Contrast Enhanced CT Radiogenomics in a Retrospective NSCLC Cohort: Models, Attempted Validation of a Published Model and the Relevance of the Clinical Context.

RATIONALE AND OBJECTIVE: To develop a radiogenomic predictive model for non-small cell lung cancer (NSCLC) patients studied through contrast enhanced chest computed tomography (CE-CT) targeting the most frequent gene alterations. M&M: A retrospective study of patients with NSCLC imaged with CE-CT before treatment and had their tumor genomics sequenced at our institution was performed. Data was gathered from their imaging studies, their electronic medical records and a web-based database search (cBioPortal.ca). All of the patient data was tabulated for analysis. Two predictive models (M1 & M2) were created using different approaches and a third model was extracted from the literature to also be tested in our population. RESULTS: Out of 157 patients, eighty were male (51%) and 124 (79%) had a history of smoking. The three most prevalent genes were KRAS, TP53 and EGFR. The M1 radiomics-only model median AUC were 0.61 (TP53), 0.53 (KRAS) and 0.64 (EGFR) and for M1 radiomics + clinical were 0.61 (TP53), 0.61 (KRAS) and 0.80 (EGFR). The M2 radiomics-only model median AUC were 0.63 (TP53), 0.60 (KRAS) and 0.65 (EGFR) and for M2 radiomics + clinical were 0.64 (TP53), 0.62 (KRAS) and 0.81 (EGFR). The external EGFR radiomic model showed an AUC of 0.69 and 0.86 for the radiomics-only and combined radiomics + clinical respectively. CONCLUSION: Our study was able to provide robust predictive radiomics model evaluation for the detection of TP53, KRAS and EGFR. We also compared our performance with an already published model and observed how impactful clinical variables can be on models' performance. CLINICAL RELEVANCE STATEMENT: Identifying tumor mutations in patients that can't undergo biopsy is critical for their outcomes. KEYPOINTS: • Tumor genomic profiling is critical for treatment selection • CE-CT radiomics produce robust predictive models comparable to those already published • Clinical variables should be considered/included in predictive models.

18F-fluorocholine PET/MRI versus ultrasound and sestamibi for the localization of parathyroid adenomas.

PURPOSE: Accurate preoperative localization is imperative to facilitate a minimally invasive parathyroidectomy (MIP) in primary hyperparathyroidism (pHPT). This study aims to compare the diagnostic value of standard-of-care localization techniques (ultrasound [US] and 99mTechnetium (99mTc) -sestamibi scintigraphy) to [F-18]-fluorocholine positron emission tomography/magnetic resonance imaging (FCH-PET/MRI) to determine the additional clinical usefulness of PET/MRI in a Canadian cohort. METHODS: We conducted a prospective, appropriately powered, study to compare the diagnostic value of -FCH PET/MRI to that of the US and 99mTc-sestamibi scintigraphy for localization of parathyroid adenomas in a patient with pHPT. The primary outcome was the per-lesion sensitivity and positive predictive value (PPV) of FCH-PET/MRI, US, and 99mTc-sestamibi scintigraphy. Intraoperative surgeon localization, parathormone levels, and histopathological findings were used as reference standards. RESULTS: Forty-one patients underwent FCH-PET/MRI of which 36 patients had parathyroidectomy. In these 36 patients, 41 parathyroid lesions were histologically confirmed as adenomas or hyperplastic glands. Per-lesion sensitivity of FCH-PET/MRI was 82.9% and of US and 99mTc-sestamibi scintigraphy combined at 50.0%, respectively. The sensitivity of FCH-PET/MRI was superior to that of US and 99mTc-sestamibi scintigraphy (p = 0.002). In the 19 patients in whom both US and 99mTc-sestamibi scintigraphy were negative, PET/MRI correctly identified the parathyroid adenoma in 13 patients (68%). CONCLUSIONS: FCH-PET/MRI is a highly accurate imaging modality for localization of parathyroid adenomas in a tertiary center in North America. It is a superior functional imaging modality to 99mTc-sestamibi scintigraphy alone and more sensitive for localization of parathyroid lesions than US and 99mTc-sestamibi scintigraphy combined. This imaging modality could become the most valuable preoperative localization study given its superior performance in localizing parathyroid adenomas.

18 F-Fluorodeoxyglucose positron-emission tomography for the investigation of malignancy in patients with suspected paraneoplastic neurologic syndromes and negative or indeterminate conventional imaging: a retrospective analysis of the Ontario PET Access Program, with systematic review and meta-analysis.

Objective: Paraneoplastic neurologic syndrome (pns) is a rare condition indirectly caused by an underlying malignancy. In many cases, the malignancy is occult at the time of the pns diagnosis, and the optimal diagnostic modality to detect the underlying tumour is unclear. In the present study, we aimed to assess the utility of 18F-fluorodeoxyglucose positron-emission tomography (fdg-pet) or pet integrated with computed tomography (pet/ct) in the investigation of these patients. Methods: We retrospectively analyzed data from the PET Access Program (pap) database in the province of Ontario to identify patients who underwent fdg-pet/ct imaging as part of a workup for pns. In all patients, prior conventional imaging was negative or indeterminate. To determine the diagnostic accuracy of fdg-pet/ct, data about demographics, presenting symptoms, and biochemical and radiologic workup, including fdg-pet/ct imaging results, were compared with data collected by the Ontario Cancer Registry (ocr). A systematic review of the literature and meta-analysis using our study inclusion criteria were performed for studies of fdg-pet accuracy. Results: Of 29 patients identified in the pap database, 9 had fdg-pet/ct results suspicious for malignancy. When correlated with data from the ocr, 5 fdg-pet/ct results were informative, resulting in a detection rate of 17%. Local sensitivity and specificity were 0.83 and 0.83 respectively. Two studies meeting our criteria were identified in the literature. The pooled sensitivity and specificity from the literature and local data were 0.88 and 0.90 respectively. Conclusions: When investigating for underlying malignancy in patients with suspected pns and negative conventional imaging, pet has high sensitivity and specificity.

Detection of extra-regional tumour recurrence with 18F-FDG-PET/CT in patients with recurrent gynaecological malignancies being considered for radical salvage surgery.

AIM: To compare the detection rate of extra-regional metastases in patients with recurrent gynaecological malignancies being considered for radical salvage surgery with combined 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) positron-emission tomography (PET)/computed tomography (CT) compared to conventional imaging. MATERIALS AND METHODS: A retrospective review was performed of all patients in a provincial database with recurrent gynaecological malignancies being considered for pelvic exenteration that underwent restaging with CT/PET between March 2011 and October 2014. Findings on PET and conventional imaging (CT±pelvic MRI) were abstracted. Disease sites were classified according to the location (regional nodal metastases, extra-regional nodal metastases, peritoneum, or other distant sites) and diagnostic certainty (definitive or equivocal). The proportion of patients positive for extra-regional recurrence was calculated for PET and conventional imaging. In addition, the proportion of patients with indeterminate lesions only was calculated for each modality and the sites of indeterminate findings were tabulated. RESULTS: There were 85 patients (median age, 50 years; range: 30-81 years) with carcinoma of cervix (n=51), endometrium (n=18), vagina (n=6), or vulva (n=10). Extra-regional recurrence was detected in 8/85 (9.4%) and 24/85 (28.2%) patients on conventional imaging and PET, respectively (p=0.0017). The greatest impact of PET compared to conventional imaging was in the detection of extra-regional nodal metastases. PET had significantly fewer examinations equivocal for extra-regional recurrence versus conventional imaging (6/85 [7.1%] and 38/85 [44.7%], respectively, p<0.001). CONCLUSION: In patients with recurrent gynaecological malignancies being considered for radical salvage surgery, PET may identify significantly more extra-regional recurrence than conventional imaging. PET may also result in fewer equivocal lesions. The impact of these results on patient management and outcome should be confirmed in future prospective trials.

Pilot study on 18 F-FDG PET/CT for detection of inflammatory changes in blood-induced knee arthropathy in a rabbit model.

RATIONALE: 18 F-FDG-PET/CT has a potential role in the early detection of haemophilic arthritis, at a time when treatment may still avoid further joint degeneration. The purposes of this pilot study were to determine the ability of 18 F-FDG-PET/CT to detect inflammatory changes associated with blood-induced arthropathy in knees of a rabbit model. METHODS: Ten juvenile rabbits were imaged at baseline and weeks 5 and 17 post intraarticular autologous blood injections (ABI). Five rabbits in group 1 (G1) had ABI into the same knee joint every 2 weeks (total, eight injections). Five rabbits in group 2 (G2) had only two injections into the same knee, at weeks 5 and 17. Images were assessed visually and semi-quantitatively by measuring maximal standardized uptake values (SUVmax) and standardized uptake ratio (SUR = SUVmax in affected knee/SUVmax in non-affected knee). RESULTS: More rabbits in G1 than G2 presented with positive chronic inflammatory synovial scores at week 17. Mean iron staining scores in injected knees were greater for G1 than for G2 (P = 0.049). No increased uptake was identified in the injected knees in any of the rabbits at baseline or at week 5. At week 17, all G1 rabbits demonstrated increased uptake in their affected knees with higher mean SUVmax (1.5) than normal knees (1.0) (P < 0.02). None of the G2 rabbits showed asymmetric increased uptake. The SUR of G1 was higher at week 17 compared to baseline (P < 0.01) and week 5 (P < 0.01). The SUR at week 17 was higher for G1 than for G2 (1.13) rabbits (P < 0.01). CONCLUSION: 18 F-FDG-PET is able to detect the inflammatory changes associated with haemophilic arthropathy in this experimental model.

Intraoperative lymph node evaluation using 18F-FDG and a hand-held gamma probe in endometrial cancer surgery--a pilot study.

PURPOSE: The purpose of this pilot study was to assess feasibility, safety, and accuracy of detection of metastatic nodes intraoperatively with a hand-held gamma (PET) probe after administration of 18F-FDG in patients with high risk endometrial cancer (EC). MATERIALS AND METHODS: This is a prospective, cohort study. Twenty-two patients with clinical Stage I or II EC with high-risk histologic subtypes who were candidates for open surgical intervention were screened for the study. After screening, there were seven study patients (mean age: 64; range: 53-77) who were eligible for the study. In the entire cohort, there were 61 nodal stations that were assessed with a gamma counter intraoperatively, in vivo and again after removal of the node. All adverse events were recorded and operating room staff was monitored for radiation exposure. Resected nodes underwent histological assessment as per routine clinical practice. RESULTS: Range of maximal counts per second recorded in vivo and ex vivo were 0-86 and 0-17, respectively. Of all the nodes examined, one node was positive for metastatic disease; however, intraoperatively the lymph node readings were not higher than other lymph node basins assessed in same patient. No adverse events were recorded. The surgeons recorded the maximum average radiation exposure of all healthcare personnel with an average exposure of 0.08 mSV per case (range, 0.06-0.15). CONCLUSION: Use of hand-held gamma probe for intraoperative staging of patients with high risk EC is feasible, safe, and radiation exposure levels for all members of the healthcare team were within radiation safety guidelines. However, its use for detection of lymph node metastases needs further evaluation.

Follow-up for cervical cancer: a Program in Evidence-Based Care systematic review and clinical practice guideline update.

BACKGROUND: In 2009, the Program in Evidence-based Care (pebc) of Cancer Care Ontario published a guideline on the follow-up of cervical cancer. In 2014, the pebc undertook an update of the systematic review and clinical practice guideline for women in this target population. METHODS: The literature from 2007 to August 2014 was searched using medline and embase [extended to 2000 for studies of human papillomavirus (hpv) dna testing]. Outcomes of interest were measures of survival, diagnostic accuracy, and quality of life. A working group evaluated the need for changes to the earlier guidelines and incorporated comments and feedback from internal and external reviewers. RESULTS: One systematic review and six individual studies were included. The working group concluded that the new evidence did not warrant changes to the 2009 recommendations, although hpv dna testing was added as a potentially more sensitive method of detecting recurrence in patients treated with radiotherapy. Comments from internal and external reviewers were incorporated. RECOMMENDATIONS SUMMARY: Follow-up care after primary treatment should be conducted and coordinated by a physician experienced in the surveillance of cancer patients. A reasonable follow-up strategy involves visits every 3-4 months within the first 2 years, and every 6-12 months during years 3-5. Visits should include a patient history and complete physical examination, with elicitation of relevant symptoms. Vaginal vault cytology examination should not be performed more frequently than annually. Combined positron-emission tomography and computed tomography, other imaging, and biomarker evaluation are not advocated; hpv dna testing could be useful as a method of detection of recurrence after radiotherapy. General recommendations for follow-up after 5 years are also provided.

Impact of (18)F-FDG PET/CT on the staging and management of follicular lymphoma.

Follicular lymphoma (FL) is the most common indolent lymphoma. Despite the evidence-based utilization of fluorine-18 fludeoxyglucose positron emission tomography ((18)F-FDG PET)/CT in aggressive lymphomas, the utility of PET in FL remains controversial and varies across different jurisdictions. The management of patients with FL differs from aggressive lymphomas and is usually reserved for patients with localized disease in whom long-term control may potentially be achieved by involved field radiotherapy, or for symptomatic patients with advanced-stage disease in whom systemic therapy is indicated. There is a growing body of literature supporting the use of PET/CT in initial staging of FL to guide management decisions. In this review, we summarize the existing literature and present cases from our experience to illustrate current knowledge on the potential role of (18)F-FDG PET/CT in FL.

Non-cutaneous melanoma: is there a role for (18)F-FDG PET-CT?

Non-cutaneous melanomas (NCM) are diverse and relatively uncommon. They often differ from cutaneous melanomas in their epidemiology, genetic profile and biological behaviour. Despite the growing body of evidence regarding the utility of positron emission tomography (PET)/CT in cutaneous melanoma, the data on its use in NCM are scarce. In this review, we will summarize the existing literature and present cases from our experience with NCM to illustrate current knowledge on the potential role and limitations of fluorine-18 fludeoxyglucose PET/CT in NCM.

Degree of tumor shrinkage following neoadjuvant chemoradiotherapy: a potential predictor for complete pathological response in esophageal cancer?

Neoadjuvant chemoradiotherapy (CRT) before surgery results in a pathological complete response (pCR) rate in about 1/3 of the patients, which is correlated with survival. It was hypothesized that volumetric tumor response to CRT would correlate with outcomes. Patients who completed trimodality therapy, where planning, pre-, and post-CRT computed tomography scans were available, and pathology was reviewed by a central pathologist, were eligible for analysis. Absolute and relative tumor volume change pretreatment and post-treatment were correlated with pCR, locoregional recurrence (LRR), disease-free survival, and overall survival. Fifty-six patients were analyzed. pCR was observed in 30% of patients. Median follow up was 20.3 (range 4-89) months. The 2- and 4-year overall survival was 61.3% (95% confidence interval [CI]: 45-74) and 25.0% (95%CI: 11-41); proportion disease free was 32.1% (95% CI: 19-46) and 20.6% (9-36) at 2 and 4 years, respectively. The median relative volume reduction was 17% (95% CI: -24, -3%). Using 20% as the criteria, the proportion of patients with pCR of ≥20% versus <20% was 13/25 (52%) versus 4/31 (13%) for those who did not (odds ratio 7.3; 95% CI: 2-27). The LRR at 2 and 4 years were 29.5% (95% CI: 16-43) and 36.2% (95% CI: 23-50). The relative tumor reduction ≥20% was significantly correlated with LRR (hazard ratio 0.24; 95% CI: 0.07-0.8; p 0.02) at 2 and 4 years, respectively. Relative tumor volume reduction following CRT is correlated with pCR and LRR. Further investigations are warranted to examine the effect of volume change, alone or in conjunction with other factors as potential predictors for pathological response.

Lymphoscintigraphy for sentinel node mapping using a hybrid single photon emission CT (SPECT)/CT system in oral cavity squamous cell carcinoma.

BACKGROUND: We assessed the added clinical value of fused single photon emission computed tomography (SPECT) and low-dose CT images compared with planar images for sentinel node (SN) mapping in patients with oral cavity squamous cell carcinoma (SCC). METHODS: Twenty consecutive patients with newly diagnosed biopsy-proven SCC of the oral cavity were enrolled. Scintigraphy was performed using a hybrid gamma-camera/low-dose CT system. Planar images and fused SPECT/CT images were interpreted separately. All patients underwent a sentinel node biopsy (SNB) followed by a neck dissection. All SNs underwent meticulous pathologic examination and immunohistochemistry staining (cytokeratin complex) in addition to routine pathologic examinations of the neck dissection specimen. RESULTS: The sensitivity for the detection of nodal metastases was 87.5%. SPECT/CT improved SN identification and/or localization compared with planar images in 6 patients (30%). CONCLUSIONS: SPECT/CT SN mapping provides additional preoperative data of clinical relevance to SNB in patients with oral cavity SCC.

PET-CT findings in surgically transposed ovaries.

The aim of this study is to present the PET/CT findings of surgically transposed ovaries. PET/CT studies and associated abdominal imaging studies of seven women, aged 28-43 years, with 11 transposed ovaries were retrospectively reviewed. Attention was directed to the location and the 18F-Fluorodeoxyglucose (FDG) avidity of the transposed ovaries. On the CT part of the PET/CT, location of the transposed ovaries was in the ipsilateral iliac fossa or paracolic gutter abutting the anterior aspect of the ipsilateral colon (n = 6), posterolateral to the cecum (n = 4) and in the anterior abdominal cavity (n = 1). Ovaries were of soft-tissue density (n = 10 with a hypodense region in two) and one was cystic. In three patients, the transposed ovary was associated with increased FDG uptake with standard uptake values ranging from 2.4 to 4.8. Two of the latter patients had more than one PET/CT study. FDG uptake altered between studies, probably related to the performance of the study on different phases of the cycle. Menstrual history in one of the patients confirmed that the study was performed at the ovulatory-phase of the cycle. To conclude, a transposed ovary may appear on a PET-CT study as a mass with occasionally increased FDG uptake that may be related to its preserved functionality. Physicians interpreting PET/CT should be aware of surgically transposed ovaries in young female patients to avoid misdiagnosing it as tumour.

Mesenteric panniculitis in oncologic patients: PET-CT findings.

The aim of this study is to assess the role of PET/CT in differentiating between mesenteric panniculitis (MP) and co-existing MP and mesenteric tumoural involvement. A total of 33 PET/CT examinations, of 19 oncologic patients (16 men and three women with ages ranging from 48 years to 83 years) with findings of MP on the CT part of the study were retrospectively reviewed. The FDG uptake in mesenteric nodules was recorded. The final diagnosis of malignant mesenteric involvement was based on clinical and imaging follow-up. Based on the FDG uptake in mesenteric nodules, patients were categorized as group A: increased mesenteric uptake (n=8) and group B: no mesenteric uptake (n=11). In seven of the eight patients in group A, a co-existing MP and mesenteric tumour involvement was found: one patient had a recurrent cervical carcinoma and the other six patients had lymphoma. In four of these six patients, the positive PET findings disappeared on follow-up PET/CT with complete remission while the CT findings of the MP remained unchanged. In the other two, the PET findings progressed along with clinical deterioration. In the last patient of group A, with rectal carcinoma without evidence of recurrence, the mesenteric FDG uptake was a false positive uptake. In all 11 patients with CT findings of MP and negative PET, no malignant involvement of the mesentery was diagnosed. To conclude, a negative PET has a high diagnostic accuracy in excluding tumoural mesenteric involvement while increased uptake suggests the co-existing of mesenteric deposits, particularly in patients with lymphoma.

Lymphoscintigraphic sentinel node identification in patients with breast cancer: the role of SPECT-CT.

PURPOSE: Lymph node status is a major factor in determining the stage, appropriate therapy and outcome in patients with breast cancer. It is therefore of clinical importance to accurately identify all sentinel nodes (SNs) for each individual tumour before surgery. The purpose of this study was to assess the role of SPECT-CT lymphoscintigraphy in SN identification in patients with breast cancer. METHODS: Lymphoscintigraphy comprising planar and SPECT-CT acquisition was performed in 157 consecutive patients with breast cancer (mean age 54.7+/-10.6, range 27-81 years) with a palpable mass (n=100), with a non-palpable mass (n=52) or post lumpectomy (n=5). Planar and SPECT-CT images were interpreted separately and the two imaging techniques were compared with respect to their ability to identify hot nodes. RESULTS: Planar imaging alone was negative for identification of hot nodes in 15% of the patients. SPECT-CT alone was negative in 10% and both techniques were negative in 9% of the patients. Forty-six of the total of 361 (13%) hot nodes identified by lymphoscintigraphy were detected only on SPECT-CT, including 21 nodes obscured by the scattered radiation from the injection site, nine adjacent nodes misinterpreted on planar images as a single node and 16 nodes which were missed on planar images and detected on SPECT data. SPECT-CT detected additional sites of drainage unexpected on planar images, including axillary (n=23 patients), internal mammary (n=5 patients), interpectoral (n=3 patients) and intramammary (n=2 patients) lymph node sites. Fourteen of the 329 (4%) hot lesions seen on planar images were false positive non-nodal sites of uptake that were accurately assessed by SPECT-CT and further validated by surgery. In a single patient, SPECT-CT was negative while planar images identified the SN. CONCLUSION: SPECT-CT may improve the preoperative localisation of draining nodes in patients with breast cancer. It may detect hot nodes missed by planar imaging, exclude non-nodal false positive sites of uptake and accurately localise axillary and extra-axillary nodes.

Is CT scan still necessary for staging in Hodgkin and non-Hodgkin lymphoma patients in the PET/CT era?

BACKGROUND: The clinical impact of fused PET/CT data on staging and patient management of Hodgkin disease (HD) and non-Hodgkin lymphoma (NHL) was assessed. PATIENTS AND METHODS: A total of 103 consecutive patients with newly diagnosed NHL (n = 68) and HD (n = 35) were assessed retrospectively. Three comparisons were carried out in an attempt to assess the added value of each modality. RESULTS: For NHL patients, there were significant differences between staging by CT versus PET/CT (P = 0.0001). Disease was upstaged by PET/CT in 31% (mostly in stages I and II) and downstaged in only 1% of patients. In 25% of the patients, the treatment approach was changed according to CT versus PET/CT findings. For HD patients, disease was upstaged by PET/CT in 32% and downstaged by PET/CT in 15% (P = NS). As for NHL, upstaging by PET/CT versus CT was evident mostly for stages I and II. The treatment strategy was altered as determined by CT versus PET/CT in 45% of the patients. CONCLUSIONS: The addition of PET/CT to CT changed the management decisions in approximately a quarter of NHL and a third of HD patients, mostly in early disease stages. Thus, PET/CT performed as the initial staging procedure may well obviate the need for additional diagnostic CT in the majority of patients.

Morphometric study of the midsagittal MR imaging plane in cases of hydrocephalus and atrophy and in normal brains.

BACKGROUND AND PURPOSE: Midsagittal morphologic changes often aid in the diagnosis of hydrocephalus. Stretching and upward displacement of the corpus callosum, widening of third ventricular recesses, and decreased mammillopontine distance have been described as indicating the possibility of hydrocephalus. Quantitative studies are scarce. We performed retrospective, quantitative analysis to verify and quantify changes in midline morphology that might differentiate hydrocephalus and ventriculomegaly due to atrophy. METHODS: Sagittal MR imaging studies of 22 patients with hydrocephalus and 32 patients with atrophy were analyzed, as were 42 studies with normal findings. The studied parameters included mammillopontine and mammillocommissural distances, callosal height at two points, and the distances between the lines passing through the chiasm (chiasmal line) and the edge of the callosal splenium. Various angles between the chiasmal line and surrounding structures were measured. Similar measurements were done with the line passing through the third ventricular floor segment anterior to the mammillary bodies (third ventricular line). RESULTS: In hydrocephalus, mammillopontine distance decreased, mammillocommissural distance increased, the third ventricular floor segment was concave in most cases, and the chiasmal line rotated clockwise. These changes were not seen in atrophy. Callosal height was increased in hydrocephalus significantly more than in atrophy. CONCLUSION: Specific changes of the midsagittal plane in hydrocephalus, some of which have not been described previously, can be observed and quantified, which might aid in differentiating this condition from atrophy.

Renal multigated spectral Doppler imaging before and after captopril challenge.

RATIONALE AND OBJECTIVES: A new method of measurement, simultaneous multigated spectral Doppler imaging (MSDI), was used to quantify the hemodynamic changes in kidneys after administration of captopril. METHODS: Forty kidneys in 22 hypertensive patients were included in the study. All underwent MSDI and scintigraphy before and after administration of captopril. RESULTS: With scintigraphy used as the gold standard for diagnosing renal artery stenosis (RAS), three kidneys were found to be positive for RAS. Multigated spectral Doppler imaging detected a decrease in the resistive index after administration of captopril in all patients with RAS and correctly excluded RAS in one patient who was diagnosed as having RAS on scintigraphy. The resistive index was increased after captopril administration in normally functioning kidneys and was unchanged in kidneys with impaired function. CONCLUSIONS: With further supportive evidence, MSDI may prove to be a powerful tool for the acquisition of resistive index information and may increase the value of the resistive index as a physiological hemodynamic parameter in the evaluation of normal and abnormal conditions.

Acute normovolaemic haemodilution and idiopathic scoliosis surgery: effects on homologous blood requirements.

After the introduction of acute normovolaemic haemodilution(NVHD) in our hospital, we prospectively studied 19 patients managed with moderate NVHD (mean haematocrit 0.28, SD 0.02) during idiopathic scoliosis surgery (mean angle 53.2, SD 16.7 degrees) with the Cotrel-Dubousset instrumentation (CDI). Our standard scoliosis anaesthetic technique was used. Intraoperatively, one patient received one unit of homologous blood. Postoperatively, seven patients received ten units of homologous blood. Homologous blood used was reduced by about 83% for this procedure in our institution. In the assessment of fluid and blood requirements we found physical signs reflecting tissue perfusion and oxygen supply more reliable than the estimated blood loss using the suction bottle and swabs. The similar postoperative complications (nine fever, five atelectasis/pneumonia, one urinary infection, one phlebitis), anaesthetic duration (mean 5.21, SD 1.13) hours, hospitalisation (mean 6.67, SD 1.19) days and return to normal activity (mean 8, SD 7.68) weeks indicate that the NVHD patients did just as well as with our previous regimen when only homologous blood was used.