1,355,698 research outputs found
Caecum morgan Vannozzi & Pizzini & Raines 2015, sp. n.
No full textCaecum morgan sp. n. Figs 2A–F, 3, 22D, E, 23D, E, 26J, K Etymology: Derived from the type locality (Cape Morgan) and used as a noun in apposition. Description:Tube small, subcylindrical, proportionally thick, whitish, smooth.Aperture slightly oblique toward the ventral side, showing a well-developed swelling followed by a contraction and finally by a very small ring. Surface smooth, dull, without microsculpture. Septum opaque, slightly protruding over the cutting plane, with a sharp, nail-like mucro directed toward the right side, giving a dome-shaped outline to the septum when viewed from the side. Early stages and operculum unknown. Length: 1.6–1.8 mm. Type locality: SOUTH AFRICA: Eastern Cape: Agulhas Bank, off Cape Morgan Lighthouse, - 100 m. Holotype (Figs 2A–C, 22D, 23D): SOUTH AFRICA: Eastern Cape: sh, Agulhas Bank, off Cape Morgan Lighthouse, - 100 m, broken coral + shell, don. A. Connell, 1977, (NMSA B7132 / T3377), length 1.66 mm, min. diam. (posterior end) 0.22 mm, diam. in the middle of the tube 0.30 mm, max. diam. (apertural end) 0.34 mm. Paratypes: 6 sh, same data as holotype (NMSA W9676 / T3378). Comparative material examined: C. campanulatum Raines & Pizzini, 2005, holotype (LACM 3027); C. chinense de Folin, 1868, lectotype (MNHN-IM-2000-24905); C.dakuwaqa Pizzini, Raines & Vannozzi, 2013, holotype (MNHN-IM-2000-24843); C. subquadratum Carpenter, 1859, lectotype (NHMUK 1858.12.9.13, Fig. 21E); C. fijiense Pizzini, Raines & Vannozzi, 2013, holotype (MNHN-IM-2000-24857). Distribution: Currently known only from the type locality, Cape Morgan, north of East London (Fig. 3). Remarks: Caecum morgan sp. n. strongly resembles C. subquadratum due to the lack of both sculpture and microsculpture, as well as a similar shape of the mucro. It can however be separated by the distinctly subcylindrical and more curved shape of the tube, and by the presence of a conspicuous swelling above the aperture, barely visible in C. subquadratum. In C. morgan sp. n. the septum is only somewhat emerging above the cutting plane. Conversely, in C. subquadratum the septum is more protruding, on the whole giving the mamillate-ungulate appearance pointed out by Carpenter (1859). Caecum morgan sp. n. resembles C. gofasi Pizzini & Nofroni, 2001 in general aspect, but the latter has a dorsal spatulate mucro and shows a distinct worm-like microsculpture absent in the new species. Moreover, C. morgan sp. n. is also similar to C. campanulatum Raines & Pizzini 2005, C. dakuwaqa, and C. fijiense (both Pizzini, Raines & Vannozzi, 2013), having the same bell-shaped aperture, but in these species the septum is domeshaped without any mucro. Additionally, C. morgan sp. n. differs from C. dakuwaqa by the lack of the exasperate torsion of the tube occurring in the latter. Caecum morgan is also similar to C. musorstomi Pizzini, Raines & Vannozzi, 2013, from which it can be separated by the smooth surface without sculpture, and microsculpture and by a different orientation and shape of the mucro.Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on pages 104-105, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/766186
Parastrophia avaricosa Vannozzi & Pizzini & Raines 2015, sp. n.
No full textParastrophia avaricosa sp. n. Figs 19A–C, 20, 25A Etymology: The name is composed by the Greek α (not) and the Latin adjective varicosus (= provided with a varix) due to the absence of the varix between the uncoiled protoconch and the teleoconch that occurs in all the other Parastrophia species. Description: Tube slightly bisinuous, very thin, vitreous, tapered. Coiled protoconch small, ovoid, of half a whorl. Uncoiled protoconch smooth, conical in the adapical half, then subcylindrical, curved and with a slight constriction before the transition to the teleoconch, which is marked by a simple scar. Teleoconch gently curved and slowly growing, characterized by the presence of a microsculpture composed by shallow, irregularly set grooves spaced about 5 µm apart. Aperture rounded, simple, without any feature. Length 1.5 mm. Operculum unknown. Type locality: SOUTH AFRICA: Eastern Cape: Mzamba. Holotype (Figs 19A–C, 25A): SOUTH AFRICA: Eastern Cape: sh, Mzamba, beach, leg. J.P. Marais vii.1976 (NMSA E1665 / T3354), length 1.47 mm, protoconch diam. 0.08 mm, max. diam. (apertural end) 0.26 mm. Paratypes: MADAGASCAR: 9 sh, E of Cap Antsirabe, 25°02.8–03.0'S 47°01.3–02.0'E, sable vaso-sableux compact, - 49–52 m, 6.v.2010 (MNHN-IM- 2012 - 2726); 1 sh, Phare Flacourt, 25°01.3'S, 47°00.5'E, fond rocheux avec dalle,- 18 m, 1.v.2010 (MNHN-IM- 2012 - 2727); 1 sh, SW of CapAndavaka,chalutier “NosyBe II”, - 53–54 m, 25°16.9'S, 46°31.3'E, 4.v.2010 (MNHN-IM- 2012 - 2728). Comparative material examined: P.cornucopiae de Folin, 1869, lectotype (MNHN-IM-2000-24917) selected by Pizzini et al. 2013 (2013: 43, fig. 16F, G); P. filum Melvill, 1906, holotype from Gulf of Oman, 156 fms (NHMUK 190610.23.47); P. japonica Hinoide & Habe, 1978, holotype (NSMT-Mo 55474); P. melanesiana Pizzini, Raines & Vannozzi, 2013, holotype (MNHN-IM-2000-24882). Distribution: This species is known only from the eastern coast of South Africa (type locality, Fig. 20) and from the southern coast of Madagascar around Talanaro. Remarks: Parastrophia avaricosa sp. n. is the only known Parastrophia species without a separation varix between protoconch and teleoconch, thus it is immediately distinguished from all the other congeners. The new species resembles P. cornucopiae de Folin, 1869, P. japonica Hinoide & Habe, 1978 and P. melanesiana Pizzini, Raines & Vannozzi, 2013 (all figured in Pizzini et al. 2013) due to the paucispiral protoconch. Parastrophia cornucopiae is similar to P. avaricosa, having in common a similar shape of the protoconch, but the latter completely lacks the varix separating the uncoiled protoconch from teleoconch. Moreover, Parastrophia avaricosa shows a microsculpture composed by fine collabral grooves that is not observed in P. cornucopiae. Parastrophia avaricosa is also similar to P. japonica and P. melanesiana, but the latter two show a distinct separation varix and a longitudinal microsculpture (Pizzini et al. 2013).Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on pages 123-125, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/766186
Frank Pizzini family reunion
No full textPhotograph shows the group posed in field near trees. Pizzini is in a black hat and vest (center).Photographer's name on lower right.;Inscription on border reads ''Frank Pizzini country, Aug 15, 1913'
Caecum inhacaense : Albano & Pizzini 2011
No full textCaecum inhacaense Albano & Pizzini, 2011 Figs 12A–C, 13, 22K, 23K, 24G, 26A, B Caecum inhacaense: Albano & Pizzini 2011: 5, 6, fig. 3A–C, E. Type locality: MOZAMBIQUE: Ilha de Inhaca, Barreira Vermelha. Type material examined: MOZAMBIQUE: holotype (MZB 15000). Material examined: SOUTH AFRICA: Eastern Cape: 10 sh, Mzamba, near Natal border, vii.1976 (JPM 2119); 1 lv, Mtentu R. Mouth, iv.1982 (JPM 2414); KwaZulu-Natal: 1 sh, Aliwal Shoal, off Umkomaas area, - 27 m, SCUBA, i.1988 (JPM); 2 sh (1 juv), Stn ZO 4, off Cape St. Lucia (28°31.8'S 32°26.9'E), - 76–80 m, coarse sand with mud, dredged R.V. Meiring Naudé, NMDP, 12.vi.1988 (NMSA W9665). Doubtful: SOUTH AFRICA: Western Cape: 1 sh, Knysna, Gericke Point, Sedgefield (NMSA W9679); Eastern Cape: 1 sh, Algoa Bay, St. Croix I., East, - 50–60 ft, coarse sand, dived A. Connell, don. C.S.I.R. Water Res. 1977 (NMSA A6770); 1 sh, Mzamba, beachdrift, leg. R. Kilburn & D. Herbert 12– 30.5.1986 (NMSA W9664). Comparative material examined: C. incisum sp. n. Original description: “Tube cylindrical, smooth, crossed only by fine growth striation. Septum mucronate, turned to right side by about 30° and protruding over the cutting plane. Mucro has the form of a small flattened ball, almost obsolete in juvenile specimens. Dorsal margin of mucro strongly convex, while its ventral margin slightly S-shaped and inflated near the cutting plane. Aperture circular, weakly ringed and slightly contracted. Juveniles have more slender shell, and aperture lip thin and fragile. Colour whitish. Operculum and soft parts morphology unknown. Holotype dimensions: length 1.4 mm, diameter 0.3 mm.” Additional description: Tube cylindrical, colourless, whitish in beached specimens, the last portion bent toward the ventral side. No sculpture. Aperture slightly flaring and oblique. Surface with only oblique growth lines. Septum opaque, dome-shaped, variably protruding. Mucro illdefined, placed on the right side, typically higher than the septum, dorsally protruding with a resulting concave outline just above the cutting plane. Macula white, small, roundish to chevron-shaped, located in the middle of the ventral side of the tube, slightly displaced toward the left side (Fig. 24G). Periostracum light brown, somewhat glossy, persistent. Length: 1.2–1.6 mm. Distribution: Originally described from south of Mozambique, its distribution is herein extended to the eastern coast of South Africa up to the Mtentu River (Fig. 13). Its occurrence on the southern coast needs confirmation. Remarks: Caecum inhacaense resembles the sympatric C. incisum sp. n. as regards to the general proportions, but it can be distinguished by the presence of a white macula, the lack of incised collabral grooves, the presence of a slight apertural swelling and the mucro that forms a lower angle with respect to the ventral-dorsal direction. Caecum inhacaense is a rather elusive species due to the lack of striking characters. A careful examination of South African specimens revealed that the bending of the last quarter of the tube and the shape of the mucro are useful characters. In particular, the mucro is neither nail- nor ear-like as in other species with similar appearance, but has a convex outline, shaped like a flattened ball that protrudes dorsally, leaving a concave region just above the cutting plane. Also the presence of a small, white macula is a useful character.Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on pages 114-115, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/766186
Caecum lindae Vannozzi & Pizzini & Raines 2015, sp. n.
No full textCaecum lindae sp. n. Figs 15, 25K Etymology: Named after Linda Davis, collections manager for Mollusca at NMSA. Description: Tube subcylindrical, flaring towards the aperture. Aperture oblique, contracted, ending with three concentric rings. Septum protruding, with a strong, pointed mucro with subtriangular outline, slightly displaced toward the right side. Ventral side of the septum convex, dorsal one slightly concave. Early stages and operculum unknown. Length: 2.5 mm. Type locality: SOUTH AFRICA: Eastern Cape: Agulhas Bank, off Cape Morgan Lighthouse, - 100 m. Holotype (Fig. 25K): SOUTH AFRICA: Eastern Cape: dd, Agulhas Bank, off Cape Morgan Lighthouse, - 100 m, depth broken coral + shell from (NMSA W9682 / T3924), length 2.5 mm, min. diam. (posterior end) 0.39 mm, diam. in the middle of the tube 0.5 mm, max. diam. (apertural end) 0.56 mm. Distribution: Currently known only from the type locality, Cape Morgan, north of East London (Fig. 15). Remarks: Caecum lindae sp. n. shows a unique shape of the septum among South African species. It can only be compared with C. geigeri Pizzini & Raines, 2011, described from Austral Is., due to the similar shape of the septum, but it can be distinguished by the different shape of the tube and by the absence of the strong annulations preceding the aperture.Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on page 118, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/766186
Parastrophia ornata Vannozzi & Pizzini & Raines 2015, sp. n.
No full textParastrophia ornata sp. n. Figs 18A–H, 20, 25B, C Etymology: Derived from the Latin adjective ornatus (= adorned), referring to the longitudinal microsculpture that adorns the teleoconch. Description: Tube bisinuous, semitransparent, vitreous. Coiled protoconch formed by about 1.1 whorls; uncoiled protoconch conical, about 0.5 mm long, ending in a clear varix. The varix is asymmetrical, flangelike in the adapical side, shaped into a ring in the abapical side. Teleoconch smooth, with only some growth lines, especially close to the aperture, defining irregular rings. Microsculpture composed by fine longitudinal threads, slightly dextrally wound around the tube, rather sparse adapically, finer and denser abapically. The threads are interrupted by the growth lines, producing a wavy appearance. Operculum unknown. Length: 2.5–2.7 mm. Type locality: SOUTH AFRICA: Eastern Cape: Mzamba. Holotype (Fig. 25B): SOUTH AFRICA: Eastern Cape: sh, Mzamba, near KwaZulu-Natal border, vii.1976 (W9677 / T3379), length 2.71 mm, protoconch diam.0.14 mm, max. diam. (apertural end) 0.46 mm. Paratypes: SOUTH AFRICA: Eastern Cape: 1 sh, same data as holotype (JPM 2119); 1 sh (broken), Mzamba, beach, leg. J.P. Marais vii.1976 (NMSA W9678 / T3380). Additional material examined: SOUTH AFRICA: KwaZulu-Natal: 2 sh, off Richards bay, shallow dredgings, viii.1986 (JPM) (lost). Distribution: Eastern coast of South Africa (Fig. 20). Remarks: This species can be compared with the Australian Parastrophia cygnicollis (Hedley, 1904) and P. erseusi Hughes, 1993. It differs from the former by the different shape of the tube, which is longer and more slender in P. cygnicollis, by the shape of the adapical side of the varix, smoothly flaring in cygnicollis, flangelike in ornata, and by the presence of a microsculpture composed of fine longitudinal threads, whereas in cygnicollis a microsculpture composed of a few longitudinal wavy grooves is sometimes visible (Pizzini et al. 2013: fig. 16O). Conversely, Parastrophia erseusi differs by the more or less symmetrical, evenly rounded varix and by the absence of microsculpture (Hughes 1993). Parastrophia ornata sp. n. is also similar to P. melanesiana Pizzini, Raines & Vannozzi, 2013, which shares a similar microsculpture, but differs from it by the paucispiral coiled protoconch and by the different shape of the separation varix.Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on page 123, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/766186
Caecum leilae Vannozzi & Pizzini & Raines 2015, sp. n.
No full textCaecum leilae sp. n. Figs 10A–N, 11, 22P, Q, 23P, Q, 24E, F, 26M–P Etymology: Named after the late Leila Zitelli, second author’s mother. Description: Tube rather large, cylindrical, colourless and glossy, semitransparent, evenly arched, sculptured by very fine, slightly oblique rings, more evident in the abapical half, separated by narrower interspaces. Aperture simple, contracted, slightly oblique toward the ventral side. Surface grooved by gross, shallow, worm-like incisions visible at low magnifications especially in the adapical half. Septum domeshaped, opaque, smooth, very protruding. Mucro ear-like, of variable height with respect to the septum, positioned at a variable angle between the dorsal and the right side. Surface of the septum with orange-peel aspect. Sparse, irregular grooves arranged like waves coming from the mucro are often visible on the septum. Macula small, heart-shaped, hardly visible, transparent, slightly displaced to the left side. Periostracum light brown, dull, easily lost, sculptured by fine longitudinal wormlike grooves. Juveniles quite similar to the adults, having the same morphology of the aperture, sculpture and microsculpture and are distinguished by the smaller diameter, the more curved tube, the less defined rings and by the slightly less protruding septum. Larval stage unknown. Operculum thin, corneous, circular, multispiral, composed by a small central nucleus surrounded by an initially tight spiral of 7–8 whorls. External side slightly concave, internal side with a slightly convex nucleus. Length: 2.5–3.2 mm. Type locality: SOUTH AFRICA: Eastern Cape: Mzamba. Holotype (Figs 10A–C, 22P, 23P): SOUTH AFRICA: Eastern Cape: sh, Mzamba, beach drift, leg. R. Kilburn & D. Herbert 12–30.v.1986 (NMSA D3032 /T3374), length 3.1 mm, min. diam. (posterior end) 0.51 mm, diam. in the middle of the tube 0.6 mm, max. diam. (apertural end) 0.62 mm. Paratypes: SOUTH AFRICA: Eastern Cape: 7 lv and 26 sh, Mzamba, near Natal border, vii.1976 (JPM 2119); 2 lv and 6 sh, same data as holotype (NMSA W9674 /T3375); 1 lv, Mbotyi, beach drift, leg. R. Kilburn, D. Herbert v-vi.1985 (NMSA C8454 /T3885); KwaZulu-Natal: 2 lv, Mapelane, S of St. Lucia, iv.1981 (JPM 2116); 1 lv, off Richards bay, shallow dredgings, viii.1986 (JPM); 2 sh, off Durban Bluff, 18–22 m, fine sand, leg. RK, RF 1983 (NMSA E981 /T3883); 1 lv and 3 sh (1 broken), Mission Rocks, N of St. Lucia, v.1989 (JPM); 1 lv and 2 sh (1 broken, 1 with two attached growth stages), Mapelane, leg J. Marais iv.1981 (NMSA B4607 /T3882); 1 lv, Umtamvuna R. mouth, beach-drift, leg. J.P. Marais vi.1996 (NMSA V3999 /T3884). Comparative material examined: C. inflatum de Folin, 1869, lectotype (MNHN-IM-2000-24915) selected by Pizzini et al. (2013: 30, fig. 12P–R); C. attenuatum de Folin, 1880, lectotype (NHMUK 1887.2.9.2315) selected by Pizzini et al. (2013: 3, fig. 9O, P); C. cooki Pizzini & Raines, 2011, holotype (MNHNIM-2000-23124); C. incisum sp. n.; C. inhacaense Albano & Pizzini, 2011, holotype (MZB 15000). Distribution: Eastern coast of South Africa from Mbotyi (south of Port Edward) to St. Lucia (Fig. 11). Remarks: Caecum leilae resembles C. inflatum de Folin, 1869 and C. attenuatum de Folin, 1880 which show a similar annulated sculpture, but the septum is different, with a larger and illdefined mucro in C. inflatum and with a triangular outline in C. attenuatum. Caecum leilae can also be compared with the IndoWest Pacific species C. cooki Pizzini & Raines, 2011 with which it shares the shape of the ear-like mucro, but shows no sculpture and a different shape of the aperture as well. Juveniles of C. leilae can be confused with C. incisum and C. inhacaense. However, C. leilae can be distinguished by the different sculpture (obsolete rings in leilae, incised collabral grooves defining flat rings in incisum) and by the mucro (broader in C. incisum and by the presence of the longitudinal microsculpture, while the latter shows a different shape of the mucro and lacks the regular annular sculpture crossed by the longitudinal microsculpture occurring throughout the tube that is typical of C. leilae). Moreover, the maculae in C. leilae and C. inhacaense are different in both shape and colour (heartshaped and transparent in the former, roundish to chevron-shaped and opaque white in the latter) (Fig. 24E–G).Published as part of Vannozzi, Angelo, Pizzini, Mauro & Raines, Bret, 2015, Revision of South African Caecidae (Mollusca: Gastropoda), pp. 99 in African Invertebrates 56 (1) on pages 112-114, DOI: 10.5733/afin.056.0109, http://zenodo.org/record/766186
Caecum inhacaense Albano & Pizzini 2011, sp. n.
No full textCaecum inhacaense sp. n. <p>Figs 3A–C, E</p> <p>Etymology: From Ilha da Inhaca, southern Mozambique, the type locality.</p> <p>Description:</p> <p> <b>7XEH F\OLQGULFDO, VPRRWK, FURVVHG RQO\ E\ ¿QH JURZWK VWULDWLRQ. 6HSWXP PXFURQDWH,</b> turned to right side by about 30° and protruding over the cutting plane. Mucro (Fig.3C) <b>KDV WKH IRUP RI D VPDOO ÀDWWHQHG EDOO, DOPRVW REVROHWH LQ MXYHQLOH VSHFLPHQV. 'RUVDO PDUJLQ RI PXFUR VWURQJO\ FRQYH[, ZKLOH LWV YHQWUDO PDUJLQ VOLJKWO\ 6‒VKDSHG DQG LQÀDWHG</b> near the cutting plane.Aperture circular, weakly ringed and slightly contracted. Juveniles (Fig. 3E) have more slender shell, and aperture lip thin and fragile. Colour whitish.</p> <p>Operculum and soft parts morphology unknown.</p> <p>Holotype dimensions: length 1.4 mm, diameter 0.3 mm.</p> <p>Holotype (Figs 3A–C): Loc. 2035; gold coated for SEM photography (MZB 15000).</p> <p> Paratypes:A (juvenile) from the type locality(Fig.3E), gold coated for SEM photography (MZB 15001). B from Loc. 2036 (MNHN 23121). C from Loc. 2036 (NMSA L8452 /T2659).D from Loc. 2036 (BMNH 20100510). Comparative material examined: <i>C</i>. <i>amputatum</i> Hedley, 1899 holotype AMS C68589 (Fig. 3D). Type locality: Cabbage Tree Bay, near Manly, in shell-sand, New South Wales (Australia).</p> <p>Distribution: Inhaca Island, Mozambique.</p> <p> Comparison:The new species is closely related to <i>C</i>. <i>amputatum</i> Hedley, 1899 (Fig. 3D), described from New South Wales, Australia. The greatest difference is in the septum, which in <i>C</i>. <i>amputatum</i> is “… well exerted, surrounded by a crown of the truncated tube, apex placed on the side of convex aperture” (Hedley 1899: 504). The position of the mucro (the “apex” in Hedley’s description) is dorsal in <i>C</i>. <i>inhacaense</i> and ventral in <i>C</i>. <i>amputatum</i>. Moreover, there is a wide geographical distance between the two type localities since no similar species have been found by the second author while studying <b>WKH KXJH FROOHFWLRQV RI WKH 01+1 LQ WKH 7URSLFDO,QGR‒3DFL¿F.</b></p> <p> The new species can be compared to the endemic Mediterranean species <i>C</i>. <i>auriculatum</i> Folin, 1868 due to the overall form of the tube. Neither has any sculpture but has a ringed aperture. However, the form of the septum is markedly different: it has <b>WKH VKDSH RI D VPDOO, ÀDWWHQHG EDOO LQ</b> <i>inhacaense</i>, while it is hemispheric with ear-like right-oriented mucro in <i>auriculatum</i>. Moreover, the distribution is greatly disjunct.</p>Published as part of <i>Albano, Paolo G. & Pizzini, Mauro, 2011, Notes on Caecidae (Mollusca: Gastropoda) from southern Mozambique, with the description of a new species, pp. 1 in African Invertebrates 52 (1)</i> on pages 5-6, DOI: 10.5733/afin.052.0101, <a href="http://zenodo.org/record/7913825">http://zenodo.org/record/7913825</a>
Andrew Pizzini, Jr., New Market cadet, 1864
No full textCadet Andrew Pizzini Jr., Class of 1865 & New Market cadet. Copy of a photo taken around the time of the Battle of New Market.cracked, brittle, adhesive residu
Arterial Spin-Labeled MR Perfusion Imaging Techniques
No full textArterial spin labeling (ASL) is a relatively new technique for MR perfusion assessment that is particularly useful in brain tissues. From a technical point of view, ASL-MRI is essentially a classic tracer experiment where the injected blood-borne tracer has been replaced by a procedure whereby water protons in the blood have been “labeled” on their way to the organ of interest. This labeling is achieved remotely by the application of radio-frequency (RF) waves that effect an inversion of the magnetization of the blood–water in the region where the RF is applied. This is achieved either for all blood within a region (pulsed ASL) or for blood flowing through a plane (continuous ASL), and for brain perfusion, it is usually performed in the neck. Conventional MR imaging can be used to capture this inverted blood signal once it has arrived in the organ, allowing time for it to arrive. However, the image will also contain contribution from the normal soft tissue in the image, which is much larger in magnitude than is the perfusion signal. Hence, the basic ASL experiment contains two images, one with labeling of blood–water and a second without: the subtraction of the two revealing the perfusion. The reliance on an endogenous tracer means that the ASL technique is noninvasive and, for most variants, readily available on existing hardware. However, the small signal magnitude relative to noise in the images and the relatively short “half-life” of the labeled water mean that careful and optimal acquisition and quantification are required. The primary goal of this chapter is to provide a complete overview of ASL from the technical issues, such as acquisition and quantification, to the clinical application in the brain including neuro-oncology, neurodegeneration, psychiatry, vascular and inflammatory disease, and epilepsy. The final section is focused on common pitfalls in ASL that should be avoided in diagnosis and a procedure to assess quality. A white paper1 regarding technical aspects of ASL has recently been published, from which technical recommendations in this chapter are drawn
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