Comparison of readers' detection of right-sided and left-sided breast cancers and microcalcifications.

INTRODUCTION: Aim of this study was to determine if there is a statistically and clinically significant difference in diagnostic performance (cancer diagnosis) and perceptual performance (microcalcification detection) when detecting left-sided or right-sided breast cancers and microcalcifications. METHODS: Eight radiologist readers (8-20 years experience in radiology, five current BreastScreen readers) read a set of 100 digital mammograms (23/100 had proven malignancies and 52/100 had confirmed microcalcifications) for three reads (random case order in each read). The same mammograms were presented on two reads, serving as the baseline reads. The data from these reads were used to calculate intra-observer variability (presented in an earlier study). The experimental read consisted of left-right mirror images of the original mammograms. In each read, the radiologists were requested to 'clear' or 'call-back' cases and to indicate if any microcalcifications (benign and malignant) were present on the mammograms. Reading conditions were standardised. RESULTS: Comparison of intra-reader performance difference for left-sided versus right-sided breast cancers and microcalcifications with intra-observer variability for breast cancer diagnosis and microcalcification detection, respectively, revealed no clinically significant difference between left-sided and right-sided detections. Per-case analysis showed more left-sided breast cancers and microcalcifications correctly detected. This left-right difference in detection did not reach statistical significance, P-value of 0.28 for cancer diagnosis and 0.74 for microcalcification detection. CONCLUSION: There is no statistically or clinically significant difference between left-sided and right-sided breast cancer diagnosis and microcalcification detection in a group of experienced radiologists. Individual reading patterns do not affect detection rates of left-sided and right-sided cancers and microcalcifications.

Reproducibility of "intelligent" contouring of gross tumor volume in non-small-cell lung cancer on PET/CT images using a standardized visual method.

PURPOSE: Positron emission tomography/computed tomography (PET/CT) is increasingly used for delineating gross tumor volume (GTV) in non-small-cell lung cancer (NSCLC). The methodology for contouring tumor margins remains controversial. We developed a rigorous visual protocol for contouring GTV that uses all available clinical information and studied its reproducibility in patients from a prospective PET/CT planning trial. METHODS AND MATERIALS: Planning PET/CT scans from 6 consecutive patients were selected. Six "observers" (two radiation oncologists, two nuclear medicine physicians, and two radiologists) contoured GTVs for each patient using a predefined protocol and subsequently recontoured 2 patients. For the estimated GTVs and axial distances, least-squares means for each observer and for each case were calculated and compared, using the F test and pairwise t-tests. In five cases, tumor margins were also autocontoured using standardized uptake value (SUV) cutoffs of 2.5 and 3.5 and 40% SUV(max). RESULTS: The magnitude of variation between observers was small relative to the mean (coefficient of variation [CV] = 3%), and the total variation (intraclass correlation coefficient [ICC] = 3%). For estimation of superior/inferior (SI), left/right (LR), and anterior/posterior (AP) borders of the GTV, differences between observers were also small (AP, CV = 2%, ICC = 0.4%; LR, CV = 6%, ICC = 2%; SI, CV 4%, ICC = 2%). GTVs autocontoured generated using SUV 2.5, 3.5, and 40% SUV(max) differed widely in each case. An SUV contour of 2.5 was most closely correlated with the mean GTV defined by the human observers. CONCLUSIONS: Observer variation contributed little to total variation in the GTV and axial distances. A visual contouring protocol gave reproducible results for contouring GTV in NSCLC.

Magnetic resonance colonography for colorectal cancer screening in patients with Lynch syndrome gene mutation.

Lynch syndrome gene carriers have a 50-80% risk of colorectal cancer (CRC). Current guidelines recommend yearly colonoscopy, with associated procedure-related risks. Magnetic resonance colonography (MRC) was evaluated as a non-invasive alternative for CRC screening in this high-risk population. Adult Lynch syndrome gene carriers underwent both screening procedures on the same day. MRI radiologists read the scans and rated image quality. Endoscopists performed colonoscopy unaware of MRC findings until after procedure completion. If lesions were detected, their number, size and location were noted. Post-procedure, patients compared discomfort and inconvenience of MRC and colonoscopy on a visual analogue scale. Thirty patients were recruited. 83% of the MRC scans were of adequate to good quality. MRC detected three lesions in three patients (70, 36, 17 mm). All 3 were independently detected on colonoscopy, excised and found to be CRC. MRC failed to detect a 3 mm CRC found on colonoscopy. CRC prevalence was 13%. Colonoscopy detected a further 30 polyps, all <10 mm. Of these, 17 were hyperplastic polyps and 10 normal mucosa. Colonoscopy had a false positive rate of 32% as defined by histology. MRC failed to detect any polyp <10 mm. Mean patient discomfort scores were 20% for MRC and 68% for colonoscopy, P = 0.003. Mean patient inconvenience scores were 54% for MRC and 52% for colonoscopy, P = 0.931. MRC was reliable in detecting large polyps, potentially CRC. However MRC currently has poor sensitivity in detecting small polyps, limiting its utility in adenoma screening at this time. MRC was associated with less discomfort than CC.

[Preliminary result of dynamic contrast-enhanced MR imaging in assessment of cellularity characteristics of bone marrow in patients with haematological malignancies].

OBJECTIVE: To evaluate the correlation of bone marrow status in haemotological malignancy patient with the variable value of dynamic contrast-enhanced MR (DCE-MRI). METHODS: DCE-MRI result were obtained from 25 patients with pathologically proven haematological malignancies. Time-signal intensity curves (TIC) was generated from the region of the iliac crest corresponding to the planned biopsy site. Enhancement characteristics including peak enhance ratio (PER) , maximum slope (Slopemax), time to peak ( TP) and mean time (MT) were analyzed. The patients received bone marrow biopsy on the crest 30 min after DCE-MRI, and then the parameters of bone marrow histology including cellularity was analyzed. RESULTS: In this series, 3 patients showed type B TIC, 7 type C, 13 type D and 2 type E. The bone marrow cellularity with haematological malignancies cannot be demostrated by TIC type. The mean PER value and Slopemax value in the patients with hypercellularity was significantly higher than that with normal cellularity and hypocellularity. The mean TTP value of the patients with hypercellularity (60.20 +/- 61.62) was significantly lower than that in the patients with hypocellularity (97.43 +/- 1.07) or normal cellularity (78.44 +/- 38.02). There was no significant difference in the mean MT value among three groups. CONCLUSION: Our preliminary findings suggest that the bone marrow cellularity in the patient with haematological malignancies can not be revealed by conventional MR, but it may be demonstrated by semi-quantitative calculation of the variable value from DCE-MR imaging.

Tumor infiltration of bone marrow in patients with hemato-logical malignancies: dynamic contrast-enhanced magnetic resonance imaging.

BACKGROUND: Conventional magnetic resonance (MR) scanning techniques can identify bone marrow (BM) containing mostly fat cells. But they are not able to differentiate BM tumor infiltration, BM fibrosis and normal red BM. This is particularly problematic in assessment of recurrent or refractory hematological malignancy. This pilot study used dynamic contrast-enhanced MR imaging (DCE-MRI) to evaluate the bone marrow status and to determine whether several calculated parameters derived from the DCE-MRI correlate with histological characteristics of marrow, especially with the tumor fraction (TF). METHODS: DCE-MRI scans were performed in 25 patients with proven or known hematological malignancy who were about to undergo bone marrow biopsy of the posterior iliac crest. The location chosen for biopsy was examined with MRI approximately one hour prior to the biopsy. Time-signal intensity curves (TIC) were generated from the region of the iliac crest corresponding to the planned biopsy site. Enhancement parameters were calculated, including peak enhancement ratio (PER), maximum enhancement slope (Slope(max)), time to peak (TTP) and mean time (MT). The biopsy specimen was reported synoptically, with relevant reported parameters including cellularity and tumor fraction (TF). RESULTS: PER values were significantly higher for the bone marrow tumor infiltration group than for the normal bone marrow group (P < 0.05). A significant positive correlation was found between PER and TF as well as Slope(max) and TF. A negative correlation was found between TTP and TF. There was no significant difference in the mean TTP and MT values between the BM tumor infiltration group and the normal bone marrow group. CONCLUSIONS: The presence of diffuse bone marrow infiltration in patients with haematological malignancies could be verified using DCE-MRI.

Myocardial perfusion imaging - a validated and mature cardiac imaging modality.

BACKGROUND: Nuclear myocardial perfusion imaging (MPI) involves the use of radiotracers to generate scintigraphic images of the myocardium. It is the best validated and most standardised of all cardiac imaging modalities, demonstrating regional perfusion ventricular wall motion and accurately calculating reproducible left ventricular ejection fraction. Physiological or pharmacological stress can be used to uncover myocardial ischaemia. OBJECTIVE: This article provides an update on the use of MPI for the triaging of chest pain, monitoring of known ischaemic heart disease, and cardiac event prediction in the general practice setting. DISCUSSION: A normal stress MPI study is an unambiguous outcome. A perfusion defect on a stress MPI study may be produced by stress ischaemia, stable infarction, hibernating myocardium, or by a variable mixture of all three. Patient access to nuclear MPI is good with most nuclear medicine departments offering nuclear cardiology services. Nuclear cardiology is safe and reliable, and deserves to be a part of the routine diagnostic armamentarium in general practice.

Chondrosarcoma of bone complicating Ollier's disease: report of a favourable response to radiotherapy.

Because chondrosarcoma of bone is traditionally thought to be a radioresistant malignancy, it is usually managed surgically. We report a case of multifocal chondrosarcoma arising in Ollier's disease for which the patient declined surgery. He was given a course of radical radiotherapy that resulted in symptom palliation and a radiologically confirmed response before he died of disseminated disease. In patients with inoperable chondrosarcoma, radiotherapy can provide palliative benefit.

Inadvertent 2-deoxy-2-[18F]fluoro-D-glucose lymphoscintigraphy: a potential pitfall characterized by hybrid PET-CT.

PURPOSE: To communicate an important pitfall in positron emission tomography (PET) oncologic staging using 2-deoxy-2-[18F]fluoro-D-glucose (FDG). PROCEDURE: A 60-year-old man with a right upper lobe bronchogenic carcinoma was injected with FDG through a cannula in his left cubital fossa, with a small amount of the dose extravasating. RESULTS: Images obtained one hour post-injection with a positron emission tomography-computerized tomography (PET-CT) scanner demonstrated linear FDG activity running with the left arm brachial vascular bundle and along collateral channels, and accumulation of FDG in a low left axillary lymph node of normal size and CT appearance. CONCLUSIONS: Following inadvertent extravasation, FDG appears to accumulate in regional lymph nodes in the same fashion as bone scanning agents or lymphoscintigraphy colloid. Physicians and technologists need to be aware of this important pitfall in order to avoid the false positive diagnosis of nodal metastases. The ability of PET to demonstrate lymphatics and lymph nodes indicates its possible future use in lymphoscintigraphy.