT after local radiotherapy (RT) as an early predictor of final treatment response.

Materials

Fifty patients who underwent local RT for HCCs had both pre-RT and post-RT CT scans including 1-month follow-up CT. We assessed the final treatment response by using the change in maximal tumor size on 6-12-month follow-up CT scan after RT. We also evaluated the change in tumor enhancement between pre-RT and 1-month follow-up CT scans.

Results

A final treatment response was achieved in 27 (54%) of 50 patients, who showed either a complete response (n = 11) or a partial response (n = 16). Compared with non-responsive patients (n = 23), responsive patients showed a significant decrease in tumor enhancement on 1-month follow-up CT after RT in both objective and subjective analyses (each P < 0.001).

Conclusion

The change in contrast enhancement of HCC seen on the 1-month follow-up CT in patients after local RT may be used as an early predictor of final treatment response.     

Previous imaging findings of breast cancers that occurred in combined screening negatives

Purpose

To retrospectively evaluate previous imaging findings of breast cancers that occurred in women whose combined screening using both mammography and ultrasonography was negative.

Materials and methods

A search of the institutional database identified 65 patients with breast cancers who had comparable previous negative screening mammography and ultrasonography (BI-RADS category 1 or 2) within 2 years. We classified each case as true or false negative. The previous imaging findings and the final outcome were analyzed.

Results

Among 65 cases, 42 (65%) were true negatives, 23 (35%) were false negatives. The abnormalities of false negatives were underestimated in 16 (70%) and unrecognized in 7 (30%). The findings were calcifications (n = 8) or a mass (n = 6) on mammography, a mass (n = 5) or a non-mass (n = 3) on ultrasonography and a density on mammography correlated with non-mass on ultrasonography (n = 1). Ductal carcinoma in situ among false and true negatives accounted for 5 (22%) and 7 (17%), respectively. Symptomatic cancers among false and true negatives were 6 (26%) and 13 (31%), respectively.

Conclusion

Breast cancers that rarely occurred in combined screening negatives are often retrospectively seen as minimal abnormalities on previous imaging studies.